Detailed tutorial on jdk installation and environment variable configuration under Win10

Preface

Why did I write this article? Because I don’t want to search other people’s articles on Baidu anymore, so I wrote one myself as a record.

1. Preparation

JDK8 download address

JDK8 download address 2

Since some readers said that Oracle requires an account to download, and you don’t want to go through the trouble of registering another one, you can download it through download address 2.

A JDK installer, this is version 1.8, because the new JDK version does not have any big highlights, as shown below,

2. Installation

Double-click the mouse to run.

Select "Yes", and then the following figure:

Click Next:

I am not going to modify the JDK installation path here, so there is no need to change it, click Next:

During the installation process, a JRE installation prompt box will pop up, as shown below:

No changes are needed here, click Next, and you will see this:

Since you are bored anyway, why not tell me the meaning of this graph? Java has become the driver for 300 million people. Java belongs to ORACLE. Friends who work in the background here should know this better. The new features of Java8 have also made the subsequent JDK replacement of Java dim, so now 90% of developers still choose Java8, and no one is interested in the latest Java14, mainly because of the stability of Java8. Another point is that Java's future JDK may not be open source, which means that no matter what tricks they do in the future, people who have used previous Java versions will be caught off guard. At this time, Google, the old fox, is very cunning and uses a new language. As a result, the preferred language of the Android Studio compiler will become Kotlin instead of Java. This can be regarded as a precautionary measure. After reading this, the installation should have been completed.

The installation is now complete, click "Close", and then configure the environment variables.

3. Configure environment variables

Right click "This PC" and select Properties. A pop-up window will appear. Click "Advanced System Settings"

As shown below:

Click "Environment Variables" and you will see a screen like this:

The key is the following content, user variables can be ignored:

Now you have completed all the preparation steps, the next step is to configure the environment:

1. Click "New" and a pop-up window will appear:

Variable Name: JAVA_HOME

Variable value: C:\Program Files\Java\jdk1.8.0_162 ( JDK installation path, here is based on your own installation path )

After the input is completed, click Confirm. The first configuration is completed. Next, proceed to the second step.

2. Create a new CLASSPATH variable

Create a new CLASSPATH variable with the following value:

.;%JAVA_HOME%\lib;%JAVA_HOME%\lib\tools.jar ( Note that there is a dot in front. ), after configuration, it will be as shown below, you can copy and paste it here.

Then click OK to save the variables and proceed to step 3

3. Configure the path, find the path, double-click or click Edit

Then you can see that there is already a lot of content in the path. Let's create a new one at the end:

Enter %JAVA_HOME%\bin

Then click OK to save, click OK again after exiting, and then click OK again. At this point, the environment variables are configured. The next step is to test whether there are any problems with the environment variables configuration.

4. Verify environment variable configuration

Press the shortcut key "win + R" to open the run window, enter cmd, and click OK to open the command line window.

① Java verification

Type java and press Enter to execute.

② Javac verification

Type javac and press Enter to execute

At this step, many people will see "javac不是內部或外部命令,也不是可運行的程序。 Later, I checked my environment variables and entered the java, javac, and java -version commands one by one, and they were all normal. Then a reader said that part of the Path content in my system variables was missing, so I compared the content of other people's blogs and found that I was indeed missing a part, but I ran javac normally.

If you find that javac does not work after configuration, add another item %JAVA_HOME%\jre\bin to Path

Then click OK. Try javac again to see if it works.

In fact, for me, it is normal to increase this variable or not, but readers who have problems javac can give it a try, maybe it will work? This discovery came from a reader who posted a long comment. Thank you.

Of course, some friends also performed the above operations and still failed to enter javac . I was shocked. However, some enthusiastic readers found a successful method after going through the above operations. I will also make a record here, because maybe you can do it. That is to change the content in Path . First, let's look at the content of my current Path :

You will find that there is a %JAVA_HOME% here, this value is the installation path of the JDK configured previously.

This is the path, so the way to modify it is to change the above reference path to the full path.

%JAVA_HOME%\bin

%JAVA_HOME%\jre\bin

I am now安裝路徑D:\Program Files\Java\jdk1.8.0_162 , so change it to the following

D:\Program Files\Java\jdk1.8.0_162\bin

D:\Program Files\Java\jdk1.8.0_162\jre\bin

Then save and confirm, then open cmd and enter javac to try:

Can. Here I am just recording the solution. If you still can't solve it, don't panic, keep looking, and record the process after solving it. You can also tell me and I will add it to the article.

③ java -version verification

Then enter java -version and press Enter to execute. ( Note that there is a space in the middle of java -version. I have seen too many failures due to careless omission of a space. Remember, remember, remember. ）

At this point, the environment variables have been configured. If you are using the win7 operating system, the third step needs to be slightly modified.

QA: Some people cannot use commands completely to get corresponding results after installing JDK. First, check whether the command is entered incorrectly, such as Chinese and English status, and spaces. If javac does not respond or prompts that it is not an internal or external command, check whether the installed files are complete and check whether there are jdk and jre in the installation folder.

If you have checked that there are no problems with the installation file, try restarting. Environment variables may take effect differently on different computers. This method comes from the comments. There is no harm in trying it.

This concludes this article on the detailed tutorial on jdk installation and environment variable configuration under Win10. I hope it will be helpful for everyone’s study, and I also hope that everyone will support 123WORDPRESS.COM.