Hiberate基础用法实例

下面通过一个实际的列子来展示Hibernate的基本用法。

实例：

package com.ydoing.domain;

import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.persistence.Basic;
import javax.persistence.CollectionTable;
import javax.persistence.Column;
import javax.persistence.ElementCollection;
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.Lob;
import javax.persistence.MapKeyClass;
import javax.persistence.MapKeyColumn;
import javax.persistence.OrderColumn;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Transient;

import org.hibernate.annotations.Formula;

@Entity
@Table(name = "person")
public class Person {

    // 主键为ＩＤ，最好设置为包装类型Integer
    @Id
    @Column(name = "person_id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    // 指定字符长度
    @Column(name = "name", length = 50, nullable = false)
    private String name;

    @Column(name = "age")
    private int age;

    // 也可以不指定列名，默认为类的属性名
    @Column
    private String sex;

    // @Transient表示不用持久化
    @Transient
    private String alias;

    // @Lob表示大数据类型，FetchType.LAZY表示延迟加载，减少性能开销
    @Lob
    @Basic(fetch = FetchType.LAZY)
    private byte[] image;

    // 指定为日期类型
    @Temporal(TemporalType.DATE)
    private Date birthdate;

    // 属性动态生成
    @Formula("(select concat(p.name, p.age, p.sex) from person p where p.person_id = person_id)")
    private String profile;

    // List集合类型
    // 需要显示初始化集合的类型
    @ElementCollection(targetClass = String.class)
    @CollectionTable(name = "pet_inf",// 指定表名
    // 用于映射外键
    joinColumns = @JoinColumn(name = "person_id", nullable = false))
    @Column(name = "pet_name")
    @OrderColumn(name = "list_order")
    private List<String> pets = new ArrayList<>();

    // 数组属性
    @ElementCollection(targetClass = String.class)
    @CollectionTable(name = "school_inf", joinColumns = @JoinColumn(name = "person_id", nullable = false))
    @Column(name = "school_name")
    @OrderColumn(name = "array_order")
    private String[] schools;

    // Set集合属性,Set是无序的，不可重复的，因此Set集合属性无须使用@OrderColumn注解映射集合的索引列
    @ElementCollection(targetClass = String.class)
    @CollectionTable(name = "car_inf", joinColumns = @JoinColumn(name = "person_id", nullable = false))
    @Column(name = "car_name")
    private Set<String> cars = new HashSet<>();// 必须指定接口实现类

    // Map集合属性
    @ElementCollection(targetClass = Float.class)
    @CollectionTable(name = "salary_inf", joinColumns = @JoinColumn(name = "person_id", nullable = false))
    // 指定key的类型
    @MapKeyColumn(name = "salary_type")
    @MapKeyClass(String.class)
    // 映射Map的value
    @Column(name = "money")
    private Map<String, Float> payroll = new HashMap<>(); // 必须指定接口实现类

    // 映射组件属性，所谓组件的意思是：不是基本数据类型，而是自定义的复合类型，且不是持久化实体
    private Address address;

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    public Map<String, Float> getPayroll() {
        return payroll;
    }

    public void setPayroll(Map<String, Float> payroll) {
        this.payroll = payroll;
    }

    public String[] getSchools() {
        return schools;
    }

    public void setSchools(String[] schools) {
        this.schools = schools;
    }

    public String getSex() {
        return sex;
    }

    public Set<String> getCars() {
        return cars;
    }

    public void setCars(Set<String> cars) {
        this.cars = cars;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getProfile() {
        return profile;
    }

    public void setProfile(String profile) {
        this.profile = profile;
    }

    public Person() {
    }

    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 getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAlias() {
        return alias;
    }

    public void setAlias(String alias) {
        this.alias = alias;
    }

    public byte[] getImage() {
        return image;
    }

    public void setImage(byte[] image) {
        this.image = image;
    }

    public Date getBirthdate() {
        return birthdate;
    }

    public void setBirthdate(Date birthdate) {
        this.birthdate = birthdate;
    }

    public List<String> getPets() {
        return pets;
    }

    public void setPets(List<String> pets) {
        this.pets = pets;
    }

    public void setId(Integer id) {
        this.id = id;
    }

}

组件类

package com.ydoing.domain;
import javax.persistence.Column;
import javax.persistence.Embeddable;
import org.hibernate.annotations.Parent;
@Embeddable
public class Address {
    @Column(name = "person_province")
    private String province;
    @Column(name = "person_city")
    private String city;
    public Address() {
    }
    // 属于哪个实体组件
    @Parent
    private Person person;
    public Person getPerson() {
        return person;
    }
    public void setPerson(Person person) {
        this.person = person;
    }
    public Address(String province, String city) {
        super();
        this.province = province;
        this.city = city;
    }
    public String getProvince() {
        return province;
    }
    public void setProvince(String province) {
        this.province = province;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
}

测试：

package com.ydoing.test;

import java.util.Arrays;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

import com.ydoing.domain.Address;
import com.ydoing.domain.Person;

public class Main {
    public static void main(String[] args) {
        Configuration conf = new Configuration();
        conf.configure();
        // ServiceRegistry serviceRegistry = new
        // ServiceRegistryBuilder().applySettings(conf.getProperties())
        // .buildServiceRegistry();
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(conf.getProperties())
                .build();
        SessionFactory factory = conf.buildSessionFactory(serviceRegistry);
        Session session = factory.openSession();

        Person person = new Person();
        person.setName("Jack");
        person.setAge(22);
        person.setSex("男");

        // 不会持久化
        person.setAlias("Arron");

        // List属性
        String[] array = { "cat", "dog", "snake" };
        List<String> pets = Arrays.asList(array);
        person.setPets(pets);

        // 数组属性
        String[] schools = { "清华", "北大" };
        person.setSchools(schools);

        // Set集合属性
        person.getCars().add("奥迪");
        person.getCars().add("大众");

        // Map属性
        person.getPayroll().put("基本工资", (float) 5000);
        person.getPayroll().put("绩效", (float) 3000);

        person.setAddress(new Address("浙江", "杭州"));

        Transaction tx = session.getTransaction();
        tx.begin();
        session.save(person);

        Person p = (Person) session.load(Person.class, 12);
        System.out.println(p.getProfile());

        tx.commit();
        session.close();
    }
}

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