/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.citrus.util.io;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* 将数据从任意<code>InputStream</code>复制到<code>FilterOutputStream</code>的输出引擎.
* 本代码移植自IBM developer works文章:
* <ul>
* <li><a
* href="http://www.ibm.com/developerworks/cn/java/j-io1/index.shtml">彻底转变流,第 1
* 部分:从输出流中读取</a>
* <li><a
* href="http://www.ibm.com/developerworks/cn/java/j-io2/index.shtml">彻底转变流,第 2
* 部分:优化 Java 内部 I/O</a>
* </ul>
*
* @author Michael Zhou
*/
public class InputStreamOutputEngine implements OutputEngine {
private static final int DEFAULT_BUFFER_SIZE = 8192;
private InputStream in;
private OutputStreamFactory factory;
private byte[] buffer;
private OutputStream out;
public InputStreamOutputEngine(InputStream in, OutputStreamFactory factory) {
this(in, factory, DEFAULT_BUFFER_SIZE);
}
public InputStreamOutputEngine(InputStream in, OutputStreamFactory factory, int bufferSize) {
this.in = in;
this.factory = factory == null ? DEFAULT_OUTPUT_STREAM_FACTORY : factory;
buffer = new byte[bufferSize];
}
public void open(OutputStream out) throws IOException {
if (this.out != null) {
throw new IOException("Already initialized");
} else {
this.out = factory.getOutputStream(out);
}
}
public void execute() throws IOException {
if (out == null) {
throw new IOException("Not yet initialized");
} else {
int amount = in.read(buffer);
if (amount < 0) {
out.close();
} else {
out.write(buffer, 0, amount);
}
}
}
public void close() throws IOException {
in.close();
}
}