struts

struts1原理：

            Action相当于servlet的一部分，他的execute方法会被struts的入口程序ActionServlet调用。servlet是Struts的入口，任何以*.do结尾的URI 都会被映射到Struts的servlet上，这个servlet会根据Struts-config.xml里面的配置，将请求分配到指定的Action上（这里Struts是通过反射调用Action的）。

来看如下配置文件：

目录：struts-1.3.5-all\struts-1.3.5\apps\struts-blank-1.3.5\WEB-INF**********************以下代码是struts-config.xml****************************<?xml version="1.0" encoding="ISO-8859-1" ?><!DOCTYPE struts-config PUBLIC          "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"          "http://struts.apache.org/dtds/struts-config_1_3.dtd"><!--     This is a blank Struts configuration file with an example     welcome action/page and other commented sample elements.     Struts Validator is configured using the factory defaults     and is ready-to-use.     NOTE: If you have a generator tool to create the corresponding Java classes     for you, you could include the details in the "form-bean" declarations.     Otherwise, you would only define the "form-bean" element itself, with the     corresponding "name" and "type" attributes, as shown here.--><struts-config><!-- ================================================ Form Bean Definitions -->    <form-beans>    <!-- sample form bean descriptor for an ActionForm        <form-bean            name="inputForm"            type="app.InputForm"/>    end sample -->    <!-- sample form bean descriptor for a DynaActionForm        <form-bean            name="logonForm"            type="org.apache.struts.action.DynaActionForm">            <form-property                name="username"                type="java.lang.String"/>            <form-property                name="password"                type="java.lang.String"/>       </form-bean>    end sample -->    </form-beans><!-- ========================================= Global Exception Definitions -->    <global-exceptions>        <!-- sample exception handler        <exception            key="expired.password"            type="app.ExpiredPasswordException"            path="/changePassword.jsp"/>        end sample -->    </global-exceptions><!-- =========================================== Global Forward Definitions -->    <global-forwards>        <!-- Default forward to "Welcome" action -->        <!-- Demonstrates using index.jsp to forward -->        <forward            name="welcome"            path="/Welcome.do"/>    </global-forwards><!-- =========================================== Action Mapping Definitions -->    <action-mappings>            <!-- Default "Welcome" action -->            <!-- Forwards to Welcome.jsp -->        <action            path="/Welcome"            forward="/pages/Welcome.jsp"/>    <!-- sample input and input submit actions        <action            path="/Input"            type="org.apache.struts.actions.ForwardAction"            parameter="/pages/Input.jsp"/>        <action            path="/InputSubmit"            type="app.InputAction"            name="inputForm"            scope="request"            validate="true"            input="/pages/Input.jsp"/>            <action                path="/edit*"                type="app.Edit{1}Action"                name="inputForm"                scope="request"                validate="true"                input="/pages/Edit{1}.jsp"/>    end samples -->    </action-mappings><!-- ======================================== Message Resources Definitions -->    <message-resources parameter="MessageResources" /><!-- =============================================== Plug Ins Configuration -->  <!-- ======================================================= Tiles plugin -->  <!--     This plugin initialize Tiles definition factory. This later can takes some  parameters explained here after. The plugin first read parameters from  web.xml, thenoverload them with parameters defined here. All parameters  are optional.     The plugin should be declared in each struts-config file.       - definitions-config: (optional)            Specify configuration file names. There can be several comma      separated file names (default: ?? )       - moduleAware: (optional - struts1.1)            Specify if the Tiles definition factory is module aware. If true            (default), there will be one factory for each Struts module.   If false, there will be one common factory for all module. In this            later case, it is still needed to declare one plugin per module.            The factory will be initialized with parameters found in the first            initialized plugin (generally the one associated with the default            module).     true : One factory per module. (default)     false : one single shared factory for all modules    - definitions-parser-validate: (optional)         Specify if xml parser should validate the Tiles configuration file.     true : validate. DTD should be specified in file header (default)     false : no validation   Paths found in Tiles definitions are relative to the main context.      To use this plugin, download and add the Tiles jar to your WEB-INF/lib      directory then uncomment the plugin definition below.    <plug-in className="org.apache.struts.tiles.TilesPlugin" >      <set-property property="definitions-config"                       value="/WEB-INF/tiles-defs.xml" />      <set-property property="moduleAware" value="true" />    </plug-in>  -->   <!-- =================================================== Validator plugin -->  <plug-in className="org.apache.struts.validator.ValidatorPlugIn">    <set-property        property="pathnames"        value="/org/apache/struts/validator/validator-rules.xml,               /WEB-INF/validation.xml"/>  </plug-in></struts-config>  *************************以下代码是validation.xml***********************<?xml version="1.0" encoding="ISO-8859-1" ?><!DOCTYPE form-validation PUBLIC     "-//Apache Software Foundation//DTD Commons Validator Rules Configuration 1.3.0//EN"     "http://jakarta.apache.org/commons/dtds/validator_1_3_0.dtd"><form-validation><!--     This is a minimal Validator form file with a couple of examples.-->    <global>        <!-- An example global constant        <constant>            <constant-name>postalCode</constant-name>            <constant-value>^\d{5}\d*$</constant-value>        </constant>        end example-->    </global>    <formset>        <!-- An example form -->        <form name="logonForm">            <field                property="username"                depends="required">                    <arg key="logonForm.username"/>            </field>            <field                property="password"                depends="required,mask">                    <arg key="logonForm.password"/>                    <var>                        <var-name>mask</var-name>                        <var-value>^[0-9a-zA-Z]*$</var-value>                    </var>            </field>        </form>    </formset>    <!-- An example formset for another locale -->    <formset language="fr">        <constant>            <constant-name>postalCode</constant-name>            <constant-value>^[0-9a-zA-Z]*$</constant-value>        </constant>        <!-- An example form -->        <form name="logonForm">            <field                property="username"                depends="required">                    <arg key="logonForm.username"/>            </field>            <field                property="password"                depends="required,mask">                    <arg key="logonForm.password"/>                    <var>                        <var-name>mask</var-name>                        <var-value>^[0-9a-zA-Z]*$</var-value>                    </var>            </field>        </form>   </formset></form-validation> *************************以下代码是web.xml*************************<?xml version="1.0" encoding="ISO-8859-1"?>  <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app>  <display-name>Struts Blank Application</display-name>   <!-- Standard Action Servlet Configuration -->  <servlet>    <servlet-name>action</servlet-name>    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>    <init-param>      <param-name>config</param-name>      <param-value>/WEB-INF/struts-config.xml</param-value>    </init-param>    <load-on-startup>2</load-on-startup> </servlet>  <!-- Standard Action Servlet Mapping -->  <servlet-mapping>    <servlet-name>action</servlet-name>    <url-pattern>*.do</url-pattern>  </servlet-mapping>  <!-- The Usual Welcome File List -->  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>