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package footmark.springdata.jpa.domain; import java.util.ArrayList; import java.util.Collection; import javax.persistence.CascadeType; 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.OneToMany; import org.apache.log4j.Logger; @Entity public class Custom { /** * Logger for this class */ private static final Logger logger = Logger.getLogger(Custom.class); private Long custId; private String detail; private Collection<Address> addresses = new ArrayList<Address>(); @Id @GeneratedValue(strategy = GenerationType.AUTO) public Long getCustId() { return custId; } public String getDetail() { return detail; } /* * 三種配置方式： * 1. @OneToMany(cascade= {CascadeType.ALL},fetch=FetchType.LAZY ,mappedBy="customId") * mappedBy屬性用於雙向關聯實體時使用， * mappedBy屬性：用在雙向關聯中，把關係的維護權反轉 ； 跟hibernate XML映射中的property-ref一樣。 * * JPA執行步驟：一、插入數據到CUSTOM表， * 二、執行getAddresses()獲取需要持久化的ADDRESS（ADDRESS必須代碼設置外鍵CUSTID）， * 三、插入數據到ADDRESS表 * * 2.@OneToMany(cascade= {CascadeType.ALL},fetch=FetchType.LAZY ) * JPA執行步驟: 一、插入數據到CUSTOM表， * 二、執行getAddresses()獲取需要持久化的ADDRESS（ADDRESS代碼不需要設置外鍵CUSTID），ADDRESS和CUSTOM關係保存在關聯表中； * 三、插入數據到ADDRESS表 * 四、插入關聯信息到CUSTOM_ADDRESS 表中 * 另外關聯表的字段對應關係也可以手工設置， * @JoinTable(name="ref_customer_address", * joinColumns={@JoinColumn(name="customer_id",referencedColumnName="custId")}, * inverseJoinColumns={@JoinColumn(name="address_id",referencedColumnName="addrId")} * * 3.@OneToMany(cascade= {CascadeType.ALL},fetch=FetchType.LAZY ) * @JoinColumn(name="customer_id") 對應的是表中的字段，會在最後一步進行該字段的更新 * 該設置屬於單向關聯， 該設置需要執行三條SQL操作，不推薦；JPA推薦第一種和第二種做法； * JPA執行步驟如下：一、插入數據到CUSTOM表， * 二、執行getAddresses()獲取需要持久化的ADDRESS（ADDRESS必須代碼設置外鍵CUSTID或者將外鍵屬性設置爲可以爲空）， * 三、插入數據到ADDRESS表 * 四、 然後再UPDATE ADDRESS 設置外鍵關係customer_id * * 4.另外多端需要初始化一個空數組 * private Collection<Address> addresses = new ArrayList<Address>(); * * */ //級聯操作 @OneToMany(cascade= {CascadeType.ALL},fetch=FetchType.LAZY ,mappedBy="customId" ) // 雙向關聯,mappedBy="customId" 不可共存 @JoinColumn(name="customer_id") // 2 @JoinTable(name="ref_customer_address", // joinColumns={@JoinColumn(name="customer_id",referencedColumnName="custId")}, // inverseJoinColumns={@JoinColumn(name="address_id",referencedColumnName="addrId")} // ) public Collection<Address> getAddresses() { if (logger.isDebugEnabled()) { logger.debug("getAddresses() - start"); //$NON-NLS-1$ } // cascade屬性和mappedBy用在一起時，一定要通過調用雙方的set方法來建立關係 for (Address add :addresses) add.setCustomId(custId);//設置ADDRESS的CUSTOM外鍵 if (logger.isDebugEnabled()) { logger.debug("getAddresses() - end"); //$NON-NLS-1$ } return addresses; } public void pushAddress(Address add){ addresses.add(add); } public void setAddresses(Collection<Address> addresses) { this.addresses = addresses; } public void setCustId(Long custId) { this.custId = custId; } public void setDetail(String detail) { this.detail = detail; } } ------------ package footmark.springdata.jpa.domain; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; @Entity public class Address { private Long addrId; private Long customId; @Column(nullable=false) public Long getCustomId() { return customId; } public void setCustomId(Long customId) { this.customId = customId; } private String detail; @Id @GeneratedValue(strategy= GenerationType.AUTO) public Long getAddrId() { return addrId; } public String getDetail() { return detail; } public void setAddrId(Long addrId) { this.addrId = addrId; } public void setDetail(String detail) { this.detail = detail; } }
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