blobimpl.java

来自「用Java实现的23个常用设计模式源代码」· Java 代码 · 共 105 行

//$Id: BlobImpl.java,v 1.4.2.2 2003/11/27 16:09:59 oneovthafew Exp $
package net.sf.hibernate.lob;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.SQLException;

/**
 * A dummy implementation of <tt>java.sql.Blob</tt> that
 * may be used to insert new data into a BLOB.
 * @author Gavin King
 */
public class BlobImpl implements Blob {
	
	private InputStream stream;
	private int length;

	public BlobImpl(byte[] bytes) {
		this.stream = new ByteArrayInputStream(bytes);
		this.length = bytes.length;
	}
	
	public BlobImpl(InputStream stream, int length) {
		this.stream = stream;
		this.length = length;
	}
	
	/**
	 * @see java.sql.Blob#length()
	 */
	public long length() throws SQLException {
		return length;
	}
	
	/**
	 * @see java.sql.Blob#truncate(long)
	 */
	public void truncate(long arg0) throws SQLException {
		excep();
	}
	
	/**
	 * @see java.sql.Blob#getBytes(long, int)
	 */
	public byte[] getBytes(long arg0, int arg1) throws SQLException {
		excep(); return null;
	}
	
	/**
	 * @see java.sql.Blob#setBytes(long, byte[])
	 */
	public int setBytes(long arg0, byte[] arg1) throws SQLException {
		excep(); return 0;
	}
	
	/**
	 * @see java.sql.Blob#setBytes(long, byte[], int, int)
	 */
	public int setBytes(long arg0, byte[] arg1, int arg2, int arg3)
	throws SQLException {
		excep(); return 0;
	}
	
	/**
	 * @see java.sql.Blob#position(byte[], long)
	 */
	public long position(byte[] arg0, long arg1) throws SQLException {
		excep(); return 0;
	}
	
	/**
	 * @see java.sql.Blob#getBinaryStream()
	 */
	public InputStream getBinaryStream() throws SQLException {
		return stream;
	}
	
	/**
	 * @see java.sql.Blob#setBinaryStream(long)
	 */
	public OutputStream setBinaryStream(long arg0) throws SQLException {
		excep(); return null;
	}
	
	/**
	 * @see java.sql.Blob#position(Blob, long)
	 */
	public long position(Blob arg0, long arg1) throws SQLException {
		excep(); return 0;
	}
	
	private static void excep() {
		throw new UnsupportedOperationException("Blob may not be manipulated from creating session");
	}
	
}