public static void foo() throws IOException {
// some code here, when something goes wrong, you might do:
throw new IOException("error message");
}
public static void main(String[] args) {
try {
foo();
} catch (IOException e) {
System.out.println(e.getMessage());
}
}//f a method does not handle a checked exception, the method must declare it using the throws keyword. The throws keyword appears at the end of a method's signature.
One can throw an exception, either a newly instantiated one or an exception that you just caught, by using the throw keyword.
Understand the difference between throws and throw keywords, throws is used to postpone the handling of a checked exception and throw is used to invoke an exception explicitly.
Example
import java.io.*;
public class className {
public void deposit(double amount) throws RemoteException {
// Method implementation
throw new RemoteException();
}
// Remainder of class definition
}import java.io.*;
class Main {
// declareing the type of exception
public static void findFile() throws IOException {
// code that may generate IOException
File newFile = new File("test.txt");
FileInputStream stream = new FileInputStream(newFile);
}
public static void main(String[] args) {
try {
findFile();
}
catch (IOException e) {
System.out.println(e);
}
}
}public class Main {
static void checkAge(int age) throws ArithmeticException {
if (age < 18) {
throw new ArithmeticException("Access denied - You must be at least 18 years old.");
}
else {
System.out.println("Access granted - You are old enough!");
}
}
public static void main(String[] args) {
checkAge(15); // Set age to 15 (which is below 18...)
}
}accessModifier returnType methodName() throws ExceptionType1, ExceptionType2 … {
// code
}import java.io.*;
class Main {
public static void findFile() throws IOException {
// code that may produce IOException
File newFile=new File("test.txt");
FileInputStream stream=new FileInputStream(newFile);
}
public static void main(String[] args) {
try{
findFile();
} catch(IOException e){
System.out.println(e);
}
}
}