de.unkrig.commons.lang.ProcessUtil Maven / Gradle / Ivy
/*
* de.unkrig.commons - A general-purpose Java class library
*
* Copyright (c) 2015, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. Redistributions 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.
* 3. The name of the author may not be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.unkrig.commons.lang;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.List;
import de.unkrig.commons.lang.protocol.Stoppable;
import de.unkrig.commons.nullanalysis.Nullable;
/**
* Various {@code Process}-related utility methods.
*/
public final
class ProcessUtil {
private
ProcessUtil() {}
interface ProcessStarter {
/**
* Starts a processes from the {@code processBuilder} such that the process reads from {@code stdin} and
* writes to {@code stdout} and {@code stderr}.
*/
Process
startProcess(
ProcessBuilder processBuilder,
InputStream stdin,
boolean closeStdin,
OutputStream stdout,
boolean closeStdout,
OutputStream stderr,
boolean closeStderr
) throws IOException;
}
private static final ProcessStarter PROCESS_STARTER;
static {
ProcessStarter ps;
try {
Class redirect = Class.forName("java.lang.ProcessBuilder.Redirect");
final Object redirectInherit;
final Method redirectInput;
final Method redirectOutput;
final Method redirectError;
try {
redirectInherit = redirect.getField("INHERIT");
redirectInput = redirect.getMethod("redirectInput", redirect);
redirectOutput = redirect.getMethod("redirectOutput", redirect);
redirectError = redirect.getMethod("redirectError", redirect);
} catch (Throwable t) { // SUPPRESS CHECKSTYLE IllegalCatch
throw new ExceptionInInitializerError(t);
}
ps = new ProcessStarter() {
@Override public Process
startProcess(
ProcessBuilder processBuilder,
InputStream stdin,
boolean closeStdin,
OutputStream stdout,
boolean closeStdout,
OutputStream stderr,
boolean closeStderr
) throws IOException {
// Use "ProcessBuilder.redirect(Input|Output|Error)()" iff stdin/out/err is not redirectoed.
try {
if (stdin == System.in) {
// Only available in Java 7:
// processBuilder.redirectInput(Redirect.INHERIT);
redirectInput.invoke(processBuilder, redirectInherit);
}
if (stdout == System.out) {
// Only available in Java 7:
// processBuilder.redirectOutput(Redirect.INHERIT);
redirectOutput.invoke(processBuilder, redirectInherit);
}
if (stderr == System.err) {
// Only available in Java 7:
// processBuilder.redirectError(Redirect.INHERIT);
redirectError.invoke(processBuilder, redirectInherit);
}
} catch (Exception e) {
throw ExceptionUtil.wrap(null, e, AssertionError.class);
}
final Process process = processBuilder.start();
// Copy the process's stdin/out/err iff it is redirected.
if (stdout != System.out) {
ProcessUtil.copyInBackground(process.getInputStream(), false, stdout, closeStdout);
}
if (stderr != System.err) {
ProcessUtil.copyInBackground(process.getErrorStream(), false, stderr, closeStderr);
}
if (stdin != System.in) {
try {
ProcessUtil.copy(stdin, closeStdin, process.getOutputStream(), true);
} catch (IOException e) {
// IOExceptions are normal here, because the processes may legitimately terminate before it
// has completely read ist standard input.
;
}
}
return process;
}
};
} catch (ClassNotFoundException e) {
ps = new ProcessStarter() {
@Override public Process
startProcess(
ProcessBuilder processBuilder,
InputStream stdin,
boolean closeStdin,
OutputStream stdout,
boolean closeStdout,
OutputStream stderr,
boolean closeStderr
) throws IOException {
final Process process = processBuilder.start();
ProcessUtil.copyInBackground(process.getInputStream(), false, stdout, closeStdout);
ProcessUtil.copyInBackground(process.getErrorStream(), false, stderr, closeStderr);
try {
ProcessUtil.copy(stdin, closeStdin, process.getOutputStream(), true);
} catch (IOException e) {
// IOExceptions are normal here, because the processes may legitimately terminate before it has
// completely read ist standard input.
}
return process;
}
};
}
PROCESS_STARTER = ps;
}
/**
* Executes the given {@code command} and waits until it completes.
*
* @param workingDirectory See {@link ProcessBuilder#directory(File)}
* @param stdin Where the {@code command}'s standard input is read from
* @param closeStdin Whether {@code stdin} should be closed
* @param stdout Where the {@code command}'s standard output is written to
* @param closeStdout Whether {@code stdout} should be closed
* @param stderr Where the {@code command}'s standard error is written to
* @param closeStderr Whether {@code stderr} should be closed
* @return Whether the {@code command} terminated with exit status zero (i.e. success)
* @throws IOException
* @throws InterruptedException
*/
public static boolean
execute(
List command,
@Nullable File workingDirectory,
InputStream stdin,
boolean closeStdin,
OutputStream stdout,
boolean closeStdout,
OutputStream stderr,
boolean closeStderr
) throws IOException, InterruptedException {
ProcessBuilder processBuilder = new ProcessBuilder(command);
processBuilder.directory(workingDirectory);
Process process = ProcessUtil.PROCESS_STARTER.startProcess(
processBuilder,
stdin,
closeStdin,
stdout,
closeStdout,
stderr,
closeStderr
);
return process.waitFor() == 0;
}
private static Stoppable
copyInBackground(final InputStream in, final boolean closeIn, final OutputStream out, final boolean closeOut) {
return ThreadUtil.runInBackground(new Runnable() {
@Override public void
run() {
try {
ProcessUtil.copy(in, closeIn, out, closeOut);
} catch (IOException e) {
;
}
}
}, "copy-in-background");
}
/**
* A copy of {@code IoUtil.copy()}, to avoid a dependency on project {@code de.unkrig.commons.io}.
*/
private static void
copy(InputStream inputStream, boolean closeInputStream, OutputStream outputStream, boolean closeOutputStream)
throws IOException {
try {
byte[] buffer = new byte[4096];
for (;;) {
int m = inputStream.read(buffer);
if (m == -1) break;
outputStream.write(buffer, 0, m);
}
outputStream.flush();
if (closeInputStream) inputStream.close();
if (closeOutputStream) outputStream.close();
} catch (IOException ioe) {
if (closeInputStream) try { inputStream.close(); } catch (Exception e) {}
if (closeOutputStream) try { outputStream.close(); } catch (Exception e) {}
throw ioe;
}
}
}
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