com.simpligility.maven.plugins.android.DefaultJavaProcessExecutor.java Source code

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Here is the source code for com.simpligility.maven.plugins.android.DefaultJavaProcessExecutor.java

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/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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.simpligility.maven.plugins.android;

import com.android.annotations.NonNull;
import com.android.ide.common.process.JavaProcessExecutor;
import com.android.ide.common.process.JavaProcessInfo;
import com.android.ide.common.process.ProcessException;
import com.android.ide.common.process.ProcessOutput;
import com.android.ide.common.process.ProcessOutputHandler;
import com.android.ide.common.process.ProcessResult;
import com.android.utils.ILogger;
import com.google.common.base.Joiner;
import com.google.common.collect.Lists;
import com.google.common.io.ByteStreams;
import com.google.common.io.Closeables;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import java.util.Map;

/**
 * Simple implementation of ProcessExecutor, using the standard Java Process(Builder) API.
 */
public class DefaultJavaProcessExecutor implements JavaProcessExecutor {
    private final ILogger mLogger;

    public DefaultJavaProcessExecutor(ILogger logger) {
        mLogger = logger;
    }

    @NonNull
    @Override
    public ProcessResult execute(@NonNull JavaProcessInfo processInfo,
            @NonNull ProcessOutputHandler processOutputHandler) {
        List<String> command = Lists.newArrayList();
        command.add(processInfo.getExecutable());
        command.addAll(processInfo.getArgs());
        String commandString = Joiner.on(' ').join(command);
        mLogger.info("command: " + commandString);
        try {
            // launch the command line process
            ProcessBuilder processBuilder = new ProcessBuilder(command);
            Map<String, Object> envVariableMap = processInfo.getEnvironment();
            if (!envVariableMap.isEmpty()) {
                Map<String, String> env = processBuilder.environment();
                for (Map.Entry<String, Object> entry : envVariableMap.entrySet()) {
                    env.put(entry.getKey(), entry.getValue().toString());
                }
            }
            // start the process
            Process process = processBuilder.start();
            // and grab the output, and the exit code
            ProcessOutput output = processOutputHandler.createOutput();
            int exitCode = grabProcessOutput(process, output);
            processOutputHandler.handleOutput(output);
            return new ProcessResultImplCopy(commandString, exitCode);
        } catch (IOException e) {
            return new ProcessResultImplCopy(commandString, e);
        } catch (InterruptedException e) {
            // Restore the interrupted status
            Thread.currentThread().interrupt();
            return new ProcessResultImplCopy(commandString, e);
        } catch (ProcessException e) {
            return new ProcessResultImplCopy(commandString, e);
        }
    }

    /**
     * Get the stderr/stdout outputs of a process and return when the process is done.
     * Both <b>must</b> be read or the process will block on windows.
     *
     * @param process The process to get the output from.
     * @param output The processOutput containing where to send the output.
     *      Note that on Windows capturing the output is not optional. If output is null
     *      the stdout/stderr will be captured and discarded.
     * @return the process return code.
     * @throws InterruptedException if {@link Process#waitFor()} was interrupted.
     */
    private static int grabProcessOutput(@NonNull final Process process, @NonNull final ProcessOutput output)
            throws InterruptedException {
        Thread threadErr = new Thread("stderr") {
            @Override
            public void run() {
                InputStream stderr = process.getErrorStream();
                OutputStream stream = output.getErrorOutput();
                try {
                    ByteStreams.copy(stderr, stream);
                    stream.flush();
                } catch (IOException e) {
                    // ignore?
                } finally {
                    try {
                        Closeables.close(stderr, true /* swallowIOException */ );
                    } catch (IOException e) {
                        // cannot happen
                    }
                    try {
                        Closeables.close(stream, true /* swallowIOException */ );
                    } catch (IOException e) {
                        // cannot happen
                    }
                }
            }
        };
        Thread threadOut = new Thread("stdout") {
            @Override
            public void run() {
                InputStream stdout = process.getInputStream();
                OutputStream stream = output.getStandardOutput();
                try {
                    ByteStreams.copy(stdout, stream);
                    stream.flush();
                } catch (IOException e) {
                    // ignore?
                } finally {
                    try {
                        Closeables.close(stdout, true /* swallowIOException */ );
                    } catch (IOException e) {
                        // cannot happen
                    }
                    try {
                        Closeables.close(stream, true /* swallowIOException */ );
                    } catch (IOException e) {
                        // cannot happen
                    }
                }
            }
        };
        threadErr.start();
        threadOut.start();
        // it looks like on windows process#waitFor() can return
        // before the thread have filled the arrays, so we wait for both threads and the
        // process itself.
        threadErr.join();
        threadOut.join();
        // get the return code from the process
        return process.waitFor();
    }
}