在 Struts 2 中获取拦截器参数 [英] Getting Interceptor Parameters in Struts 2
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.
这篇关于在 Struts 2 中获取拦截器参数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
