Java运行的Bash实时输出

Question

I have the following bash script, example.sh that has some lines of code.To reproduce what I need let's say that I have in the script the following lines:

#!/bin/bash
echo First part of program
sleep 3
echo Second part of program

So, when I run this directly from terminal I get the first part printed to the screen(First part of program) then wait 3 seconds and after that I get the next part on the screen(Second part of program). When I run this in java, I execute the scipt, wait 3 seconds then I get both parts printed on screen. Is there a way to get the same effect as when running from terminal?

EDIT! This is my code:

 public void executeCommand(String command) {
    String line;
        StringBuffer output = new StringBuffer();
        Process p;

    try {
        p = Runtime.getRuntime().exec(command);
        p.waitFor();
        BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
        line = "";           
        while ((line = reader.readLine())!= null) {
            output.append(line + "\n");
        }
        setOutput(output.toString());
        output = new StringBuffer();
        BufferedReader error = new BufferedReader(new InputStreamReader(p.getErrorStream()));
        line="";
        while ((line = error.readLine())!= null) {
            output.append(line + "\n");
        }
        setError(output.toString());

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

Answer 1

If you start your script with the Process -Class then you can fetch the output of the script with for example:

ProcessBuilder pb = new ProcessBuilder("<bashname>", "<scriptpath>");    
Process p = pb.start();
OutputStream ops = p.getOutputStream();

There must be the output immediatly.

Answer 2

SOLVED: redirect output and error into files using:

ProcessBuilder builder = new ProcessBuilder("sh",command);
builder.redirectOutput(new File("out.txt"));
builder.redirectError(new File("err.txt"));
try{
     Process p = builder.start();
}catch(IOException e){
     e.printStackTrace();
}