Default Installation Of JDK (SDK)?

Question

Can anyone give me a list of default installtion dir of JDK or SDK for windows, linux, and other platforms? I need to find tools.jar in JDK, but using java.home doesn't always work because the user could be using the JRE, in which case java.home will point to the JRE dir, not JDK.
Any help appreciated,
CoolAsIce

Answer 1

I don't think my original query was understood. I want your default installation of the JDK. Perhaps giving you my code will make you understand my intentions better:
import java.lang.reflect.*;
import java.io.*;
import java.net.*;
public class Compile
     private static Class mainClass = null;
     private static Method compileMethod = null;
     static
          try
               File toolsJar = null;
               File[] possibleLocations = new File[]
                    new File(new File(System.getProperty("java.home")).getParent(), "lib/tools.jar"),
                    new File("C:/Program Files/Java/jdk1.5.0_02/lib/tools.jar"),
                    new File("C:/j2sdk1.4.2_08/lib/tools.jar")
               for(int i=0; i<possibleLocations.length; i++)
                    if(possibleLocations.exists())
                         toolsJar = possibleLocations[i];
                         break;
               if(toolsJar != null)
                    mainClass = new URLClassLoader(new URL[]{toolsJar.toURL()}).loadClass("com.sun.tools.javac.Main");
                    compileMethod = mainClass.getMethod("compile", new Class[]{String[].class, PrintWriter.class});
          catch(Throwable t)
               //t.printStackTrace();
     public static void main(String[] args)throws Throwable
          System.out.println(compile(new File(args.length>0 ? args[0] : "Test.java")));
     public static String compile(File file)
          if(mainClass == null)
               throw new RuntimeException("tools.jar cannot be found!");
          try
               //invoke compile() method of Main.
               StringWriter sw = new StringWriter();
               PrintWriter pw = new PrintWriter(sw, true);
               Object[] arguments = new Object[]{new String[]{"-g:none", file.getAbsolutePath()}, pw};
               compileMethod.invoke(mainClass.newInstance(), arguments);
               pw.close();
               sw.close();
               return sw.toString();
          catch(Throwable t)
               return null;
What I need is more files for possibleLocations. Using java.home may not work because if the application is running under JRE, java.home will return the location of the JRE installation dir and tools.jar is not included in the JRE.
Best regards,
CoolAsIce