What is JDK (Java Development Kit)

JDK (Java Development Kit)
As the name suggests, JDK is required for java development.
You need to have JDK in your system for >
  • developing,
  • compiling and
  • running Java programs.
In short  JDK = JRE + JVM.

JDK diagram >

More about JDK >
  • Java Compiler - Java compiler is javac tool located in /bin folder of the directory in which JDK is installed. The javac compiles .java file into .class (bytecode) files.
    • There are 2 ways of using javac command >
      • For compiling one file
      • For compiling more than one files >
Enter name of all java files in a file (separated by blank or line breaks(next line) ).  Then enter javac @ fileName
Example -
Let’s say we have three java files  

Enter name of  name of all java files in a MyFile separated by blank.

E:\MyFile will look like this >
E:\MyClass1.java  E:\MyClass2.java  E:\MyClass3.java


E:\>javac @MyFile


  • Java Disassembler - javap command disassembles class files. output depends on option used with command.
If no option is used than, javap prints out
  • package,
  • protected and public fields/methods of the classes passed to it.

  • Java Documentation - javadoc contains information about class and methods.

  • Java Debugger -  jdb is debugger for Java classes.

Read :

JDK (Java Development Kit), JRE (Java Runtime environment), JVM (java virtual machine), Differences between JDK, JRE and JVM, OpenJDK, JIT Compiler (Just In Time Compiler) internal working

Must read for you :