JDK stands for Java SE Development Kit, that is the standard Java Development Kit is provided by Sun for the development of a set of Java application development package, which provides a compilation, run Java access a variety of tools and resources, including ava compilers, Java runtime environment and Java class libraries commonly used.
Here also involves a concept: Java Runtime Environment, which already stands for Java Runntime Environment ,, it is also known JRE, which is a necessary condition for running Java queries.
1.JRE relations and the JVM
JVM is a core Java virtual machine to run the program, and run Java programs need not only the core virtual machines, but also other class loader, bytecode verifier, and a lot of basic libraries. In addition to JRE included JVM, also contains other environmental support to run Java programs.
2.JDK relations and the JRE
If you need to install the Java program, you should choose to install JDK; of course after JDK installed, contains the JRE, you can also run Java programs.
However, if only to run Java programs, you need to install the JRE on a computer, install only the JVM is not enough. In fact, that is, the JRE download available on Oracle's website, it does not provide a separate JVM download.
JDK, JVM, JRE relationship diagram, shown in FIG.
3.JDK installation path folder description
(. 1) bin: this stored path of the JDK command tools, commonly javac, java, etc. stored in the command path. Jdk path in the bin, do "javac A.java", the Java source files A compiled into bytecode file that A.class, then execute "javaA" Run A. Note: The parameters of the command java is the Java class name, rather than byte code file name, not the Java source file name.
(2) db: This path is the path to install Java database.
(3) the include: - some platform-specific header file.
(4) jre: run Java programs necessary for the JRE.
(5) lib: to hold the actual execution of the program JDK tool orders. For java.exe command compiles Java programs used, is written in Java, Main class in this class is the next libo path tools.jar file sun toolsVjavac path. Javac.exe command of JDK bin path is merely wraps the Java class. Not only that, most of the commands in the bin paths are packed tools tools.jar files.
(6) javaf-src.zip: The compressed file is stored in JavaFX all the core class library source code.
(7) src.zip: The compressed file is stored in all the core Java class library source code.
(8) README and LICENSE: descriptive documents.
