基于mysql数据库 增删改查 的web demo

package com.daoimpl; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.dao.stuDao; import com.entity.students; import java.sql.Statement; import java.sql.PreparedStatement; import com.util.DBConnection; public class stuDaoimpl implements stuDao{ Connection conn=DBConnection.getConnection(); PreparedStatement st=null; //Statement statement=null; ResultSet rs=null; /** * 查询 * @author HCL * */ public List<students> findAll() { // TODO Auto-generated method stub List<students> stulist=null; try { st=conn.prepareStatement("select * from students;"); rs=st.executeQuery(); stulist=new ArrayList<students>(); while(rs.next()){ students s=new students(); s.setId(rs.getInt("id")); s.setAge(rs.getInt("age")); s.setName(rs.getString("name")); s.setClasss(rs.getString("class")); s.setGender(rs.getString("gender")); s.setPhone(rs.getString("phone")); stulist.add(s); //System.out.println(s.getName()); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return stulist; } /** * 通过学号查询 */ public students findById(int id) { // TODO Auto-generated method stub students s=new students(); try { st=conn.prepareStatement("select * from students where id=?;"); st.setInt(1,id); rs=st.executeQuery(); if(rs.next()){ s.setAge(rs.getInt("age")); s.setClasss(rs.getString("class")); s.setPassword(rs.getString("password")); s.setGender(rs.getString("gender")); s.setId(rs.getInt("id")); s.setName(rs.getString("name")); s.setPhone(rs.getString("phone")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ DBConnection.CloseConnection(conn,st,rs); } return s; } /** * 删除 */ public int deleteById(int id) { // TODO Auto-generated method stub int result=-1; try { st=conn.prepareStatement("delete from students where id=?;"); st.setInt(1,id); result=st.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return result; } /** * 添加 */ public int addSutdent(students s) { // TODO Auto-generated method stub int result=-1; try { st=conn.prepareStatement("insert into students(id,password,name,gender,class,phone,age) values(?,?,?,?,?,?,?)"); st.setInt(1,s.getId()); st.setString(2,s.getPassword()); st.setString(3,s.getName()); st.setString(4,s.getGender()); st.setString(5,s.getClasss()); st.setString(6,s.getPhone()); st.setInt(7,s.getAge()); result=st.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block System.out.println("插入数据产生异常！"); e.printStackTrace(); } return result; } /** * 修改学生信息。 */ public int updateStudentById(students s,int id) { // TODO Auto-generated method stub int result = -1; try { st=conn.prepareStatement("update students set name=?,gender=?,class=?,phone=?,age=?,password=? where id=?"); st.setString(1,s.getName()); st.setString(2,s.getGender()); st.setString(3,s.getClasss()); st.setString(4,s.getPhone()); st.setInt(5,s.getAge()); st.setString(6,s.getPassword()); st.setInt(7,s.getId()); result=st.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block System.out.println("更新数据出现异常！"); e.printStackTrace(); } return result; } /** * 登录检测功能 */ public boolean loginCheck(int id,String password) { // TODO Auto-generated method stub try { st=conn.prepareStatement("select id,password from students where id=? and password=?"); st.setInt(1,id); st.setString(2,password); rs=st.executeQuery(); if(rs.next()){ return true; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return false; } // public void isUserCookie(String[] cookie,String id,String password) { // // TODO Auto-generated method stub // if(cookie!=null&&cookie.length>0){ // Cookie idcookie = new Cookie("id",id); // Cookie pswcookie = new Cookie("passwrod",password); // idcookie.setMaxAge(1*24*60*60); // pswcookie.setMaxAge(1*24*60*60); // // } // } public static void main(String[] args) { stuDao s= new stuDaoimpl(); s.findAll(); students stu=s.findById(3); System.out.println(stu.getPhone()); int result=s.deleteById(5); if(result==1){ System.out.println(" delete success!"); }else{ System.out.println(" delete failure!"); } } }