Introduction - If you have any usage issues, please Google them yourself
OGNL The expression is the object graphical navigation language. It's an open source project, and Struts2 uses default OGNL expression language to display data. The same function as the El expression in serlvet. The OGNL expression has the following features:
Support object method invocation, for example: objName.methodName ();
Supports static class method calls and value access. The format of the expression is
@[class name (including the road)]
@[method name | value name]
For example:
@java.lang.String@format ('foo%s','bar')
@tutorial.MyConstant@APP_NAME;
Support assignment operations and expressions in series, for example:
Price=100, discount=0.8, calculatePrice (), and this expression returns 80;
Access the OGNL context (OGNL context) and ActionContext
Operation collection object