To generate xml schema definition (xsd) from java objects just it required few steps
1. create jaxb project in eclipse.
2. copy/create java pojo classes under src which u want to create as xml schema definition.
3. right click on folder src in eclipse go to other-> jaxb-> generate xsd from javaclasses .
4. XSD will generate from java classes.
Below is the link for detailed referece with steps
http://theopentutorials.com/examples/java/jaxb/generate-xml-schema-from-java-class-in-eclipse-ide/
