In a certain try block, I have two `String` variables which could cause `NumberFormatException` when I user `Integer.parseInt(string1)` and`Integer.parseInt(string2)`. The question is, if I `catch` an exception, how to know which string is the troublemaker? I need to get the troublemaker's variable name.

Here is some example code:

```
public class test {
    public static void main(String[] args) {
        try {
            String string1 = "fdsa";
            String string2 = "fbbbb";
            Integer.parseInt(string1);
            Integer.parseInt(string2);
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }
        }
    }

```

And the method `e.printStackTrace()` doesn't tell me the variable name; it just tells me the content of the troublemaker.

> 
> java.lang.NumberFormatException: For input string: "fdsa" at
>  java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
>  at java.lang.Integer.parseInt(Integer.java:580) at
>  java.lang.Integer.parseInt(Integer.java:615) at
>  test.main(test.java:9) at
>  sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
>  sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
>  at
>  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>  at java.lang.reflect.Method.invoke(Method.java:498) at
>  com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
> 
> 
> Process finished with exit code 0
> 
> 
> 

The reason that I need to know the variable's name is that I need to prompt the user what's going on. For instance, tell the user that string1 is wrong by using

```
System.out.println(troubleMakerName + "is wrong!")

```

---

In my Requirements, the user should input

```
fd=(fileName,maxLength,minLength)

```

then I will analyse the input string and create some responses. So I'd like to check whether the `maxLength` and `minLength` will throw `NumberFormatException`. In this case, if `minLength` has something wrong, then I need to prompt the user that the minLength is wrong.