0
执行chain.doFilter(request, response);时出现错误。这个错误有时只会发生。Servlet过滤器中的错误
堆栈跟踪低于::
enter code here
<i>javax.servlet.ServletException: For input string: "NULL"
at org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:516)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:423)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:397)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:835)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:341)
at com.evermind.server.http.ServletRequestDispatcher.forward(ServletRequestDispatcher.java:261)
at com.evermind.server.http.GetParametersRequestDispatcher.forward(GetParametersRequestDispatcher.java:257)
at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1056)
at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:388)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:397)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)
at my.SampleFilter.doFilter(SampleFilter.java:120)
at com.evermind.server.http.EvermindFilterChain.doFilter(EvermindFilterChain.java:16)
at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:176)
at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:381)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:670)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:341)
at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:816)
at com.evermind.server.http.AJPRequestHandler.run(AJPRequestHandler.java:231)
at com.evermind.server.http.AJPRequestHandler.run(AJPRequestHandler.java:136)
at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:186)
at java.lang.Thread.run(Thread.java:534)</i>
我的滤波代码为如下::
<i>public class SampleFilter
implements Filter
{
private transient FilterConfig filterConfig;
Context initialContext;
public SampleFilter()
{
filterConfig = null;
initialContext = null;
}
public void destroy()
{
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws ServletException, IOException
{
Connection conn=getJNDIConnection();
request.setAttribute("CONNECTION", conn);
try
{
System.out.println("Filter start GOOG Website");
chain.doFilter(request, response);
}
catch(Exception e)
{
//System.out.println("@@@@@@@@@@@@@@@@@@@@@ Exception occured in doFilter @@@@@@@@@@@@@@@");
closeConnection(initialContext, conn);
System.out.println("@@@@@@@@@@@@@@@@@@@@@ Connection Closed @@@@@@@@@@@@@@@");
String fullStackTrace = org.apache.commons.lang.exception.ExceptionUtils.getFullStackTrace(e);
e.printStackTrace();
}
closeConnection(initialContext, conn);
System.out.println("Filter end ");
}
Connection getJNDIConnection()
{
Connection conn = null;
try
{
initialContext = new InitialContext();
if(initialContext == null)
{
System.out.println("JNDI problem. Cannot get InitialContext.");
}
DataSource datasource = (DataSource)initialContext.lookup("jdbc/MY_DS");
if(datasource != null)
{
conn = datasource.getConnection();
} else
{
System.out.println("Failed to lookup datasource.");
}
}
catch(NamingException ex)
{
System.out.println("Cannot get connection: " + ex);
}
catch(SQLException ex)
{
System.out.println("Cannot get connection: " + ex);
}
return conn;
}
void closeConnection(Context ctx, Connection conn) {
try {
if (ctx != null) {
ctx.close();
ctx = null;
}
if (conn != null && !conn.isClosed()) {
conn.close();
conn = null;
}
} catch (NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException sqe) {
sqe.printStackTrace();
} finally {
conn = null;
}
}
public void init(FilterConfig filterConfig)
throws ServletException
{
this.filterConfig = filterConfig;
}
}
</i>
我的web.xml中含量低于::
<i><?xml version="1.0" encoding="UTF-8"?>
<web-app>
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<init-param>
<param-name>debug</param-name>
<param-value>3</param-value>
</init-param>
<init-param>
<param-name>detail</param-name>
<param-value>3</param-value>
</init-param>
<load-on-startup>0</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<filter>
<filter-name>UrlRewriteFilter</filter-name>
<filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>UrlRewriteFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter>
<filter-name>SampleFilter</filter-name>
<filter-class> my.SampleFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>SampleFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<session-config>
<session-timeout>720</session-timeout>
</session-config>
</web-app>
</i>
感谢