在 Struts 2 中获取拦截器参数_Java开发问题-跟版网

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问题描述

我有以下动作映射

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

我可以使用 Interceptor 中的以下行获取参数映射

I can get parameter map using following line in Interceptor

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

如上，有没有办法获取拦截器参数，如下映射中定义的那样.

Just as above, is there any way to get interceptor parameters as defined in following mapping.

<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>

动作参数的定义方式如下，动作参数和拦截器参数应该分开访问.

And action parameters are defined in following way, action parameters and interceptor parameters should be accessible separately.

<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，我不想将拦截器中的参数字段声明为

Please note that I don't want to declare parameter fields in my interceptor as

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

<小时>

在 Dev Blanked 的回答之后，我实施了他的技术.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.

After Dev Blanked's asnwer, I implemented his technique. It did not work so I am sharing my code here. I am using Struts 2.3.1.2.

库

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
",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=%.
",configName, configValue);
        interceptorConfigs.put(configName, configValue);
    }

}

控制台输出，当 theAction 被点击时.

Calling 'intercept' method.

推荐答案

在您的自定义拦截器中，您可以定义如下图

In your custom interceptor you can define a map like below

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);
}

然后在您的动作映射中，您可以传入如下参数 .. 这些将存储在拦截器的映射中

Then in your action mappings you can pass in parameters like below .. these will be stored in the map of the interceptor

    <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" 是指你在将拦截器添加到 struts.xml 时给出的拦截器的名称.当像上面那样配置'interceptorConfigs'时，拦截器内的映射将有，键/值对.

"yourInterceptor" refers to the name of the interceptor you have given when adding your interceptor to the struts.xml. When configured like above 'interceptorConfigs' map inside the interceptor will have , key/value pairs.

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

If you want to make these available to your action, you can just set the map as a context variable in the ActionContext. This can then be retrieved inside the action.

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在 Struts 2 中获取拦截器参数

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