The solution of java:unresolved compilation problem

To see the literal meaning of this exception is the unresolved compilation problem, but there may be many reasons for this problem.

Today, this problem is due to the fact that a new project has just been checked out and the project was built with a few details that caused the error.

1, your server's runtime environment may have specified Tomcat, but right-click the Java build of your project Properties option Tomcat in the Libraries tab in path may still be unbound state, and you will have this exception.

2. The compiler version of your project is lower than the version of the running Environment JRE, which can also cause this exception.

The information I found on the internet said that there was also a problem with the jar package when using the Maven tool, but I didn't use MAVEN, so it's not clear that the two situations are known.

The solution of java:unresolved compilation problem