bytearraydatasource.java

100多M的J2EE培训内容

/*
 * @(#)ByteArrayDataSource.java	1.4 01/05/23
 *
 * Copyright 1998-2000 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND
 * ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES OR LIABILITIES
 * SUFFERED BY LICENSEE AS A RESULT OF  OR RELATING TO USE, MODIFICATION
 * OR DISTRIBUTION OF THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL
 * SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR
 * FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS
 * BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that Software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */

import java.io.*;
import javax.activation.*;

/**
 * A simple DataSource for demonstration purposes.
 * This class implements a DataSource from:
 * 	an InputStream
 *	a byte array
 * 	a String
 *
 * @author John Mani
 * @author Bill Shannon
 * @author Max Spivak
 */
public class ByteArrayDataSource implements DataSource {
    private byte[] data;	// data
    private String type;	// content-type

    /* Create a DataSource from an input stream */
    public ByteArrayDataSource(InputStream is, String type) {
        this.type = type;
        try { 
            ByteArrayOutputStream os = new ByteArrayOutputStream();
	    int ch;

	    while ((ch = is.read()) != -1)
                // XXX - must be made more efficient by
	        // doing buffered reads, rather than one byte reads
	        os.write(ch);
	    data = os.toByteArray();

        } catch (IOException ioex) { }
    }

    /* Create a DataSource from a byte array */
    public ByteArrayDataSource(byte[] data, String type) {
        this.data = data;
	this.type = type;
    }

    /* Create a DataSource from a String */
    public ByteArrayDataSource(String data, String type) {
	try {
	    // Assumption that the string contains only ASCII
	    // characters!  Otherwise just pass a charset into this
	    // constructor and use it in getBytes()
	    this.data = data.getBytes("iso-8859-1");
	} catch (UnsupportedEncodingException uex) { }
	this.type = type;
    }

    /**
     * Return an InputStream for the data.
     * Note - a new stream must be returned each time.
     */
    public InputStream getInputStream() throws IOException {
	if (data == null)
	    throw new IOException("no data");
	return new ByteArrayInputStream(data);
    }

    public OutputStream getOutputStream() throws IOException {
	throw new IOException("cannot do this");
    }

    public String getContentType() {
        return type;
    }

    public String getName() {
        return "dummy";
    }
}