import java.sql.*; /**課題：封裝數(shù)據(jù)庫的增刪改查的工具類的實現(xiàn)。 * * 假設相關數(shù)據(jù)庫的表結構如下： * 表名：user * 列名及屬性：id(int 自增)，name(varchar(20))，tele(char(12))，birthday(date) * @author shy2850 */ public class UserDAO { Connection conn; public UserDAO(Connection conn) { this.conn = conn; } public int save(User user) throws SQLException { String sql = insert into user values(0,?,?,?); PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setString(1, user.getName()); pstmt.setString(2, user.getTele()); pstmt.setDate(3, user.getBirthday()); int n = pstmt.executeUpdate(); pstmt.close(); return n; } public int delete(User user) throws SQLException{ String sql = delete from user where id = +user.getId(); Statement stmt = conn.createStatement(); int n = stmt.executeUpdate(sql); stmt.close(); return n; } public int update(User user) throws SQLException{ String sql = update user set name=?, tele=?, birthday=? where id = +user.getId(); PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setString(2, user.getName()); pstmt.setString(3, user.getTele()); pstmt.setDate(4, user.getBirthday()); int n = pstmt.executeUpdate(sql); pstmt.close(); return n; } public User getUser(Integer id) throws SQLException{ String sql = select * from user where id = + id; Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery(sql); User user = getUserFromResultSet(rs); rs.close(); stmt.close(); return user; } static User getUserFromResultSet(ResultSet rs) throws SQLException{ Integer id = rs.getInt(id); String name= rs.getString(name); String tele= rs.getString(tele); Date birthday = rs.getDate(birthday); return new User(id, name, tele, birthday); } } /** * 構建數(shù)據(jù)庫表的java類映射 */ class User{ private Integer id; private String name; private String tele; private Date birthday; public User() { } public User(Integer id, String name, String tele, Date birthday) { super(); this.id = id; this.name = name; this.tele = tele; this.birthday = birthday; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getTele() { return tele; } public void setTele(String tele) { this.tele = tele; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } }