首先要創建要映射的實體類

一對多映射，一個人可以有多個收貨地址

User.java

package star.july.b_annotation; import java.util.HashSet; import java.util.Set; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.OneToMany; import javax.persistence.Table; /*** 使用注解映射*/ /*** @author Starjuly**/ //實體類 @Entity //表名稱 @Table(name="t_user") public class User {@Id//自增長@GeneratedValue@Columnprivate int id;@Column(name="uName")private String name;//一對多連接//級聯操作：CascadeType.ALL//主鍵維護策略：mappedBy:把關聯維護權交給Address的user@OneToMany(cascade={CascadeType.ALL},mappedBy="user")//加入外鍵//使用mappedBy后就不能使用JoinColumn和JoinTable了 // @JoinColumn(name="uid")private Set<Address> address = new HashSet<Address>();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 Set<Address> getAddress() {return address;}public void setAddress(Set<Address> address) {this.address = address;}}Address.java package star.july.b_annotation; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.Table; @Entity @Table(name="t_address") public class Address {@Id@GeneratedValue@Columnprivate int id;@Column(name="adsName")private String name;@Columnprivate String address;public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}//多對一連接@ManyToOne@JoinColumn(name="uid")private User user = new User();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 User getUser() {return user;}public void setUser(User user) {this.user = user;}}
再要hibernate.cfg.xml中配置映射類

<!-- 映射類 --> ??????????<mapping class="star.july.b_annotation.User"/>?????????? ??????????<mapping class="star.july.b_annotation.Course"/>

測試類，包括一對多，多對多，一對一

package star.july.b_annotation; import org.hibernate.Session; import org.hibernate.Transaction; import org.junit.Test; import star.july.util.HibernateUtil; //測試注解配置 public class TestDemo {//一對多連接@Testpublic void test(){Session session = HibernateUtil.getSession();Transaction ts = session.getTransaction();try{ts.begin();User u = new User();u.setName("徐鳳年");Address ads = new Address();ads.setName("姜妮");ads.setAddress("北涼龍虎山");Address ads2 = new Address();ads2.setName("婓南葦");ads2.setAddress("北涼胭脂郡");u.getAddress().add(ads);u.getAddress().add(ads2);ads.setUser(u);ads2.setUser(u);session.save(u);ts.commit();}catch(Exception e ){e.printStackTrace();ts.rollback();}}//一對多連接@Testpublic void test2(){Session session = HibernateUtil.getSession();Transaction ts = session.getTransaction();try{ts.begin();Student s1 = new Student();s1.setName("小火");Student s2 = new Student();s2.setName("小火");Course c1 = new Course();c1.setName("java開發");Course c2 = new Course();c2.setName("java開發");s1.getCourse().add(c1);s1.getCourse().add(c2);s2.getCourse().add(c1);c1.getStudent().add(s1);c1.getStudent().add(s2);c2.getStudent().add(s1);session.save(s1);session.save(s2);session.save(c1);session.save(c2);ts.commit();}catch(Exception e ){e.printStackTrace();ts.rollback();}}//一對一連接@Testpublic void test3(){Session session = HibernateUtil.getSession();Transaction ts = session.getTransaction();try{ts.begin();Person p1 = new Person();p1.setName("左莫");Person p2 = new Person();p2.setName("楊紫");IdCard c1 = new IdCard();c1.setName("232443453");IdCard c2 = new IdCard();c2.setName("5687651543");p1.setCard(c1);p2.setCard(c2);c1.setPerson(p1);c2.setPerson(p2);session.save(p1);session.save(p2);session.save(c1);session.save(c2);ts.commit();}catch(Exception e ){e.printStackTrace();ts.rollback();}} }

接下來是多對多的注解映射

Course package star.july.b_annotation; import java.util.HashSet; import java.util.Set; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.Table; @Entity @Table(name="t_course") public class Course {@Id@GeneratedValue@Columnprivate int id;@Column(name="cName")private String name;@ManyToMany(mappedBy="course",cascade={CascadeType.ALL})/*@JoinTable(//中間表的表名name="student_course",//當前表的外鍵joinColumns=@JoinColumn(name="cid"),//關聯表的外鍵inverseJoinColumns=@JoinColumn(name="sid"))*/private Set<Student> student = new HashSet<Student>();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 Set<Student> getStudent() {return student;}public void setStudent(Set<Student> student) {this.student = student;}}Student..java package star.july.b_annotation; import java.util.HashSet; import java.util.Set; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.Table; import org.hibernate.annotations.CascadeType; @Entity @Table(name="t_student") public class Student {@Id@GeneratedValue@Columnprivate int id;@Column(name="sName")private String name;@ManyToMany@JoinTable(//中間表的表名name="student_course",//當前表的外鍵joinColumns=@JoinColumn(name="sid"),//關聯表的外鍵inverseJoinColumns=@JoinColumn(name="cid"))private Set<Course> course = new HashSet<Course>();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 Set<Course> getCourse() {return course;}public void setCourse(Set<Course> course) {this.course = course;}}

最后是一對一的注解映射 人和身份證 摘取其中最重要的代碼片段： Person.java @OneToOne(cascade={CascadeType.ALL},mappedBy="person") ??????????private IdCard card;
IdCard.java ??????????@OneToOne ? ? ? ? ?? //外鍵唯一 ??????????@JoinColumn(name="uid",unique=true) ??????????private Person person ;

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