java - 在 Struts 2 中获取拦截器参数

Question

我有以下 Action 映射

<action name="theAction" ...>
...
    <param name="param1">one</param>
    <param name="param2">two</param>
    ...
    <param name="paramN">nth-number</param>
...
</action>

我可以在拦截器中使用以下行获取参数映射

Map<String, Object> params = ActionContext.getContext().getParameters();

和上面一样，有没有办法获取拦截器参数，定义在下面的映射中。

<action name="theAction" ...>
...
    <interceptor-ref name="theInterceptor">
        <param name="param1">one</param>
        <param name="param2">two</param>
        ...
        <param name="paramN">nth-number</param>
    </interceptor-ref>
...
</action>

并且 Action 参数定义如下， Action 参数和拦截器参数应该是分开访问的。

<action name="theAction" ...>
...
    <param name="param1">one</param>
    <param name="param2">two</param>
    ...
    <param name="paramN">nth-number</param>
    ....
    <interceptor-ref name="theInterceptor">
        <param name="param1">one</param>
        <param name="param2">two</param>
        ...
        <param name="paramN">nth-number</param>
    </interceptor-ref>
...
</action>

请注意，我不想在我的拦截器中将参数字段声明为

//all fields with their getters and setters
private String param1;
private String param2;
...
private String paramN;

---

在 Dev Blanked 的回答后，我实现了他的技术。它没有用，所以我在这里分享我的代码。我正在使用 Struts 2.3.1.2。

图书馆

• asm-3.3.jar
• asm-commons-3.3.jar
• asm-tree-3.3.jar
• commons-fileupload-1.2.2.jar
• commons-io-2.0.1.jar
• commons-lang-2.5.jar
• freemarker-2.3.18.jar
• javassist-3.11.0.GA.jar
• ognl-3.0.4.jar
• struts2-core-2.3.1.2.jar
• xwork-core-2.3.1.2.jar

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="true" />

    <package name="the-base" namespace="/" extends="struts-default" abstract="true">

        <interceptors>
            <interceptor name="header" class="demo.interceptors.HttpHeaderInterceptor"></interceptor>

        <interceptor-stack name="theStack">
            <interceptor-ref name="defaultStack"></interceptor-ref>
                <interceptor-ref name="header"></interceptor-ref>
            </interceptor-stack>
        </interceptors>

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

    </package>

    <package name="the-module" extends="the-base">
        <action name="theAction">
            <result>/the-action.jsp</result>
            <interceptor-ref name="theStack">
                <param name="header.Cache-control">no-store,no-cache</param>
                <param name="header.Pragma">no-cache</param>
                <param name="header.Expires">-1</param>
                <param name="header.arbitrary">true</param>
            </interceptor-ref>
        </action>
    </package>
</struts>

拦截器

package demo.interceptors;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.StrutsStatics;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class HttpHeaderInterceptor extends AbstractInterceptor {

    private final Map<String, String> interceptorConfigs = new HashMap<String, String>();

    @Override
    public String intercept(ActionInvocation invocation) throws Exception {
        System.out.println("Calling 'intercept' method.");
        HttpServletResponse response = (HttpServletResponse) invocation.getInvocationContext().get(StrutsStatics.HTTP_RESPONSE);

        for(Entry<String, String> entry: interceptorConfigs.entrySet()) {
            String header = entry.getKey();
            String value = entry.getValue();
            System.out.printf("Adding header: %s=%s\n",header,value);
            response.setHeader(header, value);
        }

        return invocation.invoke();
    }

    public Map<String, String> getInterceptorConfigs() {
        System.out.println("calling method 'getInterceptorConfigs'");
        return interceptorConfigs;
    }

    public void addInterceptorConfig(final String configName, final String configValue) {
        System.out.printf("Calling method 'addInterceptorConfig' with params configName = %s, configValue=%.\n",configName, configValue);
        interceptorConfigs.put(configName, configValue);
    }

}

控制台输出 theAction 被点击时。

Calling 'intercept' method. 

Answer 1

在您的自定义拦截器中，您可以定义如下图

private final Map<String, String> interceptorConfigs = new HashMap<String, String>();

public Map<String, String> getInterceptorConfigs() {
    return interceptorConfigs;
}


public void addInterceptorConfig(final String configName, final String configValue) {
    interceptorConfigs.put(configName, configValue);
}

然后在你的 Action 映射中你可以传递如下参数..这些将被存储在拦截器的映射中

    <action name="yourAction" class="your.actionClass">
        <result name="success">some.jsp</result>
        <interceptor-ref name="defaultStack">
            <param name="yourInterceptor.interceptorConfigs.key">value</param>
            <param name="yourInterceptor.interceptorConfigs.aParamName">paramValue</param>            </interceptor-ref>
    </action>

“yourInterceptor”指的是您在将拦截器添加到struts.xml 时提供的拦截器名称。当像上面那样配置时，拦截器内部的“interceptorConfigs”映射将具有 , 键/值对。

如果您想让这些对您的操作可用，您只需将 map 设置为 ActionContext 中的上下文变量。然后可以在操作中检索它。