Three ways to embed Java code in a JSP

1. Expression labels

   <%=%> display function label

   Function: Evaluates the value of an expression, such as the return value of:<%=1+1%>; in a page display expression

   Note: There is no semicolon in <%=%>

2. Declarative labels

   <%! %>

   Function: Declare variables and functions that can be called by Java code. For example <%! String a= "Hello world!"%>

   Note: 1.<%! Semicolons can appear in%>

   2. Statement script can be placed above or below the page

   3. It is not recommended to declare variables in the declaration script, which can cause thread insecurity

3. Normal script

   <%%>

   Function: In addition to declaring functions, other Java code can be placed in the script. More for declaring variables and controlling process code

   
   

Three ways to embed Java code in a JSP