Annotations

An annotation is metadata. Annotations do not directly affect program semantics, but they do affect the way programs are treated by tools and libraries, which can in turn affect the semantics of the running program. Annotations can be read from source files, class files, or reflectively at run time.

For Example

public class SuperClass {
 public void print(){
 
 }
}

import java.lang.annotation.Annotation;

public class SubClass extends SuperClass{    
 @Override
    public void Print(){
 
 }
}

When you tries to compile the above program below error thrown.

SubClass.java:4: error: method does not override or implement a method from a supertype
        @Override
        ^
1 error

Since Print method in SubClass.java actually not overriding the method in SuperClass.java. Becaue the method Print in SubClass.java starts with Capital 'P' where as SuperClass.java starts with small 'p'.

Now change the method name in SubClass.java and recompile.

import java.lang.annotation.Annotation;

public class SubClass extends SuperClass{    
 @Override
    public void print(){
 
 }
} 

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