/*
 * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.io;

import java.util.Objects;
import java.util.Formatter;
import java.util.Locale;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;

Prints formatted representations of objects to a text-output stream.  This
class implements all of the print methods found in PrintStream. It does not contain methods for writing raw bytes, for which a program should use unencoded byte streams. 
 Unlike the PrintStream class, if automatic flushing is enabled it will be done only when one of the println, printf, or
format methods is invoked, rather than whenever a newline character
happens to be output.  These methods use the platform's own notion of line
separator rather than the newline character.
 Methods in this class never throw I/O exceptions, although some of its constructors may. The client may inquire as to whether any errors have occurred by invoking checkError(). 
Author:
     Frank Yellin,      Mark Reinhold
Since:
      JDK1.1/**
 * Prints formatted representations of objects to a text-output stream.  This
 * class implements all of the <tt>print</tt> methods found in {@link
 * PrintStream}.  It does not contain methods for writing raw bytes, for which
 * a program should use unencoded byte streams.
 *
 * <p> Unlike the {@link PrintStream} class, if automatic flushing is enabled
 * it will be done only when one of the <tt>println</tt>, <tt>printf</tt>, or
 * <tt>format</tt> methods is invoked, rather than whenever a newline character
 * happens to be output.  These methods use the platform's own notion of line
 * separator rather than the newline character.
 *
 * <p> Methods in this class never throw I/O exceptions, although some of its
 * constructors may.  The client may inquire as to whether any errors have
 * occurred by invoking {@link #checkError checkError()}.
 *
 * @author      Frank Yellin
 * @author      Mark Reinhold
 * @since       JDK1.1
 */

public class PrintWriter extends Writer {

    
The underlying character-output stream of this
PrintWriter.
Since:
1.2/**
     * The underlying character-output stream of this
     * <code>PrintWriter</code>.
     *
     * @since 1.2
     */
    protected Writer out;

    private final boolean autoFlush;
    private boolean trouble = false;
    private Formatter formatter;
    private PrintStream psOut = null;

    
Line separator string.  This is the value of the line.separator
property at the moment that the stream was created.
/**
     * Line separator string.  This is the value of the line.separator
     * property at the moment that the stream was created.
     */
    private final String lineSeparator;

    
Returns a charset object for the given charset name.
Throws:
NullPointerException –          is csn is null
UnsupportedEncodingException –  if the charset is not supported/**
     * Returns a charset object for the given charset name.
     * @throws NullPointerException          is csn is null
     * @throws UnsupportedEncodingException  if the charset is not supported
     */
    private static Charset toCharset(String csn)
        throws UnsupportedEncodingException
    {
        Objects.requireNonNull(csn, "charsetName");
        try {
            return Charset.forName(csn);
        } catch (IllegalCharsetNameException|UnsupportedCharsetException unused) {
            // UnsupportedEncodingException should be thrown
            throw new UnsupportedEncodingException(csn);
        }
    }

    
Creates a new PrintWriter, without automatic line flushing.
Params:
out –        A character-output stream/**
     * Creates a new PrintWriter, without automatic line flushing.
     *
     * @param  out        A character-output stream
     */
    public PrintWriter (Writer out) {
        this(out, false);
    }

    
Creates a new PrintWriter.
Params:
out –        A character-output stream
autoFlush –  A boolean; if true, the println,
                   printf, or format methods will
                   flush the output buffer/**
     * Creates a new PrintWriter.
     *
     * @param  out        A character-output stream
     * @param  autoFlush  A boolean; if true, the <tt>println</tt>,
     *                    <tt>printf</tt>, or <tt>format</tt> methods will
     *                    flush the output buffer
     */
    public PrintWriter(Writer out,
                       boolean autoFlush) {
        super(out);
        this.out = out;
        this.autoFlush = autoFlush;
        lineSeparator = java.security.AccessController.doPrivileged(
            new sun.security.action.GetPropertyAction("line.separator"));
    }

    
Creates a new PrintWriter, without automatic line flushing, from an
existing OutputStream.  This convenience constructor creates the
necessary intermediate OutputStreamWriter, which will convert characters
into bytes using the default character encoding.
Params:
out –        An output stream
See Also:
OutputStreamWriter(OutputStream)/**
     * Creates a new PrintWriter, without automatic line flushing, from an
     * existing OutputStream.  This convenience constructor creates the
     * necessary intermediate OutputStreamWriter, which will convert characters
     * into bytes using the default character encoding.
     *
     * @param  out        An output stream
     *
     * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream)
     */
    public PrintWriter(OutputStream out) {
        this(out, false);
    }

    
Creates a new PrintWriter from an existing OutputStream.  This
convenience constructor creates the necessary intermediate
OutputStreamWriter, which will convert characters into bytes using the
default character encoding.
Params:
out –        An output stream
autoFlush –  A boolean; if true, the println,
                   printf, or format methods will
                   flush the output buffer
See Also:
OutputStreamWriter(OutputStream)/**
     * Creates a new PrintWriter from an existing OutputStream.  This
     * convenience constructor creates the necessary intermediate
     * OutputStreamWriter, which will convert characters into bytes using the
     * default character encoding.
     *
     * @param  out        An output stream
     * @param  autoFlush  A boolean; if true, the <tt>println</tt>,
     *                    <tt>printf</tt>, or <tt>format</tt> methods will
     *                    flush the output buffer
     *
     * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream)
     */
    public PrintWriter(OutputStream out, boolean autoFlush) {
        this(new BufferedWriter(new OutputStreamWriter(out)), autoFlush);

        // save print stream for error propagation
        if (out instanceof java.io.PrintStream) {
            psOut = (PrintStream) out;
        }
    }

    
Creates a new PrintWriter, without automatic line flushing, with the specified file name. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the default charset for this instance of the Java virtual machine. 
Params:
fileName – 
        The name of the file to use as the destination of this writer.
        If the file exists then it will be truncated to zero size;
        otherwise, a new file will be created.  The output will be
        written to the file and is buffered.
Throws:
FileNotFoundException – 
         If the given string does not denote an existing, writable
         regular file and a new regular file of that name cannot be
         created, or if some other error occurs while opening or
         creating the file
SecurityException –  If a security manager is present and checkWrite(fileName) denies write access to the file
Since:
 1.5/**
     * Creates a new PrintWriter, without automatic line flushing, with the
     * specified file name.  This convenience constructor creates the necessary
     * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},
     * which will encode characters using the {@linkplain
     * java.nio.charset.Charset#defaultCharset() default charset} for this
     * instance of the Java virtual machine.
     *
     * @param  fileName
     *         The name of the file to use as the destination of this writer.
     *         If the file exists then it will be truncated to zero size;
     *         otherwise, a new file will be created.  The output will be
     *         written to the file and is buffered.
     *
     * @throws  FileNotFoundException
     *          If the given string does not denote an existing, writable
     *          regular file and a new regular file of that name cannot be
     *          created, or if some other error occurs while opening or
     *          creating the file
     *
     * @throws  SecurityException
     *          If a security manager is present and {@link
     *          SecurityManager#checkWrite checkWrite(fileName)} denies write
     *          access to the file
     *
     * @since  1.5
     */
    public PrintWriter(String fileName) throws FileNotFoundException {
        this(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileName))),
             false);
    }

    /* Private constructor */
    private PrintWriter(Charset charset, File file)
        throws FileNotFoundException
    {
        this(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), charset)),
             false);
    }

    
Creates a new PrintWriter, without automatic line flushing, with the specified file name and charset. This convenience constructor creates the necessary intermediate 
OutputStreamWriter, which will encode characters using the provided charset. 
Params:
fileName – 
        The name of the file to use as the destination of this writer.
        If the file exists then it will be truncated to zero size;
        otherwise, a new file will be created.  The output will be
        written to the file and is buffered.
csn –  The name of a supported 
        charset
Throws:
FileNotFoundException – 
         If the given string does not denote an existing, writable
         regular file and a new regular file of that name cannot be
         created, or if some other error occurs while opening or
         creating the file
SecurityException –  If a security manager is present and checkWrite(fileName) denies write access to the file
UnsupportedEncodingException – 
         If the named charset is not supported
Since:
 1.5/**
     * Creates a new PrintWriter, without automatic line flushing, with the
     * specified file name and charset.  This convenience constructor creates
     * the necessary intermediate {@link java.io.OutputStreamWriter
     * OutputStreamWriter}, which will encode characters using the provided
     * charset.
     *
     * @param  fileName
     *         The name of the file to use as the destination of this writer.
     *         If the file exists then it will be truncated to zero size;
     *         otherwise, a new file will be created.  The output will be
     *         written to the file and is buffered.
     *
     * @param  csn
     *         The name of a supported {@linkplain java.nio.charset.Charset
     *         charset}
     *
     * @throws  FileNotFoundException
     *          If the given string does not denote an existing, writable
     *          regular file and a new regular file of that name cannot be
     *          created, or if some other error occurs while opening or
     *          creating the file
     *
     * @throws  SecurityException
     *          If a security manager is present and {@link
     *          SecurityManager#checkWrite checkWrite(fileName)} denies write
     *          access to the file
     *
     * @throws  UnsupportedEncodingException
     *          If the named charset is not supported
     *
     * @since  1.5
     */
    public PrintWriter(String fileName, String csn)
        throws FileNotFoundException, UnsupportedEncodingException
    {
        this(toCharset(csn), new File(fileName));
    }

    
Creates a new PrintWriter, without automatic line flushing, with the specified file. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the default charset for this instance of the Java virtual machine. 
Params:
file – 
        The file to use as the destination of this writer.  If the file
        exists then it will be truncated to zero size; otherwise, a new
        file will be created.  The output will be written to the file
        and is buffered.
Throws:
FileNotFoundException – 
         If the given file object does not denote an existing, writable
         regular file and a new regular file of that name cannot be
         created, or if some other error occurs while opening or
         creating the file
SecurityException –  If a security manager is present and checkWrite(file.getPath()) denies write access to the file
Since:
 1.5/**
     * Creates a new PrintWriter, without automatic line flushing, with the
     * specified file.  This convenience constructor creates the necessary
     * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},
     * which will encode characters using the {@linkplain
     * java.nio.charset.Charset#defaultCharset() default charset} for this
     * instance of the Java virtual machine.
     *
     * @param  file
     *         The file to use as the destination of this writer.  If the file
     *         exists then it will be truncated to zero size; otherwise, a new
     *         file will be created.  The output will be written to the file
     *         and is buffered.
     *
     * @throws  FileNotFoundException
     *          If the given file object does not denote an existing, writable
     *          regular file and a new regular file of that name cannot be
     *          created, or if some other error occurs while opening or
     *          creating the file
     *
     * @throws  SecurityException
     *          If a security manager is present and {@link
     *          SecurityManager#checkWrite checkWrite(file.getPath())}
     *          denies write access to the file
     *
     * @since  1.5
     */
    public PrintWriter(File file) throws FileNotFoundException {
        this(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file))),
             false);
    }

    
Creates a new PrintWriter, without automatic line flushing, with the specified file and charset. This convenience constructor creates the necessary intermediate 
OutputStreamWriter, which will encode characters using the provided charset. 
Params:
file – 
        The file to use as the destination of this writer.  If the file
        exists then it will be truncated to zero size; otherwise, a new
        file will be created.  The output will be written to the file
        and is buffered.
csn –  The name of a supported 
        charset
Throws:
FileNotFoundException – 
         If the given file object does not denote an existing, writable
         regular file and a new regular file of that name cannot be
         created, or if some other error occurs while opening or
         creating the file
SecurityException –  If a security manager is present and checkWrite(file.getPath()) denies write access to the file
UnsupportedEncodingException – 
         If the named charset is not supported
Since:
 1.5/**
     * Creates a new PrintWriter, without automatic line flushing, with the
     * specified file and charset.  This convenience constructor creates the
     * necessary intermediate {@link java.io.OutputStreamWriter
     * OutputStreamWriter}, which will encode characters using the provided
     * charset.
     *
     * @param  file
     *         The file to use as the destination of this writer.  If the file
     *         exists then it will be truncated to zero size; otherwise, a new
     *         file will be created.  The output will be written to the file
     *         and is buffered.
     *
     * @param  csn
     *         The name of a supported {@linkplain java.nio.charset.Charset
     *         charset}
     *
     * @throws  FileNotFoundException
     *          If the given file object does not denote an existing, writable
     *          regular file and a new regular file of that name cannot be
     *          created, or if some other error occurs while opening or
     *          creating the file
     *
     * @throws  SecurityException
     *          If a security manager is present and {@link
     *          SecurityManager#checkWrite checkWrite(file.getPath())}
     *          denies write access to the file
     *
     * @throws  UnsupportedEncodingException
     *          If the named charset is not supported
     *
     * @since  1.5
     */
    public PrintWriter(File file, String csn)
        throws FileNotFoundException, UnsupportedEncodingException
    {
        this(toCharset(csn), file);
    }

    
Checks to make sure that the stream has not been closed /** Checks to make sure that the stream has not been closed */
    private void ensureOpen() throws IOException {
        if (out == null)
            throw new IOException("Stream closed");
    }

    
Flushes the stream.
See Also:
checkError()/**
     * Flushes the stream.
     * @see #checkError()
     */
    public void flush() {
        try {
            synchronized (lock) {
                ensureOpen();
                out.flush();
            }
        }
        catch (IOException x) {
            trouble = true;
        }
    }

    
Closes the stream and releases any system resources associated
with it. Closing a previously closed stream has no effect.
See Also:
checkError()/**
     * Closes the stream and releases any system resources associated
     * with it. Closing a previously closed stream has no effect.
     *
     * @see #checkError()
     */
    public void close() {
        try {
            synchronized (lock) {
                if (out == null)
                    return;
                out.close();
                out = null;
            }
        }
        catch (IOException x) {
            trouble = true;
        }
    }

    
Flushes the stream if it's not closed and checks its error state.
Returns:
true if the print stream has encountered an error,
         either on the underlying output stream or during a format
         conversion./**
     * Flushes the stream if it's not closed and checks its error state.
     *
     * @return <code>true</code> if the print stream has encountered an error,
     *          either on the underlying output stream or during a format
     *          conversion.
     */
    public boolean checkError() {
        if (out != null) {
            flush();
        }
        if (out instanceof java.io.PrintWriter) {
            PrintWriter pw = (PrintWriter) out;
            return pw.checkError();
        } else if (psOut != null) {
            return psOut.checkError();
        }
        return trouble;
    }

    
Indicates that an error has occurred.
 This method will cause subsequent invocations of checkError() to return true until clearError() is invoked. /**
     * Indicates that an error has occurred.
     *
     * <p> This method will cause subsequent invocations of {@link
     * #checkError()} to return <tt>true</tt> until {@link
     * #clearError()} is invoked.
     */
    protected void setError() {
        trouble = true;
    }

    
Clears the error state of this stream.
 This method will cause subsequent invocations of checkError() to return false until another write operation fails and invokes setError(). 
Since:
1.6/**
     * Clears the error state of this stream.
     *
     * <p> This method will cause subsequent invocations of {@link
     * #checkError()} to return <tt>false</tt> until another write
     * operation fails and invokes {@link #setError()}.
     *
     * @since 1.6
     */
    protected void clearError() {
        trouble = false;
    }

    /*
     * Exception-catching, synchronized output operations,
     * which also implement the write() methods of Writer
     */

    
Writes a single character.
Params:
c – int specifying a character to be written./**
     * Writes a single character.
     * @param c int specifying a character to be written.
     */
    public void write(int c) {
        try {
            synchronized (lock) {
                ensureOpen();
                out.write(c);
            }
        }
        catch (InterruptedIOException x) {
            Thread.currentThread().interrupt();
        }
        catch (IOException x) {
            trouble = true;
        }
    }

    
Writes A Portion of an array of characters.
Params:
buf – Array of characters
off – Offset from which to start writing characters
len – Number of characters to write/**
     * Writes A Portion of an array of characters.
     * @param buf Array of characters
     * @param off Offset from which to start writing characters
     * @param len Number of characters to write
     */
    public void write(char buf[], int off, int len) {
        try {
            synchronized (lock) {
                ensureOpen();
                out.write(buf, off, len);
            }
        }
        catch (InterruptedIOException x) {
            Thread.currentThread().interrupt();
        }
        catch (IOException x) {
            trouble = true;
        }
    }

    
Writes an array of characters.  This method cannot be inherited from the
Writer class because it must suppress I/O exceptions.
Params:
buf – Array of characters to be written/**
     * Writes an array of characters.  This method cannot be inherited from the
     * Writer class because it must suppress I/O exceptions.
     * @param buf Array of characters to be written
     */
    public void write(char buf[]) {
        write(buf, 0, buf.length);
    }

    
Writes a portion of a string.
Params:
s – A String
off – Offset from which to start writing characters
len – Number of characters to write/**
     * Writes a portion of a string.
     * @param s A String
     * @param off Offset from which to start writing characters
     * @param len Number of characters to write
     */
    public void write(String s, int off, int len) {
        try {
            synchronized (lock) {
                ensureOpen();
                out.write(s, off, len);
            }
        }
        catch (InterruptedIOException x) {
            Thread.currentThread().interrupt();
        }
        catch (IOException x) {
            trouble = true;
        }
    }

    
Writes a string.  This method cannot be inherited from the Writer class
because it must suppress I/O exceptions.
Params:
s – String to be written/**
     * Writes a string.  This method cannot be inherited from the Writer class
     * because it must suppress I/O exceptions.
     * @param s String to be written
     */
    public void write(String s) {
        write(s, 0, s.length());
    }

    private void newLine() {
        try {
            synchronized (lock) {
                ensureOpen();
                out.write(lineSeparator);
                if (autoFlush)
                    out.flush();
            }
        }
        catch (InterruptedIOException x) {
            Thread.currentThread().interrupt();
        }
        catch (IOException x) {
            trouble = true;
        }
    }

    /* Methods that do not terminate lines */

    
Prints a boolean value.  The string produced by String.valueOf(boolean) is translated into bytes
according to the platform's default character encoding, and these bytes
are written in exactly the manner of the write(int) method.
Params:
b –   The boolean to be printed/**
     * Prints a boolean value.  The string produced by <code>{@link
     * java.lang.String#valueOf(boolean)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      b   The <code>boolean</code> to be printed
     */
    public void print(boolean b) {
        write(b ? "true" : "false");
    }

    
Prints a character.  The character is translated into one or more bytes
according to the platform's default character encoding, and these bytes
are written in exactly the manner of the write(int) method.
Params:
c –   The char to be printed/**
     * Prints a character.  The character is translated into one or more bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      c   The <code>char</code> to be printed
     */
    public void print(char c) {
        write(c);
    }

    
Prints an integer.  The string produced by String.valueOf(int) is translated into bytes according
to the platform's default character encoding, and these bytes are
written in exactly the manner of the write(int)
method.
Params:
i –   The int to be printed
See Also:
Integer.toString(int)/**
     * Prints an integer.  The string produced by <code>{@link
     * java.lang.String#valueOf(int)}</code> is translated into bytes according
     * to the platform's default character encoding, and these bytes are
     * written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      i   The <code>int</code> to be printed
     * @see        java.lang.Integer#toString(int)
     */
    public void print(int i) {
        write(String.valueOf(i));
    }

    
Prints a long integer.  The string produced by String.valueOf(long) is translated into bytes
according to the platform's default character encoding, and these bytes
are written in exactly the manner of the write(int)
method.
Params:
l –   The long to be printed
See Also:
Long.toString(long)/**
     * Prints a long integer.  The string produced by <code>{@link
     * java.lang.String#valueOf(long)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      l   The <code>long</code> to be printed
     * @see        java.lang.Long#toString(long)
     */
    public void print(long l) {
        write(String.valueOf(l));
    }

    
Prints a floating-point number.  The string produced by String.valueOf(float) is translated into bytes
according to the platform's default character encoding, and these bytes
are written in exactly the manner of the write(int)
method.
Params:
f –   The float to be printed
See Also:
Float.toString(float)/**
     * Prints a floating-point number.  The string produced by <code>{@link
     * java.lang.String#valueOf(float)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      f   The <code>float</code> to be printed
     * @see        java.lang.Float#toString(float)
     */
    public void print(float f) {
        write(String.valueOf(f));
    }

    
Prints a double-precision floating-point number.  The string produced by
String.valueOf(double) is translated into
bytes according to the platform's default character encoding, and these
bytes are written in exactly the manner of the write(int) method.
Params:
d –   The double to be printed
See Also:
Double.toString(double)/**
     * Prints a double-precision floating-point number.  The string produced by
     * <code>{@link java.lang.String#valueOf(double)}</code> is translated into
     * bytes according to the platform's default character encoding, and these
     * bytes are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      d   The <code>double</code> to be printed
     * @see        java.lang.Double#toString(double)
     */
    public void print(double d) {
        write(String.valueOf(d));
    }

    
Prints an array of characters.  The characters are converted into bytes
according to the platform's default character encoding, and these bytes
are written in exactly the manner of the write(int)
method.
Params:
s –   The array of chars to be printed
Throws:
NullPointerException –  If s is null/**
     * Prints an array of characters.  The characters are converted into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      s   The array of chars to be printed
     *
     * @throws  NullPointerException  If <code>s</code> is <code>null</code>
     */
    public void print(char s[]) {
        write(s);
    }

    
Prints a string.  If the argument is null then the string
"null" is printed.  Otherwise, the string's characters are
converted into bytes according to the platform's default character
encoding, and these bytes are written in exactly the manner of the
write(int) method.
Params:
s –   The String to be printed/**
     * Prints a string.  If the argument is <code>null</code> then the string
     * <code>"null"</code> is printed.  Otherwise, the string's characters are
     * converted into bytes according to the platform's default character
     * encoding, and these bytes are written in exactly the manner of the
     * <code>{@link #write(int)}</code> method.
     *
     * @param      s   The <code>String</code> to be printed
     */
    public void print(String s) {
        if (s == null) {
            s = "null";
        }
        write(s);
    }

    
Prints an object.  The string produced by the String.valueOf(Object) method is translated into bytes
according to the platform's default character encoding, and these bytes
are written in exactly the manner of the write(int)
method.
Params:
obj –   The Object to be printed
See Also:
Object.toString()/**
     * Prints an object.  The string produced by the <code>{@link
     * java.lang.String#valueOf(Object)}</code> method is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      obj   The <code>Object</code> to be printed
     * @see        java.lang.Object#toString()
     */
    public void print(Object obj) {
        write(String.valueOf(obj));
    }

    /* Methods that do terminate lines */

    
Terminates the current line by writing the line separator string.  The
line separator string is defined by the system property
line.separator, and is not necessarily a single newline
character ('\n').
/**
     * Terminates the current line by writing the line separator string.  The
     * line separator string is defined by the system property
     * <code>line.separator</code>, and is not necessarily a single newline
     * character (<code>'\n'</code>).
     */
    public void println() {
        newLine();
    }

    
Prints a boolean value and then terminates the line.  This method behaves
as though it invokes print(boolean) and then
println().
Params:
x – the boolean value to be printed/**
     * Prints a boolean value and then terminates the line.  This method behaves
     * as though it invokes <code>{@link #print(boolean)}</code> and then
     * <code>{@link #println()}</code>.
     *
     * @param x the <code>boolean</code> value to be printed
     */
    public void println(boolean x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints a character and then terminates the line.  This method behaves as
though it invokes print(char) and then println().
Params:
x – the char value to be printed/**
     * Prints a character and then terminates the line.  This method behaves as
     * though it invokes <code>{@link #print(char)}</code> and then <code>{@link
     * #println()}</code>.
     *
     * @param x the <code>char</code> value to be printed
     */
    public void println(char x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints an integer and then terminates the line.  This method behaves as
though it invokes print(int) and then println().
Params:
x – the int value to be printed/**
     * Prints an integer and then terminates the line.  This method behaves as
     * though it invokes <code>{@link #print(int)}</code> and then <code>{@link
     * #println()}</code>.
     *
     * @param x the <code>int</code> value to be printed
     */
    public void println(int x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints a long integer and then terminates the line.  This method behaves
as though it invokes print(long) and then
println().
Params:
x – the long value to be printed/**
     * Prints a long integer and then terminates the line.  This method behaves
     * as though it invokes <code>{@link #print(long)}</code> and then
     * <code>{@link #println()}</code>.
     *
     * @param x the <code>long</code> value to be printed
     */
    public void println(long x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints a floating-point number and then terminates the line.  This method
behaves as though it invokes print(float) and then
println().
Params:
x – the float value to be printed/**
     * Prints a floating-point number and then terminates the line.  This method
     * behaves as though it invokes <code>{@link #print(float)}</code> and then
     * <code>{@link #println()}</code>.
     *
     * @param x the <code>float</code> value to be printed
     */
    public void println(float x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints a double-precision floating-point number and then terminates the
line.  This method behaves as though it invokes print(double) and then println().
Params:
x – the double value to be printed/**
     * Prints a double-precision floating-point number and then terminates the
     * line.  This method behaves as though it invokes <code>{@link
     * #print(double)}</code> and then <code>{@link #println()}</code>.
     *
     * @param x the <code>double</code> value to be printed
     */
    public void println(double x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints an array of characters and then terminates the line.  This method
behaves as though it invokes print(char[]) and then
println().
Params:
x – the array of char values to be printed/**
     * Prints an array of characters and then terminates the line.  This method
     * behaves as though it invokes <code>{@link #print(char[])}</code> and then
     * <code>{@link #println()}</code>.
     *
     * @param x the array of <code>char</code> values to be printed
     */
    public void println(char x[]) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints a String and then terminates the line.  This method behaves as
though it invokes print(String) and then
println().
Params:
x – the String value to be printed/**
     * Prints a String and then terminates the line.  This method behaves as
     * though it invokes <code>{@link #print(String)}</code> and then
     * <code>{@link #println()}</code>.
     *
     * @param x the <code>String</code> value to be printed
     */
    public void println(String x) {
        synchronized (lock) {
            print(x);
            println();
        }
    }

    
Prints an Object and then terminates the line.  This method calls
at first String.valueOf(x) to get the printed object's string value,
then behaves as
though it invokes print(String) and then
println().
Params:
x –  The Object to be printed./**
     * Prints an Object and then terminates the line.  This method calls
     * at first String.valueOf(x) to get the printed object's string value,
     * then behaves as
     * though it invokes <code>{@link #print(String)}</code> and then
     * <code>{@link #println()}</code>.
     *
     * @param x  The <code>Object</code> to be printed.
     */
    public void println(Object x) {
        String s = String.valueOf(x);
        synchronized (lock) {
            print(s);
            println();
        }
    }

    
A convenience method to write a formatted string to this writer using
the specified format string and arguments.  If automatic flushing is
enabled, calls to this method will flush the output buffer.
 An invocation of this method of the form out.printf(format,
args) behaves in exactly the same way as the invocation
    out.format(format, args) 
Params:
format – 
        A format string as described in Format string syntax.
args – 
        Arguments referenced by the format specifiers in the format
        string.  If there are more arguments than format specifiers, the
        extra arguments are ignored.  The number of arguments is
        variable and may be zero.  The maximum number of arguments is
        limited by the maximum dimension of a Java array as defined by
        The Java™ Virtual Machine Specification.
        The behaviour on a
        null argument depends on the conversion.
Throws:
IllegalFormatException – 
         If a format string contains an illegal syntax, a format
         specifier that is incompatible with the given arguments,
         insufficient arguments given the format string, or other
         illegal conditions.  For specification of all possible
         formatting errors, see the Details section of the
         formatter class specification.
NullPointerException – 
         If the format is null
Returns:
 This writer
Since:
 1.5/**
     * A convenience method to write a formatted string to this writer using
     * the specified format string and arguments.  If automatic flushing is
     * enabled, calls to this method will flush the output buffer.
     *
     * <p> An invocation of this method of the form <tt>out.printf(format,
     * args)</tt> behaves in exactly the same way as the invocation
     *
     * <pre>
     *     out.format(format, args) </pre>
     *
     * @param  format
     *         A format string as described in <a
     *         href="../util/Formatter.html#syntax">Format string syntax</a>.
     *
     * @param  args
     *         Arguments referenced by the format specifiers in the format
     *         string.  If there are more arguments than format specifiers, the
     *         extra arguments are ignored.  The number of arguments is
     *         variable and may be zero.  The maximum number of arguments is
     *         limited by the maximum dimension of a Java array as defined by
     *         <cite>The Java&trade; Virtual Machine Specification</cite>.
     *         The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     *
     * @throws  java.util.IllegalFormatException
     *          If a format string contains an illegal syntax, a format
     *          specifier that is incompatible with the given arguments,
     *          insufficient arguments given the format string, or other
     *          illegal conditions.  For specification of all possible
     *          formatting errors, see the <a
     *          href="../util/Formatter.html#detail">Details</a> section of the
     *          formatter class specification.
     *
     * @throws  NullPointerException
     *          If the <tt>format</tt> is <tt>null</tt>
     *
     * @return  This writer
     *
     * @since  1.5
     */
    public PrintWriter printf(String format, Object ... args) {
        return format(format, args);
    }

    
A convenience method to write a formatted string to this writer using
the specified format string and arguments.  If automatic flushing is
enabled, calls to this method will flush the output buffer.
 An invocation of this method of the form out.printf(l, format,
args) behaves in exactly the same way as the invocation
    out.format(l, format, args) 
Params:
l –  The locale to apply during formatting. If l is null then no localization
        is applied.
format – 
        A format string as described in Format string syntax.
args – 
        Arguments referenced by the format specifiers in the format
        string.  If there are more arguments than format specifiers, the
        extra arguments are ignored.  The number of arguments is
        variable and may be zero.  The maximum number of arguments is
        limited by the maximum dimension of a Java array as defined by
        The Java™ Virtual Machine Specification.
        The behaviour on a
        null argument depends on the conversion.
Throws:
IllegalFormatException – 
         If a format string contains an illegal syntax, a format
         specifier that is incompatible with the given arguments,
         insufficient arguments given the format string, or other
         illegal conditions.  For specification of all possible
         formatting errors, see the Details section of the
         formatter class specification.
NullPointerException – 
         If the format is null
Returns:
 This writer
Since:
 1.5/**
     * A convenience method to write a formatted string to this writer using
     * the specified format string and arguments.  If automatic flushing is
     * enabled, calls to this method will flush the output buffer.
     *
     * <p> An invocation of this method of the form <tt>out.printf(l, format,
     * args)</tt> behaves in exactly the same way as the invocation
     *
     * <pre>
     *     out.format(l, format, args) </pre>
     *
     * @param  l
     *         The {@linkplain java.util.Locale locale} to apply during
     *         formatting.  If <tt>l</tt> is <tt>null</tt> then no localization
     *         is applied.
     *
     * @param  format
     *         A format string as described in <a
     *         href="../util/Formatter.html#syntax">Format string syntax</a>.
     *
     * @param  args
     *         Arguments referenced by the format specifiers in the format
     *         string.  If there are more arguments than format specifiers, the
     *         extra arguments are ignored.  The number of arguments is
     *         variable and may be zero.  The maximum number of arguments is
     *         limited by the maximum dimension of a Java array as defined by
     *         <cite>The Java&trade; Virtual Machine Specification</cite>.
     *         The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     *
     * @throws  java.util.IllegalFormatException
     *          If a format string contains an illegal syntax, a format
     *          specifier that is incompatible with the given arguments,
     *          insufficient arguments given the format string, or other
     *          illegal conditions.  For specification of all possible
     *          formatting errors, see the <a
     *          href="../util/Formatter.html#detail">Details</a> section of the
     *          formatter class specification.
     *
     * @throws  NullPointerException
     *          If the <tt>format</tt> is <tt>null</tt>
     *
     * @return  This writer
     *
     * @since  1.5
     */
    public PrintWriter printf(Locale l, String format, Object ... args) {
        return format(l, format, args);
    }

    
Writes a formatted string to this writer using the specified format
string and arguments.  If automatic flushing is enabled, calls to this
method will flush the output buffer.
 The locale always used is the one returned by Locale.getDefault(), regardless of any previous invocations of other formatting methods on this object. 
Params:
format – 
        A format string as described in Format string syntax.
args – 
        Arguments referenced by the format specifiers in the format
        string.  If there are more arguments than format specifiers, the
        extra arguments are ignored.  The number of arguments is
        variable and may be zero.  The maximum number of arguments is
        limited by the maximum dimension of a Java array as defined by
        The Java™ Virtual Machine Specification.
        The behaviour on a
        null argument depends on the conversion.
Throws:
IllegalFormatException – 
         If a format string contains an illegal syntax, a format
         specifier that is incompatible with the given arguments,
         insufficient arguments given the format string, or other
         illegal conditions.  For specification of all possible
         formatting errors, see the Details section of the
         Formatter class specification.
NullPointerException – 
         If the format is null
Returns:
 This writer
Since:
 1.5/**
     * Writes a formatted string to this writer using the specified format
     * string and arguments.  If automatic flushing is enabled, calls to this
     * method will flush the output buffer.
     *
     * <p> The locale always used is the one returned by {@link
     * java.util.Locale#getDefault() Locale.getDefault()}, regardless of any
     * previous invocations of other formatting methods on this object.
     *
     * @param  format
     *         A format string as described in <a
     *         href="../util/Formatter.html#syntax">Format string syntax</a>.
     *
     * @param  args
     *         Arguments referenced by the format specifiers in the format
     *         string.  If there are more arguments than format specifiers, the
     *         extra arguments are ignored.  The number of arguments is
     *         variable and may be zero.  The maximum number of arguments is
     *         limited by the maximum dimension of a Java array as defined by
     *         <cite>The Java&trade; Virtual Machine Specification</cite>.
     *         The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     *
     * @throws  java.util.IllegalFormatException
     *          If a format string contains an illegal syntax, a format
     *          specifier that is incompatible with the given arguments,
     *          insufficient arguments given the format string, or other
     *          illegal conditions.  For specification of all possible
     *          formatting errors, see the <a
     *          href="../util/Formatter.html#detail">Details</a> section of the
     *          Formatter class specification.
     *
     * @throws  NullPointerException
     *          If the <tt>format</tt> is <tt>null</tt>
     *
     * @return  This writer
     *
     * @since  1.5
     */
    public PrintWriter format(String format, Object ... args) {
        try {
            synchronized (lock) {
                ensureOpen();
                if ((formatter == null)
                    || (formatter.locale() != Locale.getDefault()))
                    formatter = new Formatter(this);
                formatter.format(Locale.getDefault(), format, args);
                if (autoFlush)
                    out.flush();
            }
        } catch (InterruptedIOException x) {
            Thread.currentThread().interrupt();
        } catch (IOException x) {
            trouble = true;
        }
        return this;
    }

    
Writes a formatted string to this writer using the specified format
string and arguments.  If automatic flushing is enabled, calls to this
method will flush the output buffer.
Params:
l –  The locale to apply during formatting. If l is null then no localization
        is applied.
format – 
        A format string as described in Format string syntax.
args – 
        Arguments referenced by the format specifiers in the format
        string.  If there are more arguments than format specifiers, the
        extra arguments are ignored.  The number of arguments is
        variable and may be zero.  The maximum number of arguments is
        limited by the maximum dimension of a Java array as defined by
        The Java™ Virtual Machine Specification.
        The behaviour on a
        null argument depends on the conversion.
Throws:
IllegalFormatException – 
         If a format string contains an illegal syntax, a format
         specifier that is incompatible with the given arguments,
         insufficient arguments given the format string, or other
         illegal conditions.  For specification of all possible
         formatting errors, see the Details section of the
         formatter class specification.
NullPointerException – 
         If the format is null
Returns:
 This writer
Since:
 1.5/**
     * Writes a formatted string to this writer using the specified format
     * string and arguments.  If automatic flushing is enabled, calls to this
     * method will flush the output buffer.
     *
     * @param  l
     *         The {@linkplain java.util.Locale locale} to apply during
     *         formatting.  If <tt>l</tt> is <tt>null</tt> then no localization
     *         is applied.
     *
     * @param  format
     *         A format string as described in <a
     *         href="../util/Formatter.html#syntax">Format string syntax</a>.
     *
     * @param  args
     *         Arguments referenced by the format specifiers in the format
     *         string.  If there are more arguments than format specifiers, the
     *         extra arguments are ignored.  The number of arguments is
     *         variable and may be zero.  The maximum number of arguments is
     *         limited by the maximum dimension of a Java array as defined by
     *         <cite>The Java&trade; Virtual Machine Specification</cite>.
     *         The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     *
     * @throws  java.util.IllegalFormatException
     *          If a format string contains an illegal syntax, a format
     *          specifier that is incompatible with the given arguments,
     *          insufficient arguments given the format string, or other
     *          illegal conditions.  For specification of all possible
     *          formatting errors, see the <a
     *          href="../util/Formatter.html#detail">Details</a> section of the
     *          formatter class specification.
     *
     * @throws  NullPointerException
     *          If the <tt>format</tt> is <tt>null</tt>
     *
     * @return  This writer
     *
     * @since  1.5
     */
    public PrintWriter format(Locale l, String format, Object ... args) {
        try {
            synchronized (lock) {
                ensureOpen();
                if ((formatter == null) || (formatter.locale() != l))
                    formatter = new Formatter(this, l);
                formatter.format(l, format, args);
                if (autoFlush)
                    out.flush();
            }
        } catch (InterruptedIOException x) {
            Thread.currentThread().interrupt();
        } catch (IOException x) {
            trouble = true;
        }
        return this;
    }

    
Appends the specified character sequence to this writer.
 An invocation of this method of the form out.append(csq)
behaves in exactly the same way as the invocation
    out.write(csq.toString()) 
 Depending on the specification of toString for the
character sequence csq, the entire sequence may not be
appended. For instance, invoking the toString method of a
character buffer will return a subsequence whose content depends upon
the buffer's position and limit.
Params:
csq – 
        The character sequence to append.  If csq is
        null, then the four characters "null" are
        appended to this writer.
Returns:
 This writer
Since:
 1.5/**
     * Appends the specified character sequence to this writer.
     *
     * <p> An invocation of this method of the form <tt>out.append(csq)</tt>
     * behaves in exactly the same way as the invocation
     *
     * <pre>
     *     out.write(csq.toString()) </pre>
     *
     * <p> Depending on the specification of <tt>toString</tt> for the
     * character sequence <tt>csq</tt>, the entire sequence may not be
     * appended. For instance, invoking the <tt>toString</tt> method of a
     * character buffer will return a subsequence whose content depends upon
     * the buffer's position and limit.
     *
     * @param  csq
     *         The character sequence to append.  If <tt>csq</tt> is
     *         <tt>null</tt>, then the four characters <tt>"null"</tt> are
     *         appended to this writer.
     *
     * @return  This writer
     *
     * @since  1.5
     */
    public PrintWriter append(CharSequence csq) {
        if (csq == null)
            write("null");
        else
            write(csq.toString());
        return this;
    }

    
Appends a subsequence of the specified character sequence to this writer.
 An invocation of this method of the form out.append(csq, start,
end) when csq is not null, behaves in
exactly the same way as the invocation
    out.write(csq.subSequence(start, end).toString()) 
Params:
csq – 
        The character sequence from which a subsequence will be
        appended.  If csq is null, then characters
        will be appended as if csq contained the four
        characters "null".
start – 
        The index of the first character in the subsequence
end – 
        The index of the character following the last character in the
        subsequence
Throws:
IndexOutOfBoundsException – 
         If start or end are negative, start
         is greater than end, or end is greater than
         csq.length()
Returns:
 This writer
Since:
 1.5/**
     * Appends a subsequence of the specified character sequence to this writer.
     *
     * <p> An invocation of this method of the form <tt>out.append(csq, start,
     * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in
     * exactly the same way as the invocation
     *
     * <pre>
     *     out.write(csq.subSequence(start, end).toString()) </pre>
     *
     * @param  csq
     *         The character sequence from which a subsequence will be
     *         appended.  If <tt>csq</tt> is <tt>null</tt>, then characters
     *         will be appended as if <tt>csq</tt> contained the four
     *         characters <tt>"null"</tt>.
     *
     * @param  start
     *         The index of the first character in the subsequence
     *
     * @param  end
     *         The index of the character following the last character in the
     *         subsequence
     *
     * @return  This writer
     *
     * @throws  IndexOutOfBoundsException
     *          If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt>
     *          is greater than <tt>end</tt>, or <tt>end</tt> is greater than
     *          <tt>csq.length()</tt>
     *
     * @since  1.5
     */
    public PrintWriter append(CharSequence csq, int start, int end) {
        CharSequence cs = (csq == null ? "null" : csq);
        write(cs.subSequence(start, end).toString());
        return this;
    }

    
Appends the specified character to this writer.
 An invocation of this method of the form out.append(c)
behaves in exactly the same way as the invocation
    out.write(c) 
Params:
c – 
        The 16-bit character to append
Returns:
 This writer
Since:
1.5/**
     * Appends the specified character to this writer.
     *
     * <p> An invocation of this method of the form <tt>out.append(c)</tt>
     * behaves in exactly the same way as the invocation
     *
     * <pre>
     *     out.write(c) </pre>
     *
     * @param  c
     *         The 16-bit character to append
     *
     * @return  This writer
     *
     * @since 1.5
     */
    public PrintWriter append(char c) {
        write(c);
        return this;
    }
}