How to execute Java code from Batch script?

Question

I have to execute a java code using batch script where java code has to take a variable value generated from the .bat file and execute java code and then return the another variable value back to .bat .

In say, exec.bat file i l get a value "456" .this "456" has to be sent to java file and there after execution we get another value "789" .And I want this "789" to be return back to exe.bat .

Please let me know the code and syntax to be written in both java and batch file.

Thanks in Advance

Answer 1

Here is one way to do it:

In Java code :

At the end of the program put this line

System.exit(789);

Here 789 is the value you would return to your batch file.

In the batch file:

@echo off
java Test %1
set exitcode=%ERRORLEVEL%
echo %exitcode%

Here

java Test %1 is the usual java execution with argument passed from batch file where %1 will map to the first parameter passed to the batch file from command prompt (like wise you could have %2 etc ... Check this article ).

ERRORLEVEL is the standard batch variable use to store the value returned from java

Assuming that your batch file name is Test.bat, you run this from command prompt batch as

Test 456

EDIT:Example for adding two numbers

Example.java

public class Example extends TestBase<String>
{
     public static void  main(String[] arg){
         int result = Integer.parseInt(arg[0].trim()) ;+Integer.parseInt(arg[1].trim())
          System.exit(result);
     }

}

Compile this file and generate a class file Example.class

Batch file :

Example.bat

@echo off
java Example %1 %2
set exitcode=%ERRORLEVEL%
echo %exitcode%

Put this batch file and Example.class in a folder. Open command prompt from that folder and run as follows

Example 111 222

This will print the addition of these two numbers