Misc

Case sensitivity

  • Java is case sensitive.

Version history

Java Platform, Standard Edition

  • JDK 1.0 - 1.1 (Java)
  • J2SE 1.2 - 1.4 (Java 2)
  • J2SE 5 (Java 5) [originally: J2SE 1.5]
  • Java SE 6 ... (Java 6 ...)

Java Platform, Enterprise Edition

  • J2EE 1.2 - 1.4 (Java 2)
  • Java EE 5 ... (Java 5 ...)

GUI Toolkits

  • Widget toolkits

AWT

  • Abstract Windows Toolkit
  • AWT components are platform independent
  • AWT components are wrappers for platform-specific components
  • The appearance of GUI components varies based on the platform

Swing

  • Part of the Java Foundation Classes (JFC)
  • The appearance of GUI components is platform independent
  • Implented entirely in Java
  • Does not rely on platform-specific components

SWT

  • Standard Widget Toolkit
  • Third-generation widget toolkit for Java (with AWT and Swing being the first- and second-generation toolkits, respectively)
  • A richer, more-sophisticated version of AWT
  • Accesses platform-specific libraries through JNI

Type conversions


Safe, implicit conversions
  • byte -> short -> int -> long -> float -> double
  • char -> int

Terms


Byte-code
  • Compiled java code in a machine independent form. To be run in a Java Virtual Machine (JVM)
Java Virtual Machine
  • An interpreter that converts Java byte-code to native machine code at run-time, one instruction at a time
JIT compiler
  • Just-In-Time compiler
  • Translates byte-code into native machine code at run-time, as the program is loaded
Java class libraries
  • Libraries that can be called at run-time
JRE
  • Java Runtime Environment
  • JVM and class libraries
J2SE
  • Java Platform, Standard Edition (Java SE)
  • Set of Java APIs for Java programs
J2EE
  • Java Platform, Enterprise Edition (Java EE)
  • Set of Java APIs for enterprise Java programs
  • Includes an engine for servlets and JavaServer Pages
  • Includes containers for Enterprise JavaBeans
J2ME
  • Java Platform, Micro Edition (Java ME)
  • Set of Java APIs for emedded Java programs
Java SDK
  • Java Software Development Kit (J2SDK)
  • Development tools
JDK
  • Java Development Kit
  • Sun's Java SDK
JAR
  • Java Archive file
  • Zip file used to distribute a set of Java classes
WAR
  • Web application Archive
  • Zip file used to distribute a set of Java classes
  • Contains JSPs, HTML and related files, servlets, and tag libraries.
  • WEB-INF/web.xml  // Used for routing URL requests to servlets