After the code pulled from svn yesterday was imported into the local myeclipse, some code errors were reported. It turned out that the error was caused by the lack of jar packages or the inconsistency between the jdk version of others and the jdk version you installed.
1：window---->preferences------>tomcat---->jdk
Specify jdk.
2: build path ---->add libraries ----> jre system library ----> next ---->alternate jre Select the corresponding jdk.