hibernate 简单CRUD操作
首先我们要搭建好hibernate的开发环境我是在Eclipse下搭建的建立javaProject
下载hibernate3.2
加入jar包
从下载过来的hibernate3.2文件中COPY一份hibernate.cfg.xml 写上你的数据库配置
搭建日志环境.
hibernate中对实体的CRUD操作 建立了两个实体类 其关系在数据库中是ManyToMany的两张表
pojo:Person
package com.test.bean;import java.util.Date;import java.util.HashSet;import java.util.Set;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.JoinTable;import javax.persistence.ManyToMany;import javax.persistence.Table;import javax.persistence.Temporal;import javax.persistence.TemporalType;import org.hibernate.annotations.CascadeType;import org.hibernate.annotations.Cascade;@Entity@Table(name="person1")public class Person {@Id@Column(name="personId",length=10)@GeneratedValue(strategy= GenerationType.AUTO)private int personId;@Column(name="userName",length=60)private String userName;@Column(name="password",length=60)private String password;/**TIMESTAMP ：等于java.sql.Timestamp*/@Temporal(TemporalType.TIMESTAMP)private Date birthday;/** * ManyToMany 主控方配置 * 其实既然是所谓的多对多就无所谓的被控和主控了* 这样配置我可以通过删除person 做到删除friend但是无法通过删除friend 做到删除person * 所以个人认为实应该两边都配置成主控方 希望大家来讨论 * 不知道为什么 这里写成CascadeType.PERSIST,CascadeType.MERGE}不能做到联机更新 * 利用sesson.persist()估计能做到联机更新 这个我没去测试， 有时间下次做吧* fetch=FetchType.LAZY 延迟加载 */@ManyToMany(fetch=FetchType.LAZY)@Cascade(value={CascadeType.SAVE_UPDATE})/**name-中间表名称JoinTable-描述了MTM的数据表关系joinColumns-定义中间表与person(当前类)的外键关系 inverseJoninCoulums-定义了中间表与另一端的外键关系*/@JoinTable(name="person_friend",joinColumns={@JoinColumn(name="p_id")},inverseJoinColumns={@JoinColumn(name="f_id")})Set<Friend> friend = new HashSet<Friend>();/**getter setter*/public int getPersonId() {return personId;}public void setPersonId(int personId) {this.personId = personId;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public Set<Friend> getFriend() {return friend;}public void setFriend(Set<Friend> friend) {this.friend = friend;}}
pojo:Friend
package com.test.bean;import java.util.HashSet;import java.util.Set;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.ManyToMany;import javax.persistence.Table;import org.hibernate.annotations.Cascade;import org.hibernate.annotations.CascadeType;@Entity@Table(name="friend1")public class Friend {@Id@Column(name="friendId",length=10)@GeneratedValue(strategy= GenerationType.AUTO)private Integer friendId;@Column(name="fName",length=60)private String fName;@Column(name="fPass",length=60)private String fPass;/**ManyToMany 被控方的配置 *//** * mappedBy 属性定义了此类为双向关系的维护端 它的值应该是此关系的另一端的属性名（可见Person类中定义的friend） */@ManyToMany(fetch=FetchType.LAZY,mappedBy="friend")@Cascade(value={CascadeType.SAVE_UPDATE})Set<Person> person = new HashSet<Person>();public Integer getFriendId() {return friendId;}public void setFriendId(Integer friendId) {this.friendId = friendId;}public String getfName() {return fName;}public void setfName(String fName) {this.fName = fName;}public String getfPass() {return fPass;}public void setfPass(String fPass) {this.fPass = fPass;}public Set<Person> getPerson() {return person;}public void setPerson(Set<Person> person) {this.person = person;}}
CRUD---
package com.test.testBean;import java.util.ArrayList;import java.util.Date;import java.util.List;import java.util.Set;import javax.transaction.HeuristicMixedException;import javax.transaction.HeuristicRollbackException;import javax.transaction.RollbackException;import javax.transaction.SystemException;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.AnnotationConfiguration;import org.hibernate.tool.hbm2ddl.SchemaExport;import com.test.bean.Friend;import com.test.bean.Person;public class TestPerson {private static SessionFactory sessionFactory;private static Transaction ts;private Date date = new Date();/** * 构造方法 里面 创建sessionFactory */publicTestPerson(){@SuppressWarnings("unused")Session session = null;try{/** SchemaExport 每次都会将表的数据清空*///new SchemaExport(new AnnotationConfiguration().configure()).create(false, true);//sessionFactorysessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();System.out.println("创建sessionFactory成功");}catch(Exception e){e.printStackTrace();System.out.println("创建sessionFactory出错");}finally{}}/** * @param args * @throws Exception*/public static void main(String[] args) throws Exception {TestPerson tp = new TestPerson();//tp.addPF();//tp.query();//tp.update();tp.testRemove();}/** * 填充数据 * @throws Exception*/public void addPF() throws Exception{Person p = new Person();Friend f = new Friend();p.setBirthday(date);p.setPassword("fffff");p.setUserName("fff");//---------=============-------------------f.setfName("FFFFFF");f.setfPass("FFFFFFF");this.save(p, f);}/** * 建立关系 并且保存到数据库 * @param p person对象 * @param f friend 对象 * @return boolean */public void save(Person p,Friend f)throws Exception{p.getFriend().add(f);/** * 这里需要注意下 如果你的f是被控方那么在save的时候 能save两张表的数据 但是不能建立关系 * 即中间表中没有数据 */Session session = sessionFactory.getCurrentSession();org.hibernate.Transaction ts = session.beginTransaction();// session.save(f);//session.persist(arg0)try{session.save(p);System.out.println("保存成功");ts.commit();}catch (Exception e) {e.printStackTrace();System.out.println("保存失败");ts.rollback();}}/** * 查询数据 * @throws SecurityException * @throws IllegalStateException * @throws RollbackException * @throws HeuristicMixedException * @throws HeuristicRollbackException * @throws SystemException */@SuppressWarnings({ "unchecked", "static-access"})public void query() throws SecurityException, IllegalStateException, RollbackException, HeuristicMixedException, HeuristicRollbackException, SystemException{/**定义hql*/String hql="from Person";/**获得session*/Session session = this.sessionFactory.getCurrentSession();/**开始事务*/ts = (Transaction) session.beginTransaction();/**执行hql语句*/Query query = session.createQuery(hql);/**定义一个list来存放数据*/List<Person>list = new ArrayList<Person>();list = query.list(); /**遍历LIST*/for(Person p: list){System.out.println(p.getPassword());System.out.println(p.getUserName());}/**事务提交*/ts.commit();/**关闭session ts*/this.closeSession(session, ts);}/** * 根据ID查询出对象--person * @param personId * @return */@SuppressWarnings("static-access")public Person queryPersonById(int queryId,String queryHql){Session session = this.sessionFactory.getCurrentSession();ts = (Transaction) session.beginTransaction();Query query = session.createQuery(queryHql);query.setInteger(0, queryId);Person person =(Person) query.list().get(0);return person;}/** * 根据ID查询出对象--friend * @param personId * @return */@SuppressWarnings("static-access")public Friend queryFriendById(int queryId,String queryHql){Session session = this.sessionFactory.getCurrentSession();ts = (Transaction) session.beginTransaction();Query query = session.createQuery(queryHql);query.setInteger(0, queryId);Friend friend =(Friend) query.list().get(0);return friend;}/** * 更新对象 * @throws Exception */@SuppressWarnings("static-access")public void update()throws Exception{/**首先查询出对象*///定义查询语句String queryHql="from Person p where p.personId=?";Person person = queryPersonById(5,queryHql);person.setPassword("update--paw123");person.setUserName("update--pserson--Lyvee");Session session = this.sessionFactory.getCurrentSession();ts=session.beginTransaction();try{session.update(person);ts.commit();System.out.println("更新成功！！！");}catch(Exception e){e.printStackTrace();//事务回滚ts.rollback();System.out.println("更新出错啦!!!");}finally{this.closeSession(session, ts);}}/** * 删除方法---通过person删除 * @param person * @throws Exception */@SuppressWarnings("static-access")public void del(Person person)throws Exception{Session session = this.sessionFactory.getCurrentSession();ts=session.beginTransaction();try{/**在此 由于我把person配置成了主控制方 故此删除person 由于没有配置联级删除故此被控方Friend仍然会存在 但是中间表记录会删除----关系不存在*/session.delete(person);ts.commit();System.out.println("删除成功！");}catch(Exception e){e.printStackTrace();//回滚事务ts.rollback();System.out.println("删除失败");}finally{this.closeSession(session, ts);}}public void del(Friend friend){Session session = this.sessionFactory.getCurrentSession();ts=session.beginTransaction();try{/**这里由于friend是被控方 直接删除friend 会报错我们应该首先断关系 然后delete*/Set<Person> persons = friend.getPerson();for(Person person :persons){person.getFriend().remove(friend);}session.delete(friend);ts.commit();System.out.println("删除成功");}catch (Exception e) {e.printStackTrace();System.out.println("删除失败");ts.rollback();}finally{this.closeSession(session, ts);}}/** * 测试删除的方法 * @throws Exception */public void testRemove() throws Exception{Session session = this.sessionFactory.getCurrentSession();ts=session.beginTransaction();/**根据ID查询出person对象*///Person person = (Person) session.get(Person.class,1);Friend friend = (Friend) session.get(Friend.class, 4);//del(person);del(friend);}/** * session transacation 关闭 * @param session * @param ts * @return boolean */public boolean closeSession(Session session,Transaction ts){if(ts!=null){ts=null;}return false;}}
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