For help, thymeleaf decide questions of null objects-CodePudding

 & lt; The label & gt; The teacher & lt;/label> 
Th: text="${I} + '& lt; Br> '" & gt;

If pass the background is an empty object to do ah, such complains, always can not find a solution,
Under Caused by: org. Attoparser. ParseException: Exception evaluating SpringEL expression: "course. Head" (the template: "index" - the line 126, col 19)
The at org. Attoparser. MarkupParser. ParseDocument (MarkupParser. Java: 393) ~ [attoparser - 2.0.4. RELEASE. Jar: 2.0.4. RELEASE]
The at org. Attoparser. MarkupParser. Parse (MarkupParser. Java: 257) ~ [attoparser - 2.0.4. RELEASE. Jar: 2.0.4. RELEASE]
The at org. Thymeleaf. Templateparser. Markup. AbstractMarkupTemplateParser. Parse (AbstractMarkupTemplateParser. Java: 230) ~ [thymeleaf - 3.0.9. RELEASE. Jar: 3.0.9. RELEASE]
. 52 common frames omitted

CodePudding user response:

Th: text="${I} + '& lt; Br> '" & gt;

Empty is false

CodePudding user response:

Think of some way to don't let the course is empty.
For example: write 0 or 1

CodePudding user response:

Add a judgment of bai:

 
Th: text="${I} + '& lt; Br> '" & gt;

CodePudding user response:

 & lt; Span th: each="I: ${course? The head} 
"Th: text="${I} + '& lt; Br> '" & gt;

To need to add a question mark can determine object!

CodePudding user response:

This kind of writing is the most convenient, thank you