1. JAVA Introduction

Java is the general term for the Java object-oriented programming language and the Java platform launched by Sun Microsystems in May 1995. Developed by James Gosling and colleagues, and officially launched in 1995.

Later, Sun was acquired by Oracle (Oracle), and Java also became a product of Oracle.

Java is divided into three systems:

JavaSE (J2SE) (Java2 Platform Standard Edition, java platform Standard Edition)
JavaEE (J2EE) (Java 2 Platform, Enterprise Edition, java platform Enterprise Edition)
JavaME (J2ME) (Java 2 Platform Micro Edition, java platform Micro Edition).
In June 2005, the JavaOne conference was held, and SUN released Java SE 6. By this time, the various versions of Java had been renamed to remove the number "2": J2EE became Java EE, J2SE became Java SE, and J2ME became Java ME.

Two, JAVA download

If you have a specified version requirement, you can go to the official website to download it. If you don’t have a specified version requirement, you can go to Baidu Netdisk to download the installation package directly.

Baidu network disk download: https://pan.baidu.com/s/1Ll-cZjvZRDrTSdlesXdxJg

Extraction code: 1111

Official website download: https://www.oracle.com/java/technologies/javase/javase8u211-later-archive-downloads.html

Here the wooden man demonstrates to everyone that it was downloaded from Baidu Netdisk . After the download is complete, it can be directly decompressed to the corresponding location.

Three, JAVA installation

1. Open the folder

2. Double click to open

3. Double-click the exe file

4. Double-click the exe file to start the installation

5. Go directly to the next step

6. Here, you can change the path by yourself. The wooden man will not change it here. It is not recommended to modify it here . After you are done, go to the next step

Note: If you have installed JAVA before, you can directly overwrite it. You don’t need to delete and uninstall it separately.

7. Click OK

8 Click Next

9. Installing

Just close it here

10. At this point, JAVA is installed. If you have configured the JAVA environment before, you can directly verify it without configuring the environment.

4. Configuration environment

1. Find the installation path we just installed

2. Double-click the JDK copy path

3. Right-click This PC, click Properties

4. Click Advanced System Settings - Environment Variables - New

5. Variable name: JAVA_HOME , variable value: C:\Program Files\Java\jdk1.8.0_201, click OK;

6. Double-click the jre copy path

7. Continue to build

8. Find the variable name: CLASSPATH , variable value: .;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar;, notice that there is a . in front of the variable value , click OK;