How to catch exception in Java?

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I am getting following exception in my code and I want to catch the inner exception. Is it possible to catch that?

java.lang.RuntimeException: error
some stack trace
some stack trace
some stack trace
! Caused by: java.util.concurrent.TimeoutException: null
some stack trace
some stack trace
some stack trace

Lets say I have following code.

function abc() {
  try{
    xyz()
  } catch (TimeoutException e) {
     do stuff
  }
}

xyz() function is generating that exception. Would catching the TimeoutException like this work?


You can't do it directly. You have to catch the outer exception, check its getCause() to see if it's what you want, and then either handle that cause or re-throw the top-level exception.

(You could also technically re-throw just the inner one, but I would strongly discourage that; the stack trace will be very confusing, and it'll be harder to debug -- especially a year from now, when you've forgotten that you did that.)

Try Catch in Java - Exception handling, You can catch different exceptions in different catch blocks. When an exception occurs in try block, the corresponding catch block that handles that particular exception executes. For example if an arithmetic exception occurs in try block then the statements enclosed in catch block for arithmetic exception executes. Whenever you use a statement that might throw an exception in Java, you should write special code to anticipate and catch the exception. That way, your program won’t crash if the exception occurs. You catch an exception by using a try statement, which has this general form: try { statements that can throw exceptions } […]


You cannot directly catch a RuntimeException caused by a TimeoutException.

But you achieve it like this:

    try {
        xyz();
    } catch (RuntimeException e) {
        if (e.getCause() instanceof TimeoutException) {
            // handle TimeoutException
            doStuff();
        } else {
            // rethrow all exceptions with other causes
            throw e;
        }
    }

Java Exception Handling: How to Specify and Handle Exceptions, Errors happen all the time. Java provides a powerful exception handling mechanism that allows you to handle or propagate them. The technical term for this is: Java will throw an exception (throw an error). Java try and catch The try statement allows you to define a block of code to be tested for errors while it is being executed.


No, you can't catch a RuntimeException with catch(TimeoutException e).

However, you could do

} catch (RuntimeException e) {
  Throwable cause = e.getCause(); 
}

to get the cause.

9 Best Practices to Handle Java Exceptions, When we catch the exception, the program's flow control is handled to the exception-handling block. There, we can make the necessary  Then, the try- with-resources statement, introduced in Java SE 7, is explained. The try- with-resources statement is particularly suited to situations that use Closeable resources, such as streams. The last part of this section walks through an example and analyzes what occurs during various scenarios.


Exceptions in Java, If an exception occurs within the try block, it is thrown. Your code can catch this exception (using catch block) and handle it in some rational manner. System-generated exceptions are automatically thrown by the Java run-time system. To manually throw an exception, use the keyword throw. Java exception handling mechanism provides a try-catch-finally tool. Example: try { // Your code that can throw an exception } catch (YourException e) { // handle an exception here } finally { // This block will be executed at the end even if new exception // will be thrown inside of catch block }


Java try-catch, Java try block is used to enclose the code that might throw an exception. It must be used within Duration: 4:21 Posted: Jan 16, 2019 Its worth mentioning that it is common for many programmers to catch an exception like so: try { //something } catch(Exception e) { e.printStackTrace(); } Even if they know what the problem is or doesnt want to do anything in the catch clause. Its just good programming and can be a pretty useful diagnostic tool.


The catch Blocks (The Java™ Tutorials > Essential Classes , Each catch block is an exception handler that handles the type of exception indicated by its argument. The argument type, ExceptionType , declares the type of  Throwing an exception involves two basic steps: Use the throw statement to throw an exception object. Use the throws clause to inform the compiler. Later sections will focus on catching exceptions and cleaning up after them, but first let's learn more about throwables.