The Java API over the years has deprecated quite a few classes and methods. This means new methods and classes have been added that provide a better way to achieve the same task; therefore, the deprecated classes and methods need not be used any more by developers. Such entities are marked with the @Deprecated annotation. One such class is StringBufferInputStream.

Let’s see what happens when we use this class in the program code here:

public class DeprecatedAnnotation {               

           public static void main(String[] args) {

                                             java.io.StringBufferInputStream in =

                                                              new java.io.StringBufferInputStream("A sample string");

           }

}

 We compile this code with the following command line:

javac -Xlint:deprecation DeprecatedAnnotation.java

The compiler output is shown here:

DeprecatedAnnotation.java:9: warning: [deprecation] StringBufferInputStream in java.io has been deprecated
java.io.StringBufferInputStream in =

^

DeprecatedAnnotation.java:10: warning: [deprecation] StringBufferInputStream in java.io has been deprecated
new java.io.StringBufferInputStream("A sample string");

^

2 warnings

The compiler generates two warnings, showing us the lines in our program where we have used the deprecated class.

We can even use this @Deprecated annotation in our own code for marking the elements we want to phase out eventually. Consider the code shown here:  

public class DeprecatedAnnotationDemo {

                     public static void main(String[] args) {

                             MyTestClass testObject = new MyTestClass();

                             testObject.doSomething();

                             testObject.doSomethingNew("Bowling");
                     }

}

class MyTestClass {
                     @Deprecated
                     public void doSomething() { 
                     }                      public void doSomethingNew(String SomeFun) { 
                     } 
}

javac -Xlint:deprecation DeprecatedAnnotationDemo.java
DeprecatedAnnotationDemo.java:10: warning: [deprecation] doSomething() in
MyTest Class has been deprecated
testObject.doSomething();
^
1 warning