[RESOLVED] problem with java runtime compilation in my jsp file

[Pouncer]

I've embedded this java code in my test.jsp file (it attempts to compile a file at runtime)

  <% 		
			// Attempt to automatically compile a file.
			String s = null;
			String dir = "C:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\eg\\submissions\\msk9\\";
			String f = dir + "TestPlayer.java";
			
			try {
				Process p = Runtime.getRuntime().exec("javac \"" + f + "\"");
				
				BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
				
				ArrayList array = new ArrayList();
				
            	while ((s = stdError.readLine()) != null) {
                	array.add(s);
           		}
				
				if (array.size() > 0) {
					out.println("Your submission had compilation errors:<br><br>");
					
					for (int i = 0; i < array.size(); i++) {
						out.println(array.get(i) + "<br>");
					}
				}
				else {
					out.println("Your submission successfully compiled and has been accepted by the system.");
				}
				
			}
			catch (IOException e) { }
%>

Now when i browse to my test.jsp on the web, the page gives me:

Your submission had compilation errors:

C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\eg\submissions\msk9\TestPlayer.java:3: cannot find symbol
symbol: class ComputerPlayerInterface
public class TestPlayer implements ComputerPlayerInterface {
^
1 error

Now this is a problem, it should compile fine.. it compiles absolutely fine when i execute the normal javac command in the cmd window. but this doesnt seem to work on the web jsp. the ComputerPlayerInterface,java is also in the same directory so i dont know why it throws that error

This is TestPlayer.java

import java.io.*;

public class TestPlayer implements ComputerPlayerInterface {

    public String test() {
	return "Tom";
    }
}

This is ComputerPlayerInterface.java

public interface ComputerPlayerInterface {
    
    // Method signatures, which all submitted computer players must have.
    String test();
}

Both files are in this folder;
C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\eg\submissions\msk9

i dont know why the runtime code doesnt compile on the web

[ComputerJy]

I'm not a JSP expert but I think you need to add the import tag to your code

[Pouncer]

Yes ive got this at the top of the jsp

 <%@ page contentType="text/html; charset=iso-8859-1" language="java" import="java.util.*,java.io.*,java.sql.*,java.io.File" %>

it just doesnt compile the file over the web. any other way it compiles fine.

if i remove the 'implemets ComputerPlayerInterface' from the TestPlayer.java then it compiles fine over the web...

[ComputerJy]

try moving ComputerPlayerInterface to a package then import it in your jsp file

[Pouncer]

Ok i now did the package stuff, ComputerPlayerInterface.java is in a folder called ACS

package ACS;

public interface ComputerPlayerInterface {
    
    // Method signatures, which all submitted computer players must have.
    String test();
}

now on my test.jsp page: I did the necessary import

 <%@ page contentType="text/html; charset=iso-8859-1" language="java" import="java.util.*,java.io.*,java.sql.*,java.io.File,ACS.ComputerPlayerInterface.*;" %>
 
 <% 		
			// Attempt to automatically compile a file.
			String s = null;
			String dir = "C:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\eg\\submissions\\msk9\\";
			String f = dir + "TestPlayer.java";
			
			try {
				Process p = Runtime.getRuntime().exec("javac -classpath \"ComputerPlayerInterface\" \"" + f + "\"");
				
				BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
				
				ArrayList array = new ArrayList();
				
            	while ((s = stdError.readLine()) != null) {
                	array.add(s);
           		}
				
				if (array.size() > 0) {
					out.println("Your submission had compilation errors:<br><br>");
					
					for (int i = 0; i < array.size(); i++) {
						out.println(array.get(i) + "<br>");
					}
				}
				else {
					out.println("Your submission successfully compiled and has been accepted by the system.");
				}
				
			}
			catch (IOException e) { }
%>

when i open the page i still have the same problem, it doesnt seem to compile:

Your submission had compilation errors:

C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\eg\submissions\msk9\TestPlayer.java:3: cannot find symbol
symbol: class ComputerPlayerInterface
public class TestPlayer implements ComputerPlayerInterface {
^
1 error

it just can't seem to find the ComputerPlayerInterface for some reason

[ComputerJy]

package myPackage;

public interface ComputerPlayerInterface {
 // Method signatures, which all submitted computer players must have. 
 String test(); 
}

dude, that's java 101

[Pouncer]

tried the package stuff, didnt work. im trying to navigate to the directory first then doing the javac command:

 <%@ page contentType="text/html; charset=iso-8859-1" language="java" import="java.util.*,java.io.*,java.sql.*,java.io.File" %>
 
 <% 		
			// Attempt to automatically compile a file.
			String s = null;
			String dir = "C:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\eg\\submissions\\msk9";
			
			try {
				Process p = Runtime.getRuntime().exec("cd \"" + dir + "\" : javac \"TestPlayer.java\"");
				
				BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
				
				ArrayList array = new ArrayList();
				
            	while ((s = stdError.readLine()) != null) {
                	array.add(s);
           		}
				
				if (array.size() > 0) {
					out.println("Your submission had compilation errors:<br><br>");
					
					for (int i = 0; i < array.size(); i++) {
						out.println(array.get(i) + "<br>");
					}
				}
				else {
					out.println("Your submission successfully compiled and has been accepted by the system.");
				}
				
			}
			catch (Exception e) { out.println(e.toString()); }
%>

but its giving me an exception error

java.io.IOException: CreateProcess: cd "C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\eg\submissions\msk9" : javac "TestPlayer.java" error=2

even when i put this in my cmd window:

cd "C:\Program Files\Apache Software Foundation\
Tomcat 6.0\webapps\eg\submissions\msk9" : javac "TestPlayer.java"

The system cannot find the path specified.

[ComputerJy]

Java is a programming language not a shell script

[Pouncer]

i found a way to execute 2 commands in 1 go via the &&. e.g:

cd "C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\eg\submiss
ions\msk9" && javac "TestPlayer.java"

that works when i typed it in my cmd window.

but my code below in my jsp file:

 <%@ page contentType="text/html; charset=iso-8859-1" language="java" import="java.util.*,java.io.*,java.sql.*,java.io.File" %>
 
 <% 		
			// Attempt to automatically compile a file.
			String s = null;
			String dir = "C:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\eg\\submissions\\msk9";
			
			try {
				Process p = Runtime.getRuntime().exec("cd \"" + dir + "\" && javac \"TestPlayer.java\"");
				
				BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
				
				ArrayList array = new ArrayList();
				
            	while ((s = stdError.readLine()) != null) {
                	array.add(s);
           		}
				
				if (array.size() > 0) {
					out.println("Your submission had compilation errors:<br><br>");
					
					for (int i = 0; i < array.size(); i++) {
						out.println(array.get(i) + "<br>");
					}
				}
				else {
					out.println("Your submission successfully compiled and has been accepted by the system.");
				}
				
			}
			catch (Exception e) { out.println(e.toString()); }
%>

when i run the jsp file in my browser, it gives me an error:

java.io.IOException: CreateProcess: cd "C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\eg\submissions\msk9" && javac "TestPlayer.java" error=2