IMO Surviving in the present market (Assuming you are refering Indian IT Market) depends how technically competent they are, after 4+ years of hands on experience in java the must have skill sets ( IMO) are
1) Should be really strong in Core Java (Collections,Generics, Multithreading, OOPS and Exception Handling)
2) J2EE Stack ( Strong in JSP's Servlets and EJB's (Optional) )
3) Framworks (Struts or Spring)
4) ORM ( Hibernate or IBatis)
5) Database ( Preferably Oracle and expert in writing complex Queries)
Technology is moving towards the advancement day by day, So having knowledge in below Skills would be really helpful..
1) Flex, Ajax, Dojo, GWT.