Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright (c) 2016 Aalto University
 *
 * 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.
 */

import java.io.BufferedReader;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import java.util.Map;

public class Main {
    /**
     * create a child process with environment variables
     * @param command
     * @param envVars
     * @return
     * @throws InterruptedException
     * @throws IOException
     */
    public static String execUnixCommand(String[] command, Map<String, String> envVars)
            throws InterruptedException, IOException {

        /*
        ProcessBuilder processBuilder = new ProcessBuilder(command);
            
        if ( envVars != null ){
        Map<String, String> env = processBuilder.environment();
        env.clear();
        env.putAll(envVars);
        }
            
        Process process = processBuilder.start();
        processBuilder.redirectErrorStream(false);
        process.waitFor();
        String outputWithError = loadStream(process.getInputStream()) + loadStream(process.getErrorStream());
        return outputWithError;
         */

        ProcessBuilder processBuilder = new ProcessBuilder(command);

        if (envVars != null) {
            Map<String, String> env = processBuilder.environment();
            env.clear();
            env.putAll(envVars);
        }
        Process process = processBuilder.start();
        String output = loadStream(process.getInputStream());
        String error = loadStream(process.getErrorStream());
        process.waitFor();
        return output + "\n" + error;
    }

    /**
     * read the inputstream to String
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static String loadStream(InputStream inputStream) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
        StringBuilder sb = new StringBuilder();

        String tmpLine;
        while ((tmpLine = br.readLine()) != null) {
            sb.append(tmpLine);
        }
        br.close();
        return sb.toString();
    }
}