Hibernate和JPA使用连接表处理多对一映射

 

在项目中，原有的持久化操作时使用JPA进行的，通过注解多对一映射被映射成中间表和两个数据库表，其代码如下：

1. import javax.persistence.Column;
2. import javax.persistence.Entity;
3. import javax.persistence.GeneratedValue;
4. import javax.persistence.GenerationType;
5. import javax.persistence.Id;
6. import javax.persistence.NamedQueries;
7. import javax.persistence.NamedQuery;
8. import javax.persistence.Table;
10. /**
11.  * 产品实体类
12.  * @author 李文锴
13.  */
14. @Entity
15. @Table(name = "yunda_product")
16. @NamedQueries({
17.     @NamedQuery(name = "getProduct", query = "SELECT p FROM OrderProduct AS p"),
18.     @NamedQuery(name = "getProductByName", query = "SELECT p FROM OrderProduct AS p WHERE p.name=:name")
19. })
20. public class OrderProduct implements java.io.Serializable {
22.     private static final long serialVersionUID = 1L;
23.     /**
24.      * 货物id
25.      */
26.     @Id
27.     @GeneratedValue(strategy = GenerationType.AUTO)
28.     private Long id;
29.     /**
30.      * 货物名称
31.      */
32.     @Column(name = "p_name", length = 80, nullable = false)
33.     private String name;
34.     /**
35.      * 货物类型
36.      */
37.     @Column(name = "p_type", length = 80, nullable = false)
38.     private String type;
39.     /**
40.      * 货物数量
41.      */
42.     @Column(name = "p_quantity", nullable = false)
43.     private int quantity;
45.     public OrderProduct() {
46.     }
48.     public OrderProduct(String name, String type, int quantity) {
49.         setName(name);
50.         setType(type);
51.         setQuantity(quantity);
52.     }
54.     public Long getId() {
55.         return id;
56.     }
58.     public void setId(Long id) {
59.         this.id = id;
60.     }
62.     public String getName() {
63.         return name;
64.     }
66.     public void setName(String name) {
67.         this.name = name;
68.     }
70.     public int getQuantity() {
71.         return quantity;
72.     }
74.     public void setQuantity(int quantity) {
75.         this.quantity = quantity;
76.     }
78.     public String getType() {
79.         return type;
80.     }
82.     public void setType(String type) {
83.         this.type = type;
84.     }
86.     @Override
87.     public boolean equals(Object obj) {
88.         if (obj == null) {
89.             return false;
90.         }
91.         if (getClass() != obj.getClass()) {
92.             return false;
93.         }
94.         final OrderProduct other = (OrderProduct) obj;
95.         if ((this.name == null) ? (other.name != null) : !this.name.equals(other.name)) {
96.             return false;
97.         }
98.         if ((this.type == null) ? (other.type != null) : !this.type.equals(other.type)) {
99.             return false;
100.         }
101.         if (this.quantity != other.quantity) {
102.             return false;
103.         }
104.         return true;
105.     }
107.     @Override
108.     public int hashCode() {
109.         int hash = 7;
110.         hash = 61 * hash + (this.name != null ? this.name.hashCode() : 0);
111.         hash = 61 * hash + (this.type != null ? this.type.hashCode() : 0);
112.         hash = 61 * hash + this.quantity;
113.         return hash;
114.     }
115. }

 

1. import java.util.Date;
2. import java.util.Set;
3. import javax.persistence.CascadeType;
4. import javax.persistence.Column;
5. import javax.persistence.Entity;
6. import javax.persistence.GeneratedValue;
7. import javax.persistence.GenerationType;
8. import javax.persistence.Id;
9. import javax.persistence.JoinColumn;
10. import javax.persistence.JoinTable;
11. import javax.persistence.OneToMany;
12. import javax.persistence.Table;
13. import javax.persistence.Temporal;
15. /**
16.  * 存储订单实体类，其中和产品实体进行关联
17.  * @author 李文锴
18.  */
19. @Entity
20. @Table(name = "stock_order")
21. public class StockOrder implements java.io.Serializable {
23.     private static final long serialVersionUID = 1L;
24.     /**
25.      * 订单id
26.      */
27.     @Id
28.     @GeneratedValue(strategy = GenerationType.AUTO)
29.     private Long id;
30.     /**
31.      * 客户编号
32.      */
33.     @Column(name = "customer_no", length = 20, nullable = false)
34.     private String customerNO;
35.     /**
36.      * 客户名称
37.      */
38.     @Column(name = "customer_name", length = 80, nullable = false)
39.     private String customerName;
40.     /**
41.      * 产品
42.      */
43.     @OneToMany(cascade = CascadeType.ALL)
44.     @JoinTable(name = "stock_order_product", joinColumns = {@JoinColumn(name = "stock_order_id")}, inverseJoinColumns = {@JoinColumn(name = "product_id")})
45.     private Set<OrderProduct> prdoucts;
46.     /**
47.      * 到达日期
48.      */
49.     @Column(name = "arrival_date", nullable = false)
50.     @Temporal(javax.persistence.TemporalType.DATE)
51.     private Date arrivalDate;
53.     public StockOrder() {
54.     }
56.     public StockOrder(String customerNO, String customerName, Set<OrderProduct> prdoucts, Date arrivalDate) {
57.         setCustomerNO(customerNO);
58.         setCustomerName(customerName);
59.         setPrdoucts(prdoucts);
60.         setArrivalDate(arrivalDate);
61.     }
63.     public Date getArrivalDate() {
64.         return arrivalDate;
65.     }
67.     public void setArrivalDate(Date arrivalDate) {
68.         this.arrivalDate = arrivalDate;
69.     }
71.     public String getCustomerNO() {
72.         return customerNO;
73.     }
75.     public void setCustomerNO(String customerNO) {
76.         this.customerNO = customerNO;
77.     }
79.     public Long getId() {
80.         return id;
81.     }
83.     public void setId(Long id) {
84.         this.id = id;
85.     }
87.     public Set<OrderProduct> getPrdoucts() {
88.         return prdoucts;
89.     }
91.     public void setPrdoucts(Set<OrderProduct> prdoucts) {
92.         this.prdoucts = prdoucts;
93.     }
95.     public String getCustomerName() {
96.         return customerName;
97.     }
99.     public void setCustomerName(String customerName) {
100.         this.customerName = customerName;
101.     }
103.     @Override
104.     public boolean equals(Object obj) {
105.         if (obj == null) {
106.             return false;
107.         }
108.         if (getClass() != obj.getClass()) {
109.             return false;
110.         }
111.         final StockOrder other = (StockOrder) obj;
112.         if ((this.customerNO == null) ? (other.customerNO != null) : !this.customerNO.equals(other.customerNO)) {
113.             return false;
114.         }
115.         if ((this.customerName == null) ? (other.customerName != null) : !this.customerName.equals(other.customerName)) {
116.             return false;
117.         }
118.         if (this.prdoucts != other.prdoucts && (this.prdoucts == null || !this.prdoucts.equals(other.prdoucts))) {
119.             return false;
120.         }
121.         if (this.arrivalDate != other.arrivalDate && (this.arrivalDate == null || !this.arrivalDate.equals(other.arrivalDate))) {
122.             return false;
123.         }
124.         return true;
125.     }
127.     @Override
128.     public int hashCode() {
129.         int hash = 5;
130.         hash = 59 * hash + (this.customerNO != null ? this.customerNO.hashCode() : 0);
131.         hash = 59 * hash + (this.customerName != null ? this.customerName.hashCode() : 0);
132.         hash = 59 * hash + (this.prdoucts != null ? this.prdoucts.hashCode() : 0);
133.         hash = 59 * hash + (this.arrivalDate != null ? this.arrivalDate.hashCode() : 0);
134.         return hash;
135.     }
136. }

1. import java.util.Date;
2. import java.util.Set;
3. import javax.persistence.CascadeType;
4. import javax.persistence.Column;
5. import javax.persistence.Entity;
6. import javax.persistence.GeneratedValue;
7. import javax.persistence.GenerationType;
8. import javax.persistence.Id;
9. import javax.persistence.JoinColumn;
10. import javax.persistence.JoinTable;
11. import javax.persistence.OneToMany;
12. import javax.persistence.Table;
13. import javax.persistence.Temporal;
15. /**
16.  * 运输订单实体类，并于产品实体进行关联
17.  * @author 李文锴
18.  */
19. @Entity
20. @Table(name = "trans_order")
21. public class TransOrder implements java.io.Serializable {
23.     private static final long serialVersionUID = 1L;
24.     /**
25.      * 订单id
26.      */
27.     @Id
28.     @GeneratedValue(strategy = GenerationType.AUTO)
29.     private Long id;
30.     /**
31.      * 客户编号
32.      */
33.     @Column(name = "customer_no", length = 20, nullable = false)
34.     private String customerNO;
35.     /**
36.      * 客户名称
37.      */
38.     @Column(name = "customer_name", length = 80, nullable = false)
39.     private String customerName;
40.     /**
41.      * 产品
42.      */
43.     @OneToMany(cascade = CascadeType.ALL)
44.     @JoinTable(name = "trans_order_product", joinColumns = {@JoinColumn(name = "trans_order_id")}, inverseJoinColumns = {@JoinColumn(name = "product_id")})
45.     private Set<OrderProduct> prdoucts;
46.     /**
47.      * 其实地址
48.      */
49.     @Column(name = "start_address", length = 80, nullable = false)
50.     private String startAddress;
51.     /**
52.      * 目的地址
53.      */
54.     @Column(name = "end_address", length = 80, nullable = false)
55.     private String endAddress;
56.     /**
57.      * 运输日期
58.      */
59.     @Column(name = "trans_date", nullable = false)
60.     @Temporal(javax.persistence.TemporalType.DATE)
61.     private Date transportationDate;
63.     public TransOrder() {
64.     }
66.     public TransOrder(String customerNO, String customerName, Set<OrderProduct> prdoucts, String startAddress, String endAddress, Date transportationDate) {
67.         setCustomerNO(customerNO);
68.         setCustomerName(customerName);
69.         setPrdoucts(prdoucts);
70.         setStartAddress(startAddress);
71.         setEndAddress(endAddress);
72.         setTransportationDate(transportationDate);
73.     }
75.     public Date getTransportationDate() {
76.         return transportationDate;
77.     }
79.     public void setTransportationDate(Date transportationDate) {
80.         this.transportationDate = transportationDate;
81.     }
83.     public String getCustomerNO() {
84.         return customerNO;
85.     }
87.     public void setCustomerNO(String customerNO) {
88.         this.customerNO = customerNO;
89.     }
91.     public Long getId() {
92.         return id;
93.     }
95.     public void setId(Long id) {
96.         this.id = id;
97.     }
99.     public Set<OrderProduct> getPrdoucts() {
100.         return prdoucts;
101.     }
103.     public void setPrdoucts(Set<OrderProduct> prdoucts) {
104.         this.prdoucts = prdoucts;
105.     }
107.     public String getCustomerName() {
108.         return customerName;
109.     }
111.     public void setCustomerName(String customerName) {
112.         this.customerName = customerName;
113.     }
115.     public String getEndAddress() {
116.         return endAddress;
117.     }
119.     public void setEndAddress(String endAddress) {
120.         this.endAddress = endAddress;
121.     }
123.     public String getStartAddress() {
124.         return startAddress;
125.     }
127.     public void setStartAddress(String startAddress) {
128.         this.startAddress = startAddress;
129.     }
131.     @Override
132.     public boolean equals(Object obj) {
133.         if (obj == null) {
134.             return false;
135.         }
136.         if (getClass() != obj.getClass()) {
137.             return false;
138.         }
139.         final TransOrder other = (TransOrder) obj;
140.         if ((this.customerNO == null) ? (other.customerNO != null) : !this.customerNO.equals(other.customerNO)) {
141.             return false;
142.         }
143.         if ((this.customerName == null) ? (other.customerName != null) : !this.customerName.equals(other.customerName)) {
144.             return false;
145.         }
146.         if (this.prdoucts != other.prdoucts && (this.prdoucts == null || !this.prdoucts.equals(other.prdoucts))) {
147.             return false;
148.         }
149.         if ((this.startAddress == null) ? (other.startAddress != null) : !this.startAddress.equals(other.startAddress)) {
150.             return false;
151.         }
152.         if ((this.endAddress == null) ? (other.endAddress != null) : !this.endAddress.equals(other.endAddress)) {
153.             return false;
154.         }
155.         if (this.transportationDate != other.transportationDate && (this.transportationDate == null || !this.transportationDate.equals(other.transportationDate))) {
156.             return false;
157.         }
158.         return true;
159.     }
161.     @Override
162.     public int hashCode() {
163.         int hash = 3;
164.         hash = 79 * hash + (this.customerNO != null ? this.customerNO.hashCode() : 0);
165.         hash = 79 * hash + (this.customerName != null ? this.customerName.hashCode() : 0);
166.         hash = 79 * hash + (this.prdoucts != null ? this.prdoucts.hashCode() : 0);
167.         hash = 79 * hash + (this.startAddress != null ? this.startAddress.hashCode() : 0);
168.         hash = 79 * hash + (this.endAddress != null ? this.endAddress.hashCode() : 0);
169.         hash = 79 * hash + (this.transportationDate != null ? this.transportationDate.hashCode() : 0);
170.         return hash;
171.     }
172. }

 

先要使用Hibernate对其进行映射，由于产生了中间表，所以它的配置文件有些不同，如下：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
3. <hibernate-mapping>
4.     <class name="com.yunda.dao.domain.Product" table="yunda_product">
5.         <id name="id" type="long">
6.             <generator class="native"/>
7.         </id>
8.         <property name="name" column="p_name" type="string" length="80" not-null="true"/>
9.         <property name="type" column="p_type" type="string" length="80" not-null="true"/>
10.         <property name="quantity" column="p_quantity" type="integer" length="80" not-null="true"/>
11.         <!-- 使用join来配置多对一的连接,以table属性来表示连接表的多对一，连接表为stock_order_id -->
12.         <!-- optional属性表示这是一个外连接,inverse属性可以出现在一端和多端，这里选择出现在多端，效果相同 -->
13.         <join table="stock_order_product" optional="true" inverse="true">
14.             <!-- 该key的字段为连接表中的字段，作为外键 -->
15.             <key column="product_id" />
16.             <!-- 连接表中配置多对一，对应的字段为stock_order_id -->
17.             <many-to-one name="stockOrder" column="stock_order_id" not-null="true" />
18.         </join>
19.         <!-- 使用join来配置多对一的连接,以table属性来表示连接表的多对一，连接表为trans_order_id -->
20.         <!-- optional属性表示这是一个外连接,inverse属性可以出现在一端和多端，这里选择出现在多端，效果相同 -->
21.         <join table="trans_order_product" optional="true" inverse="true">
22.             <!-- 该key的字段为连接表中的字段，作为外键 -->
23.             <key column="product_id" />
24.             <!-- 连接表中配置多对一，对应的字段为trans_order_id -->
25.             <many-to-one name="transOrder" column="trans_order_id" not-null="true" />
26.         </join>
27.     </class>
28. </hibernate-mapping>

 

1. <?xml version="1.0" encoding="UTF-8"?>
2. <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
3. <hibernate-mapping>
4.     <class name="com.yunda.dao.domain.StockOrder" table="stock_order">
5.         <id name="id" type="long">
6.             <generator class="native"/>
7.         </id>
8.         <property name="customerNO" column="customer_no" type="string" length="20" not-null="true"/>
9.         <property name="customerName" column="customer_name" type="string" length="80" not-null="true"/>
10.         <property name="arrivalDate" column="arrival_date" type="date" not-null="true"/>
11.         <!-- 通过连接表的一端，因此需要table属性为stock_order_product -->
12.         <set name="prdoucts" cascade="all" table="stock_order_product" lazy="false">
13.             <!-- 该key的字段为连接表中的字段，作为外键 -->
14.             <key column="stock_order_id" />
15.             <!-- 配置多对多 -->
16.             <!-- 但是unique属性为true,表示product_id字段为不可重复,保证一对多关系 -->
17.             <many-to-many class="com.yunda.dao.domain.Product" column="product_id" unique="true" />
18.         </set>
19.     </class>
20. </hibernate-mapping>

 

1. <?xml version="1.0" encoding="UTF-8"?>
2. <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
3. <hibernate-mapping>
4.     <class name="com.yunda.dao.domain.TransOrder" table="trans_order">
5.         <id name="id" type="long">
6.             <generator class="native"/>
7.         </id>
8.         <property name="customerNO" column="customer_no" type="string" length="20" not-null="true"/>
9.         <property name="customerName" column="customer_name" type="string" length="80" not-null="true"/>
10.         <property name="startAddress" column="start_address" type="string" length="80" not-null="true"/>
11.         <property name="endAddress" column="end_address" type="string" length="80" not-null="true"/>
12.         <property name="transportationDate" column="trans_date" type="date" not-null="true"/>
13.         <!-- 通过连接表的一端，因此需要table属性为stock_order_product -->
14.         <set name="prdoucts" cascade="all" table="trans_order_product" lazy="false">
15.             <!-- 该key的字段为连接表中的字段，作为外键 -->
16.             <key column="trans_order_id" />
17.             <!-- 配置多对多 -->
18.             <!-- 但是unique属性为true,表示product_id字段为不可重复,保证一对多关系 -->
19.             <many-to-many class="com.yunda.dao.domain.Product" column="product_id" unique="true" />
20.         </set>
21.     </class>
22. </hibernate-mapping>