org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating SpringEL expression解决方案

查看thymeleaf标签是不是没有接收到后台传递过来的值

Caused by: org.springframework.expression.spel.SpelevaluationException: EL1007E: Property or field 'headerUrl' cannot be found on null
	at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:213) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:104) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.springframework.expression.spel.ast.PropertyOrFieldReference.access$000(PropertyOrFieldReference.java:51) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.springframework.expression.spel.ast.PropertyOrFieldReference$AccessorLValue.getValue(PropertyOrFieldReference.java:406) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.springframework.expression.spel.ast.Compoundexpression.getValueInternal(Compoundexpression.java:92) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:112) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.springframework.expression.spel.standard.Spelexpression.getValue(Spelexpression.java:337) ~[spring-expression-5.3.14.jar:5.3.14]
	at org.thymeleaf.spring5.expression.SPELVariableexpressionevaluator.evaluate(SPELVariableexpressionevaluator.java:265) ~[thymeleaf-spring5-3.0.14.RELEASE.jar:3.0.14.RELEASE]
	... 64 common frames omitted

传过来的值错误，前端获取不到，改为UserId类型，解决。