---恢复内容开始---
1.程序设计思想
用jsp编写登录界面,addput中加入一些java方法
2
package com.jaovo.msg.dao; import java.util.List; import com.jaovo.msg.model.User; public interface IUserDao { public void add(User user); public void delete(int id);
package com.jaovo.msg.Util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class DBUtil { public static Connection getConnection() { try { //1 鍔犺浇椹卞姩 Class.forName("com.mysql.jdbc.Driver").newInstance(); } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } String user = "root"; String password = "20163558"; String url = "jdbc:mysql://localhost:3306/jaovo_msg"; Connection connection = null; try { //2 鍒涘缓閾炬帴瀵硅薄connection connection = DriverManager.getConnection(url,user,password); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return connection; } //鍏抽棴璧勬簮鐨勬柟娉� public static void close(Connection connection ) { try { if (connection != null) { connection.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void close(PreparedStatement preparedStatement ) { try { if (preparedStatement != null) { preparedStatement.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void close(ResultSet resultSet ) { try { if (resultSet != null) { resultSet.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
package com.jaovo.msg.model; public class User { private int id; private String username; private String nickname; private String password; 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 getNickname() { return nickname; } public void setNickname(String nickname) { this.nickname = nickname; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
package com.jaovo.msg.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 com.jaovo.msg.Util.DBUtil; import com.jaovo.msg.Util.UserException; import com.jaovo.msg.model.User; import sun.net.www.content.text.plain; public class UserDaoImpl implements IUserDao { @Override public void add(User user) { //鑾峰緱閾炬帴瀵硅薄 Connection connection = DBUtil.getConnection(); //鍑嗗�sql璇�彞 String sql = "select count(*) from t_user where username = ?"; //鍒涘缓璇�彞浼犺緭瀵硅薄 PreparedStatement preparedStatement = null; ResultSet resultSet = null; try { preparedStatement = connection.prepareStatement(sql); preparedStatement.setString(1, user.getUsername()); //鎺ユ敹缁撴灉闆� resultSet = preparedStatement.executeQuery(); //閬嶅巻缁撴灉闆� while(resultSet.next()) { if (resultSet.getInt(1) > 0) { throw new UserException("鐢ㄦ埛宸插瓨鍦�") ; } } sql = "insert into t_user(username,password,nickname) value (?,?,?)"; preparedStatement = connection.prepareStatement(sql); preparedStatement.setString(1, user.getUsername()); preparedStatement.setString(2, user.getPassword()); preparedStatement.setString(3, user.getNickname()); preparedStatement.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { //鍏抽棴璧勬簮 DBUtil.close(resultSet); DBUtil.close(preparedStatement); DBUtil.close(connection); } } @Override public void delete(int id) { Connection connection = DBUtil.getConnection(); String sql = "delete from t_user where id = ?"; PreparedStatement preparedStatement = null; try { preparedStatement = connection.prepareStatement(sql); preparedStatement.setInt(1, id); preparedStatement.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { DBUtil.close(preparedStatement); DBUtil.close(connection); } } @Override public void update(User user) { Connection connection = DBUtil.getConnection(); //鍑嗗�sql璇�彞 String sql = "update t_user set password = ? , nickname=? where id = ?"; //鍒涘缓璇�彞浼犺緭瀵硅薄 PreparedStatement preparedStatement = null; try { preparedStatement = connection.prepareStatement(sql); preparedStatement.setString(1, user.getPassword()); preparedStatement.setString(2, user.getNickname()); preparedStatement.setInt(3, user.getId()); preparedStatement.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { DBUtil.close(preparedStatement); DBUtil.close(connection); } } @Override public User load(int id) { Connection connection = DBUtil.getConnection(); //鍑嗗�sql璇�彞 String sql = "select * from t_user where id = ?"; //鍒涘缓璇�彞浼犺緭瀵硅薄 PreparedStatement preparedStatement = null; ResultSet resultSet = null; User user = null; try { preparedStatement = connection.prepareStatement(sql); preparedStatement.setInt(1, id); resultSet = preparedStatement.executeQuery(); while(resultSet.next()) { user = new User(); user.setId(id); user.setUsername(resultSet.getString("username")); user.setPassword(resultSet.getString("password")); user.setNickname(resultSet.getString("nickname")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { DBUtil.close(resultSet); DBUtil.close(preparedStatement); DBUtil.close(connection); } return user; } @Override public User load(String username) { // TODO Auto-generated method stub return null; } @Override public List<User> load() { Connection connection = DBUtil.getConnection(); //鍑嗗�sql璇�彞 String sql = "select * from t_user "; //鍒涘缓璇�彞浼犺緭瀵硅薄 PreparedStatement preparedStatement = null; ResultSet resultSet = null; //闆嗗悎涓�彧鑳芥斁鍏�ser瀵硅薄 List<User> users = new ArrayList<User>(); User user = null; try { preparedStatement = connection.prepareStatement(sql); resultSet = preparedStatement.executeQuery(); while(resultSet.next()) { user = new User(); user.setId(resultSet.getInt("id")); user.setUsername(resultSet.getString("username")); user.setPassword(resultSet.getString("password")); user.setNickname(resultSet.getString("nickname")); users.add(user); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { DBUtil.close(resultSet); DBUtil.close(preparedStatement); DBUtil.close(connection); } return users; } }
public void update(User user); public User load(int id); public User load(String username); public List<User> load(); }
package com.jaovo.msg.Util; public class UserException extends RuntimeException{ public UserException() { super(); // TODO Auto-generated constructor stub } public UserException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) { super(message, cause, enableSuppression, writableStackTrace); // TODO Auto-generated constructor stub } public UserException(String message, Throwable cause) { super(message, cause); // TODO Auto-generated constructor stub } public UserException(String message) { super(message); // TODO Auto-generated constructor stub } public UserException(Throwable cause) { super(cause); // TODO Auto-generated constructor stub } }
3.