北京地铁系统

选择不同数据表的数据

Dao

public class RouteDao {
	
	
	public List<Route> findno1(){
		List<Route> list=new ArrayList<>();
		Connection conn=null;
		ResultSet rs=null;
		PreparedStatement pstm=null;
		Route route=null;
		
		
		try {
			conn=DBUtil.getConnection();
			
			
			
			String sql="select * from no1";
			pstm=conn.prepareStatement(sql);
			rs=pstm.executeQuery();
			while(rs.next()) {
				String name=rs.getString("name");
				int number=rs.getInt("number");
				String nearline=rs.getString("nearline");
				String xianlu=rs.getString("xianlu");
				
				route=new Route(name,number,nearline, xianlu);
				list.add(route);
				
				System.out.println("name:"+name);
				System.out.println("number:"+number);
				System.out.println("nearline:"+nearline);
			}
		}catch(Exception e) {
			e.printStackTrace();
		}finally {
			DBUtil.close(conn, pstm, rs);
		}
		return list;
		}
		public List<Route> findno2(){
			List<Route> list=new ArrayList<>();
			Connection conn=null;
			ResultSet rs=null;
			PreparedStatement pstm=null;
			Route route=null;
			
			
			try {
				conn=DBUtil.getConnection();
				
				
				
				String sql="select * from no2";
				pstm=conn.prepareStatement(sql);
				rs=pstm.executeQuery();
				while(rs.next()) {
					String name=rs.getString("name");
					int number=rs.getInt("number");
					String nearline=rs.getString("nearline");
					String xianlu=rs.getString("xianlu");
					
					route=new Route(name,number,nearline, xianlu);
					list.add(route);
					
					System.out.println("name:"+name);
					System.out.println("number:"+number);
					System.out.println("nearline:"+nearline);
				}
			}catch(Exception e) {
				e.printStackTrace();
			}finally {
				DBUtil.close(conn, pstm, rs);
			}
			return list;
	}
		public List<Route> findno3(){
			List<Route> list=new ArrayList<>();
			Connection conn=null;
			ResultSet rs=null;
			PreparedStatement pstm=null;
			Route route=null;
			
			
			try {
				conn=DBUtil.getConnection();
				
				
				
				String sql="select * from no3";
				pstm=conn.prepareStatement(sql);
				rs=pstm.executeQuery();
				while(rs.next()) {
					String name=rs.getString("name");
					int number=rs.getInt("number");
					String nearline=rs.getString("nearline");
					String xianlu=rs.getString("xianlu");
					
					route=new Route(name,number,nearline, xianlu);
					list.add(route);
					
					System.out.println("name:"+name);
					System.out.println("number:"+number);
					System.out.println("nearline:"+nearline);
				}
			}catch(Exception e) {
				e.printStackTrace();
			}finally {
				DBUtil.close(conn, pstm, rs);
			}
			return list;
		}
	
}

　　Servlet

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

    RouteDao dao=new RouteDao();
	
    
    public void findno1(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	response.setCharacterEncoding("UTF-8");
		List<Route> list=dao.findno1( );
		request.setAttribute("list", list);
		
		System.out.println("查询成功");
		request.getRequestDispatcher("showRoute.jsp").forward(request,response);
		
    }
    public void findno2(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	response.setCharacterEncoding("UTF-8");
		List<Route> list=dao.findno2( );
		request.setAttribute("list", list);
		
		System.out.println("查询成功");
		request.getRequestDispatcher("showRoute2.jsp").forward(request,response);
		
    }
    public void findno3(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	response.setCharacterEncoding("UTF-8");
		List<Route> list=dao.findno3( );
		request.setAttribute("list", list);
		
		System.out.println("查询成功");
		request.getRequestDispatcher("showRoute3.jsp").forward(request,response);
		
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setCharacterEncoding("UTF-8");
		request.setCharacterEncoding("UTF-8");
		System.out.println("进入Servlet");
		
		String method = request.getParameter("method");
	  	System.out.println(method);
	  	if("findno1".equals(method)) { 
	  		findno1(request,response);
	  	}
        else if("findno2".equals(method)) { 
  		findno2(request,response);
  	}
    else if("findno3".equals(method))
		findno3(request,response);
	}
	/**
	 * @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);
	}

}