How to Re-Throw Exception in Java

MD Aminul Islam Feb 02, 2024
How to Re-Throw Exception in Java

In Java, throw is the most commonly used keyword to throw either a built-in exception or a -user-defined exception, but sometimes we have to throw the same exception through the catch block.

This situation is called the re-throwing an exception. In this tutorial article, we will learn about the re-throwing exception and perform this task without making any changes to the original stack trace.

Demonstration of Re-Throwing an Exception in Java

If you are working with sensitive programs, such as manipulating the database, tracking the exception is essential before propagating it to a higher level.

We need to perform some activities on the catch block and re-throw the exception so that the higher level of the program gets notified that an exception occurs in the system.

In our example below, we will re-throw an exception when a string value sets to null. The code for this purpose will be like the below:

public class JavaException {
  public static void main(String args[]) {
    String Name = null;

    try {
      if (Name.equals("Mark"))
        System.out.println("Matched"); // This will cause NullPointerException
    } catch (Exception e) {
      throw e;

In the above code fence, we first set the value of a string variable Name to null. After that, we used the exception handler of java try{ ... } catch { ... }, and inside it, we compared the string value with another string.

Now this will cause a NullPointerException error. After running the above example code, you will get the below output in your console.

Exception in thread "main" java.lang.NullPointerException
    at javacodes.JavaException.main(

If we look at the code of the example sincerely, we will see that our code re-throws any exception is caught, and we get the original stack trace without making any changes.

MD Aminul Islam avatar MD Aminul Islam avatar

Aminul Is an Expert Technical Writer and Full-Stack Developer. He has hands-on working experience on numerous Developer Platforms and SAAS startups. He is highly skilled in numerous Programming languages and Frameworks. He can write professional technical articles like Reviews, Programming, Documentation, SOP, User manual, Whitepaper, etc.


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