In IntelliJ IDEA I get this warning message regarding the “@Autowired” field: “Field injection is not recommended”. Why?

Using SSH public key anthentication makes the SSH login process securer and easier, that you don’t need to remember the password.

From here.

It seems by default CentOS doesn’t allow network be accessed from outside. Here are the instructions how to make it work on CentOS 7. From here and here.

Today I got an error when running a Java application on a new CentOS server:

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SunCertPathBuilderException: unable to find valid certification path to requested target

Here is the solution.

From here and here.

When I’m writting an Spring Boot command line application and I find this issue. Here is how I solve it.

The question is straightforward. The solution is from here.

Recently I upgraded a computer from Ubuntu 16.04 to 18.04. Then I found when I closed the lid, the notebook computer would go to sleep. Here is the instructions from here how to disable the auto-sleep feature.