I. About Download and manner:
1. Baidu search JDK, to enter download the official website, specifically at the following address:
https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
2. Your choice of different computer systems based on the corresponding download, of course, first you have to click Accept License Agreement agree to be!
3. After the download is complete, click Install
Second, with regard to the installation process:
1. Select the installation path, note that the path must not include Chinese name
Here we can select the directory you want to install by "Change", and then click Next to.
Here we just installed jdk, the installation wizard will check your jre is not installed, then prompts you to install jre, it would be best fitted.
2. Install JRE
Select a folder you like, do not pay attention to this folder is jdk installation directory, otherwise it will overwrite the jre directory in the directory jdk
Here we select and install the JDK directory at the same level, then click Next to complete the installation, then you have successfully installed
3. To verify that you have properly installed, press window + R or click run type cmd, open a command line window, type java -version in the interface, that is if the following text appears correctly show download
III. About Environment Configuration
1. My Computer → Right → Properties → Advanced System Settings → Environment Variables
Create a new variable named "JAVA_HOME" system variable, the variable value "C: \ Program Files \ Java \ jdk1.8.0_161" (jdk installation directory, personal directory modification installed in accordance)
2. then create a new variable named "CLASSPATH", variable value ";.% JAVA_HOME% \ lib \ dt.jar;% JAVA_HOME% \ lib \ tools.jar;" system variables, and pay attention to the front of the dot points some numbers are
3. Open the "Path" System Variables, click New, add "% JAVA_HOME% \ bin" and "% JAVA_HOME% \ jre \ bin" two system variables. Path java command so that the system can recognize at any path
Four verification:
点击保存后，按window+R或者点击运行输入cmd，打开命令行窗口
分别输入java和javac都正常运行即代表java已经正确安装。
如果出现类似"javac不是内部或外部命令"等提示语句，请再三检查你的环境变量是否正确配置，或者JDK和JRE安装目录是否重复，如果重复，可以选择再次运行下载的jdk安装程序重新安装。
