/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tools.ant.taskdefs;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.tools.ant.util.FileUtils;
/**
* Copies standard output and error of subprocesses to standard output and
* error of the parent process.
*
* @since Ant 1.2
*/
public class PumpStreamHandler implements ExecuteStreamHandler {
private Thread outputThread;
private Thread errorThread;
private Thread inputThread;
private OutputStream out;
private OutputStream err;
private InputStream input;
private final boolean nonBlockingRead;
/**
* Construct a new <code>PumpStreamHandler</code>.
* @param out the output <code>OutputStream</code>.
* @param err the error <code>OutputStream</code>.
* @param input the input <code>InputStream</code>.
* @param nonBlockingRead set it to <code>true</code> if the input should be
* read with simulated non blocking IO.
*/
public PumpStreamHandler(OutputStream out, OutputStream err,
InputStream input, boolean nonBlockingRead) {
this.out = out;
this.err = err;
this.input = input;
this.nonBlockingRead = nonBlockingRead;
}
/**
* Construct a new <code>PumpStreamHandler</code>.
* @param out the output <code>OutputStream</code>.
* @param err the error <code>OutputStream</code>.
* @param input the input <code>InputStream</code>.
*/
public PumpStreamHandler(OutputStream out, OutputStream err,
InputStream input) {
this(out, err, input, false);
}
/**
* Construct a new <code>PumpStreamHandler</code>.
* @param out the output <code>OutputStream</code>.
* @param err the error <code>OutputStream</code>.
*/
public PumpStreamHandler(OutputStream out, OutputStream err) {
this(out, err, null);
}
/**
* Construct a new <code>PumpStreamHandler</code>.
* @param outAndErr the output/error <code>OutputStream</code>.
*/
public PumpStreamHandler(OutputStream outAndErr) {
this(outAndErr, outAndErr);
}
/**
* Construct a new <code>PumpStreamHandler</code>.
*/
public PumpStreamHandler() {
this(System.out, System.err);
}
/**
* Set the <code>InputStream</code> from which to read the
* standard output of the process.
* @param is the <code>InputStream</code>.
*/
public void setProcessOutputStream(InputStream is) {
createProcessOutputPump(is, out);
}
/**
* Set the <code>InputStream</code> from which to read the
* standard error of the process.
* @param is the <code>InputStream</code>.
*/
public void setProcessErrorStream(InputStream is) {
if (err != null) {
createProcessErrorPump(is, err);
}
}
/**
* Set the <code>OutputStream</code> by means of which
* input can be sent to the process.
* @param os the <code>OutputStream</code>.
*/
public void setProcessInputStream(OutputStream os) {
if (input != null) {
inputThread = createPump(input, os, true, nonBlockingRead);
} else {
FileUtils.close(os);
}
}
/**
* Start the <code>Thread</code>s.
*/
public void start() {
outputThread.start();
errorThread.start();
if (inputThread != null) {
inputThread.start();
}
}
/**
* Stop pumping the streams.
*/
public void stop() {
finish(inputThread);
try {
err.flush();
} catch (IOException e) {
// ignore
}
try {
out.flush();
} catch (IOException e) {
// ignore
}
finish(outputThread);
finish(errorThread);
}
private static final long JOIN_TIMEOUT = 200;
/**
* Waits for a thread to finish while trying to make it finish
* quicker by stopping the pumper (if the thread is a {@link
* ThreadWithPumper ThreadWithPumper} instance) or interrupting
* the thread.
*
* @since Ant 1.8.0
*/
protected final void finish(Thread t) {
if (t == null) {
// nothing to terminate
return;
}
try {
StreamPumper s = null;
if (t instanceof ThreadWithPumper) {
s = ((ThreadWithPumper) t).getPumper();
}
if (s != null && s.isFinished()) {
return;
}
if (!t.isAlive()) {
return;
}
if (s != null && !s.isFinished()) {
s.stop();
}
t.join(JOIN_TIMEOUT);
while ((s == null || !s.isFinished()) && t.isAlive()) {
t.interrupt();
t.join(JOIN_TIMEOUT);
}
} catch (InterruptedException e) {
// ignore
}
}
/**
* Get the error stream.
* @return <code>OutputStream</code>.
*/
protected OutputStream getErr() {
return err;
}
/**
* Get the output stream.
* @return <code>OutputStream</code>.
*/
protected OutputStream getOut() {
return out;
}
/**
* Create the pump to handle process output.
* @param is the <code>InputStream</code>.
* @param os the <code>OutputStream</code>.
*/
protected void createProcessOutputPump(InputStream is, OutputStream os) {
outputThread = createPump(is, os);
}
/**
* Create the pump to handle error output.
* @param is the input stream to copy from.
* @param os the output stream to copy to.
*/
protected void createProcessErrorPump(InputStream is, OutputStream os) {
errorThread = createPump(is, os);
}
/**
* Creates a stream pumper to copy the given input stream to the
* given output stream.
* @param is the input stream to copy from.
* @param os the output stream to copy to.
* @return a thread object that does the pumping.
*/
protected Thread createPump(InputStream is, OutputStream os) {
return createPump(is, os, false);
}
/**
* Creates a stream pumper to copy the given input stream to the
* given output stream.
* @param is the input stream to copy from.
* @param os the output stream to copy to.
* @param closeWhenExhausted if true close the inputstream.
* @return a thread object that does the pumping, subclasses
* should return an instance of {@link ThreadWithPumper
* ThreadWithPumper}.
*/
protected Thread createPump(InputStream is, OutputStream os,
boolean closeWhenExhausted) {
return createPump(is, os, closeWhenExhausted, true);
}
/**
* Creates a stream pumper to copy the given input stream to the
* given output stream.
* @param is the input stream to copy from.
* @param os the output stream to copy to.
* @param closeWhenExhausted if true close the inputstream.
* @param nonBlockingIO set it to <code>true</code> to use simulated non
* blocking IO.
* @return a thread object that does the pumping, subclasses
* should return an instance of {@link ThreadWithPumper
* ThreadWithPumper}.
* @since Ant 1.8.2
*/
protected Thread createPump(InputStream is, OutputStream os,
boolean closeWhenExhausted, boolean nonBlockingIO) {
StreamPumper pumper = new StreamPumper(is, os, closeWhenExhausted, nonBlockingIO);
pumper.setAutoflush(true);
final Thread result = new ThreadWithPumper(pumper);
result.setDaemon(true);
return result;
}
/**
* Specialized subclass that allows access to the running StreamPumper.
*
* @since Ant 1.8.0
*/
protected static class ThreadWithPumper extends Thread {
private final StreamPumper pumper;
public ThreadWithPumper(StreamPumper p) {
super(p);
pumper = p;
}
protected StreamPumper getPumper() {
return pumper;
}
}
}