pt-webProject.zip

package com.bang.DAO.Impl; import com.bang.DAO.UserDao; import com.bang.Entity.User; import com.bang.Util.DBHelper; import org.junit.Test; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; /** * @ClassName UserDaoImpl * @Description * @Author Bang * @Date 2023/6/27 17:00 * @Version v1.0 */ public class UserDaoImpl implements UserDao { @Override public User selectUserByUsername(String username) { User user = null; Connection con = null; PreparedStatement pstmt = null; ResultSet resultSet = null; try { //获取数据库连接 con = DBHelper.getConnection(); //定义sql语句 String sql = "select * from user where username = ?"; //获取PreparedStatement对象 if (con != null) { pstmt = con.prepareStatement(sql); } //赋值 pstmt.setString(1, username); //执行sql语句 resultSet = pstmt.executeQuery(); //获取查询结果集 if (resultSet.next()) { user = new User(); user.setId(resultSet.getInt("id")); user.setUsername(resultSet.getString("username")); user.setPassword(resultSet.getString("password")); user.setAge(resultSet.getInt("age")); } } catch (SQLException e) { e.printStackTrace(); } finally { //关闭数据库连接 DBHelper.getClosed(con, pstmt, resultSet); } return user; } @Test public void testSelectUserByUsername() { User user = selectUserByUsername("bang"); System.out.println(user); } @Override public int insertUser(User user) { int result = 0; Connection con = null; PreparedStatement pstmt = null; try { //获取数据库连接 con = DBHelper.getConnection(); //定义sql语句 String sql = "insert into user(username,password,age,gender,email) values(?,?,?,?,?)"; //获取PreparedStatement对象 pstmt = con.prepareStatement(sql); //赋值 pstmt.setString(1, user.getUsername()); pstmt.setString(2, user.getPassword()); pstmt.setInt(3, user.getAge()); pstmt.setString(4, user.getGender()); pstmt.setString(5, user.getEmail()); //执行sql语句 result = pstmt.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } finally { //关闭数据库连接 DBHelper.getClosed(con, pstmt, null); } return result; } @Override public List<User> selectAll() { List<User> list = new ArrayList<User>(); Connection con = null; // 定义执行对象为null PreparedStatement ps = null; // 定义结果集为null ResultSet rs = null; try { // 执行连接 con = DBHelper.getConnection(); // 执行sql语句 ps = con.prepareStatement("select * from user"); // 执行结果集 rs = ps.executeQuery(); // 遍历 while (rs.next()) { User user = new User(); user.setId((int) rs.getLong(1)); user.setUsername(rs.getString(2)); user.setAge(Integer.parseInt(rs.getString(3))); user.setGender(rs.getString(4)); user.setEmail(rs.getString(5)); list.add(user); } } catch (Exception e) { // TODO: handle exception // 处理异常 e.printStackTrace(); } finally { // 关闭资源 DBHelper.getClosed(con, ps, rs); } // 返回实体类信息 return list; } @Test public void testInsertUser(){ User user = new User(); user.setUsername("bang"); user.setPassword("123456"); user.setAge(18); user.setGender("男"); user.setEmail("[email protected]"); int i = this.insertUser(user); System.out.println(i); } }