Documentation for the Core Java APIs

The Java API (Application Programming Interface) is like a super dictionary of the Java language. It has a list of all Java packages, classes, and interfaces; along with all of their methods, fields and constructors; and also with information on how to use them.

Each API is organized into three frames: two small ones on the left listing the available packages and the interfaces and classes in that package, and a large one on the right showing details on the current selection. There is also an alphabetical index listing all classes, interfaces, fields, methods, and constructors.

Each version of Java has its own API, and you should use the API that corresponds to the Java version that you are using. The links below are for the standard edition of Java (J2SE) and include JDK 1.3 (the last major release), JDK 1.4 (the current release), and JDK 1.5 (the beta version of the next major release). For older versions, check out the Java archive. There are also links to many other APIs, such as the J2EE API, the servlet and JSP API, etc. To obtain the Java implementation itself, see the Java download page.

Any serious programmer must have the API in order to develop Java programs. The best approach is to download the API onto your own PC and use it there. That way, you can access it more quickly and use it even when you are not connected to the internet. However, the API is quite large (about 45 megabytes to download, and using around 150 megabytes of disk space), so another approach is to access it online. Links for both downloading and online access are listed below.

JDK 1.3 Documentation JDK 1.4 Documentation JDK 1.5 Documentation

* Top-level API starting point.
* Index of all fields and methods.
* All packages.
* Class hierarchy.
* Guide to new features in Java 1.3.
* API help section.
* General documentation
* Downloading the Java documentation to your local machine.



* Top-level API starting point. Uses frames.
* Index of all fields and methods.
* All packages.
* Class hierarchy.
* Guide to new features in Java 1.4.
* API help section.
* General documentation
* Downloading the Java documentation to your local machine.



* Top-level API starting point. Uses frames.
* Index of all fields and methods.
* All packages.
* Class hierarchy.
* Guide to new features in Java 1.5.
* API help section.
* General documentation
* Downloading the Java documentation to your local machine.

Official Documentation for Sun Java Tools (javac, java, javadoc, appletviewer, etc).
Below are documentation links for the basic Java tools such as javac (to compile .java files into .class files), java (to run Java programs; i.e., to execute .class files), javadoc (to generate API documentation for your classes), appletviewer (to run and debug applets without using a Web browser), jar (to create and manage Java ARchive (JAR) files), etc. There is also documentation on advanced tools such as Remote Method Invocation (RMI) tools (rmic, rmiregistry, rmid, serialver), internationalization tools (native2ascii), security tools (keytool, jarsigner, policytool, kinit, klist, ktab), Java IDL and RMI-IIOP tools (tnameserv, idlj, orbd, servertool) and Java Plug-in tools. There are also descriptions of standard procedures like the "SDK File Structure," "Setting the Classpath" and "How Classes are Found."

J2SE 1.3 J2SE 1.4 J2SE 1.5
JDK 1.3 Tool Docs JDK 1.4 Tool Docs JDK 1.5 Tool Docs
Documentation on Specialized Java Topics
Java Enterprise Edition Documentation
J2EE is the Java edition that bundles the enterprise-level APIs such as EJB, JMS, servlets, JSP, JNDI, etc. If you want the API for servlets and JSP only, see the JSP and servlet resources page.

J2EE 1.2 Documentation J2EE 1.3 Documentation J2EE 1.4 Documentation

* Top-level API starting point. Uses frames.
* Index of all fields and methods.
* All packages.
* Class Hierarchy.
* Downloading the Java documentation to your local machine (contains also the specs).
* API help section.
* General Documentation



* Top-level API starting point. Uses frames.
* Index of all fields and methods.
* All packages.
* Class Hierarchy.
* Downloading the Java documentation to your local machine (contains also the tutorials, blueprints, and specs).
* API help section.
* General Documentation



* Top-level API starting point. Uses frames.
* Index of all fields and methods.
* All packages.
* Class Hierarchy.
* Downloading the Java documentation to your local machine. (contains also the tutorials, specs, and more).
* API help section.
* General Documentation

Following are documentation sites on some of the most common Java tools and libraries. For more complete lists, see the Java home page , the Sun Java product/package list and Sun's Java documentation list.

* JavaServer Faces (JSF) Documentation
* JSP and Servlet Documentation (Also see this on-line book).
* Apache Tomcat Documentation.
* Java Micro Edition Documentation
* JavaBeans Documentation
* Enterprise Java Beans (EJB) Documentation
* CORBA Documentation
* Java Cryptography API
* JavaMail Documentation



* Java Language Specification. Core syntax; not an API ref.
* Java Virtual Machine Specification.
* RMI Documentation
* JDBC Documentation
* Java3D Documentation
* JFC Documentation
* JavaCard Documentation
* Java Plugin (formerly "Activator") Documentation
* Object signing in Netscape. Documentation on permitting digitally signed applets to have higher privileges (if user agrees, of course).