splacentino · September 15, 2024 15:11 · minhphong306 · Jul 16, 2018 · zurakin · May 31, 2022
diff --git a/jsp cheat sheet b/jsp cheat sheet
 # Java expression evaluated at run time. 

 ## Prototype 

 ```jsp
 <%=     %>
 ```

 ## Example

 ```jsp
 Current date : <%= new java.util.Date() %>
 ```

 # Scriptlets

 ## Prototype 

 ```jsp
 <%      %>
 ```

 ## Example

 ```jsp
 <%
     System.out.println("Write in console log");
     out.println("write in : javax.servlet.jsp.JspWriter \"out \" variable <br>");
     java.util.Date date = new java.util.Date();
 %>

 <%
    if ( hello ) {
        %>
        <P>Hello, world at : <%= date %>
        <%
    } else {
        %>
        <P>Goodbye, world at : <%= date %>
        <%
    }
 %>
 ```

 # Directives

 ## Prototype 

 ```jsp
 <%@     %>
 ```

 ## Example with a "page directive"

 **Java library includes**

 ```jsp

 <%@ page import="java.util.Date, java.util.ArrayList" %>

 Current date : <%= new Date() %>
 ```

 ## Example with a "include directive"

 **Physically include the contents of another file, HTML or JSP**

 ```jsp
 <html>
        <body>
                include other.jsp...<BR>
                <%@ include file="other.jsp" %>
        </body>
 </html>
 ```

 # Declarations

 **You can also add variable and method declarations to this class.  You can then use these variables and methods from your scriptlets and expressions.**

 ## Prototype 

 ```jsp
 <%!     %>
 ```

 ## Example

 **The date will be the same, no matter how often you reload the page.  This is because these are declarations, and will only be evaluated once when the page is loaded**

 ```jsp
 <%!
    Date theDate = new Date();
    Date getDate()
    {
        System.out.println( "In getDate() method" );
        return theDate;
    }
 %>
 Hello!  The time is now <%= getDate() %>
 ```

 # Tags

 ## Prototype

 ```jsp
 <some:tag>
 body
 </some:tag>
 ```

 If the tag does not require a body, the start and end can be conveniently merged together, as

 ```jsp
 <some:tag/>
 ```

 ## Example
	# Java expression evaluated at run time.

	## Prototype

	```jsp
	<%= %>
	```

	## Example

	```jsp
	Current date : <%= new java.util.Date() %>
	```

	# Scriptlets

	## Prototype

	```jsp
	<% %>
	```

	## Example

	```jsp
	<%
	System.out.println("Write in console log");
	out.println("write in : javax.servlet.jsp.JspWriter \"out \" variable <br>");
	java.util.Date date = new java.util.Date();
	%>

	<%
	if ( hello ) {
	%>
	<P>Hello, world at : <%= date %>
	<%
	} else {
	%>
	<P>Goodbye, world at : <%= date %>
	<%
	}
	%>
	```

	# Directives

	## Prototype

	```jsp
	<%@ %>
	```

	## Example with a "page directive"

	Java library includes

	```jsp

	<%@ page import="java.util.Date, java.util.ArrayList" %>

	Current date : <%= new Date() %>
	```

	## Example with a "include directive"

	Physically include the contents of another file, HTML or JSP

	```jsp
	<html>
	<body>
	include other.jsp...<BR>
	<%@ include file="other.jsp" %>
	</body>
	</html>
	```

	# Declarations

	You can also add variable and method declarations to this class. You can then use these variables and methods from your scriptlets and expressions.

	## Prototype

	```jsp
	<%! %>
	```

	## Example

	The date will be the same, no matter how often you reload the page. This is because these are declarations, and will only be evaluated once when the page is loaded

	```jsp
	<%!
	Date theDate = new Date();
	Date getDate()
	{
	System.out.println( "In getDate() method" );
	return theDate;
	}
	%>
	Hello! The time is now <%= getDate() %>
	```

	# Tags

	## Prototype

	```jsp
	<some:tag>
	body
	</some:tag>
	```

	If the tag does not require a body, the start and end can be conveniently merged together, as

	```jsp
	<some:tag/>
	```

	## Example