JDK

What is JDK                                             Download JDK

JDK stands for Java Development Kit. JDK is a set of tools that are used to create,test and debug a Java program. JDK is developed by the JavaSoft division of Sun Microsystem, the company that created Java.

The JDK consists of the Java compiler and related tools which enable users to create applications in Java.

Sun distributes the JDK as part of J2EE, J2SE, and J2ME.

What is there in the JDK ?

When you install the JDK from the internet or any other source, the following tools are installed in your computer.

• java – the loader for Java applications. This tool is an interpreter and can interpret the class files generated by the javac compiler. Now a single launcher is used for both development and deployment. The old deployment launcher, jre, no longer^[update] comes with Sun JDK, and instead it has been replaced by this new java loader.
• javac – the compiler, which converts source code into Java bytecode
• appletviewer – this tool can be used to run and debug Java applets without a web browser
• apt – the annotation-processing tool
• extcheck – a utility which can detect JAR-file conflicts
• idlj – the IDL-to-Java compiler. This utility generates Java bindings from a given Java IDL file.
• javadoc – the documentation generator, which automatically generates documentation from source code comments
• jar – the archiver, which packages related class libraries into a single JAR file. This tool also helps manage JAR files.
• javah – the C header and stub generator, used to write native methods
• javap – the class file disassembler
• javaws – the Java Web Start launcher for JNLP applications
• jconsole – Java Monitoring and Management Console
• jdb – the debugger
• jhat – Java Heap Analysis Tool (experimental)
• jinfo – This utility gets configuration information from a running Java process or crash dump. (experimental)
• jmap – This utility outputs the memory map for Java and can print shared object memory maps or heap memory details of a given process or core dump. (experimental)
• jps – Java Virtual Machine Process Status Tool lists the instrumented HotSpot Java Virtual Machines (JVMs) on the target system. (experimental)
• jrunscript – Java command-line script shell.
• jstack – utility which prints Java stack traces of Java threads (experimental)
• jstat – Java Virtual Machine statistics monitoring tool (experimental)
• jstatd – jstat daemon (experimental)
• policytool – the policy creation and management tool, which can determine policy for a Java runtime, specifying which permissions are available for code from various sources
• VisualVM – visual tool integrating several command-line JDK tools and lightweight performance and memory profiling capabilities
• wsimport – generates portable JAX-WS artifacts for invoking a web service.
• xjc – Part of the Java API for XML Binding (JAXB) API. It accepts an XML schema and generates Java classes.

What is not there in the JDK

The most significant thing that is not available in the JDK is an editor. An editor is an application that is used to create and edit a text document, for example Notepad in Windows is an editor. An editor allows the user to type, edit or delete the text. Most editors also support basic functions like find, replace etc. If there is no editor available how would the user create a Java program ? The answer is by using any of your favorite editor. Sun Microsystem have left the selection of editor on the user. You can use any editor of your choice - you can use Notepad if you are Windows user or Vi if you are a Linux/Unix user - it's upto you. As long as you are saving the program using the '.java' extension the compiler won't mind which editor you have chosen.