How to capture output of java files using Runtime.exec

Question

Hi guys,
I'm trying to capture output of java files using Runtime.exec but I don't know how. I keep receiving error message "java.lang.NoClassDefFoundError:" but I don't know how to :(
import java.io.*;
public class CmdExec {
  public CmdExec() {
  public static void main(String argv[]){
     try {
     String line;
     Runtime rt = Runtime.getRuntime();
     String[] cmd = new String[2];
     cmd[0] = "javac";
     cmd[1] = "I:\\My Documents\\My file\\CSM\\CSM00\\SmartQ\\src\\E.java";
     Process proc = rt.exec(cmd);
     cmd = new String[2];
     cmd[0] = "javac";
     cmd[1] = "I:\\My Documents\\My file\\CSM\\CSM00\\SmartQ\\src\\E";
     proc = rt.exec(cmd);
     //BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
     BufferedReader input = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
     while ((line = input.readLine()) != null) {
        System.out.println(line);
     input.close();
    catch (Exception err) {
     err.printStackTrace();
public class E {
    public static void main(String[] args) {
        System.out.println("hello world!!!!");
}Please help :)

Answer 1

Javapedia: Classpath
How Classes are Found
Setting the class path (Windows)
Setting the class path (Solaris/Linux)
Understanding the Java ClassLoader
java -cp .;<any other directories or jars> YourClassNameYou get a NoClassDefFoundError message because the JVM (Java Virtual Machine) can't find your class. The way to remedy this is to ensure that your class is included in the classpath. The example assumes that you are in the same directory as the class you're trying to run.
javac -classpath .;<any additional jar files or directories> YourClassName.javaYou get a "cannot resolve symbol" message because the compiler can't find your class. The way to remedy this is to ensure that your class is included in the classpath. The example assumes that you are in the same directory as the class you're trying to run.