java.lang.NullPointerException and return code

I’m running some java binary from bash like:

run_me.sh

$JAVA_HOME/bin/java -Djava.library.path=path1/libs/opencv/lib -jar path2/bin/application.jar
echo "Exit code: "$?

but inside application I get java.lang.NullPointerException, howewer return code is 0, but I need some non zero exit code to understand from bash that application failed.

What is the proper way to handle such cases?

Update:

Here is an exxample of ‘nested’ try catch blocks, when I throw exception in inner_package_class return code is 0. So what is the proper way to get exception from inner_package_class.method1()?

public static void main(String[] args) {

    try {
        inner_package_class.method1();
        System.out.printf("After inner method!n");
    } catch (Throwable t) {
        System.exit(1); 
    }
}

public class inner_package_class {

    public static void method1() {

        System.out.printf("From inner method!n");

        try
        {
            throw new Exception("Some exception 2.");
        } catch (Throwable t) {

        }

    }
}

Update 1: This work as expected (return non zero exit code).

public class inner_package_class {

    public static void method1() throws Exception {
        System.out.printf("From inner method!n");

        throw new Exception("Some exception 2.");
    }
}

Answer

You can add a try-catch-block around your main method and use

System.exit(1)

when you catch a Throwable

public static void main(String[] args) {
  try {
     ... // your original code
  } catch (Throwable t) {
     // log the exception 
    t.printStacktrace(); // or use your logging framework 
    System.exit(1); 
  }
}

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Answer