Java compilation and running within jsp page

Question

hi,
i need of a jsp page that has a textarea in which the java coding are entered and this coding is compiled and executed. The execution result is printed.
Please guide me.

Answer 1

I don't think you can invoke java compiler or run time environment at client side (browser). Even if you use applet, i think you will not be able to do it at client side. Moreover, though java virtual machine will be available in your target user's browser, but you should not expect a java compiler in users machine.
I have seen exam sites where they have added java code compilation and execution ability. To achieve this you can do:
1. In your JSP page use text area where user can edit java code.
2. Provide two buttons - 'Compile' and 'Run'.
3. On click of 'Compile' send the code to server side. In server machine create a file in a temporary location in disk and save the code content received from client.
4. Invoke 'javac' command (as a separate process) to compile the java class created in step 3. This process will give you error/output back which you can send back to user.
5. In case of 'Run' you must first invoke above mentioned 'Compile' service and then another service ('Run') to actually run you java class. You can build 'Run' service in similar way.
Here you challenge would be managing multiple client requests (to compile and run java class) at the same time.
Code to compile and run java classes:
import java.io.*;
* A class to compile and run java classes.
* @author Mrityunjoy Saha
public class JavaProcessor{
     public static void main(String[] args){
          // Option 1 to compile and option 2 to run.
          int option=1;
          if(args.length > 0){
               option=Integer.parseInt(args[0]);
          JavaProcessor p=new JavaProcessor();
          if(option==1){
               p.compile();
          } else {
               p.run();
     public void run(){
          String file="FoodTest";
          String directory="C:/Users/mrityunjoy_saha/Documents/Test";     
          executeCommand("java", directory, file);
     public void compile(){
          String file="FoodTest.java";
          String directory="C:/Users/mrityunjoy_saha/Documents/Test";     
          executeCommand("javac", directory, file);
     public void executeCommand(String command, String directory, String file){
          try{
               String[] envp=null;
               // Make sure that you have done Java setup in your machine.
               // To test this try invoking javac command in command prompt.
               Process p=Runtime.getRuntime().exec(command+" "+file,envp,new File(directory));
               BufferedReader errorStream=new BufferedReader(new InputStreamReader(p.getErrorStream()));
               String readData="";
               while((readData=errorStream.readLine())!=null){
                    System.out.println(readData);
               BufferedReader outStream=new BufferedReader(new InputStreamReader(p.getInputStream()));
               readData="";
               while((readData=outStream.readLine())!=null){
                    System.out.println(readData);
          catch(IOException ioe){
               ioe.printStackTrace();
}Thanks,
Mrityunjoy