src/test/java/org/apache/commons/exec/issues/Exec49Test.java

/*
 * 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
 *
 *   https://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.commons.exec.issues;

import java.io.ByteArrayOutputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.time.Duration;

import org.apache.commons.exec.CommandLine;
import org.apache.commons.exec.DefaultExecuteResultHandler;
import org.apache.commons.exec.DefaultExecutor;
import org.apache.commons.exec.Executor;
import org.apache.commons.exec.PumpStreamHandler;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.condition.DisabledOnOs;
import org.junit.jupiter.api.condition.OS;

/**
 * Test EXEC-44 (https://issues.apache.org/jira/browse/EXEC-44).
 */
class Exec49Test {

    private static final Duration WAIT = Duration.ofSeconds(10);
    private final Executor exec = DefaultExecutor.builder().get();

    /**
     * The issue was detected when trying to capture stdout/stderr with a PipedOutputStream and then pass that to a PipedInputStream. The following code will
     * produce the error. The reason for the error is the PipedOutputStream is not being closed correctly, causing the PipedInputStream to break.
     *
     * @throws Exception the test failed
     */
    @Test
    @DisabledOnOs(OS.WINDOWS)
    void testExec49Part1() throws Exception {
        final CommandLine cl = CommandLine.parse("/bin/ls");
        cl.addArgument("/opt");
        // redirect stdout/stderr to pipedOutputStream
        try (PipedOutputStream pipedOutputStream = new PipedOutputStream()) {
            final PumpStreamHandler psh = new PumpStreamHandler(pipedOutputStream);
            exec.setStreamHandler(psh);
            // start an asynchronous process to enable the main thread
            System.out.println("Preparing to execute process - commandLine=" + cl.toString());
            final DefaultExecuteResultHandler handler = new DefaultExecuteResultHandler();
            exec.execute(cl, handler);
            System.out.println("Process spun off successfully - process=" + cl.getExecutable());
            try (PipedInputStream pis = new PipedInputStream(pipedOutputStream)) {
                while (pis.read() >= 0) {
//                 System.out.println("pis.available() " + pis.available());
//                 System.out.println("x " + x);
                }
            }
            handler.waitFor(WAIT);
            handler.getExitValue(); // will fail if process has not finished
        }
    }

    /**
     * The issue was detected when trying to capture stdout with a PipedOutputStream and then pass that to a PipedInputStream. The following code will produce
     * the error. The reason for the error is the PipedOutputStream is not being closed correctly, causing the PipedInputStream to break.
     *
     * @throws Exception the test failed
     */
    @Test
    @DisabledOnOs(OS.WINDOWS)
    void testExec49Part2() throws Exception {
        final CommandLine cl = CommandLine.parse("/bin/ls");
        cl.addArgument("/opt");
        // redirect only stdout to pipedOutputStream
        try (PipedOutputStream pipedOutputStream = new PipedOutputStream()) {
            final PumpStreamHandler psh = new PumpStreamHandler(pipedOutputStream, new ByteArrayOutputStream());
            exec.setStreamHandler(psh);
            // start an asynchronous process to enable the main thread
            System.out.println("Preparing to execute process - commandLine=" + cl.toString());
            final DefaultExecuteResultHandler handler = new DefaultExecuteResultHandler();
            exec.execute(cl, handler);
            System.out.println("Process spun off successfully - process=" + cl.getExecutable());
            try (PipedInputStream pis = new PipedInputStream(pipedOutputStream)) {
                while (pis.read() >= 0) {
//                 System.out.println("pis.available() " + pis.available());
//                 System.out.println("x " + x);
                }
            }
            handler.waitFor(WAIT);
            handler.getExitValue(); // will fail if process has not finished
        }
    }

}