- /*
- * @(#)SerialBlob.java 1.8 04/05/29
- *
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package javax.sql.rowset.serial;
-
- import java.sql.*;
- import java.io.*;
- import java.lang.reflect.*;
-
-
- /**
- * A serialized mapping in the Java programming language of an SQL
- * <code>BLOB</code> value.
- * <P>
- * The <code>SerialBlob</code> class provides a constructor for creating
- * an instance from a <code>Blob</code> object. Note that the
- * <code>Blob</code>
- * object should have brought the SQL <code>BLOB</code> value's data over
- * to the client before a <code>SerialBlob</code> object
- * is constructed from it. The data of an SQL <code>BLOB</code> value can
- * be materialized on the client as an array of bytes (using the method
- * <code>Blob.getBytes</code>) or as a stream of uninterpreted bytes
- * (using the method <code>Blob.getBinaryStream</code>).
- * <P>
- * <code>SerialBlob</code> methods make it possible to make a copy of a
- * <code>SerialBlob</code> object as an array of bytes or as a stream.
- * They also make it possible to locate a given pattern of bytes or a
- * <code>Blob</code> object within a <code>SerialBlob</code> object
- * and to update or truncate a <code>Blob</code> object.
- *
- * @author Jonathan Bruce
- */
- public class SerialBlob implements Blob, Serializable, Cloneable {
-
- /**
- * A serialized array of uninterpreted bytes representing the
- * value of this <code>SerialBlob</code> object.
- * @serial
- */
- private byte buf[];
-
- /**
- * The internal representation of the <code>Blob</code> object on which this
- * <code>SerialBlob</code> object is based.
- */
- private Blob blob;
-
- /**
- * The number of bytes in this <code>SerialBlob</code> object's
- * array of bytes.
- * @serial
- */
- private long len;
-
- /**
- * The orginal number of bytes in this <code>SerialBlob</code> object's
- * array of bytes when it was first established.
- * @serial
- */
- private long origLen;
-
- /**
- * Constructs a <code>SerialBlob</code> object that is a serialized version of
- * the given <code>byte</code> array.
- * <p>
- * The new <code>SerialBlob</code> object is initialized with the data from the
- * <code>byte</code> array, thus allowing disconnected <code>RowSet</code>
- * objects to establish serialized <code>Blob</code> objects without
- * touching the data source.
- *
- * @param b the <code>byte</code> array containing the data for the
- * <code>Blob</code> object to be serialized
- * @throws SerialException if an error occurs during serialization
- * @throws SQLException if a SQL errors occurs
- */
- public SerialBlob(byte[] b) throws SerialException, SQLException {
-
- len = b.length;
- buf = new byte[(int)len];
- for(int i = 0; i < len; i++) {
- buf[i] = b[i];
- }
- origLen = len;
- }
-
-
- /**
- * Constructs a <code>SerialBlob</code> object that is a serialized
- * version of the given <code>Blob</code> object.
- * <P>
- * The new <code>SerialBlob</code> object is initialized with the
- * data from the <code>Blob</code> object; therefore, the
- * <code>Blob</code> object should have previously brought the
- * SQL <code>BLOB</code> value's data over to the client from
- * the database. Otherwise, the new <code>SerialBlob</code> object
- * will contain no data.
- *
- * @param blob the <code>Blob</code> object from which this
- * <code>SerialBlob</code> object is to be constructed;
- * cannot be null.
- * @throws SerialException if an error occurs during serialization
- * @throws SQLException if the <code>Blob</code> passed to this
- * to this constructor is a <code>null</code>.
- * @see java.sql.Blob
- */
- public SerialBlob (Blob blob) throws SerialException, SQLException {
-
- if (blob == null) {
- throw new SQLException("Cannot instantiate a SerialBlob " +
- "object with a null Blob object");
- }
-
- len = blob.length();
- buf = blob.getBytes(1, (int)len );
- this.blob = blob;
-
- //if ( len < 10240000)
- // len = 10240000;
- origLen = len;
- }
-
- /**
- * Copies the specified number of bytes, starting at the given
- * position, from this <code>SerialBlob</code> object to
- * another array of bytes.
- * <P>
- * Note that if the given number of bytes to be copied is larger than
- * the length of this <code>SerialBlob</code> object's array of
- * bytes, the given number will be shortened to the array's length.
- *
- * @param pos the ordinal position of the first byte in this
- * <code>SerialBlob</code> object to be copied;
- * numbering starts at <code>1</code> must not be less
- * than <code>1</code> and must be less than or equal
- * to the length of this <code>SerialBlob</code> object
- * @param length the number of bytes to be copied
- * @return an array of bytes that is a copy of a region of this
- * <code>SerialBlob</code> object, starting at the given
- * position and containing the given number of consecutive bytes
- * @throws SerialException if the given starting position is out of bounds
- */
- public byte[] getBytes(long pos, int length) throws SerialException {
- if (length > len) {
- length = (int)len;
- }
-
- if (pos < 1 || length - pos < 0 ) {
- throw new SerialException("Invalid arguments: position cannot be less that 1");
- }
-
- pos--; // correct pos to array index
-
- byte[] b = new byte[length];
-
- for (int i = 0; i < length; i++) {
- b[i] = this.buf[(int)pos];
- pos++;
- }
- return b;
- }
-
- /**
- * Retrieves the number of bytes in this <code>SerialBlob</code>
- * object's array of bytes.
- *
- * @return a <code>long</code> indicating the length in bytes of this
- * <code>SerialBlob</code> object's array of bytes
- * @throws SerialException if an error occurs
- */
- public long length() throws SerialException {
- return len;
- }
-
- /**
- * Returns this <code>SerialBlob</code> object as an input stream.
- * Unlike the related method, <code>setBinaryStream</code>,
- * a stream is produced regardless of whether the <code>SerialBlob</code>
- * was created with a <code>Blob</code> object or a <code>byte</code> array.
- *
- * @return a <code>java.io.InputStream</code> object that contains
- * this <code>SerialBlob</code> object's array of bytes
- * @throws SerialException if an error occurs
- * @see #setBinaryStream
- */
- public java.io.InputStream getBinaryStream() throws SerialException {
- InputStream stream = new ByteArrayInputStream(buf);
- return (java.io.InputStream)stream;
- }
-
- /**
- * Returns the position in this <code>SerialBlob</code> object where
- * the given pattern of bytes begins, starting the search at the
- * specified position.
- *
- * @param pattern the pattern of bytes for which to search
- * @param start the position of the byte in this
- * <code>SerialBlob</code> object from which to begin
- * the search; the first position is <code>1</code>
- * must not be less than <code>1</code> nor greater than
- * the length of this <code>SerialBlob</code> object
- * @return the position in this <code>SerialBlob</code> object
- * where the given pattern begins, starting at the specified
- * position; <code>-1</code> if the pattern is not found
- * or the given starting position is out of bounds; position
- * numbering for the return value starts at <code>1</code>
- * @throws SerialException if an error occurs when serializing the blob
- * @throws SQLException if there is an error accessing the <code>BLOB</code>
- * value from the database
- */
- public long position(byte[] pattern, long start)
- throws SerialException, SQLException {
- if (start < 1 || start > len) {
- return -1;
- }
-
- int pos = (int)start-1; // internally Blobs are stored as arrays.
- int i = 0;
- long patlen = pattern.length;
-
- while (pos < len) {
- if (pattern[i] == buf[pos]) {
- if (i + 1 == patlen) {
- return (pos + 1) - (patlen - 1);
- }
- i++; pos++; // increment pos, and i
- } else if (pattern[i] != buf[pos]) {
- pos++; // increment pos only
- }
- }
- return -1; // not found
- }
-
- /**
- * Returns the position in this <code>SerialBlob</code> object where
- * the given <code>Blob</code> object begins, starting the search at the
- * specified position.
- *
- * @param pattern the <code>Blob</code> object for which to search;
- * @param start the position of the byte in this
- * <code>SerialBlob</code> object from which to begin
- * the search; the first position is <code>1</code>
- * must not be less than <code>1</code> nor greater than
- * the length of this <code>SerialBlob</code> object
- * @return the position in this <code>SerialBlob</code> object
- * where the given <code>Blob</code> object begins, starting
- * at the specified position; <code>-1</code> if the pattern is
- * not found or the given starting position is out of bounds;
- * position numbering for the return value starts at <code>1</code>
- * @throws SerialException if an error occurs when serializing the blob
- * @throws SQLException if there is an error accessing the <code>BLOB</code>
- * value from the database
- */
- public long position(Blob pattern, long start)
- throws SerialException, SQLException {
- return position(pattern.getBytes(1, (int)(pattern.length())), start);
- }
-
- /**
- * Writes the given array of bytes to the <code>BLOB</code> value that
- * this <code>Blob</code> object represents, starting at position
- * <code>pos</code>, and returns the number of bytes written.
- *
- * @param pos the position in the SQL <code>BLOB</code> value at which
- * to start writing. The first position is <code>1</code>
- * must not be less than <code>1</code> nor greater than
- * the length of this <code>SerialBlob</code> object.
- * @param bytes the array of bytes to be written to the <code>BLOB</code>
- * value that this <code>Blob</code> object represents
- * @return the number of bytes written
- * @throws SerialException if there is an error accessing the
- * <code>BLOB</code> value; or if an invalid position is set; if an
- * invalid offset value is set
- * @throws SQLException if there is an error accessing the <code>BLOB</code>
- * value from the database
- * @see #getBytes
- */
- public int setBytes(long pos, byte[] bytes)
- throws SerialException, SQLException {
- return (setBytes(pos, bytes, 0, bytes.length));
- }
-
- /**
- * Writes all or part of the given <code>byte</code> array to the
- * <code>BLOB</code> value that this <code>Blob</code> object represents
- * and returns the number of bytes written.
- * Writing starts at position <code>pos</code> in the <code>BLOB</code>
- * value; <i>len</i> bytes from the given byte array are written.
- *
- * @param pos the position in the <code>BLOB</code> object at which
- * to start writing. The first position is <code>1</code>
- * must not be less than <code>1</code> nor greater than
- * the length of this <code>SerialBlob</code> object.
- * @param bytes the array of bytes to be written to the <code>BLOB</code>
- * value
- * @param offset the offset in the <code>byte</code> array at which
- * to start reading the bytes. The first offset position is
- * <code>0</code> must not be less than <code>0</code> nor greater
- * than the length of the <code>byte</code> array
- * @param length the number of bytes to be written to the
- * <code>BLOB</code> value from the array of bytes <i>bytes</i>.
- *
- * @return the number of bytes written
- * @throws SerialException if there is an error accessing the
- * <code>BLOB</code> value; if an invalid position is set; if an
- * invalid offset value is set; if number of bytes to be written
- * is greater than the <code>SerialBlob</code> length; or the combined
- * values of the length and offset is greater than the Blob buffer
- * @throws SQLException if there is an error accessing the <code>BLOB</code>
- * value from the database.
- * @see #getBytes
- */
- public int setBytes(long pos, byte[] bytes, int offset, int length)
- throws SerialException, SQLException {
-
- if (offset < 0 || offset > bytes.length) {
- throw new SerialException("Invalid offset in byte array set");
- }
-
- if (pos < 1 || pos > this.length()) {
- throw new SerialException("Invalid position in BLOB object set");
- }
-
- if ((long)(length) > origLen) {
- throw new SerialException("Buffer is not sufficient to hold the value");
- }
-
- if ((length + offset) > bytes.length) {
- throw new SerialException("Invalid OffSet. Cannot have combined offset " +
- "and length that is greater that the Blob buffer");
- }
-
- int i = 0;
- pos--; // correct to array indexing
- while ( i < length || (offset + i +1) < (bytes.length-offset) ) {
- this.buf[(int)pos + i] = bytes[offset + i ];
- i++;
- }
- return i;
- }
-
- /**
- * Retrieves a stream that can be used to write to the <code>BLOB</code>
- * value that this <code>Blob</code> object represents. The stream begins
- * at position <code>pos</code>. This method forwards the
- * <code>setBinaryStream()</code> call to the underlying <code>Blob</code> in
- * the event that this <code>SerialBlob</code> object is instantiated with a
- * <code>Blob</code>. If this <code>SerialBlob</code> is instantiated with
- * a <code>byte</code> array, a <code>SerialException</code> is thrown.
- *
- * @param pos the position in the <code>BLOB</code> value at which
- * to start writing
- * @return a <code>java.io.OutputStream</code> object to which data can
- * be written
- * @throws SQLException if there is an error accessing the
- * <code>BLOB</code> value
- * @throws SerialException if the SerialBlob in not instantiated with a
- * <code>Blob</code> object that supports <code>setBinaryStream()</code>
- * @see #getBinaryStream
- */
- public java.io.OutputStream setBinaryStream(long pos)
- throws SerialException, SQLException {
- if (this.blob.setBinaryStream(pos) != null) {
- return this.blob.setBinaryStream(pos);
- } else {
- throw new SerialException("Unsupported operation. SerialBlob cannot " +
- "return a writable binary stream, unless instantiated with a Blob object " +
- "that provides a setBinaryStream() implementation");
- }
- }
-
- /**
- * Truncates the <code>BLOB</code> value that this <code>Blob</code>
- * object represents to be <code>len</code> bytes in length.
- *
- * @param length the length, in bytes, to which the <code>BLOB</code>
- * value that this <code>Blob</code> object represents should be
- * truncated
- * @throws SerialException if there is an error accessing the Blob value;
- * or the length to truncate is greater that the SerialBlob length
- */
- public void truncate(long length) throws SerialException {
-
- if (length > len) {
- throw new SerialException
- ("Length more than what can be truncated");
- } else if((int)length == 0) {
- buf = new byte[0];
- len = length;
- } else {
- len = length;
- buf = this.getBytes(1, (int)len);
- }
- }
-
-
- /**
- * The identifier that assists in the serialization of this <code>SerialBlob</code>
- * object.
- */
-
- static final long serialVersionUID = -8144641928112860441L;
- }