/**
 * Copyright (C) 2017-2018 All Rights Reserved.
 */
package processdemo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;


public class RuntimeDemo {

    public static void main(String[] args) throws IOException, InterruptedException {

        /**
         * Process + Runtime
         * Runtime的exec執(zhí)行函數(shù)也是調(diào)用的ProcessBuilder的構(gòu)造函數(shù)來創(chuàng)建子進(jìn)程并執(zhí)行
         */
        Runtime runtime = Runtime.getRuntime();

        //新啟一個(gè)子進(jìn)程
        Process process = runtime.exec("pwd");

        //子進(jìn)程向主進(jìn)程輸出信息
        InputStream inputStream = process.getInputStream();
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        String temp = null;
        while( (temp = bufferedReader.readLine()) != null){
            System.out.println(temp);
        }

        /**
         * Process + ProecssBuilder
         */
        List<String> cmdList = Arrays.asList("ls","-a");
        ProcessBuilder processBuilder = new ProcessBuilder(cmdList);
        process = processBuilder.start();

        //waitFor()函數(shù)是讓當(dāng)前主進(jìn)程等待該子進(jìn)程執(zhí)行完畢，正常退出則返回0
        if(process.waitFor() != 0 )
            System.exit(1);

        //子進(jìn)程向主進(jìn)程輸出信息
        inputStream = process.getInputStream();
        bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        while( (temp = bufferedReader.readLine()) != null){
            System.out.println(temp);
        }
    }

}

Runtime是程序運(yùn)行時(shí)環(huán)境忘蟹，不能new一個(gè)Runtime對象斗塘，只能通過getRuntime()方式獲取Runtim運(yùn)行時(shí)對象的引用欣舵。
Runtime+Process 和 ProcessBuilder+Process的區(qū)別就是運(yùn)行子進(jìn)程的命令不相同。