Java Development Kit (JDK) is a bundle of software components that is used to develop Java based applications. JDK is an implemen...
August 06, 2017
- Java Development Kit (JDK) is a bundle of software components that is used to develop Java based applications.
- JDK is an implementation of either of Java SE, Java EE or Java ME. Usually, learners start from JDK implementation of Java SE to learn core Java features, which is also known as Java SDK.
- JDK includes the JRE, set of API classes, Java compiler, Webstart and additional files needed to write Java applets and applications.
- JDK stands for Java Development Kit. It’s a superset of JRE. The JDK includes the JRE plus command-line development tools such as compilers (javac) and debuggers (jdb) and others (jar, javadoc, etc) that are necessary or useful for developing applets and applications.
- Therefore, as a Java programmer, you have to install JDK as a minimum requirement for the development environment.
- To summary:
- JVM: is the virtual machine that runs Java applications. The JVM makes Java platform-independence.
- JRE = JVM + standard libraries: provides environment for executing Java applications.
- JDK = JRE + development tools for compiling and debugging Java applications.
- The following picture depicts the relationship among JVM, JRE and JDK:
- And here are some tips:
- You should have both JRE and JDK installations (setup) on your computer. You will need both during the development process.
- You should have multiple versions of JDK and JRE installed: 1.5, 1.6, 1.7 and 1.8 for different testing purposes in the future.
- You should install both 32-bit and 64-bit versions.
- When installing the JDK, remember to check ‘Install Demos and Samples’. Then you can explore various interesting examples in the demo directory under JDK’s installation path.
- Only the JDK includes source code of the Java runtime libraries. You can discover the source code in the src.zip file which can be found under JDK’s installation directory.
Java Development Kit is a bundle of the following software components that are needed to develop Java based applications :
- Java Compiler: Java compiler is javac tool located in /bin folder of the JDK installation directory.
- Java Interpreter: Java interpreter is used to interpret the .class Java files that have been compiled by Java compiler (javac). Java interpreter is accessed using java command.
- Java Disassembler: The javap command is the disassembly tool of JDK that disassembles one or more class files. Its output depends on the options used.
- Java Header File Generator: Java Header File Generator (javah command-line tool) generates C header and source files that are needed to implement native methods.
- Java Documentation: Java Documentation helps to maintain code.
- Java Debugger: The Java Debugger, jdb, is a simple command-line debugger for Java classes.
- Java Applet Viewer: This is used to view the Java applets.
