下面是jsp頁面：
<form action="servlet/ShowData" method="post">
查詢公司ID<input type="text" name="com_id" size="15"><br> <br>
<input type="submit" value="查詢" />
</form>
下面是web的配置文件
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>ShowData</servlet-name>
<servlet-class>com.cn.data.ShowData</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ShowData</servlet-name>
<url-pattern>/servlet/ShowData</url-pattern>
</servlet-mapping>
開發環境是myeclipse，ShowData是一個Servlet文件，運行是報錯如下：
WARN org.apache.struts2.dispatcher.Dispatcher - Could not find action or result: /Website/servlet/ShowData
There is no Action mapped for action name servletN. - [unknown location]
at com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:185)
at org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:63)
at org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:37)
at com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:58)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:554)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
一、問題的提出
先讓我們看下web.xml中struts2和servlet的配置：<!-- struts2攔截頁面請求的配置 -->
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- servlet的配置 -->
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>com.servlets.ImageServlet
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/myImageServlet/*</url-pattern>
</servlet-mapping>
當我們在頁面在請求應用時，struts2將會截獲所有請求，對於servlet請求將不能夠正常響應的
（報錯信息爲：HTTP
Status 404 - There is no Action mapped for namespace / and action name myImageServlet.）,
這是因爲struts2把servlet當成action了，因爲servlet和action都是沒有後綴的.
二、解決方案
解決方法目前有四種：
方法1：
統一在servlet後面加上.servlet結尾（包括web.xml配置文件中和頁面上使用servlet的地方）
(備註：我使用的就是這種辦法)
如下所示：
下面是修改之後的jsp頁面：
<form action="servlet/ShowData.servlet" method="post">
查詢公司ID<input type="text" name="com_id" size="15"><br> <br>
<input type="submit" value="查詢" />
</form>
下面是修改之後的web的配置文件
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>ShowData</servlet-name>
<servlet-class>com.cn.data.ShowData</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ShowData</servlet-name>
<url-pattern>/servlet/ShowData.servlet</url-pattern>
</servlet-mapping>
方法2（比較通用奧）：
在struts.xml中的<struts>的節點下面添加struts2處理的請求後綴 常量：
<!--
該屬性指定需要Struts
2處理的請求後綴，該屬性的默認值是action，即所有匹配*.action的請求都由Struts
2處理。
如果用戶需要指定多個請求後綴，則多個後綴之間以英文逗號（，）隔開。
-->
<constant name="struts.action.extension" value="action" />
方法3：
在web.xml中修改struts2攔截頁面請求的配置：
原：
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
現：
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/user/*</url-pattern>
</filter-mapping>
servlet的請求路徑不必改變
方法4：
自定義filter對servlet進行過濾：
##############################################
# 該類是定義了一個過濾器（隨便你放在摸個包下面），當既用到struts2有用到servlet時，
# 必須用該過濾器對所有的servlet做一次過濾，否則servlet將無法正常運行。
# 同時在web.xml中，在定義struts的核心控制器的過濾器前面添加該過濾器，添加代碼如下：
* <filter>
* <filter-name>redisp</filter-name>
* <filter-class>filters.ReDispatcherFilter（該過濾器的類名）</filter-class>
* <init-param>
* <param-name>includeServlets</param-name>
* <param-value>所配置的servlet，注意是那url-pattern</param-value>
* </init-param>
* </filter>
* <filter-mapping>
* <filter-name>redisp</filter-name>
* <url-pattern>/*</url-pattern>
* </filter-mapping>
*該類也可以直接繼承StrutsPrepareAndExecuteFilter的
###########################################################
public class ReDispatcherFilter implements Filter {
public void destroy() {
// TODO Auto-generated method stub
}
public void doFilter(ServletRequest req, ServletResponse resp,
FilterChain chain) throws IOException, ServletException
{
HttpServletRequest request = (HttpServletRequest)req;
String target = request.getRequestURI();
target = target.lastIndexOf("?")>0
?target.substring(target.lastIndexOf("/")+1,target.lastIndexOf("?")-target.lastIndexOf("/"))
:target.substring(target.lastIndexOf("/")+1);
System.out.println(target);
if(this.includes.contains(target))
{
RequestDispatcher rdsp = request.getRequestDispatcher(target);
System.out.println("go..............."+rdsp);
rdsp.forward(req, resp);
}
else
chain.doFilter(req, resp);
}
private ArrayList<String> includes = new ArrayList<String>();
public void init(FilterConfig config) throws ServletException {
this.includes.addAll( Arrays.asList(config.getInitParameter("includeServlets").split(",")));
}
}
怕大家還是配置錯誤，給一個web.xml的配置實例。
<filter>
<filter-name>redisp</filter-name>
<filter-class>
com.xheditor.servlet.ReDispatcherFilter</filter-class>
<init-param>
<param-name>includeServlets</param-name>
<param-value>UploadFileServlet</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>redisp</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- struts2攔截頁面請求的配置 -->
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- servlet的配置 -->
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>com.servlets.ImageServlet
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/myImageServlet/*</url-pattern>
</servlet-mapping>
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