When you frequently import Web projects in Eclipse, there is a problem with the project type that is not going to be imported, which is a Java project.
Steps to resolve:
1, enter the project directory, you can see the. project file, open.
2. Find the <natures>...</natures> code snippet.
3, in the 2nd step of the code snippet, add the following label content and save:
<nature>org.eclipse.wst.common.project.facet.core.nature</nature>
<nature>org.eclipse.wst.common.modulecore.ModuleCoreNature</nature>
<nature>org.eclipse.jem.workbench.JavaEMFNature</nature>
4. Right-click on the Eclipse project to refresh the project.
5, right-click on the project, enter the property (properties)
6. Click on "Project Facets" in the list item on the left, select "Dynamic Web Module" and "Java" on the right, click OK to save.
How eclipse turns a Java project into a Web project