/**
* 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.camel.component.exec;
import org.apache.commons.io.IOUtils;
import org.apache.commons.io.LineIterator;
/**
* A test Java main class to be executed. The behavior of the program is
* controlled by the arguments that the {@link #main(String[])} receives. Valid
* arguments are the public static fields of the class.
*/
public class ExecutableJavaProgram {
/**
* Start 2 threads that print text in the stdout and stderr, each printing
* {@link #LINES_TO_PRINT_FROM_EACH_THREAD} lines.
*/
public static final String THREADS = "threads";
public static final String SLEEP_WITH_TIMEOUT = "timeout";
public static final int SLEEP_TIME = 60 * 1000;
public static final String PRINT_IN_STDOUT = "print.in.stdout";
public static final String PRINT_ARGS_STDOUT = "print.args.stdout";
public static final String PRINT_IN_STDERR = "print.in.stderr";
public static final String READ_INPUT_LINES_AND_PRINT_THEM = "read.input.lines.and.print.them";
public static final int EXIT_WITH_VALUE_0 = 0;
public static final int EXIT_WITH_VALUE_1 = 1;
public static final int LINES_TO_PRINT_FROM_EACH_THREAD = 50;
protected ExecutableJavaProgram() {
}
public static void main(String[] args) throws Exception {
if (args == null || args.length == 0) {
throw new IllegalArgumentException("Empty args are not allowed.");
}
if (args[0].equals(PRINT_IN_STDOUT)) {
System.out.print(PRINT_IN_STDOUT);
System.exit(0);
} else if (args[0].equals(PRINT_ARGS_STDOUT)) {
for (int i = 0; i < args.length; i++) {
String arg = args[i];
System.out.println(i + arg);
}
System.exit(0);
} else if (args[0].equals(PRINT_IN_STDERR)) {
System.err.print(PRINT_IN_STDERR);
System.exit(1);
} else if (args[0].equals(String.valueOf(EXIT_WITH_VALUE_0))) {
System.exit(0);
} else if (args[0].equals(String.valueOf(EXIT_WITH_VALUE_1))) {
System.exit(1);
} else if (args[0].equals(THREADS)) {
Thread stderrPrinterThread = new Thread(new ErrPrinter());
Thread stdoutPrinterThread = new Thread(new OutPrinter());
stderrPrinterThread.start();
stdoutPrinterThread.start();
stderrPrinterThread.join();
stdoutPrinterThread.join();
} else if (args[0].equals(SLEEP_WITH_TIMEOUT)) {
doSleep();
System.exit(0);
} else if (READ_INPUT_LINES_AND_PRINT_THEM.equals(args[0])) {
LineIterator iterator = IOUtils.lineIterator(System.in, "UTF-8");
while (iterator.hasNext()) {
String line = iterator.nextLine();
System.out.println(line);
}
} else {
System.out.println(args[0]);
}
}
private static void doSleep() throws InterruptedException {
int sleepInterval = 50;
// Note, that sleeping in the main thread prevents the process from
// being destroyed for that time. The process is killed namely when
// sleep returns(observed on Windows XP)
int t = 0;
System.out.println("Sleeping every " + String.valueOf(sleepInterval) + " ms");
for (; t < SLEEP_TIME % sleepInterval; t += sleepInterval) {
Thread.sleep(sleepInterval);
}
}
private static class ErrPrinter implements Runnable {
public void run() {
for (int t = 0; t < LINES_TO_PRINT_FROM_EACH_THREAD; t++) {
System.err.println(PRINT_IN_STDERR);
}
}
}
private static class OutPrinter implements Runnable {
public void run() {
for (int t = 0; t < LINES_TO_PRINT_FROM_EACH_THREAD; t++) {
System.out.println(PRINT_IN_STDOUT);
}
}
}
}