These kinds of problems often occur when Eclipse imports projects, and they are solved by Baidu each time, which is convenient for later search and reprinted to their own blog.
Thank you for sharing. Reprint https://blog.csdn.net/luoxia0805/article/details/37969357
1. Some projects cannot be imported because they already exist in the workspace错误解决方案
This error occurs when you go to the workspace to create/import this project, but then delete it [Note: You did not check "Delete project contents on disk(cannot be undone)" when deleting, so even if you delete the project in MyEclipse project, the project is still on your hard drive ]
Solution:
Import files into MyEclipse space steps: left workspace---right click---Import command---General---Existing Projects into Workspace The following dialog box will pop up:
Select the path on the hard disk where you want to import the project, and then make sure that the project is "Copy projects into workspace" [copy a copy to your workspace], and finally click Refresh-------------ok , you can import without the " Some projects cannot be imported because they already exist in the workspace" error
2. After the project is imported, a red exclamation mark will generally appear on the project file due to the lack of related jar packages . At this time, you right-click the imported project file---Build Path---Configure Build Path [Configure your missing jar package] ,As shown below:
The box under Libraries will show the jar package you are missing [there is a red cross on the missing jar package], you can find/download it locally or from the Internet according to the name that appears, click the Add External JARs command to add it, and then add Click the Remove command to delete the information of the missing jar package marked with a red cross and it will be OK.
The project is imported successfully, and the project jar package is configured. Next, you can start the application server and deploy the project.
3. Sometimes in the imported project, there will be a red cross on the related js file, resulting in a red cross on the project.
As shown below:
Error due to js file detection authentication:
Just right-click on the corresponding js file---MyEclipse command---click Exclude from Validation to change it from selected state to unselected state---click Run Validation to validate---click Exclude from Validation again to change In this way, the red cross of the js file will disappear, and the red cross of the project will also disappear.