基于JSP+Servlet模拟闲鱼

package dao; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import com.DBConn; import com.mysql.jdbc.PreparedStatement; import bean.Admin; import bean.User; public class AdminDao { //管理员登陆 public ResultSet login(String username,String password) { Statement st = null; ResultSet rs = null; Connection conn = null; try { conn = DBConn.getConn(); st = conn.createStatement(); // SQL语句 String sql = "select * from admin where name='" + username + "' and pass = '" + password + "'"; rs = st.executeQuery(sql);// 返回查询结果 }catch (SQLException e) { e.printStackTrace(); } return rs; } //删除用户 public int delete(String username) { Statement st = null; int rs=0; Connection conn = null; try { conn = DBConn.getConn(); st = conn.createStatement(); // SQL语句 String sql = "delete from user where username='"+username+"'"; rs = st.executeUpdate(sql);// 返回查询结果 }catch (SQLException e) { e.printStackTrace(); } return rs; } public List findAll() { Statement st = null; ResultSet rs = null; Connection conn = null; List list = new ArrayList<>(); try { conn = DBConn.getConn(); st = conn.createStatement(); // SQL语句 String sql = "select * from user"; rs = st.executeQuery(sql);// 返回查询结果 String username,tel,addr,email; while (rs.next()){ User user = new User(); //从当前记录中读取各字段的值 username = rs.getString("username").trim(); tel = rs.getString("tel").trim(); addr = rs.getString("addr").trim(); email = rs.getString("email").trim(); user.setUsername(username); user.setAddr(addr); user.setTel(tel); user.setEmail(email); list.add(user); } }catch(SQLException e){ e.printStackTrace(); }finally{ if(rs != null) try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(st != null) try { st.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(conn != null) try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return list; } public List findAllOrder() { Statement st = null; ResultSet rs = null; Connection conn = null; List list = new ArrayList<>(); try { conn = DBConn.getConn(); st = conn.createStatement(); // SQL语句 String sql = "select * from user"; rs = st.executeQuery(sql);// 返回查询结果 String username,tel,addr,email; while (rs.next()){ User user = new User(); //从当前记录中读取各字段的值 username = rs.getString("username").trim(); tel = rs.getString("tel").trim(); addr = rs.getString("addr").trim(); email = rs.getString("email").trim(); user.setUsername(username); user.setAddr(addr); user.setTel(tel); user.setEmail(email); list.add(user); } }catch(SQLException e){ e.printStackTrace(); }finally{ if(rs != null) try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(st != null) try { st.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(conn != null) try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return list; } }