在java程序中执行jar文件

Question

I want to create an java program to compress an css file using YUI I am new learner in java.

My Code is:

import java.io.BufferedInputStream;
import java.io.IOException;

public class Run extends Object
{
    public static void main(String args[]) throws IOException, InterruptedException
    {
        System.out.println("Calling jar");

        Process p = Runtime.getRuntime().exec("java -Xmx32m -jar yui.jar in.css");    
        BufferedInputStream bis = new BufferedInputStream(p.getInputStream());
        synchronized(p) 
        {
            p.waitFor();
        }

        System.out.println(p.exitValue());

        int b = 0;
        while((b = bis.read()) > 0)
        {
            System.out.print((char)b);    
        }

        System.out.println("Called jar");
    }
}

I took reference from here .

the command:

java -Xmx32m -jar yui.jar in.css

works fine in cmd but I get no output when I run above program the output I get for above is:

Calling jar
1
Called jar

Please tell Me what I am doing wrong or what is the right way of doing this.

Answer 1

You are getting the "1" because there is nothing to read in the stream.

I'm guessing that you're trying to run the file from Eclipse or some other IDE. If so, you need to place your yui.jar and in.css files to same directory relative to where your Run class is.

If you're using default run configurations, you'll just want to put the files into the root directory of your eclipse project. For example, this works for me:

Test
  src
    com
      test
        Run.java
  yui.jar
  in.css

A better way to handle your situation is to use absolute or relative paths instead of just specifiying yui.jar or in.css . Create two variables for the two relative paths and then create the command string.