Hibernate框架之路（二）一對多關系
阿新 • • 發佈：2017-08-30
true pre conn 關系 編寫 none isp exce dia 
在下列案例中：
客戶是一；聯系人是多；客戶可以擁有多個聯系人；一個聯系人只有一個客戶
1、編寫實體類
package com.pojo; import java.util.HashSet; import java.util.Set; public class User { private Integer uId; //客戶ID（主表） 客戶是一 private String uName; //名字 private String uTel; //手機 // 在客戶的表中顯示多個聯系人 // 使用set集合存儲聯系人User實體類private Set<Link> link = new HashSet<Link>(); public Set<Link> getLink() { return link; } public void setLink(Set<Link> link) { this.link = link; } public Integer getuId() { return uId; } public void setuId(Integer uId) {this.uId = uId; } public String getuName() { return uName; } public void setuName(String uName) { this.uName = uName; } public String getuTel() { return uTel; } public void setuTel(String uTel) { this.uTel = uTel; } }
package com.pojo; public class Link { private Integer cId; //聯系人ID 聯系人是多 private String cName; //姓名 private String cTel; //電話 //在聯系人的實體類中顯示所屬客戶列表；一個聯系人只有一個客戶 private User user; public User getUser() { return user; } public void setUser(User user) { this.user = user; } public Integer getcId() { return cId; } public void setcId(Integer cId) { this.cId = cId; } public String getcName() { return cName; } public void setcName(String cName) { this.cName = cName; } public String getcTel() { return cTel; } public void setcTel(String cTel) { this.cTel = cTel; } }聯系人實體類
2、配置實體類映射文件
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <!-- 客戶配置文件 --> <class name="com.pojo.User" table="p_user"> <id name="uId" column="uId"> <generator class="native"></generator> </id> <property name="uName" column="uName"></property> <property name="uTel" column="uTel"></property> <!-- set標簽的name屬性：指的是寫在客戶表中的聯系人的set集合的名稱 inverse="true"：讓主表一方放棄維護 --> <set name="link" cascade="save-update,delete" inverse="false"> <!-- id 的 column 屬性的值：數據表的外鍵名稱 --> <key column="clid"></key> <!-- 客戶的所有聯系人； class寫聯系人的實體類路徑 --> <one-to-many class="com.pojo.Link"/> </set> </class> </hibernate-mapping>
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <!-- 聯系人配置文件 --> <class name="com.pojo.Link" table="p_link"> <id name="cId" column="cId"> <generator class="native"></generator> </id> <property name="cName" column="cName"></property> <property name="cTel" column="cTel"></property> <!-- 聯系人所屬客戶 name：客戶在聯系人實體類的屬性 class：聯系人實體類的路徑 column：外鍵名稱 --> <many-to-one name="user" class="com.pojo.Link" column="clid"></many-to-one> </class> </hibernate-mapping>
3、配置核心文件
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <!-- 1、配置數據庫信息 必寫的 --> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql:///person</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password">root</property> <!-- 2、配置hibernate信息 可寫 --> <!-- 輸出SQL底層語句 --> <property name="hibernate.show_sql">true</property> <!-- 輸出SQL底層語句 進行格式化 --> <property name="hibernate.format_sql">true</property> <!-- 如果沒有表。即創建，否則修改表 --> <property name="hibernate.hbm2ddl.auto">update</property> <!-- 設置數據庫方言 --> <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property> <!-- 3、把映射文件放到核心配置文件中 必須的 --> <mapping resource="com/pojo/Link.hbm.xml"/> <mapping resource="com/pojo/User.hbm.xml"/> </session-factory> </hibernate-configuration>
4、加載核心配置文件測試是否搭建成功
package com.unitl; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; public class HibernateUtils { private static Configuration cfg = null; private static SessionFactory factory = null; static{ // 加載 hibernate 核心文件 cfg = new Configuration(); cfg.configure(); // 創建 SessionFactory對象 factory = cfg.buildSessionFactory(); } //獲取 hibernate核心文件 public static SessionFactory getSessionFactory() { return factory; } //綁定本地線程session public static Session getSessionObject(){ return factory.getCurrentSession(); } /** * 調用方法 * SessionFactory factory = HibernateUtils.getSessionFactory(); * */ public static void main(String[] args) { //執行之後無報錯，則配置成功 } }
5、使用方法實現增刪改查操作
package com.junit; import static org.junit.Assert.*; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.junit.Test; import com.pojo.Link; import com.pojo.User; import com.unitl.HibernateUtils; public class Text1 { @Test public void test() { SessionFactory factory = null; Session session = null; Transaction ts = null; try { factory = HibernateUtils.getSessionFactory(); session = factory.openSession(); ts = session.beginTransaction(); /** * 創建聯系人 */ Link link1 = new Link(); link1.setcName("百度"); link1.setcTel("400-200-666"); /** * 創建客戶 */ User user1 = new User(); user1.setuName("張三"); user1.setuTel("150*******"); /** * 把聯系人對象放到客戶的set集合裏邊 */ user1.getLink().add(link1); /** * 把客戶放在聯系人對象裏 */ link1.setUser(user1); //添加到數據庫 session.save(user1); session.save(link1); //提交事務 ts.commit(); } catch (Exception e) { ts.rollback(); } finally { session.close(); factory.close(); } } /** * 簡化 * 添加操作 */ @Test public void test2() { SessionFactory factory = null; Session session = null; Transaction ts = null; try { factory = HibernateUtils.getSessionFactory(); session = factory.openSession(); ts = session.beginTransaction(); //添加一個客戶 User user1 = new User(); user1.setuName("李四"); user1.setuTel("150*******"); //創建聯系人 Link link1 = new Link(); link1.setcName("騰訊"); link1.setcTel("400-200-666"); //把聯系人放到客戶的 set 集合裏邊 user1.getLink().add(link1); // 保存到 數據庫裏 session.save(user1); ts.commit(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); ts.rollback(); }finally{ session.close(); factory.close(); } } /** * 添加一個聯系人到已知的客戶裏 * 例子：向一個已知店鋪裏添加一個商品 */ @Test public void test3() { SessionFactory factory = null; Session session = null; Transaction ts = null; try { factory = HibernateUtils.getSessionFactory(); session = factory.openSession(); ts = session.beginTransaction(); //創建一個聯系人並添加到已知客戶 Link link1 = new Link(); link1.setcName("阿裏巴巴"); link1.setcTel("400-200-666"); //獲取客戶 User user = session.get(User.class,2); user.getLink().add(link1); session.save(user); ts.commit(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); ts.rollback(); }finally{ session.close(); factory.close(); } } /** * 刪除一個客戶 */ @Test public void test4() { SessionFactory factory = null; Session session = null; Transaction ts = null; try { factory = HibernateUtils.getSessionFactory(); session = factory.openSession(); ts = session.beginTransaction(); //查詢客戶ID User user = session.get(User.class, 3); session.delete(user); ts.commit(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); ts.rollback(); }finally{ session.close(); factory.close(); } } /** * 修改操作 * 把聯系人表中的ID為2的聯系人改為客戶一的聯系人 */ @Test public void test5() { SessionFactory factory = null; Session session = null; Transaction ts = null; try { factory = HibernateUtils.getSessionFactory(); session = factory.openSession(); ts = session.beginTransaction(); //查詢聯系人ID和用戶ID User user = session.get(User.class, 1); Link link = session.get(Link.class, 2); // 把聯系人放到客戶裏邊；客戶放到聯系人裏 user.getLink().add(link); link.setUser(user); ts.commit(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); ts.rollback(); }finally{ session.close(); factory.close(); } } }View Code
Hibernate框架之路（二）一對多關系