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This code reports errors if s is a null pointer. However, it also unintentionally catches other exceptional conditions that are unlikely to be handled properly, such as if the string is being modified concurrently by another threadan index is out of bounds.

Compliant Solution

Instead of catching RuntimeException, a program should be as specific in catching exceptions as possible.

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This code only catches those exceptions that are intended to be caught. For example, a concurrency based an index-out-of-bounds exception is not caught.

Noncompliant Code Example

In this This noncompliant code example , handles a divide by zero exception is handled initially. Instead of the specific exception type ArithmeticException, a more generic type Exception is caught. This is dangerous as any future exception declaration updates to the method signature (such as, addition of IOException) may no longer require the developer to provide a handler. Consequently, the recovery process may not be tailored to the specific exception type that is thrown. Additionally, unchecked exceptions under RuntimeException are also unintentionally caught whenever the top level Exception class is caught.

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Noncompliant Code Example

This noncompliant code example improves by catching a specific divide-by-zero exception but fails on the premise that it unscrupulously accepts other undesirable runtime exceptions, by catching Exception.

try {
  division(200,5);
  division(200,0); //divide Divide by zero        
} catch (ArithmeticException ae) { 
  throw new DivideByZeroException(); 
}
  // DivideByZeroException extends Exception so is checked
  catch (Exception e) { 
  System.out.println("Exception occurred :" + e.getMessage()); 
}	

Compliant Solution

To be compliant, catching catch specific exception types is advisable especially when the types differ significantly. Here, Arithmetic Exception ArithmeticException and IOException have been unbundled as because they belong to fall under very diverse categories.

import java.io.IOException;

public class DivideException {
  public static void main(String[] args) {
    try {
      division(200,5);
      division(200,0); //divide Divide by zero        
    } catch (ArithmeticException ae) { 
      throw new DivideByZeroException(); }
      // DivideByZeroException extends Exception so is checked
      catch (IOException ie) { 
      System.out.println("I/O Exception occurred :" + ie.getMessage()); 
    }	    
  }

  public static void division(int totalSum, int totalNumber) throws ArithmeticException, IOException  {  
    int average  = totalSum/totalNumber; 
    // Additional operations that may throw IOException...
    System.out.println("Average: "+ average);   	
  }
}

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