Empty Code Block

Description

Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

In the following Java example, the code catches an ArithmeticException.

public class Main {

  public static void main(String[] args) {
    int a = 1;
    int b = 0;
    int c = 0;

    try {
      c = a / b;

    } catch(ArithmeticException ae) {
    }

  }

}

Since the exception block is empty, no action is taken.

In the code below the exception has been logged and the bad execution has been handled in the desired way allowing the program to continue in an expected way.

public class Main {

  public static void main(String[] args) {
    int a = 1;
    int b = 0;
    int c = 0;

    try {
      c = a / b;

    } catch(ArithmeticException ae) {
      log.error("Divided by zero detected, setting to -1.");
      c = -1;

    }

  }

}

Example Two

The following code attempts to synchronize on an object, but does not execute anything in the synchronized block. This does not actually accomplish anything and may be a sign that a programmer is wrestling with synchronization but has not yet achieved the result they intend.

synchronized(this) { }

Instead, in a correct usage, the synchronized statement should contain procedures that access or modify data that is exposed to multiple threads. For example, consider a scenario in which several threads are accessing student records at the same time. The method which sets the student ID to a new value will need to make sure that nobody else is accessing this data at the same time and will require synchronization.

public void setID(int ID){
  synchronized(this){
    this.ID = ID;
  }
}

See Also