Today, my jsp project has an error. I checked it for a long time before I solved this error.The solution is as follows.
org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
Copy all the tld files from the META-INF directory in the jstl.jar package and put them into the WEB-INF under the jsp project.
You can create a tlds directory under WEB-INF/, put all the tld files into this directory, the directory name can be arbitrarily named