JDK version switching in eclipse

This article applies to the server JDK version is too low, the development of the JDK version selected too high resolution.

Right-click Project propeties---project facets

Changes to the JDK version are complete, but there may be an error, the project name is preceded by an error x, but there is no indication of the specific error, the reason is

No JREs in workspace compatible with specified execution environment:javase-1.6

The execution environment specified in the workspace is compatible without jre:javase-1.6

This means that there is no 1.6 version of the JDK environment in your eclipse, and you need to add it manually

After installing the appropriate JDK version, click Windows---Preference

Add by clicking Add

Click Next > Proceed to the next step

Find the directory you want to change the version of the JDK to add

Select the JDK version you just added click OK to finish

It turns out that the wrong little red X is missing and your JDK version changes accordingly.

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