Tonight we held the class meeting for the new semester. In the video, I saw many familiar faces. After not seeing each other for two months, everyone had gained quite a bit of weight. After all, due to the pandemic, we had been staying at home eating, drinking, and having fun, with less exercise. Teacher Xiaofei told us a lot about online live-streamed classes. Starting tomorrow, the school will organize training on how to use and study online courses, and formal online teaching according to the timetable will begin the week after next.

The main professional courses next semester will be programming and web design. The content will probably cover C language and HTML + CSS. Teacher Xiaofei also mentioned Java, so next I need to configure the environment required for Java development on my little laptop—that is, the JDK.

Installation

Download the JDK

JDK download page

First, find the JDK download page on the Oracle official website: https://www.oracle.com/java/technologies/javase-downloads.html.

You can see several JDK versions: Java SE 13, Java SE 11, and Java SE 8u241.

JDK 11 is maintained long-term as an LTS version and should currently be the one most commonly used by developers. Many Java tutorials online are also based on JDK 11 or JDK 8. But I like to keep up with the times, so I chose JDK 13. If I run into problems later, I’ll tackle them one by one, right?

JDK download options

On the JDK download page, download the Windows x64 Compressed Archive version. Why not download the Windows x64 Installer? Because whenever a portable version of a program is available, I never use the installer, keeping the system clean and simple.

Extract

Extracting the JDK

Extract the downloaded jdk-13.0.2_windows-x64_bin.zip, then move it to the Java directory on the D drive. Keep the JDK directory name with its version number for easier management.

Generate the JRE

Generating the JRE

The currently installed Java version is jdk-13.0.2. As you can see, there is no jre folder (there has been no jre folder since JDK 11). It can be generated using the following command:

bin\jlink.exe --module-path jmods --add-modules java.desktop --output jre

Navigate to the JDK root directory in cmd and run the above command to generate the jre folder.

JRE directory

If the jre directory appears, everything is fine.

Configuration

After installing the JDK, you also need to configure the system environment variables. They are:

变量名：JAVA_HOME
变量值：D:\Java\jdk-13.0.2

变量名：Path
变量值：%JAVA_HOME%\bin; %JAVA_HOME%\jre\bin

Right-click This PC to open System Properties, then select Advanced system settings -> Environment Variables in sequence to open the system environment variable settings interface. Then add the three variables to the system variables.

Environment variable settings

Be careful to create two entries for Path.

Path settings

Check

Open cmd and enter java -version and javac -version to check whether the JDK environment was installed successfully.

Checking the JDK

OK, no other problems. Tomorrow I’ll come back and write about how to install IDEA from JetBrains.