"Web Development Learning note" STRUCTS2 Action Learning Notes (one)

1. Org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter Preparation and operation
2.

  <filter-mapping>      <filter-name>struts2</filter-name>      <url-pattern>/*</ Url-pattern>  </filter-mapping>

url-pattern contract cooked into only write * *, not required to write *.action
3.

<package name= "Default" namespace= "/" extends= "Struts-default" >     <action name= "Hello" >         < result>         /hello.jsp         </result>     </action>    <span style= "White-space:pre" > </span></package>

   Namespace= "/" and the access to the path meaning corresponding;
    /hello.action
    Interviewed for action. gave us the result of our result.
    The default action can be omitted.
4. Associated structs source code and Java docs
Jar file Right-click->properies->java Source Attachment
    Set source code
        D:/program Files/struts-2.1.6/src/core/src/main/java
    Javadoc documentation
        File:/d:/program files/struts-2.1.6/docs/struts2-core/apidocs/
    To set the XML hint:
        A) window–preferences– search Catalog–add

B) Select key type as URI

c) key:http://struts.apache.org/dtds/struts-2.0.dtd

d) Location: the corresponding DTD file. Located in the Struts-core package, unzip the open. Specify the appropriate location, such as D:/program files/struts-2.1.6 \LIB\STRUTS2-CORE-2.1.6\STRUTS-2.0.DTD
5. Structs Implementation Mechanism
Find the filter Dofilter method , WebApplication, Web. XML, URL---HTTP request, client--Tomacat-> ;

  <filter>  <filter-name>struts2</filter-name>  <filter-class> Org.apache.struts2.dispatcher.ng.filter.strutsprepareandexecutefilter</filter-class>  </filter>  <filter-mapping>  <filter-name>struts2</filter-name>  <url-pattern>/*</ Url-pattern>  </filter-mapping>

--Struct.xml to find the corresponding action, find the appropriate result, feedback result, request Forwad to the destination file

  <package name= "Default" namespace= "/" extends= "Struts-default" ><action name= "index" ><result>/ Index.jsp</result></action> </package>

6, namespace decided the action of the access path, the tacit feel "". Action that can receive the full path
Namespace can be written as/, or/xxx, or/xxx/yyy,
The corresponding action access path is/index.action,/xxx/index.action. or/xxx/yyy/index.action.
Namespace it is best to also use a module to name

   <constant name= "Struts.devmode" value= "true"/>    <package name= "front" extends= "Struts-default" Namespace= "/front" >        <action name= "index" >            <result>/Namespace.jsp</result>        < /action>    </package>         <package name= "main" extends= "Struts-default" namespace= "" >        < Action name= "index" >            <result>/Namespace.jsp</result>        </action>    </package >

Struct.xml Analysis
Package role: To avoid the name of action and conflict issues;
namespace= "/front", must start with a slash, namespace preferably also use a module to name;
not writing namespace, equivalent to Namespace = "", means that only the action is found and all is given to
namespace processing.
Process: First find the action under the corresponding path to match. If not, look for an action that namespace empty.
If the action is not found, an error will be given;
7, the return of the detailed view can be determined by the user-defined action;
The detailed method is to find the corresponding configuration item according to the returned string, to determine the content of the view;

<constant name= "Struts.devmode" value= "true"/><package name= "front" extends= "Struts-default" namespace= "/" ><action name= "index" class= "Com.struts2.front.action.Index" ><result name= "Success" >/ Actionintroduction.jsp</result></action> </package>

the implementation of the detailed action can be a common Java class. There is a public String execute method that can be implemented
Action interface;

    Package com.bjsxt.struts2.front.action;    Import com.opensymphony.xwork2.Action;    public class IndexAction1 implements Action {@Overridepublic String execute () {return "Success";}    }

    Configuration Analysis:
<class= "Com.bjsxt.struts2.front.action.Index" >
Struct.xml, find the appropriate class-a instantiation object-run the appropriate execute () method
Run the process:
Read XML---action is class, find class object (each visit must be a new object)
When class is not configured, the default class is Actionsupport.

Actionsupport Source code

   Public String Execute () throws Exception {        return SUCCESS;}

The most frequently used is inherited from Actionsupport. The advantage is the ability to directly use the Struts2 encapsulation method.

    Package com.struts2.front.action;    Import Com.opensymphony.xwork2.ActionSupport;    public class IndexAction2 extends Actionsupport {@Overridepublic String execute () {return ' success ';}    }

Reason: Actionsupport has encapsulated a lot of methods that can be called directly, and can be used directly in subclasses.

The above is based on the granite soldiers gathered from the teacher's tutorial.

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"Web Development Learning note" STRUCTS2 Action Learning Notes (one)