Running Command Line in Java [duplicate]

问题

This question already has an answer here:

Executing a Java application in a separate process 9 answers

Is there a way to run this command line within a Java application?

java -jar map.jar time.rel test.txt debug

I can run it with command but I couldn\'t do it within Java.

回答1:

Runtime rt = Runtime.getRuntime();
Process pr = rt.exec("java -jar map.jar time.rel test.txt debug");

http://docs.oracle.com/javase/7/docs/api/java/lang/Runtime.html

回答2:

You can also watch the output like this:

final Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

new Thread(new Runnable() {
    public void run() {
     BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
     String line = null; 

     try {
        while ((line = input.readLine()) != null)
            System.out.println(line);
     } catch (IOException e) {
            e.printStackTrace();
     }
    }
}).start();

p.waitFor();

And don't forget, if you are running in Windows, you need to put "cmd /c " in front of your command.

回答3:

To avoid the called process to be blocked if it outputs a lot of data on the standard output and/or error, you have to use the solution provided by Craigo. Note also that ProcessBuilder is better than Runtime.getRuntime().exec(). This is for a couple of reasons: it tokenizes better the arguments, and it also takes care of the error standard output (check also here).

ProcessBuilder builder = new ProcessBuilder("cmd", "arg1", ...);
builder.redirectErrorStream(true);
final Process process = builder.start();

// Watch the process
watch(process);

I use a new function "watch" to gather this data in a new thread. This thread will finish in the calling process when the called process ends.

private static void watch(final Process process) {
    new Thread() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line = null; 
            try {
                while ((line = input.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }.start();
}

回答4:

Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

回答5:

import java.io.*;

Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

Consider the following if you run into any further problems, but I'm guessing that the above will work for you:

Problems with Runtime.exec()

回答6:

what about

public class CmdExec {

public static Scanner s = null;


public static void main(String[] args) throws InterruptedException, IOException {
    s = new Scanner(System.in);
    System.out.print("$ ");
    String cmd = s.nextLine();
    final Process p = Runtime.getRuntime().exec(cmd);

    new Thread(new Runnable() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line = null; 

            try {
                while ((line = input.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    p.waitFor();
     }

 }

回答7:

Have you tried the exec command within the Runtime class?

Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug")

Runtime - Java Documentation

回答8:

Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

来源：https://stackoverflow.com/questions/8496494/running-command-line-in-java

标签

java

command-line

runtime.exec