J2SE概览

J2SE的相关概念图如下所示(https://docs.oracle.com/javase/8/docs/)：

J2SE主要包括以下部分：

一、Java Language

1.各版本JDK新增语言特性(https://docs.oracle.com/javase/8/docs/technotes/guides/language/enhancements.html)

1.1 J2SE 1.4:

1).Assertion Facility

1.2 J2SE 5.0:

• Generics（泛型）
• Enhanced for Loop 
• Autoboxing/Unboxing
• Typesafe Enums
• Varargs
• Static Import 
• Annotations

1.3 J2SE 6:

无

1.4 J2SE 7：

• Binary Literals
• Underscores in Numeric Literals
• Strings in switch Statements
• Type Inference for Generic Instance Creation
• Improved Compiler Warnings and Errors When Using Non-Reifiable Formal Parameters with Varargs Methods
• The try-with-resources Statement
• Catching Multiple Exception Types and Rethrowing Exceptions with Improved Type Checking 

1.5 J2SE 8：

• Lambda Expressions
• Improved Type Inference
• Annotations on Java Types
• Repeating Annotations
• Method Parameter Reflection

1.6 J2SE 9：

• Java Platform Module System
• New Version-String Scheme

二、Tools & Tool APIs

• java
• javac
• javadoc
• jar
• javap
• JPDA
• JConsole
• Java VisualVM
• Java DB
• Security
• Int'l
• RMI
• IDL
• Deploy
• Monitoring
• Troubleshoot
• Scripting
• JVM TI
• Web Services

三、Deployment

• Java Web Start
• Applet / Java Plug-in

四、User Interface Toolkits

• JavaFX
• AWT
• Swing
• Java 2D
• Accessibility
• Drag and Drop
• Input Methods
• Image I/O
• Print Service
• Sound

五、Integration Libraries

• IDL
• JDBC
• JNDI
• RMI
• RMI-IIOP
• Scripting

六、Other Base Libraries

• Beans
• Int'l Support
• Input/Output
• JMX
• JNI
• Math
• Networking
• Override Mechanism
• Security
• Serialization
• Extension Mechanism
• XML JAXP

七、lang and util Base Libraries

• lang and util
• Collections
• Concurrency Utilities
• JAR
• Logging
• Management
• Preferences API
• Ref Objects
• Reflection
• Regular Expressions
• Versioning
• Zip
• Instrumentation

八、Java Virtual Machine