ProcessRunner.java

package com.redhat.ceylon.compiler.java.test.fordebug;

import java.io.IOException;
import java.io.InputStream;


public class ProcessRunner {

    interface Handler {
        public void out(String s);
        public void err(String s);
    }
    
    public static int exec(ProcessBuilder pb) throws Exception {
        return exec(pb, new Handler() {

            @Override
            public void out(String s) {
                System.out.print(s);
            }

            @Override
            public void err(String s) {
                System.err.print(s);
            }});
    }
    
    public static int exec(ProcessBuilder pb, final Handler handler) throws Exception {
        final Process process = pb.start();
        {
            Thread errReader = new Thread() {
                public void run() {
                    try {
                        try (InputStream err = process.getErrorStream()) {
                            byte[] buffer = new byte[1024];
                            
                                int read = err.read(buffer);
                                while (read != -1) {
                                    synchronized(handler) {
                                        handler.err(new String(buffer, 0, read));
                                    }
                                    read = err.read(buffer);
                                }
                            
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            };
            errReader.start();
        }
        {
            Thread outReader = new Thread() {
                public void run() {
                    try {
                        try (InputStream out = process.getInputStream()) {
                            byte[] buffer = new byte[1024];
                            
                                int read = out.read(buffer);
                                while (read != -1) {
                                    synchronized(handler) {
                                        handler.out(new String(buffer, 0, read));
                                    }
                                    read = out.read(buffer);
                                }
                            
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            };
            outReader.start();
        }
        process.waitFor();
        return process.exitValue();
    }
    
}