Java ProcessBuilder示例

在Java中，我们可以使用ProcessBuilder轻松调用外部命令：

ProcessBuilder processBuilder = new ProcessBuilder();

	// -- Linux --

	// Run a shell command
	processBuilder.command("bash", "-c", "ls /home/mkyong/");

	// Run a shell script
	processBuilder.command("path/to/hello.sh");

	// -- Windows --

	// Run a command
	processBuilder.command("cmd.exe", "/c", "dir C:\\Users\\mkyong");

	// Run a bat file
	processBuilder.command("C:\\Users\\mkyong\\hello.bat");

	Process process = processBuilder.start();

1.平

1.1运行外部ping命令对网站进行ping操作3次，并显示输出信息。

ProcessBuilderExample1.java

package com.mkyong.process;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class ProcessBuilderExample1 {

    public static void main(String[] args) {

        ProcessBuilder processBuilder = new ProcessBuilder();

        // Run this on Windows, cmd, /c = terminate after this run
        processBuilder.command("cmd.exe", "/c", "ping -n 3 google.com");

        try {

            Process process = processBuilder.start();

			// blocked :(
            BufferedReader reader =
                    new BufferedReader(new InputStreamReader(process.getInputStream()));

            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }

            int exitCode = process.waitFor();
            System.out.println("\nExited with error code : " + exitCode);

        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

}

输出量

Pinging google.com [172.217.166.142] with 32 bytes of data:
Reply from 172.217.166.142: bytes=32 time=10ms TTL=55
Reply from 172.217.166.142: bytes=32 time=10ms TTL=55
Reply from 172.217.166.142: bytes=32 time=10ms TTL=55

Ping statistics for 172.217.166.142:
    Packets: Sent = 3, Received = 3, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 10ms, Maximum = 10ms, Average = 10ms

Exited with error code : 0

2. Ping +线程

在上面的示例1.1中， process.getInputStream是“ blocking”，最好为读取过程启动一个新的Thread，这样它就不会阻止其他任务。

ProcessBuilderExample2.java

package com.mkyong.process;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;
import java.util.concurrent.*;
import java.util.stream.Collectors;

public class ProcessBuilderExample2 {

    public static void main(String[] args) {

        ExecutorService pool = Executors.newSingleThreadExecutor();

        ProcessBuilder processBuilder = new ProcessBuilder();

        // Run this on Windows, cmd, /c = terminate after this run
        processBuilder.command("cmd.exe", "/c", "ping -n 3 google.com");

        try {

            Process process = processBuilder.start();

            System.out.println("process ping...");
            ProcessReadTask task = new ProcessReadTask(process.getInputStream());
            Future> future = pool.submit(task);

            // no block, can do other tasks here
            System.out.println("process task1...");
            System.out.println("process task2...");

            List result = future.get(5, TimeUnit.SECONDS);
            for (String s : result) {
                System.out.println(s);
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            pool.shutdown();
        }
    }

    private static class ProcessReadTask implements Callable> {

        private InputStream inputStream;

        public ProcessReadTask(InputStream inputStream) {
            this.inputStream = inputStream;
        }

        @Override
        public List call() {
            return new BufferedReader(new InputStreamReader(inputStream))
				.lines()
				.collect(Collectors.toList());
        }
    }

}

输出量

process ping...
process task1...
process task2...

Pinging google.com [172.217.166.142] with 32 bytes of data:
Reply from 172.217.166.142: bytes=32 time=11ms TTL=55
Reply from 172.217.166.142: bytes=32 time=10ms TTL=55
Reply from 172.217.166.142: bytes=32 time=10ms TTL=55

Ping statistics for 172.217.166.142:
    Packets: Sent = 3, Received = 3, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 10ms, Maximum = 11ms, Average = 10ms

3.更改目录

3.1转到目录C:\\users并运行external dir命令列出所有文件。

ProcessBuilderExample3.java

package com.mkyong.process;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;

public class ProcessBuilderExample3 {

    public static void main(String[] args) {

        ProcessBuilder processBuilder = new ProcessBuilder();

        processBuilder.command("cmd.exe", "/c", "dir");
        processBuilder.directory(new File("C:\\users"));

        // can also run the java file like this
        // processBuilder.command("java", "Hello");

        try {

            Process process = processBuilder.start();

            BufferedReader reader =
                    new BufferedReader(new InputStreamReader(process.getInputStream()));

            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }

            int exitCode = process.waitFor();
            System.out.println("\nExited with error code : " + exitCode);

        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

}

输出量

Volume in drive C has no label.
 Volume Serial Number is CE5B-B4C5

 Directory of C:\users

//...

参考文献

1. Microsoft系统错误代码（0-499）
2. 如何从Java执行Shell命令
3. Java文档– ProcessBuilder
4. cmd / C是什么意思？

标签： 可调用的 外部命令 java 进程 shell命令 线程

翻译自: https://mkyong.com/java/java-processbuilder-examples/