About the JSP syntax of the small tip__js

Declaring an expression <%! in a JSP int a = 3; Global variables are defined in the%>.


<% int b = 3 in the JSP script segment; The variable declared by%> is a local variable.


The servlet is a single example. So the variables defined by declaring an expression have only one copy and are shared by the user client.


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When using the JSP's <%@ include file= "*.jsp"%> the statement containing the other page;
Cannot include in the included page:
<%
String path = Request.getcontextpath ();
String basepath = request.getscheme () + "://"
+ request.getservername () + ":" + request.getserverport ()
+ path + "/";
%>

This java script segment. Otherwise it will fail.

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<jsp:forward > For a page to turn, the statements after that statement are not executed.


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<jsp:include > can also pass parameters to the included page when it is included. And <%@ include file= ""%> this thing is not to be done.



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The Request.getparameter () method and the Request.getattrbute () method are not the same. The data for the GetParameter () method is taken from the client, and
The data for getattribute () is set up on the server side itself. The setattribute () method generally appears in pairs with the GetAttribute () method.