First of all we define here the keywords throw and throws as:
throw: It is used to throw the exception in your own way. Generally JVM will identify the exception class, create the object and throw that object. Sometimes you may get a chance to do this specially in the case of user defined exceptions.
throw: It is used to throw the exception in your own way. Generally JVM will identify the exception class, create the object and throw that object. Sometimes you may get a chance to do this specially in the case of user defined exceptions.
throws :Throws keyword is used to specify the method level exception.
Generally
when you are implementing a method, code inside that method may rise
exceptions.If you want to handle the exception in the same method then use try and catch method.
Now we show the example using the throw and throws. We defined three classes-UserException.java, Aclass.java,Bclass.java and TestThrowandthrows.java.
Here we can see one bye one all classes.
UserException.java
package
com.javaforecast4u;
import java.io.*;
public class UserException
extends IOException {
}
Aclass.java
package
com.javaforecast4u;
import java.io.*;
public class Aclass {
void method1(int a) throws IOException,
ArithmeticException{
if(a==1){
throw new
ArithmeticException();
}
else{
throw new IOException();
}
}
}
package
com.javaforecast4u;
import java.io.*;
public class Bclass extends Aclass {
public void method1(int a){
System.out.println("Bclass---method1");
}
}
TestThrowandthrows.java
package
com.javaforecast4u;
import
java.io.IOException;
public class
TestThrowandthrows {
public static void main(String
arg[])throws IOException, ArithmeticException
{
Aclass
a=new Bclass();
a.method1(2);
}
}
Here I didnt see any use of UserException.
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