Java-based JDK installation and configuration

Configuring Environment Variables Noun description

??? Path: Search through the path system for executable Java files.

??? installation directory for JAVA_HOME:JDK

??? Classpath: Loading Directory

Why do I need to configure path and when do I need classpath?

??? Path

??????? The system variable path tells the system where the executable file is located, and when an executable file is found, it is first searched from the current directory, if not found

??? It will go to the path of the path set to find, and then execute.

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??? Classpath

??????? is to tell the JVM where the class file is to be used or executed, and when the class file is placed on a different path, if the class file is used or executed in the current directory.

You need to set the classpath path to tell the location where the file exists.

JDK and JRE and JVM

??? Jdk:java Development Kit, the abbreviation for Java Development Kit

??? Jre:java operating environment, is the abbreviation of Java Runtime Environment

Jvm:java virtual machine, the abbreviation for Ava Vsan

The JDK installation configuration environment variable is detailed:

??? First, double-click the JDK installation package to go to the installation Wizard

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??? Step two, Next, change the installation path, select Install all components

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??? Part III, change to D:\jdk.1.7.0_07\

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??? Fourth step, click OK

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??? Fifth step, Next, start the installation

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???? Sixth step, install JRE, this step can choose not to install because the JDK is installed, there is no need to install a separate JRE

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??? Seventh step, complete the installation, then enter the configuration link

Right-click My Computer, select Properties

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??? Eighth step, select Advanced system settings

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??? Nineth step, select environment variables

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??? Tenth step, under User variables, select New

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??? 11th step, enter Java_home, variable value for JDK installation directory

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??? 12th Step, create a new path with a value of%java_home%\bin

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???? 13th step, create a new classpath with a value of.; %java_home%\lib;

??? The 14th step, the environment variable configuration is complete. Enter Javac under DOC and the following interface appears to indicate the success of the configuration.

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Java program run process

??? 1. Compile Javac: Compile the Java source file into a class byte-code file

??? 2. Run Java: Run the class file

Java-based JDK installation and configuration