Method Class | getExceptionTypes() Method in Java (original) (raw)

Last Updated : 11 Apr, 2023

The java.lang.reflect.Method.getExceptionTypes() method of “Method class” returns an array of Exception Type Class Objects declared to be thrown by the method object to handle exception inside the method. All the exceptions handled by method using thrown clause, are returned as array of Class objects using this method. This method returns an array of length 0 if the method, on which this method is applied, declares no exceptions in its throws clause. Syntax:

public Class<?>[] getExceptionTypes()

Return Value: This method returns an array of the exception class declared using thrown clause by the this Method object Below programs illustrates getExceptionTypes() method of Method class: Example 1: Print all Exceptions

Java

import java.lang.reflect.Method;

public class GFG {

`` public static void main(String[] args)

`` {

`` try {

`` Class classobj = demoClass. class ;

`` Method[] methods = classobj.getMethods();

`` for (Method method : methods) {

`` if (method.getName().equals("setValue")

`` || method.getName().equals("getValue")) {

`` Class[] exceptions = method.getExceptionTypes();

`` System.out.println("Exception Thrown by Method: "

`` + method.getName());

`` System.out.println("Exception Array length: "

`` + exceptions.length);

`` for (Class c : exceptions) {

`` System.out.println(c.getName());

`` }

`` }

`` }

`` }

`` catch (Exception e) {

`` e.printStackTrace();

`` }

`` }

}

class demoClass {

`` public void setValue(String value)

`` throws ClassNotFoundException,

`` ArrayIndexOutOfBoundsException,

`` ArithmeticException

`` {

`` }

`` public String getValue(String value)

`` {

`` return value;

`` }

}

Output:

Exception Thrown by Method: getValue Exception Array length: 0 Exception Thrown by Method: setValue Exception Array length: 3 java.lang.ClassNotFoundException java.lang.ArrayIndexOutOfBoundsException java.lang.ArithmeticException

Example 2: Check whether certain defined Exception is thrown by Method object or not. If yes, then print true, otherwise print false.

Java

import java.lang.reflect.Method;

class GFGSampleClass {

`` String value;

`` public void setValue(String value)

`` throws ClassNotFoundException,

`` ArrayIndexOutOfBoundsException,

`` ArithmeticException

`` {

`` this .value = value;

`` }

}

public class GFG {

`` public static void main(String[] args)

`` {

`` try {

`` Class classobj = GFGSampleClass. class ;

`` Method[] methods = classobj.getMethods();

`` for (Method method : methods) {

`` if (method.getName().equals("setValue")) {

`` Class exceptionObj = IndexOutOfBoundsException. class ;

`` boolean response = isCertainExceptionIsThrown(method,

`` exceptionObj);

`` System.out.println("IndexOutOfBoundsException is "

`` + "thrown by setValue(): " + response);

`` }

`` }

`` }

`` catch (Exception e) {

`` e.printStackTrace();

`` }

`` }

`` private static boolean

`` isCertainExceptionIsThrown(Method method, Class<?> exceptionName)

`` {

`` Class exceptions[] = method.getExceptionTypes();

`` for ( int i = 0 ; i < exceptions.length; i++) {

`` if (exceptions[i] == exceptionName) {

`` return true ;

`` }

`` }

`` return false ;

`` }

}

Output:

IndexOutOfBoundsException is thrown by setValue(): false

Reference: https://docs.oracle.com/javase/8/docs/api/java/lang/reflect/Method.html#getExceptionTypes–