Hi Saravanan Velusamy ,
Have you had a look at here ?:
Programming in Java - CA Single Sign-On - 12.52 SP1 - CA Technologies Documentation
To get started, you will need to install CA SiteMinder SDK from here :
SAP NetWeaver Portal
The above link points to 12.52SP1CR5 version of SDK.
Once SDK is installed, you can find all the required samples under the samples folder.
For java specific sample refer to javaXXX folders.
For e.g if you want to write a custom auth scheme in java , refer to javauathapi directory, which has a custom sample java auth scheme by name AuthApiSample.java
All the sample uses following properties file as default, so you will need to configure as per your environment before running the sample code.
Let me know if you have any further questions.