https://openjdk.java.net/ 
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 * Copyright (c) 1998, 2006, 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,
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 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package java.sql;


An input stream that contains a stream of values representing an
instance of an SQL structured type or an SQL distinct type.
This interface, used only for custom mapping, is used by the driver
behind the scenes, and a programmer never directly invokes
SQLInput methods. The reader methods
(readLong, readBytes, and so on)
provide a way  for an implementation of the SQLData
 interface to read the values in an SQLInput object.
 And as described in SQLData, calls to reader methods must
be made in the order that their corresponding attributes appear in the
SQL definition of the type.
The method wasNull is used to determine whether
the last value read was SQL NULL.

When the method getObject is called with an
object of a class implementing the interface SQLData,
the JDBC driver calls the method SQLData.getSQLType
to determine the SQL type of the user-defined type (UDT)
being custom mapped. The driver
creates an instance of SQLInput, populating it with the
attributes of the UDT.  The driver then passes the input
stream to the method SQLData.readSQL, which in turn
calls the SQLInput reader methods
in its implementation for reading the
attributes from the input stream.

Since:1.2
/**
 * An input stream that contains a stream of values representing an
 * instance of an SQL structured type or an SQL distinct type.
 * This interface, used only for custom mapping, is used by the driver
 * behind the scenes, and a programmer never directly invokes
 * <code>SQLInput</code> methods. The <i>reader</i> methods
 * (<code>readLong</code>, <code>readBytes</code>, and so on)
 * provide a way  for an implementation of the <code>SQLData</code>
 *  interface to read the values in an <code>SQLInput</code> object.
 *  And as described in <code>SQLData</code>, calls to reader methods must
 * be made in the order that their corresponding attributes appear in the
 * SQL definition of the type.
 * The method <code>wasNull</code> is used to determine whether
 * the last value read was SQL <code>NULL</code>.
 * <P>When the method <code>getObject</code> is called with an
 * object of a class implementing the interface <code>SQLData</code>,
 * the JDBC driver calls the method <code>SQLData.getSQLType</code>
 * to determine the SQL type of the user-defined type (UDT)
 * being custom mapped. The driver
 * creates an instance of <code>SQLInput</code>, populating it with the
 * attributes of the UDT.  The driver then passes the input
 * stream to the method <code>SQLData.readSQL</code>, which in turn
 * calls the <code>SQLInput</code> reader methods
 * in its implementation for reading the
 * attributes from the input stream.
 * @since 1.2
 */

public interface SQLInput {


    //================================================================
    // Methods for reading attributes from the stream of SQL data.
    // These methods correspond to the column-accessor methods of
    // java.sql.ResultSet.
    //================================================================

    
Reads the next attribute in the stream and returns it as a String
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>String</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    String readString() throws SQLException;

    
Reads the next attribute in the stream and returns it as a boolean
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns false
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>boolean</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>false</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    boolean readBoolean() throws SQLException;

    
Reads the next attribute in the stream and returns it as a byte
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns 0
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>byte</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>0</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    byte readByte() throws SQLException;

    
Reads the next attribute in the stream and returns it as a short
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns 0
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>short</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>0</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    short readShort() throws SQLException;

    
Reads the next attribute in the stream and returns it as an int
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns 0
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as an <code>int</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>0</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    int readInt() throws SQLException;

    
Reads the next attribute in the stream and returns it as a long
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns 0
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>long</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>0</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    long readLong() throws SQLException;

    
Reads the next attribute in the stream and returns it as a float
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns 0
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>float</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>0</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    float readFloat() throws SQLException;

    
Reads the next attribute in the stream and returns it as a double
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns 0
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>double</code>
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>0</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    double readDouble() throws SQLException;

    
Reads the next attribute in the stream and returns it as a java.math.BigDecimal
object in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>java.math.BigDecimal</code>
     * object in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.math.BigDecimal readBigDecimal() throws SQLException;

    
Reads the next attribute in the stream and returns it as an array of bytes
in the Java programming language.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as an array of bytes
     * in the Java programming language.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    byte[] readBytes() throws SQLException;

    
Reads the next attribute in the stream and returns it as a java.sql.Date object.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>java.sql.Date</code> object.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.sql.Date readDate() throws SQLException;

    
Reads the next attribute in the stream and returns it as a java.sql.Time object.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>java.sql.Time</code> object.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.sql.Time readTime() throws SQLException;

    
Reads the next attribute in the stream and returns it as a java.sql.Timestamp object.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a <code>java.sql.Timestamp</code> object.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.sql.Timestamp readTimestamp() throws SQLException;

    
Reads the next attribute in the stream and returns it as a stream of Unicode characters.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a stream of Unicode characters.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.io.Reader readCharacterStream() throws SQLException;

    
Reads the next attribute in the stream and returns it as a stream of ASCII characters.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a stream of ASCII characters.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.io.InputStream readAsciiStream() throws SQLException;

    
Reads the next attribute in the stream and returns it as a stream of uninterpreted
bytes.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.2
/**
     * Reads the next attribute in the stream and returns it as a stream of uninterpreted
     * bytes.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    java.io.InputStream readBinaryStream() throws SQLException;

    //================================================================
    // Methods for reading items of SQL user-defined types from the stream.
    //================================================================

    
Reads the datum at the head of the stream and returns it as an
Object in the Java programming language.  The
actual type of the object returned is determined by the default type
mapping, and any customizations present in this stream's type map.

A type map is registered with the stream by the JDBC driver before the
stream is passed to the application.

When the datum at the head of the stream is an SQL NULL,
the method returns null.  If the datum is an SQL structured or distinct
type, it determines the SQL type of the datum at the head of the stream.
If the stream's type map has an entry for that SQL type, the driver
constructs an object of the appropriate class and calls the method
SQLData.readSQL on that object, which reads additional data from the
stream, using the protocol described for that method.

Throws:
Returns:the datum at the head of the stream as an Object in the
Java programming language;null if the datum is SQL NULL
Since:1.2
/**
     * Reads the datum at the head of the stream and returns it as an
     * <code>Object</code> in the Java programming language.  The
     * actual type of the object returned is determined by the default type
     * mapping, and any customizations present in this stream's type map.
     *
     * <P>A type map is registered with the stream by the JDBC driver before the
     * stream is passed to the application.
     *
     * <P>When the datum at the head of the stream is an SQL <code>NULL</code>,
     * the method returns <code>null</code>.  If the datum is an SQL structured or distinct
     * type, it determines the SQL type of the datum at the head of the stream.
     * If the stream's type map has an entry for that SQL type, the driver
     * constructs an object of the appropriate class and calls the method
     * <code>SQLData.readSQL</code> on that object, which reads additional data from the
     * stream, using the protocol described for that method.
     *
     * @return the datum at the head of the stream as an <code>Object</code> in the
     * Java programming language;<code>null</code> if the datum is SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    Object readObject() throws SQLException;

    
Reads an SQL REF value from the stream and returns it as a
Ref object in the Java programming language.

Throws:
Returns:a Ref object representing the SQL REF value
at the head of the stream; null if the value read is
SQL NULL
Since:1.2
/**
     * Reads an SQL <code>REF</code> value from the stream and returns it as a
     * <code>Ref</code> object in the Java programming language.
     *
     * @return a <code>Ref</code> object representing the SQL <code>REF</code> value
     * at the head of the stream; <code>null</code> if the value read is
     * SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    Ref readRef() throws SQLException;

    
Reads an SQL BLOB value from the stream and returns it as a
Blob object in the Java programming language.

Throws:
Returns:a Blob object representing data of the SQL BLOB value
at the head of the stream; null if the value read is
SQL NULL
Since:1.2
/**
     * Reads an SQL <code>BLOB</code> value from the stream and returns it as a
     * <code>Blob</code> object in the Java programming language.
     *
     * @return a <code>Blob</code> object representing data of the SQL <code>BLOB</code> value
     * at the head of the stream; <code>null</code> if the value read is
     * SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    Blob readBlob() throws SQLException;

    
Reads an SQL CLOB value from the stream and returns it as a
Clob object in the Java programming language.

Throws:
Returns:a Clob object representing data of the SQL CLOB value
at the head of the stream; null if the value read is
SQL NULL
Since:1.2
/**
     * Reads an SQL <code>CLOB</code> value from the stream and returns it as a
     * <code>Clob</code> object in the Java programming language.
     *
     * @return a <code>Clob</code> object representing data of the SQL <code>CLOB</code> value
     * at the head of the stream; <code>null</code> if the value read is
     * SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    Clob readClob() throws SQLException;

    
Reads an SQL ARRAY value from the stream and returns it as an
Array object in the Java programming language.

Throws:
Returns:an Array object representing data of the SQL
ARRAY value at the head of the stream; null
if the value read is SQL NULL
Since:1.2
/**
     * Reads an SQL <code>ARRAY</code> value from the stream and returns it as an
     * <code>Array</code> object in the Java programming language.
     *
     * @return an <code>Array</code> object representing data of the SQL
     * <code>ARRAY</code> value at the head of the stream; <code>null</code>
     * if the value read is SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    Array readArray() throws SQLException;

    
Retrieves whether the last value read was SQL NULL.

Throws:
Returns:true if the most recently read SQL value was SQL
NULL; false otherwise
Since:1.2
/**
     * Retrieves whether the last value read was SQL <code>NULL</code>.
     *
     * @return <code>true</code> if the most recently read SQL value was SQL
     * <code>NULL</code>; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     *
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.2
     */
    boolean wasNull() throws SQLException;

    //---------------------------- JDBC 3.0 -------------------------

    
Reads an SQL DATALINK value from the stream and returns it as a
java.net.URL object in the Java programming language.

Throws:
Returns:a java.net.URL object.
Since:1.4
/**
     * Reads an SQL <code>DATALINK</code> value from the stream and returns it as a
     * <code>java.net.URL</code> object in the Java programming language.
     *
     * @return a <code>java.net.URL</code> object.
     * @exception SQLException if a database access error occurs,
     *            or if a URL is malformed
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.4
     */
    java.net.URL readURL() throws SQLException;

     //---------------------------- JDBC 4.0 -------------------------

    
Reads an SQL NCLOB value from the stream and returns it as a
NClob object in the Java programming language.

Throws:
Returns:a NClob object representing data of the SQL NCLOB value
at the head of the stream; null if the value read is
SQL NULL
Since:1.6
/**
     * Reads an SQL <code>NCLOB</code> value from the stream and returns it as a
     * <code>NClob</code> object in the Java programming language.
     *
     * @return a <code>NClob</code> object representing data of the SQL <code>NCLOB</code> value
     * at the head of the stream; <code>null</code> if the value read is
     * SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.6
     */
    NClob readNClob() throws SQLException;

    
Reads the next attribute in the stream and returns it as a String
in the Java programming language. It is intended for use when
accessing  NCHAR,NVARCHAR
and LONGNVARCHAR columns.

Throws:
Returns:the attribute; if the value is SQL NULL, returns null
Since:1.6
/**
     * Reads the next attribute in the stream and returns it as a <code>String</code>
     * in the Java programming language. It is intended for use when
     * accessing  <code>NCHAR</code>,<code>NVARCHAR</code>
     * and <code>LONGNVARCHAR</code> columns.
     *
     * @return the attribute; if the value is SQL <code>NULL</code>, returns <code>null</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.6
     */
    String readNString() throws SQLException;

    
Reads an SQL XML value from the stream and returns it as a
SQLXML object in the Java programming language.

Throws:
Returns:a SQLXML object representing data of the SQL XML value
at the head of the stream; null if the value read is
SQL NULL
Since:1.6
/**
     * Reads an SQL <code>XML</code> value from the stream and returns it as a
     * <code>SQLXML</code> object in the Java programming language.
     *
     * @return a <code>SQLXML</code> object representing data of the SQL <code>XML</code> value
     * at the head of the stream; <code>null</code> if the value read is
     * SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.6
     */
    SQLXML readSQLXML() throws SQLException;

    
Reads an SQL ROWID value from the stream and returns it as a
RowId object in the Java programming language.

Throws:
Returns:a RowId object representing data of the SQL ROWID value
at the head of the stream; null if the value read is
SQL NULL
Since:1.6
/**
     * Reads an SQL <code>ROWID</code> value from the stream and returns it as a
     * <code>RowId</code> object in the Java programming language.
     *
     * @return a <code>RowId</code> object representing data of the SQL <code>ROWID</code> value
     * at the head of the stream; <code>null</code> if the value read is
     * SQL <code>NULL</code>
     * @exception SQLException if a database access error occurs
     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     * this method
     * @since 1.6
     */
    RowId readRowId() throws SQLException;

}