Comment exécuter une commande shell à partir de Java

Comment exécuter la commande shell à partir de Java

java-execute-shell-command

En Java, nous pouvons utiliserProcessBuilder ouRuntime.getRuntime().exec pour exécuter une commande shell externe:

1. ProcessBuilder

    ProcessBuilder processBuilder = new ProcessBuilder();

    // -- Linux --

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

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

    // -- Windows --

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

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

    try {

        Process process = processBuilder.start();

        StringBuilder output = new StringBuilder();

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

        String line;
        while ((line = reader.readLine()) != null) {
            output.append(line + "\n");
        }

        int exitVal = process.waitFor();
        if (exitVal == 0) {
            System.out.println("Success!");
            System.out.println(output);
            System.exit(0);
        } else {
            //abnormal...
        }

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

2. Runtime.getRuntime().exec()

    try {

        // -- Linux --

        // Run a shell command
        // Process process = Runtime.getRuntime().exec("ls /home/example/");

        // Run a shell script
        // Process process = Runtime.getRuntime().exec("path/to/hello.sh");

        // -- Windows --

        // Run a command
        //Process process = Runtime.getRuntime().exec("cmd /c dir C:\\Users\\example");

        //Run a bat file
        Process process = Runtime.getRuntime().exec(
                "cmd /c hello.bat", null, new File("C:\\Users\\example\\"));

        StringBuilder output = new StringBuilder();

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

        String line;
        while ((line = reader.readLine()) != null) {
            output.append(line + "\n");
        }

        int exitVal = process.waitFor();
        if (exitVal == 0) {
            System.out.println("Success!");
            System.out.println(output);
            System.exit(0);
        } else {
            //abnormal...
        }

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

}

3. Exemple PING

Un exemple pour exécuter une commandeping et imprimer sa sortie.

ProcessBuilderExample1.java

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();
        // Windows
        processBuilder.command("cmd.exe", "/c", "ping -n 3 google.com");

        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();
        }

    }

}

Sortie

Pinging google.com [172.217.31.78] with 32 bytes of data:
Reply from 172.217.31.78: bytes=32 time=13ms TTL=55
Reply from 172.217.31.78: bytes=32 time=7ms TTL=55
Reply from 172.217.31.78: bytes=32 time=6ms TTL=55

Ping statistics for 172.217.31.78:
    Packets: Sent = 3, Received = 3, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 6ms, Maximum = 13ms, Average = 8ms

Exited with error code : 0

Note
Plus de JavaProcessBuilder examples

4. Exemple HOST

Exemple d'exécution de la commande shellhost -t a google.com pour obtenir toutes les adresses IP associées à google.com. Plus tard, nous utilisons une expression régulière pour saisir toutes les adresses IP et les afficher.

P.S “host” command is available in *nix system only.

ExecuteShellComand.java

package com.example.shell;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ExecuteShellComand {

    private static final String IPADDRESS_PATTERN = "([01]?\\d\\d?|2[0-4]\\d|25[0-5])"
        + "\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])"
        + "\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])"
        + "\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])";

    private static Pattern pattern = Pattern.compile(IPADDRESS_PATTERN);
    private static Matcher matcher;

    public static void main(String[] args) {

        ExecuteShellComand obj = new ExecuteShellComand();

        String domainName = "google.com";
        String command = "host -t a " + domainName;

        String output = obj.executeCommand(command);

        //System.out.println(output);

        List list = obj.getIpAddress(output);

        if (list.size() > 0) {
            System.out.printf("%s has address : %n", domainName);
            for (String ip : list) {
                System.out.println(ip);
            }
        } else {
            System.out.printf("%s has NO address. %n", domainName);
        }

    }

    private String executeCommand(String command) {

        StringBuffer output = new StringBuffer();

        Process p;
        try {
            p = Runtime.getRuntime().exec(command);
            p.waitFor();
            BufferedReader reader =
                           new BufferedReader(new InputStreamReader(p.getInputStream()));

            String line = "";
            while ((line = reader.readLine())!= null) {
                output.append(line + "\n");
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return output.toString();

    }

    public List getIpAddress(String msg) {

        List ipList = new ArrayList();

        if (msg == null || msg.equals(""))
            return ipList;

        matcher = pattern.matcher(msg);
        while (matcher.find()) {
            ipList.add(matcher.group(0));
        }

        return ipList;
    }
}