com.sap.prd.mobile.ios.mios.Forker.java Source code

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Here is the source code for com.sap.prd.mobile.ios.mios.Forker.java

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/*
 * #%L
 * xcode-maven-plugin
 * %%
 * Copyright (C) 2012 SAP AG
 * %%
 * 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.
 * #L%
 */
package com.sap.prd.mobile.ios.mios;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.Arrays;

import org.apache.commons.io.IOUtils;

class Forker {

    static int forkProcess(final PrintStream out, final File executionDirectory, final String... args)
            throws IOException {

        if (out == null)
            throw new IllegalArgumentException("Print stream for log handling was not provided.");

        if (args == null || args.length == 0)
            throw new IllegalArgumentException("No arguments has been provided.");

        for (final String arg : args)
            if (arg == null || arg.isEmpty())
                throw new IllegalArgumentException(
                        "Invalid argument '" + arg + "' provided with arguments '" + Arrays.asList(args) + "'.");

        final ProcessBuilder builder = new ProcessBuilder(args);

        if (executionDirectory != null)
            builder.directory(executionDirectory);

        builder.redirectErrorStream(true);

        InputStream is = null;

        //
        // TODO: check if there is any support for forking processes in
        // maven/plexus
        //

        try {

            final Process process = builder.start();

            is = process.getInputStream();

            handleLog(is, out);

            return process.waitFor();

        } catch (InterruptedException e) {
            throw new RuntimeException(e.getClass().getName()
                    + " caught during while waiting for a forked process. This exception is not expected to be caught at that time.",
                    e);
        } finally {
            //
            // Exception raised during close operation below are not reported.
            // That is actually bad.
            // We do not have any logging facility here and we cannot throw the
            // exception since this would swallow any
            // other exception raised in the try block.
            // May be we should revisit that ...
            //
            IOUtils.closeQuietly(is);
        }
    }

    private static void handleLog(final InputStream is, final PrintStream out) throws IOException {

        if (out.checkError())
            throw new IOException(
                    "Cannot handle log output. PrintStream that should be used for log handling is damaged.");

        byte[] buff = new byte[1024];
        for (int i; (i = is.read(buff)) != -1;) {
            out.write(buff, 0, i);
            if (out.checkError())
                throw new IOException(
                        "Cannot handle log output from xcodebuild. Underlying PrintStream indicates problems.");
        }

        out.flush();
    }
}