Java - Methods from Throwable class.

Introduction

Throwable class is the superclass of all exception classes in Java.

All of the methods shown in this table are available in all exception classes.

A Partial List of Methods of the Throwable Class

Method
Description
Throwable getCause()
It returns the cause of the exception. If the cause of the exception is not set, it returns null.
String getMessage()
It returns the detailed message of the exception.
StackTraceElement[] getStackTrace()
It returns an array of stack trace elements.
Throwable initCause(Throwable cause)

There are two ways to set an exception as the cause of an exception. One way is to use the constructor, which
accepts the cause as a parameter. Another way is to use this method.
void printStackTrace()
It prints the stack trace on the standard error stream.
void printStackTrace(PrintStream s)
It prints the stack trace to the specified PrintStream object.
void printStackTrace(PrintWriter s)
It prints the stack trace to the specified PrintWriter object.
String toString()


It returns a short description of the exception object. The
description of an exception object contains the name of the
exception class and the detail message.

Printing the Stack Trace of an Exception

Demo

public class Main {
  public static void main(String[] args) {
    try {//from w w  w . ja va 2 s .  com
      m1();
    } catch (MyException e) {
      e.printStackTrace(); // Print the stack trace
    }
  }

  public static void m1() throws MyException {
    m2();
  }

  public static void m2() throws MyException {
    throw new MyException("Some error has occurred.");
  }
}

class MyException extends Exception {

  public MyException() {
    super();
  }

  public MyException(String message) {
    super(message);
  }

  public MyException(String message, Throwable cause) {
    super(message, cause);
  }

  public MyException(Throwable cause) {
    super(cause);
  }
}

Result

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