Question

I am fairly new to java esp. to some of the coding practices. I have a situation where a method throws a NullPointerException and the calling method catches it.

try {
    String test = Class.method(arg)
}    
catch (Exception ex) {
    ...
}

public String method(arg){
String str;
...
if(str == null) throw(exception)
return str;
}

Now some method inside Class.method(arg) throws a NullPointerException and it gets caught in the above catch (like above). Instead I want to do something like:

if (test == null) { do something else }

inside the try block.

What is the best way to handle this? Can I remove the throw inside method and make it return null?

Answer 1

You should catch Exception in method(arg) and return null incase of any exception.

Sample Program:

public class Test1 {

    public static void main(String[] args) {
        try{
            String test = method("1");
            if(test==null){
                //do something else
            }
        }catch(Exception e){

        }

    }

    private static String method(String str) throws Exception{
            if(str.equals("1")) return null;
            else if(str.equals("2")) throw new Exception("My Exception");
            else return str;          
    }

}

Now you can change method to something like this, it all depends on your requirement:

    private static String method(String str) throws Exception{
        try{
            if(str.equals("1")) return null;
            else if(str.equals("2")) throw new Exception("My Exception");
            else return str;
        }catch(Exception e){
            return null;
        }

    }