java - 如何使用注释将 struts2 Action 的实例化委托(delegate)给 spring

Question

您好，我有一个 Struts2 应用程序，其中在 struts.xml 文件中定义了 struts 操作。现在，我想将其委托(delegate)给 Spring，以便在 session 范围内执行操作。

• 案例 1:如果我使用注释 @Repository("myAction")，我总是会收到错误消息:无法实例化 Action，myAction，在命名空间 /omb doAction

中为 doAction 定义

• 情况 2:如果我使用 applicationContext.xml，我在 myService.callMethode(); 上有一个 NullPointerException/p>

如何使用注释来做到这一点？因为重新定义applicationContext.xml

中的所有服务会太长

struts.xml:

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
    <constant name="struts.devMode" value="false" />
    <constant name="struts.action.extension" value="do" />
    <constant name="struts.custom.i18n.resources" value="com.omb.i18n.StrutsResourceBundle" />
    <constant name="struts.objectFactory" value="org.apache.struts2.spring.StrutsSpringObjectFactory" /> 
    <constant name="struts.objectFactory.spring.autoWire" value="name" />
    <constant name="struts.i18n.encoding" value="ISO-8859-1" />
    <constant name="struts.i18n.reload" value="false" />
    <constant name="struts.configuration.xml.reload" value="false" />
    <constant name="struts.locale" value="fr" />
    <constant name="struts.multipart.maxSize" value="100000000000" />
    <constant name="struts.enable.SlashesInActionNames" value="true" />
    <constant name="struts.mapper.alwaysSelectFullNamespace" value="false"/>

    <constant name="struts.codebehind.classSuffix" value="Controller"/>
    <constant name="struts.codebehind.action.checkImplementsAction" value="false"/>
    <constant name="struts.codebehind.action.checkAnnotation" value="false"/>
    <constant name="struts.codebehind.action.defaultMethodName" value="index"/>
    <constant name="struts.configuration.classpath.defaultParentPackage" value="rest-default" />

    <package name="default" extends="tiles-default" namespace="/">

        <interceptors>

            <interceptor name="params-filter"
                class="com.opensymphony.xwork2.interceptor.ParameterFilterInterceptor" />

            <interceptor-stack name="defaultStack">
                <interceptor-ref name="exception" />
                <interceptor-ref name="alias" />
                <interceptor-ref name="servletConfig" />
                <interceptor-ref name="i18n" />
                <interceptor-ref name="chain" />
                <interceptor-ref name="modelDriven" />
                <interceptor-ref name="fileUpload">
                    <param name="maximumSize">11204928</param>
                </interceptor-ref>
                <interceptor-ref name="staticParams" />
                <interceptor-ref name="conversionError" />
                <interceptor-ref name="params" />
                <interceptor-ref name="prepare" />
                <interceptor-ref name="validation" />
                <interceptor-ref name="workflow" />
            </interceptor-stack>

        </interceptors>

        <default-interceptor-ref name="defaultStack" />

        <global-results>
            <result name="technicalError" type="chain">
                errorAction
            </result>
            <result name="sessionInvalidError" type="tiles">
                sessionInvalid
            </result>
            <result name="blank" type="tiles">blank</result>
        </global-results>

        <global-exception-mappings>
            <exception-mapping exception="java.lang.Exception"
                result="technicalError" />
            <exception-mapping
                exception="com.omb.service.exception.UserSessionInvalidException"
                result="sessionInvalidError" />

        </global-exception-mappings>

    </package>

    <package name="omb" extends="default" namespace="/omb">
        <action name="doAction.do" class="myAction" method="{1}">
            <result name="success" type="redirectAction">
                <param name="namespace">/omb</param>
                <param name="actionName">displayResult</param>
            </result>
            <result name="error" type="redirectAction">
                <param name="namespace">/error</param>
                <param name="actionName">displayError</param>
            </result>
        </action>
    </package>
</struts>

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>MyApplication</display-name>
    <description>Application OMB</description>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            classpath:applicationContext.xml,
            classpath:applicationContext-web.xml
        </param-value>
    </context-param>

    <context-param>
        <param-name>org.apache.tiles.DEFINITIONS_CONFIG</param-name>
        <param-value>/WEB-INF/tiles/tiles-defs.xml</param-value>
    </context-param>

    <context-param>
        <param-name>struts.ajax.debug</param-name>
        <param-value>${struts.ajax.debug}</param-value>
    </context-param>

    <filter>
        <filter-name>Acegi Filter Chain Proxy</filter-name>
        <filter-class>
            org.acegisecurity.util.FilterToBeanProxy
        </filter-class>
        <init-param>
            <param-name>targetClass</param-name>
            <param-value>
                org.acegisecurity.util.FilterChainProxy
            </param-value>
        </init-param>
    </filter>

    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>Acegi Filter Chain Proxy</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

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

    <!-- Java Melody filter mapping -->   
    <filter-mapping>     
          <filter-name>monitoring</filter-name>     
          <url-pattern>/*</url-pattern>   
    </filter-mapping>

    <listener>
        <listener-class>
            com.omb.listener.ApplicationListener
        </listener-class>
    </listener>

    <listener>
        <listener-class>
            org.apache.struts2.tiles.StrutsTilesListener
        </listener-class>
    </listener>

    <!--  listener>
        <listener-class>
            org.springframework.web.context.ContextLoaderListener
        </listener-class>
    </listener-->
    <listener>
        <listener-class>
            org.springframework.web.context.request.RequestContextListener
        </listener-class>
    </listener>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

MyAction.java:

package com.omb.actions;

@Repository("myAction")
@Scope("session")
public class MyAction extends ActionSupport {

    @Qualifier("myService")
    private MyService myService;

    public String execute() throws Exception {
        myService.callMethode();
        return SUCCESS;
    }


    public MyService getMyService() {
        return this.myService;
    }

    public void setMyService(MyService myService) {
        this.myService = myService;
    }
}

Answer 1

如果你使用的是 Spring 插件，那么 struts 与 spring 的集成就成功了应用上下文。但是action bean是由struts容器管理的，所以它内部保留了DI的可能性。如果您想完全委托(delegate)由 spring 管理的 bean，您应该在应用程序上下文中配置操作 bean，并在操作配置中替换对 spring id 的类引用。

在applicationContext.xml的地方

<!--<context:annotation-config/>-->
<context:component-scan base-package="your.base.package"/>

指向 spring 扫描包层次结构中的 bean。