public class JDBCUtils { // 获取对象方法 public static Connection getcon() throws Exception { // 注册驱动 Class.forName("com.mysql.jdbc.Driver"); // 获取连接 Connection con = DriverManager.getConnection( "jdbc:mysql://localhost:3306bc", "root", "root"); return con; } public static void close(Statement st, Connection con, ResultSet rs) { if (rs != null) { try { rs.close(); } catch (Exception e) { e.printStackTrace(); } finally { try { if (con != null) { con.close(); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (st != null) { st.close(); } } catch (Exception e) { e.printStackTrace(); } } } } } } JDBCUtils
public class User { private int id; private String name; private int money; private String email; private Date birthday; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getMoney() { return money; } public void setMoney(int money) { this.money = money; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } } User
public class UserDao { // 提供添加方法 public boolean insert(User user) { Connection con = null; Statement st = null; try { // 连接对象 con = JDBCUtils.getcon(); // 获取执行sql语句 st = con.createStatement(); // 执行sql语句 // java.util.Date birthday=user.getBirthday(); java.sql.Date sqlbirthday = new java.sql.Date( new java.util.Date().getTime()); int row = st .executeUpdate("insert into user(id,name,money,email,birthday)" + "values(" + user.getId() + ",'" + user.getName() + "','" + user.getMoney() + "','" + user.getEmail() + "','" + sqlbirthday + "'" + ")"); if (row > 0) { return true; } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.close(st, con, null); } return false; } public void findall(){ Connection con = null; Statement st = null; ResultSet rs = null; try { // 连接对象 con = JDBCUtils.getcon(); // 获取执行sql语句 st = con.createStatement(); //执行sql语句 rs=st.executeQuery("select * from user"); //遍历rs while(rs.next()){ System.out.println(rs.getInt("id")+" "+rs.getString("name")+" " +rs.getInt("money")+" "+rs.getString("email")+" "+rs.getDate("birthday")+""); } } catch (Exception e) { e.printStackTrace(); }finally{ JDBCUtils.close(st, con, rs); } } //提供查询所有语句的方法 public List<User> findAllUser() { Connection con = null; Statement st = null; ResultSet rs = null; try { // 连接对象 con = JDBCUtils.getcon(); // 获取执行sql语句 st = con.createStatement(); //执行sql语句 rs=st.executeQuery("select * from user"); //遍历rs List<User> list=new ArrayList<User>(); while(rs.next()){ User user=new User(); /*System.out.println(rs.getInt("id")+" "+rs.getString("name")+" " +rs.getInt("money")+" "+rs.getString("email")+" "+rs.getDate("birthday")+""); */ user.setId(rs.getInt("id")); user.setName(rs.getString("name")); user.setMoney(rs.getInt("money")); user.setEmail(rs.getString("email")); user.setBirthday(rs.getDate("birthday")); list.add(user); } return list; } catch (Exception e) { e.printStackTrace(); }finally{ JDBCUtils.close(st, con, rs); } return null; } //根据id查询对象 public User findbyid(int id){ Connection con = null; PreparedStatement st = null; ResultSet rs = null; try { // 连接对象 con = JDBCUtils.getcon(); // 获取执行sql语句 st=con.prepareStatement("select * from user where id=?"); //执行sql语句 st.setInt(1, id); rs=st.executeQuery(); //遍历rs if(rs.next()){ User user=new User(); user.setId(rs.getInt("id")); user.setName(rs.getString("name")); user.setMoney(rs.getInt("money")); user.setEmail(rs.getString("email")); user.setBirthday(rs.getDate("birthday")); return user; } } catch (Exception e) { e.printStackTrace(); }finally{ JDBCUtils.close(st, con, rs); } return null; } //提供修改数据方法 public boolean update(User user){ Connection con = null; PreparedStatement st = null; try { // 连接对象 con = JDBCUtils.getcon(); // 获取执行sql语句 st = con.prepareStatement("update user set money=?,name=? where id=?"); // 执行sql语句 st.setInt(3, user.getId()); st.setInt(1, user.getMoney()); st.setString(2, user.getName()); int row = st.executeUpdate(); if (row > 0) { return true; } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.close(st, con, null); } return false; } //提供删除数据方法 public boolean delete(int id){ Connection con = null; PreparedStatement st = null; try { // 连接对象 con = JDBCUtils.getcon(); // 获取执行sql语句 st = con.prepareStatement("delete from user where id=?"); // 执行sql语句 st.setInt(1, id); int row = st.executeUpdate(); if (row > 0) { return true; } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.close(st, con, null); } return false; } } UserDao
public class Jdbcinsettest { public static void main(String[] args) { // TODO Auto-generated method stub UserDao dao=new UserDao(); User user=new User(); user.setId(5); user.setName("wcp"); user.setMoney(1000); user.setEmail("2316726@qq.com"); user.setBirthday(new Date(1992-02-02)); boolean flag=dao.insert(user); System.out.print(flag); } } Jdbcinsettest
public class Jdbccinserttest { public static void main(String[] args) { // TODO Auto-generated method stub UserDao dao=new UserDao(); dao.findall(); List <User> list=dao.findAllUser(); System.out.print(list.size()); } }
public class Jdbccid { public static void main(String[] args) { // TODO Auto-generated method stub UserDao dao=new UserDao(); User u=dao.findbyid(2); System.out.println(u.getName()); } }
public class Jdbcupdate { public static void main(String[] args) { // TODO Auto-generated method stub UserDao dao=new UserDao(); User user=new User(); user.setId(2); user.setMoney(20); user.setName("llii"); boolean flag=dao.update(user); System.out.print(flag); } }
public class Jdbcdele { public static void main(String[] args) { // TODO Auto-generated method stub UserDao dao=new UserDao(); User u=new User(); boolean flag=dao.delete(3); System.out.print(flag); } }