The first step: SpringToolSuite4"->"preferences", the preferences setting window pops up.
Step 2: Find Java in preferences, expand the list "Editor" -> "Content Assist" in turn, click Content Assist, find the Auto activation column at the bottom of the setting window, and set the code prompt character.
.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
Step 3:
Find XML in preferences, expand the list "XML Files"->"Editor"->"Content Assist" in turn, click Content Assist, find the Auto activation column at the top of the setting window, and perform code prompt delay and code Prompt character set. Paste the following string of letters into it:
<=:abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
