dorkbox.util.process.ShellProcessBuilder Maven / Gradle / Ivy
/*
* Copyright 2010 dorkbox, llc
*
* 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 dorkbox.util.process;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import dorkbox.util.OS;
/**
* If you want to save off the output from the process, set a PrintStream to the following:
* {@code
*
* ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(8196);
* PrintStream outputStream = new PrintStream(byteArrayOutputStream);
* ...
*
* String output = ShellProcessBuilder.getOutput(byteArrayOutputStream);
* }
*/
public
class ShellProcessBuilder {
// TODO: Add the ability to get the process PID via java for mac/windows/linux. Linux is avail from jvm, windows needs JNA
private final PrintStream outputStream;
private final PrintStream outputErrorStream;
private final InputStream inputStream;
protected List arguments = new ArrayList();
private String workingDirectory = null;
private String executableName = null;
private String executableDirectory = null;
private Process process = null;
private ProcessProxy writeToProcess_input = null;
private ProcessProxy readFromProcess_output = null;
private ProcessProxy readFromProcess_error = null;
private boolean createReadWriterThreads = false;
private boolean isShell;
private String pipeToNullString = "";
private List fullCommand;
/**
* This will cause the spawned process to pipe it's output to null.
*/
public
ShellProcessBuilder() {
this(null, null, null);
}
public
ShellProcessBuilder(final PrintStream out) {
this(null, out, out);
}
public
ShellProcessBuilder(final InputStream in, final PrintStream out) {
this(in, out, out);
}
public
ShellProcessBuilder(final InputStream in, final PrintStream out, final PrintStream err) {
this.inputStream = in;
this.outputStream = out;
this.outputErrorStream = err;
}
/**
* Creates extra reader/writer threads for the sub-process. This is useful depending on how the sub-process is designed to run.
*
* For a process you want interactive IO with, this is required.
*
* For a long-running sub-process, with no interactive IO, this is what you'd want.
*
* For a run-and-get-the-results process, this isn't recommended.
*
*/
public final
ShellProcessBuilder createReadWriterThreads() {
createReadWriterThreads = true;
return this;
}
/**
* When launched from eclipse, the working directory is USUALLY the root of the project folder
*/
public final
ShellProcessBuilder setWorkingDirectory(final String workingDirectory) {
// MUST be absolute path!!
this.workingDirectory = new File(workingDirectory).getAbsolutePath();
return this;
}
public final
ShellProcessBuilder addArgument(final String argument) {
this.arguments.add(argument);
return this;
}
public final
ShellProcessBuilder addArguments(final String... paths) {
for (String path : paths) {
this.arguments.add(path);
}
return this;
}
public final
ShellProcessBuilder addArguments(final List paths) {
this.arguments.addAll(paths);
return this;
}
public final
ShellProcessBuilder setExecutable(final String executableName) {
this.executableName = executableName;
return this;
}
public
ShellProcessBuilder setExecutableDirectory(final String executableDirectory) {
// MUST be absolute path!!
this.executableDirectory = new File(executableDirectory).getAbsolutePath();
return this;
}
/**
* Sends all output data for this process to "null" in a cross platform method
*/
public
ShellProcessBuilder pipeOutputToNull() throws IllegalArgumentException {
if (outputStream != null || outputErrorStream != null) {
throw new IllegalArgumentException("Cannot pipe shell command to 'null' if an output stream is specified");
}
if (OS.isWindows()) {
// >NUL on windows
pipeToNullString = ">NUL";
}
else {
// we will "pipe" it to /dev/null on *nix
pipeToNullString = ">/dev/null 2>&1";
}
return this;
}
/**
* @return the executable command issued to the shell
*/
public
String getCommand() {
StringBuilder execCommand = new StringBuilder();
Iterator iterator = fullCommand.iterator();
while (iterator.hasNext()) {
String s = iterator.next();
execCommand.append(s);
if (iterator.hasNext()) {
execCommand.append(" ");
}
}
return execCommand.toString();
}
public
int start() {
fullCommand = new ArrayList();
// if no executable, then use the command shell
if (this.executableName == null) {
isShell = true;
if (OS.isWindows()) {
// windows
this.executableName = "cmd";
fullCommand.add(this.executableName);
fullCommand.add("/c");
}
else {
// *nix
this.executableName = "/bin/bash";
File file = new File(this.executableName);
if (!file.canExecute()) {
this.executableName = "/bin/sh";
}
fullCommand.add(this.executableName);
fullCommand.add("-c");
}
}
else {
// shell and working/exe directory are mutually exclusive
if (this.workingDirectory != null) {
if (!this.workingDirectory.endsWith(File.separator)) {
this.workingDirectory += File.separator;
}
}
if (this.executableDirectory != null) {
if (!this.executableDirectory.endsWith(File.separator)) {
this.executableDirectory += File.separator;
}
fullCommand.add(0, this.executableDirectory + this.executableName);
} else {
fullCommand.add(this.executableName);
}
}
// if we don't want output...
boolean pipeToNull = !pipeToNullString.isEmpty();
if (isShell && !OS.isWindows()) {
// when a shell AND on *nix, we have to place ALL the args into a single "arg" that is passed in
final StringBuilder stringBuilder = new StringBuilder(1024);
for (String arg : this.arguments) {
stringBuilder.append(arg).append(" ");
}
if (!arguments.isEmpty()) {
if (pipeToNull) {
stringBuilder.append(pipeToNullString);
}
else {
// delete last " "
stringBuilder.delete(stringBuilder.length() - 1, stringBuilder.length());
}
}
fullCommand.add(stringBuilder.toString());
} else {
for (String arg : this.arguments) {
if (arg.contains(" ")) {
// individual arguments MUST be in their own element in order to be processed properly
// (this is how it works on the command line!)
String[] split = arg.split(" ");
for (String s : split) {
fullCommand.add(s);
}
} else {
fullCommand.add(arg);
}
}
if (pipeToNull) {
fullCommand.add(pipeToNullString);
}
}
ProcessBuilder processBuilder = new ProcessBuilder(fullCommand);
if (this.workingDirectory != null) {
processBuilder.directory(new File(this.workingDirectory));
}
// combine these so output is properly piped to null.
if (pipeToNull || this.outputErrorStream == null) {
processBuilder.redirectErrorStream(true);
}
try {
this.process = processBuilder.start();
} catch (Exception ex) {
if (outputErrorStream != null) {
this.outputErrorStream.println("There was a problem executing the program. Details:");
} else {
System.err.println("There was a problem executing the program. Details:");
}
ex.printStackTrace(this.outputErrorStream);
if (this.process != null) {
try {
this.process.destroy();
this.process = null;
} catch (Exception e) {
if (outputErrorStream != null) {
this.outputErrorStream.println("Error destroying process:");
} else {
System.err.println("Error destroying process:");
}
e.printStackTrace(this.outputErrorStream);
}
}
}
if (this.process != null) {
if (this.outputErrorStream == null && this.outputStream == null) {
if (!pipeToNull) {
NullOutputStream nullOutputStream = new NullOutputStream();
// readers (read process -> write console)
// have to keep the output buffers from filling in the target process.
readFromProcess_output = new ProcessProxy("Process Reader: " + this.executableName,
this.process.getInputStream(),
nullOutputStream);
}
}
// we want to pipe our input/output from process to ourselves
else {
/**
* Proxy the System.out and System.err from the spawned process back
* to the user's window. This is important or the spawned process could block.
*/
// readers (read process -> write console)
readFromProcess_output = new ProcessProxy("Process Reader: " + this.executableName,
this.process.getInputStream(),
this.outputStream);
if (this.outputErrorStream != this.outputStream) {
readFromProcess_error = new ProcessProxy("Process Reader: " + this.executableName,
this.process.getErrorStream(),
this.outputErrorStream);
}
}
if (this.inputStream != null) {
/**
* Proxy System.in from the user's window to the spawned process
*/
// writer (read console -> write process)
writeToProcess_input = new ProcessProxy("Process Writer: " + this.executableName,
this.inputStream,
this.process.getOutputStream());
}
// the process can be killed in two ways
// If not in IDE, by this shutdown hook. (clicking the red square to terminate a process will not run it's shutdown hooks)
// Typing "exit" will always terminate the process
Thread hook = new Thread(new Runnable() {
@Override
public
void run() {
ShellProcessBuilder.this.process.destroy();
}
});
hook.setName("ShellProcess Shutdown Hook");
// add a shutdown hook to make sure that we properly terminate our spawned processes.
// hook is NOT set to daemon mode, because this is run during shutdown
// add a shutdown hook to make sure that we properly terminate our spawned processes.
try {
Runtime.getRuntime()
.addShutdownHook(hook);
} catch (IllegalStateException ignored) {
// can happen, safe to ignore
}
if (writeToProcess_input != null) {
if (createReadWriterThreads) {
writeToProcess_input.start();
}
else {
writeToProcess_input.run();
}
}
if (createReadWriterThreads) {
readFromProcess_output.start();
}
else {
readFromProcess_output.run();
}
if (readFromProcess_error != null) {
if (createReadWriterThreads) {
readFromProcess_error.start();
}
else {
readFromProcess_error.run();
}
}
int exitValue = 0;
try {
this.process.waitFor();
exitValue = this.process.exitValue();
// wait for the READER threads to die (meaning their streams have closed/EOF'd)
if (writeToProcess_input != null) {
// the INPUT (from stdin). It should be via the InputConsole, but if it's in eclipse,etc -- then this doesn't do anything
// We are done reading input, since our program has closed...
writeToProcess_input.close();
writeToProcess_input.join();
}
readFromProcess_output.close();
readFromProcess_output.join();
if (readFromProcess_error != null) {
readFromProcess_error.close();
readFromProcess_error.join();
}
// forcibly terminate the process when it's streams have closed.
// this is for cleanup ONLY, not to actually do anything.
this.process.destroy();
} catch (InterruptedException e) {
Thread.currentThread()
.interrupt();
}
// remove the shutdown hook now that we've shutdown.
try {
Runtime.getRuntime().removeShutdownHook(hook);
} catch (IllegalStateException ignored) {
// can happen, safe to ignore
}
return exitValue;
}
// 1 means a problem
return 1;
}
/**
* Converts the baos to a string in a safe way. There will never be a trailing newline character at the end of this output.
*
* @param byteArrayOutputStream the baos that is used in the {@link ShellProcessBuilder#ShellProcessBuilder(PrintStream)} (or similar
* calls)
*
* @return A string representing the output of the process, null if the thread for this was interrupted
*/
public static
String getOutput(final ByteArrayOutputStream byteArrayOutputStream) {
String s;
synchronized (byteArrayOutputStream) {
s = byteArrayOutputStream.toString();
byteArrayOutputStream.reset();
}
// remove trailing newline character(s)
int endIndex = s.lastIndexOf(OS.LINE_SEPARATOR);
if (endIndex > -1) {
return s.substring(0, endIndex);
}
return s;
}
/**
* Converts the baos to a string in a safe way. There will never be a trailing newline character at the end of this output. This will
* block until there is a line of input available.
*
* @param byteArrayOutputStream the baos that is used in the {@link ShellProcessBuilder#ShellProcessBuilder(PrintStream)} (or similar
* calls)
*
* @return A string representing the output of the process, null if the thread for this was interrupted
*/
public String
getOutputLineBuffered(final ByteArrayOutputStream byteArrayOutputStream) {
String s;
synchronized (byteArrayOutputStream) {
try {
byteArrayOutputStream.wait();
} catch (InterruptedException ignored) {
return null;
}
s = byteArrayOutputStream.toString();
byteArrayOutputStream.reset();
}
return s;
}
}
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