First.java :这是我的第一个 java 类
package com;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
class First extends HttpServlet {
public void doGet(HttpServletRequest req,HttpServletResponse res) throws IOException, ServletException
{
// res.setContentType("html/text");
String name= req.getParameter("fname");
Cookie ck= new Cookie("uname",name);
res.addCookie(ck);
RequestDispatcher r= req.getRequestDispatcher("Servlet2");
r.forward(req,res);
}
}
SecondServlet.java:这是第二个 java 类
package com;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class SecondServlet extends HttpServlet{
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException{
resp.setContentType("html/text");
PrintWriter out= resp.getWriter();
Cookie []ck=req.getCookies();
out.print(ck[0]);
}
}
web.xml:部署描述符
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>
cooooooooooooookie</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>A</servlet-name>
<servlet-class>com.First</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>A</servlet-name>
<url-pattern>/cook</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>B</servlet-name>
<servlet-class>com.SecondServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>B</servlet-name>
<url-pattern>/Servlet2</url-pattern>
</servlet-mapping>
</web-app>
错误:
Jun 12, 2013 9:03:15 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre6\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\Program Files\Java\jre7\bin\client;C:\Program Files\Java\jre7\bin;C:\Program Files\Broadcom\Broadcom 802.11 Network Adapter\Driver;;C:\Ruby193\bin;;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\QuickTime\QTSystem\;C:\Program Files\Java\jdk1.6.0_14\bin;.
Jun 12, 2013 9:03:15 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.j2ee.server:cooooooooooooookie' did not find a matching property.
Jun 12, 2013 9:03:15 PM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-2030
Jun 12, 2013 9:03:15 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 362 ms
Jun 12, 2013 9:03:15 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Jun 12, 2013 9:03:15 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.26
Jun 12, 2013 9:03:15 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-2030
Jun 12, 2013 9:03:15 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Jun 12, 2013 9:03:15 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/20 config=null
Jun 12, 2013 9:03:15 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 268 ms
Jun 12, 2013 9:03:22 PM org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet A as unavailable
Jun 12, 2013 9:03:22 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet A
java.lang.IllegalAccessException: Class org.apache.catalina.core.StandardWrapper can not access a member of class com.First with modifiers ""
at sun.reflect.Reflection.ensureMemberAccess(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1116)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:809)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
我在 First.java 类中遇到错误。它说“错误实例化servlet类com.First”我已经添加了像这个构建路径> configurebuildpath>libraries>add external jars这样的jar。在此之后转到订购和导出选项卡>全选。
请帮忙。