The major thing required for Java developer id sound technical knowledge of technology and good analytical skills.Candidate should knowfollowing technical details also
• OOPs Concepts & Patterns
• Abstract Classes and Interfaces
• Constructors
• File IO and Serialization
• Collections – List, Map, Set
• Exceptions – Checked, Unchecked
• Generics
• JVM and Memory Management
• Multithreading and Synchronization
• Dependency Injection
• JSP / Servlets
• Web Frameworks like Struts / Spring
• Service Oriented Architecture / Web Services – SOAP / REST
• Web Technologies like HTML, CSS, JavaScript and JQuery
• Markup Languages like XML and JSON