话不多说，请看代码
package ceet.ac.cn.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import ceet.ac.cn.model.Admin; public class AdminDao { public List<Admin> getAllAdmin(){ //查询所有信息 List<Admin> list = new ArrayList<Admin>(); //创建集合 Connection conn = DbHelper.getConnection(); String sql = "select * from admin"; //SQL查询语句 try { PreparedStatement pst = conn.prepareStatement(sql); ResultSet rst = pst.executeQuery(); while (rst.next()) { Admin admin = new Admin(); admin.setId(rst.getInt("id")); //得到ID admin.setUsername(rst.getString("username")); admin.setUserpwd(rst.getString("userpwd")); list.add(admin); } rst.close(); //关闭 pst.close(); //关闭 } catch (SQLException e) { e.printStackTrace(); //抛出异常 } return list; //返回一个集合 } public boolean addAdmin(Admin admin){ //添加信息 String sql = "INSERT INTO `admin`(`id`,`username`,`userpwd`) VALUES (?,?,?)"; //添加的SQL语句 Connection conn = DbHelper.getConnection(); try { PreparedStatement pst = conn.prepareStatement(sql); pst.setInt(1, admin.getId()); pst.setString(2, admin.getUsername()); pst.setString(3, admin.getUserpwd()); int count = pst.executeUpdate(); pst.close(); return count>0?true:false; //是否添加的判断 } catch (SQLException e) { e.printStackTrace(); } return false; } public boolean updateAdmin(Admin admin){ //修改 String sql = "UPDATE `admin` SET `username`=?,`userpwd`=? WHERE `id` = ?"; //修改的SQL语句，根据ID修改 Connection conn = DbHelper.getConnection(); try { PreparedStatement pst = conn.prepareStatement(sql); pst.setString(1, admin.getUsername()); pst.setString(2, admin.getUserpwd()); pst.setInt(3, admin.getId()); //根据的ID int count = pst.executeUpdate(); pst.close(); //关闭 return count>0?true:false; //是否修改的判断 } catch (SQLException e) { e.printStackTrace(); } return false; } public boolean deleteAdmin(int id){ //删除 String sql = "delete from admin where id = ?"; //删除的SQL语句，根据ID删除 Connection conn = DbHelper.getConnection(); try { PreparedStatement pst = conn.prepareStatement(sql); pst.setInt(1, id); int count = pst.executeUpdate(); pst.close(); return count>0?true:false; //是否删除的判断 } catch (SQLException e) { e.printStackTrace(); } return false; } public Admin selectAdminById(int id){ //根据ID进行查询 Connection conn = DbHelper.getConnection(); String sql = "select * from admin where id = "+id; Admin admin = null; try { PreparedStatement pst = conn.prepareStatement(sql); ResultSet rst = pst.executeQuery(); while (rst.next()) { admin = new Admin(); admin.setId(rst.getInt("id")); admin.setUsername(rst.getString("username")); admin.setUserpwd(rst.getString("userpwd")); } rst.close(); pst.close(); } catch (SQLException e) { e.printStackTrace(); } return admin; //返回 } }
package ceet.ac.cn.dao; import java.sql.Connection; import java.sql.DriverManager; /** * 连接数据库 * @author 画船听雨眠 * */ public class DbHelper { private static String url = "jdbc:mysql://localhost:3306/admin"; //数据库地址 private static String userName = "root"; //数据库用户名 private static String passWord = "359129127"; //数据库密码 private static Connection conn = null; private DbHelper(){ } public static Connection getConnection(){ if(null == conn){ try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(url, userName, passWord); } catch (Exception e) { e.printStackTrace(); } } return conn; } public static void main(String[] args) { //测试数据库是否连通 System.err.println(getConnection()); } }
package ceet.ac.cn.model; import java.io.Serializable; public class Admin implements Serializable{ //数据封装类 private static final long serialVersionUID = 1L; private int id; private String username; private String userpwd; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getUserpwd() { return userpwd; } public void setUserpwd(String userpwd) { this.userpwd = userpwd; } }
package ceet.ac.cn.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import ceet.ac.cn.dao.AdminDao; import ceet.ac.cn.model.Admin; public class AddServlet extends HttpServlet{ //添加数据 private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String username = req.getParameter("username"); String userpwd = req.getParameter("userpwd"); Admin admin = new Admin(); admin.setUsername(new String(username.getBytes("ISO-8859-1"),"UTF-8")); //转值，中文需要转换为utf-8 admin.setUserpwd(new String(userpwd.getBytes("ISO-8859-1"),"UTF-8")); AdminDao dao = new AdminDao(); dao.addAdmin(admin); req.getRequestDispatcher("ShowServlet").forward(req, resp); } }