org.apache.hadoop.cli.util.CommandExecutor.java Source code

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Here is the source code for org.apache.hadoop.cli.util.CommandExecutor.java

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/**
 * 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.hadoop.cli.util;

import org.apache.hadoop.cli.CLITestHelper;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.PrintStream;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.ArrayList;

/**
 *
 * This class execute commands and captures the output
 */
public abstract class CommandExecutor {
    protected String[] getCommandAsArgs(final String cmd, final String masterKey, final String master) {
        String regex = "\'([^\']*)\'|\"([^\"]*)\"|(\\S+)";
        Matcher matcher = Pattern.compile(regex).matcher(cmd);

        ArrayList<String> args = new ArrayList<String>();
        String arg = null;

        while (matcher.find()) {
            if (matcher.group(1) != null) {
                arg = matcher.group(1);
            } else if (matcher.group(2) != null) {
                arg = matcher.group(2);
            } else {
                arg = matcher.group(3);
            }

            arg = arg.replaceAll(masterKey, master);
            arg = arg.replaceAll("CLITEST_DATA",
                    new File(CLITestHelper.TEST_CACHE_DATA_DIR).toURI().toString().replace(' ', '+'));
            arg = arg.replaceAll("USERNAME", System.getProperty("user.name"));

            args.add(arg);
        }

        return args.toArray(new String[0]);
    }

    public Result executeCommand(final String cmd) throws Exception {
        int exitCode = 0;
        Exception lastException = null;

        ByteArrayOutputStream bao = new ByteArrayOutputStream();
        PrintStream origOut = System.out;
        PrintStream origErr = System.err;

        System.setOut(new PrintStream(bao));
        System.setErr(new PrintStream(bao));

        try {
            exitCode = execute(cmd);
        } catch (Exception e) {
            e.printStackTrace();
            lastException = e;
            exitCode = -1;
        } finally {
            System.setOut(origOut);
            System.setErr(origErr);
        }
        return new Result(bao.toString(), exitCode, lastException, cmd);
    }

    protected abstract int execute(String cmd) throws Exception;

    public static class Result {
        final String commandOutput;
        final int exitCode;
        final Exception exception;
        final String cmdExecuted;

        public Result(String commandOutput, int exitCode, Exception exception, String cmdExecuted) {
            this.commandOutput = commandOutput;
            this.exitCode = exitCode;
            this.exception = exception;
            this.cmdExecuted = cmdExecuted;
        }

        public String getCommandOutput() {
            return commandOutput;
        }

        public int getExitCode() {
            return exitCode;
        }

        public Exception getException() {
            return exception;
        }

        public String getCommand() {
            return cmdExecuted;
        }
    }

}