DTO類是data tranfer object也就是數據傳輸類，DTO主要用於數據的傳輸操作，其中包含屬性值，以及構造方法和getter ，setter方法等，不會包含業務邏輯。
首先是Identity類，這個是抽象類。
public abstract class IdEntity {
protected long id;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
}
Address和User類分別對應數據庫中的表格tbl_user和tbl_address.
代碼如下：
public class User extends IdEntity {
private String name;
private String password;
private String email;
public User(String name, String password, String email) {
this.name = name;
this.password = password;
this.email = email;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Override
public String toString() {
return "User [name=" + name + ", password=" + password + ", email="
+ email + ", id=" + id + "]";
}
}
Address類的代碼：
public class Address extends IdEntity {
private String city;
private String country;
private String userid;
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public String getUserid() {
return userid;
}
public void setUserid(String userid) {
this.userid = userid;
}
@Override
public String toString() {
return "Address [city=" + city + ", country=" + country + ", userid="
+ userid + ", id=" + id + "]";
}
}
DAO 是data access object即是數據訪問對象的縮寫。
使用了PreparedStatement這個類，這個類可以使用占位符，然後使用方法再來設置參數。
最後execute執行。
具體代碼如下：
首先定了借口UserDao
public interface UserDao {
public void save(Connection conn,User user) throws SQLException;
public void update(Connection conn,Long id,User user)throws SQLException;
public void delete(Connection conn,User user) throws SQLException;
}
具體實現類代碼：
public void save(Connection conn, User user) throws SQLException {
// TODO Auto-generated method stub
PreparedStatement ps = conn.prepareCall("INSERT INTO tbl_user(name,password,email) VALUES (?,?,?)");
ps.setString(1, user.getName());
ps.setString(2, user.getPassword());
ps.setString(3, user.getEmail());
ps.execute();
}
@Override
public void update(Connection conn, Long id, User user) throws SQLException {
// TODO Auto-generated method stub
String sql = "UPDATE tbl_user SET name=?,password=?,email=? WHERE id=?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1, user.getName());
ps.setString(2, user.getPassword());
ps.setString(3, user.getEmail());
ps.setLong(4, id);
ps.execute();
}
@Override
public void delete(Connection conn, User user) throws SQLException {
// TODO Auto-generated method stub
PreparedStatement ps = conn.prepareStatement("DELETE FROM tbl_user WHERE id=?");
ps.setLong(1, user.getId());
ps.execute();
}
}
寫了一個一個測試類往tbl_user裡面插入一行數據。
具體代碼如下：
public class DaoTest {
/**
* @param args
*/
public static void main(String[] args) {
Connection conn = null;
try {
conn = ConnectionFactory.getInstance().makeConnection();
conn.setAutoCommit(false);
UserDao userDao = new UserDaoImpl();
User tom = new User("Tom", "123456", "[email protected]");
userDao.save(conn, tom);
conn.commit();
} catch (Exception e) {
e.printStackTrace();
try {
conn.rollback();
} catch (Exception e2) {
e2.printStackTrace();
}
}
}
}
