javax.mail.util.ByteArrayDataSource Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.mail.util;
import java.io.*;
import jakarta.activation.*;
import jakarta.mail.internet.*;
/**
* A DataSource backed by a byte array. The byte array may be
* passed in directly, or may be initialized from an InputStream
* or a String.
*
* @since JavaMail 1.4
* @author John Mani
* @author Bill Shannon
* @author Max Spivak
*/
public class ByteArrayDataSource implements DataSource {
private byte[] data; // data
private int len = -1;
private String type; // content-type
private String name = "";
static class DSByteArrayOutputStream extends ByteArrayOutputStream {
public byte[] getBuf() {
return buf;
}
public int getCount() {
return count;
}
}
/**
* Create a ByteArrayDataSource with data from the
* specified InputStream and with the specified MIME type.
* The InputStream is read completely and the data is
* stored in a byte array.
*
* @param is the InputStream
* @param type the MIME type
* @exception IOException errors reading the stream
*/
public ByteArrayDataSource(InputStream is, String type) throws IOException {
DSByteArrayOutputStream os = new DSByteArrayOutputStream();
byte[] buf = new byte[8192];
int len;
while ((len = is.read(buf)) > 0)
os.write(buf, 0, len);
this.data = os.getBuf();
this.len = os.getCount();
/*
* ByteArrayOutputStream doubles the size of the buffer every time
* it needs to expand, which can waste a lot of memory in the worst
* case with large buffers. Check how much is wasted here and if
* it's too much, copy the data into a new buffer and allow the
* old buffer to be garbage collected.
*/
if (this.data.length - this.len > 256*1024) {
this.data = os.toByteArray();
this.len = this.data.length; // should be the same
}
this.type = type;
}
/**
* Create a ByteArrayDataSource with data from the
* specified byte array and with the specified MIME type.
*
* @param data the data
* @param type the MIME type
*/
public ByteArrayDataSource(byte[] data, String type) {
this.data = data;
this.type = type;
}
/**
* Create a ByteArrayDataSource with data from the
* specified String and with the specified MIME type.
* The MIME type should include a charset
* parameter specifying the charset to be used for the
* string. If the parameter is not included, the
* default charset is used.
*
* @param data the String
* @param type the MIME type
* @exception IOException errors reading the String
*/
public ByteArrayDataSource(String data, String type) throws IOException {
String charset = null;
try {
ContentType ct = new ContentType(type);
charset = ct.getParameter("charset");
} catch (ParseException pex) {
// ignore parse error
}
charset = MimeUtility.javaCharset(charset);
if (charset == null)
charset = MimeUtility.getDefaultJavaCharset();
// XXX - could convert to bytes on demand rather than copying here
this.data = data.getBytes(charset);
this.type = type;
}
/**
* Return an InputStream for the data.
* Note that a new stream is returned each time
* this method is called.
*
* @return the InputStream
* @exception IOException if no data has been set
*/
@Override
public InputStream getInputStream() throws IOException {
if (data == null)
throw new IOException("no data");
if (len < 0)
len = data.length;
return new SharedByteArrayInputStream(data, 0, len);
}
/**
* Return an OutputStream for the data.
* Writing the data is not supported; an IOException
* is always thrown.
*
* @exception IOException always
*/
@Override
public OutputStream getOutputStream() throws IOException {
throw new IOException("cannot do this");
}
/**
* Get the MIME content type of the data.
*
* @return the MIME type
*/
@Override
public String getContentType() {
return type;
}
/**
* Get the name of the data.
* By default, an empty string ("") is returned.
*
* @return the name of this data
*/
@Override
public String getName() {
return name;
}
/**
* Set the name of the data.
*
* @param name the name of this data
*/
public void setName(String name) {
this.name = name;
}
}