Invoking jvm from a java application

Question

hello people,
i would like to run a java application 'B' from within another java application 'A'. i have a thread sub class that does this. it is given
below: (please pay attention to the run method)
import java.io.*;
import javax.swing.*;
public class InvokingThread extends Thread
private File n=null;
private JTextArea outputArea;
private String message="",action="";
private String pathToBin,errors,input,classpath;
private EvaluatorClient clientRef;
//initialize InvokingThread object
public InvokingThread(File name,String act,String path,String cp)
outputArea=new JTextArea(10,25);
outputArea.setEditable(false);
outputArea.setLineWrap(true);
n=name;
pathToBin=path;
classpath=cp;
action=act;
System.out.println((action.equals("compile"))?"compiling":"executing");
public void setClientRef(EvaluatorClient r)
clientRef=r;
//process action
public void run()
Process proce=null;
try
if(action.equals("compile"))
proce = Runtime.getRuntime().exec(pathToBin+"/javac "+n);
else if(action.equals("execute"))
proce = Runtime.getRuntime().exec(pathToBin+"/java "+classpath+" "+n); //run application
Thread.sleep(5000);
byte[] errorData = new byte[proce.getErrorStream().available()];
proce.getErrorStream().read(errorData);
byte[] inputData = new byte[proce.getInputStream().available()];
proce.getInputStream().read(inputData);
errors = new String(errorData);
input = new String(inputData);
System.out.println((errors.length()>0)?"error string"+errors:"no errors");
System.out.println((input.length()>0)?"input string"+input:"");
if (errors.length() == 0 & action.equals("compile"))
outputArea.setText("Compiled successfully");
if(clientRef!=null)
if(!clientRef.isTimeUp())
clientRef.toggleMenuItemState(4,true);
clientRef.toggleMenuItemState(5,true);
clientRef.compilationOutcome("success");
JOptionPane.showMessageDialog(null,new JScrollPane(outputArea));
else if (errors.length() != 0 & action.equals("compile"))
outputArea.setText("Compile Errors:\n" + errors+""+input);
if(clientRef!=null)
clientRef.compilationOutcome("failure");
JOptionPane.showMessageDialog(null,new JScrollPane(outputArea));
else if(action.equals("execute"))
if(errors.length() != 0)
outputArea.setText("Runtime errors:\n" + errors);
JOptionPane.showMessageDialog(null,new JScrollPane(outputArea));
else if(input.length()!=0 )
outputArea.setText(input);
JOptionPane.showMessageDialog(null,new JScrollPane(outputArea));
catch(Exception e)
e.printStackTrace();
System.out.println("thread awake,invoking thread terminating");
}//end run
The above code worked when i used it with the rest of my program.
as we can see the thread waits for 5 seconds before it reads the inputstream and error stream of the sub process returned by Runtime.getRuntime().exec(). But what happens after the thread terminates; i am unable to process subsequent runtime messages/exceptions from the application 'B'.
so my question goes thus: is there a way that my thread can continually listen to the error stream and input stream of the sub process while application 'B' is still running so as to process any messages returned by java form the application 'B' ? or is there a better way of doing what i set out to achieve i.e running a java application from within another java application
timi

Answer 1

Runtime.getRuntime().exec("rundll32
url.dll,FileProtocolHandler
mailto:[email protected]&subject=Foo&body=Bar");yawmark, where do you get such information from? (in all seriousness :-) )
How (the hell) can you find out what args to pass to a program?
and is "FileProtocolHandler" a place-holder? if so what for?
thanks, :)
lutha