新手 eclipse servlet就收参数tomcat404

[longcm]

package aa;

import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class TextServlet
 */
@WebServlet("/TextServlet")
public class TextServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public TextServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//response.getWriter().append("Served at: ").append(request.getContextPath());
		String username = request.getParameter("userName");
		String password = request.getParameter("passWord");
	   
        System.out.println("username:"+username);
        System.out.println("password:"+password);
		
		 /*
		 response.setHeader("content-type", "text/html;charset=UTF-8");
	     OutputStream outputStream = response.getOutputStream();//获取OutputStream输出流
	     if("123".equals(password))
	     {
		 outputStream.write((5+"").getBytes());
		 System.out.println(5);
		 }
	     else
	     {outputStream.write((4+"").getBytes());
		  System.out.println(4);}
		  */
 		try {  
             //1.加载驱动  
             Class.forName("oracle.jdbc.driver.OracleDriver");  
               
             //2.得到连接  
             Connection conn = (Connection) DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:lcm", "system", "Lcm19960808");  
             System.out.println("加载数据库驱动成功！");  
               
             //3.从下面开始和 sql server 一模一样  
             Statement statement = conn.createStatement();
             System.out.println("createStatement");
             
             String sql="select * from student where sno="+username;
             ResultSet resultSet = statement.executeQuery(sql);
             System.out.println("查询数据库信息");
             //用来查询数据库信息   
             
             while(resultSet.next()){  
             	System.out.print("学号:" + resultSet.getString("sno"));
                 //用户名  
                 System.out.println("密码:" + resultSet.getString("spassword")); 
                 System.out.println("password" + password);
                 String rr=resultSet.getString("spassword");    
             
                 System.out.println(rr);
                 response.setHeader("content-type", "text/html;charset=UTF-8");
                 OutputStream outputStream = response.getOutputStream();//获取OutputStream输出流
                 if(rr.equals(password))
                 {        //登录成功          
                 	outputStream.write((5+"").getBytes());System.out.println(5);
                 }
                 else{outputStream.write((4+"").getBytes());System.out.println(4);}
           }
             //else{outputStream.write((4+"").getBytes());System.out.println(4);}
             
             
                                    
               //登录失败，密码错误                           
             //resultSet.close();  
             //statement.close();  
             //conn.close();                    
         } catch (Exception e) {  
             e.printStackTrace(); 
             //登录失败，加载数据库驱动失败   
             response.setHeader("content-type", "text/html;charset=UTF-8");
             OutputStream outputStream = response.getOutputStream();//获取OutputStream输出流
            
             outputStream.write((3+"").getBytes());System.out.println(3); 
             
         }
 		 
       
        
        
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

加参数就404，这个什么问题，求解？