DWR (1)

 

<Init-param>

<Param-Name> debug </param-Name>

<Param-value> true </param-value>

</Init-param>

Resolution: <init-param>

Parameters in the servlet range can only be obtained in the servlet Init () method. The configuration in Web. XML is as follows:

<Servlet>

<Servlet-Name> mainservlet </servlet-Name>

<Servlet-class> com. Wes. Controller. mainservlet </servlet-class>

<Init-param>

<Param-Name> param1 </param-Name>

<Param-value> avalible in servlet Init () </param-value>

</Init-param>

<Load-on-startup> 0 </load-on-startup>

</Servlet>

In servlet, you can use the following code:

Package com. Wes. Controller;

IMPORT javax. servlet. servletexception;

IMPORT javax. servlet. http. httpservlet;

Public class mainservlet extends httpservlet ...{

 

Public mainservlet ()...{

Super ();

}

Public void Init () throws servletexception ...{

System. Out. println ("the following two parameters param1 are stored in servlet ");
System. Out. println (this. getinitparameter ("param1 "));

System. Out. println ("the following parameters are stored in servletcontext ");
System. Out. println (getservletcontext (). getinitparameter ("context/Param "));

}

}

Parameters can only be obtained through this. getinitparameter ("param1") in the servlet Init () method.

----------------------------------------------------------------------------

<URL-pattern>/DWR/* </url-pattern>

Resolution: It indicates that all files containing the WDR name when the project is started will be called here.

----------------------------------------------------------------------------

<Create javascript = "hello" creator = "new">
<Param name = "class" value = "com. Yinhe. Service. hellodwr"> </param>

 

Parse: javascript = "hello" Name the hellowdr class "hello" in JavaScript to call the data in the hellowdr class.

Creator = "new" is created in the form of new

----------------------------------------------------------------------------

<SCRIPT type ='Text/JavaScript'Src ='/DWR/engine. js'> </SCRIPT>

<SCRIPT type ='Text/JavaScript'Src ='/DWR/interface/Hello. js'> </SCRIPT>

<SCRIPT type ='Text/JavaScript'Src ='/DWR/util. js'> </SCRIPT>

Resolution: The three items are directly copied to the JSP file displayed on the successfully tested page.

----------------------------------------------------------------------------

Hello. gethello (username, callback );

The Hello. gethello parameter in JS has an additional callback parameter used to return data.

 

Note: prompts in JS to call the methods in the hellowdr class are not prompted by callback.

Write by yourself