我的程序：
import java.io.*;
import java.util.*;
import javax.servlet.*;

public class Morning extends HttpServlet
{
public void service(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
res.setContentType("text/html;charset=Big5");
PrintWriter pw=res.getWriter();
pw.println("");
pw.println("");
pw.println("");
pw.println("");
pw.println("GOOD MORNING!!
");
pw.println("");
pw.println("");
}
}

*******編譯成class出現的問題*********************************
D:WorkingTomcathowjspWeb-INFclassesMorning.java:5: cannot resolve symbol
symbol  : class HttpServlet  
location: class Morning
public class Morning extends HttpServlet
                             ^
D:WorkingTomcathowjspWeb-INFclassesMorning.java:7: cannot resolve symbol
symbol  : class HttpServletRequest  
location: class Morning
public void service(HttpServletRequest req,HttpServletResponse res)
                            ^
D:WorkingTomcathowjspWeb-INFclassesMorning.java:7: cannot resolve symbol
symbol  : class HttpServletResponse  
location: class Morning
public void service(HttpServletRequest req,HttpServletResponse res)
                                                   ^
3 errors

Tool completed with exit code 1


問題在哪里？怎么解決？HELP

改为
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class GetEnvVar extends GenericServlet
{
public void service(ServletRequest req,ServletResponse res)
throws ServletException,IOException
{
ServletContext sc=getServletContext();
res.setContentType("text/plain");
ServletOutputStream sos=res.getOutputStream();
PrintWriter pw=new PrintWriter(sos,true);
pw.println("名稱："+req.getServerName());
pw.println("端口："+req.getServerPort());
pw.println("網頁路徑"+sc.getRealPath("/"));
pw.println("遠端主機名稱"+req.getRemoteHost());
pw.println("遠端主機位置"+req.getRemoteAddr());
}
}

粗心的错误
public void service(ServletRequest req,ServletRequest res)
两个参数的类型都是ServletRequest了!!!!
service(javax.servlet.ServletRequest,javax.servlet.ServletResponse)

这个类应该继承HttpServlet这个类才可以在下面用
ServletRequest req,ServletRequest res,

不是继承GenericServlet
而是继承HttpServlet

少了import javax.servlet.http.*;
完整下面:
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class Morning extends HttpServlet
{
public void service(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
res.setContentType("text/html;charset=Big5");
PrintWriter pw=res.getWriter();
pw.println("");
pw.println("");
pw.println("");
pw.println("");
pw.println("GOOD MORNING!!
");
pw.println("");
pw.println("");
}
}

1.未定义GetEnvVar()方法,将service()换成GetEnvVar()
2.3.可能是jdk版本的问题,我遇到过类似的,jdk1.3的session.getAttribute()在jdk1.2中是getValue()

去下载一个servlet.jar的包
去java.sun.com找找
然后把它设置到classpath中去

怎么设的?