569

New Features in Java

There are many new features that have been added in java. There are major enhancement made in Java5, Java6, Java7 and Java8 like auto-boxing, generics, var-args, java annotations, enum, premain method , lambda expressions, functional interface, method references etc.

Most of the interviewers ask questions from this chapter.

Do You Know?

1. How to create generic class and generic method in java ?
2. What is annotation and how to create custom annotation ?
3. What is the advantage of assertion and where we should not use it ?
4. What is variable argument and what rules are defined for variable argument ?
5. What is the difference between import and static import ?
6. How autoboxing is applied in method overloading. Which concept beats autoboxing ?
7. What is enum type and how to specify specific value to the enum constants ?

---

JavaSE 8 Features

The important features of JavaSE 8 are lambda expressions, methods references, default methods, functional interface, java 8 date/time, stream classes etc.

• Java 8 Date/Time API (Java 8)
• Lambda Expressions (Java 8)
• Method References (Java 8)
• Functional Interfaces (Java 8)
• Stream (Java 8)
• Base64 Encode Decode (Java 8)
• Default Methods (Java 8)
• forEach method(Java 8)
• Collectors(Java 8)
• StringJoiner(Java 8)
• Optional class (Java 8)
• Nashorn JavaScript (Java 8)
• Parallel Array Sorting (Java 8)
• Type Inference (Java 8)
• Method Parameter Reflection (Java 8)
• Type annotations and repeating annotations (Java 8)
• Java JDBC Improvements (Java 8)
• Java IO Improvement (Java 8)
• Java Concurrency Improvement (Java 8)

---

JavaSE 7 Features

The important features of JavaSE 7 are try with resource, catching multiple exceptions etc.

• String in switch statement (Java 7)
• Binary Literals (Java 7)
• The try-with-resources (Java 7)
• Caching Multiple Exceptions by single catch (Java 7)
• Underscores in Numeric Literals (Java 7)

---

JavaSE 6 Features

The important feature of JavaSE 6 is premain method (also known as instrumentation).

• Instrumentation (premain method) (Java 6)

---

J2SE 5 Features

The important features of J2SE 5 are generics and assertions. Others are auto-boxing, enum, var-args, static import, for-each loop (enhanced for loop etc.

• For-each loop (Java 5)
• Varargs (Java 5)
• Static Import (Java 5)
• Autoboxing and Unboxing (Java 5)
• Enum (Java 5)
• Covariant Return Type (Java 5)
• Annotation (Java 5)
• Generics (Java 5)

---

J2SE 4 Features

The important feature of J2SE 4 is assertions. It is used for testing.

• Assertion (Java 4)