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 * Licensed to the Apache Software Foundation (ASF) under one or more
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 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
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 * distributed under the License is distributed on an "AS IS" BASIS,
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package com.sun.org.apache.xerces.internal.util;

import com.sun.org.apache.xerces.internal.xni.XMLString;

XMLString is a structure used to pass character arrays. However,
XMLStringBuffer is a buffer in which characters can be appended
and extends XMLString so that it can be passed to methods
expecting an XMLString object. This is a safe operation because
it is assumed that any callee will not modify
the contents of the XMLString structure.

The contents of the string are managed by the string buffer. As
characters are appended, the string buffer will grow as needed.

Note: Never set the ch,
offset, and length fields directly.
These fields are managed by the string buffer. In order to reset
the buffer, call clear().
Author:
Andy Clark, IBM, Eric Ye, IBM/**
 * XMLString is a structure used to pass character arrays. However,
 * XMLStringBuffer is a buffer in which characters can be appended
 * and extends XMLString so that it can be passed to methods
 * expecting an XMLString object. This is a safe operation because
 * it is assumed that any callee will <strong>not</strong> modify
 * the contents of the XMLString structure.
 * <p>
 * The contents of the string are managed by the string buffer. As
 * characters are appended, the string buffer will grow as needed.
 * <p>
 * <strong>Note:</strong> Never set the <code>ch</code>,
 * <code>offset</code>, and <code>length</code> fields directly.
 * These fields are managed by the string buffer. In order to reset
 * the buffer, call <code>clear()</code>.
 *
 * @author Andy Clark, IBM
 * @author Eric Ye, IBM
 *
 */
public class XMLStringBuffer
extends XMLString {

    //
    // Constants
    //


    
Default buffer size (32). /** Default buffer size (32). */
    public static final int DEFAULT_SIZE = 32;

    //
    // Data
    //

    //
    // Constructors
    //

    /**
     *
     */
    public XMLStringBuffer() {
        this(DEFAULT_SIZE);
    } // <init>()

    
Params:
size – /**
     *
     *
     * @param size
     */
    public XMLStringBuffer(int size) {
        ch = new char[size];
    } // <init>(int)

    
Constructs a string buffer from a char. /** Constructs a string buffer from a char. */
    public XMLStringBuffer(char c) {
        this(1);
        append(c);
    } // <init>(char)

    
Constructs a string buffer from a String. /** Constructs a string buffer from a String. */
    public XMLStringBuffer(String s) {
        this(s.length());
        append(s);
    } // <init>(String)

    
Constructs a string buffer from the specified character array. /** Constructs a string buffer from the specified character array. */
    public XMLStringBuffer(char[] ch, int offset, int length) {
        this(length);
        append(ch, offset, length);
    } // <init>(char[],int,int)

    
Constructs a string buffer from the specified XMLString. /** Constructs a string buffer from the specified XMLString. */
    public XMLStringBuffer(XMLString s) {
        this(s.length);
        append(s);
    } // <init>(XMLString)

    //
    // Public methods
    //

    
Clears the string buffer. /** Clears the string buffer. */
    public void clear() {
        offset = 0;
        length = 0;
    }

    
append
Params:
c – /**
     * append
     *
     * @param c
     */
    public void append(char c) {
        if(this.length + 1 > this.ch.length){
            int newLength = this.ch.length * 2 ;
            if(newLength < this.ch.length + DEFAULT_SIZE){
                newLength = this.ch.length + DEFAULT_SIZE;
            }
            char [] tmp = new char[newLength];
            System.arraycopy(this.ch, 0, tmp, 0, this.length);
            this.ch = tmp;
        }
        this.ch[this.length] = c ;
        this.length++;
    } // append(char)

    
append
Params:
s – /**
     * append
     *
     * @param s
     */
    public void append(String s) {
        int length = s.length();
        if (this.length + length > this.ch.length) {
            int newLength = this.ch.length * 2 ;
            if(newLength < this.ch.length + length + DEFAULT_SIZE){
                newLength = this.ch.length + length+ DEFAULT_SIZE;
            }

            char[] newch = new char[newLength];
            System.arraycopy(this.ch, 0, newch, 0, this.length);
            this.ch = newch;
        }
        s.getChars(0, length, this.ch, this.length);
        this.length += length;
    } // append(String)

    
append
Params:
ch – 
offset – 
length – /**
     * append
     *
     * @param ch
     * @param offset
     * @param length
     */
    public void append(char[] ch, int offset, int length) {
        if (this.length + length > this.ch.length) {
            int newLength = this.ch.length * 2 ;
            if(newLength < this.ch.length + length + DEFAULT_SIZE){
                newLength = this.ch.length + length + DEFAULT_SIZE;
            }
            char[] newch = new char[newLength];
            System.arraycopy(this.ch, 0, newch, 0, this.length);
            this.ch = newch;
        }
        //making the code more robust as it would handle null or 0 length data,
        //add the data only when it contains some thing
        if(ch != null && length > 0){
            System.arraycopy(ch, offset, this.ch, this.length, length);
            this.length += length;
        }
    } // append(char[],int,int)

    
append
Params:
s – /**
     * append
     *
     * @param s
     */
    public void append(XMLString s) {
        append(s.ch, s.offset, s.length);
    } // append(XMLString)


} // class XMLStringBuffer