java hibernate使用注解來(lái)定義聯(lián)合主鍵

更新時(shí)間：2017年01月19日 09:45:15 投稿：lqh

這篇文章主要介紹了java hibernate使用注解來(lái)定義聯(lián)合主鍵的相關(guān)資料,需要的朋友可以參考下

java hibernate使用注解來(lái)定義聯(lián)合主鍵

下面使用hibernate的API中說(shuō)明的三種方式來(lái)定義主鍵，主要使用Annotation來(lái)定義hibernate中的聯(lián)合主鍵

下面取至hibernate的API文檔：

定義組合主鍵的幾種語(yǔ)法：

1、將組件類(lèi)注解為@Embeddable，并將組件的屬性注解為@Id
2、將組件的屬性注解為@EmbeddedId
3、將類(lèi)注解為@IdClass，并將該實(shí)體中所有屬于主鍵的屬性都注解為@Id

下面就分別使用這三種方式來(lái)定義聯(lián)合主鍵。

建表的SQL語(yǔ)句：

CREATE TABLE `syslogs` ( 
 `id` varchar(50) NOT NULL, 
 `yhid` varchar(50) NOT NULL, 
 `modelname` varchar(100) DEFAULT NULL, 
 `content` varchar(500) DEFAULT NULL, 
 `inserttime` varchar(20) DEFAULT NULL, 
 `remark` varchar(50) DEFAULT NULL, 
 PRIMARY KEY (`id`,`yhid`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf-8;

一、將組件類(lèi)注解為@Embeddable

/** 
 * SysLogsDtoId代表主鍵類(lèi) 
 */ 
package com.hibernate.dto; 
 
import javax.persistence.Embeddable; 
/** 
 * 1、主鍵類(lèi)必須要實(shí)現(xiàn)java.io.Serializable接口 
 * 2、主鍵類(lèi)必須要重寫(xiě)equals和hashCode方法 
 * @author ibm 
 */ 
@Embeddable 
public class SysLogsDtoId implements java.io.Serializable { 
 
  private static final long serialVersionUID = 1L; 
  private String id; 
  private String yhid; 
 
  public SysLogsDtoId() { 
  } 
 
  public SysLogsDtoId(String id, String yhid) { 
    this.id = id; 
    this.yhid = yhid; 
  } 
 
  public String getId() { 
    return this.id; 
  } 
 
  public void setId(String id) { 
    this.id = id; 
  } 
 
  public String getYhid() { 
    return this.yhid; 
  } 
 
  public void setYhid(String yhid) { 
    this.yhid = yhid; 
  } 
 
  public boolean equals(Object other) { 
    if ((this == other)) 
      return true; 
    if ((other == null)) 
      return false; 
    if (!(other instanceof SysLogsDtoId)) 
      return false; 
    SysLogsDtoId castOther = (SysLogsDtoId) other; 
 
    return ((this.getId() == castOther.getId()) || (this.getId() != null && castOther.getId() != null && this.getId().equals(castOther.getId()))) 
        && ((this.getYhid() == castOther.getYhid()) || (this.getYhid() != null && castOther.getYhid() != null && this.getYhid().equals( 
            castOther.getYhid()))); 
  } 
 
  public int hashCode() { 
    int result = 17; 
 
    result = 37 * result + (getId() == null ? 0 : this.getId().hashCode()); 
    result = 37 * result + (getYhid() == null ? 0 : this.getYhid().hashCode()); 
    return result; 
  } 
 
}

/** 
 * SysLogsDto為表對(duì)象映射類(lèi)，其中主鍵為主鍵類(lèi)SysLogsDtoId 
 */ 
package com.hibernate.dto; 
 
import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.Id; 
import javax.persistence.Table; 
 
@Entity 
@Table(name = "syslogs") 
public class SysLogsDto implements java.io.Serializable { 
  private static final long serialVersionUID = 1L; 
  private SysLogsDtoId id; 
  private String modelname; 
  private String content; 
  private String inserttime; 
  private String remark; 
 
  public SysLogsDto() { 
  } 
 
  public SysLogsDto(SysLogsDtoId id) { 
    this.id = id; 
  } 
 
  public SysLogsDto(SysLogsDtoId id, String modelname, String content, String inserttime, String remark) { 
    this.id = id; 
    this.modelname = modelname; 
    this.content = content; 
    this.inserttime = inserttime; 
    this.remark = remark; 
  } 
 
  @Id 
  public SysLogsDtoId getId() { 
    return this.id; 
  } 
 
  public void setId(SysLogsDtoId id) { 
    this.id = id; 
  } 
 
  @Column(name = "modelname", length = 100) 
  public String getModelname() { 
    return this.modelname; 
  } 
 
  public void setModelname(String modelname) { 
    this.modelname = modelname; 
  } 
 
  @Column(name = "content", length = 500) 
  public String getContent() { 
    return this.content; 
  } 
 
  public void setContent(String content) { 
    this.content = content; 
  } 
 
  @Column(name = "inserttime", length = 20) 
  public String getInserttime() { 
    return this.inserttime; 
  } 
 
  public void setInserttime(String inserttime) { 
    this.inserttime = inserttime; 
  } 
 
  @Column(name = "remark", length = 50) 
  public String getRemark() { 
    return this.remark; 
  } 
 
  public void setRemark(String remark) { 
    this.remark = remark; 
  } 
 
}

二、將組件的屬性注解為@EmbeddedId

這種情況最簡(jiǎn)單，主鍵類(lèi)只用定義主鍵字段，不需要寫(xiě)任何注解。然后在對(duì)象類(lèi)中在主鍵類(lèi)的get方法上加上@EmbeddedId注解。

/** 
 * SysLogsDtoId代表主鍵類(lèi) 
 */ 
package com.hibernate.dto; 
 
public class SysLogsDtoId implements java.io.Serializable { 
 
  private static final long serialVersionUID = 1L; 
  private String id; 
  private String yhid; 
 
  public SysLogsDtoId() { 
  } 
 
  public SysLogsDtoId(String id, String yhid) { 
    this.id = id; 
    this.yhid = yhid; 
  } 
 
  public String getId() { 
    return this.id; 
  } 
 
  public void setId(String id) { 
    this.id = id; 
  } 
 
  public String getYhid() { 
    return this.yhid; 
  } 
 
  public void setYhid(String yhid) { 
    this.yhid = yhid; 
  } 
 
  public boolean equals(Object other) { 
    if ((this == other)) 
      return true; 
    if ((other == null)) 
      return false; 
    if (!(other instanceof SysLogsDtoId)) 
      return false; 
    SysLogsDtoId castOther = (SysLogsDtoId) other; 
 
    return ((this.getId() == castOther.getId()) || (this.getId() != null && castOther.getId() != null && this.getId().equals(castOther.getId()))) 
        && ((this.getYhid() == castOther.getYhid()) || (this.getYhid() != null && castOther.getYhid() != null && this.getYhid().equals( 
            castOther.getYhid()))); 
  } 
 
  public int hashCode() { 
    int result = 17; 
 
    result = 37 * result + (getId() == null ? 0 : this.getId().hashCode()); 
    result = 37 * result + (getYhid() == null ? 0 : this.getYhid().hashCode()); 
    return result; 
  } 
 
}



/** 
 * SysLogsDto為表對(duì)象映射類(lèi)，其中主鍵為主鍵類(lèi)SysLogsDtoId 
 */ 
package com.hibernate.dto; 
 
import javax.persistence.Column; 
import javax.persistence.EmbeddedId; 
import javax.persistence.Entity; 
import javax.persistence.Table; 
 
@Entity 
@Table(name = "syslogs") 
public class SysLogsDto implements java.io.Serializable { 
  private static final long serialVersionUID = 1L; 
  private SysLogsDtoId id; 
  private String modelname; 
  private String content; 
  private String inserttime; 
  private String remark; 
 
  public SysLogsDto() { 
  } 
 
  public SysLogsDto(SysLogsDtoId id) { 
    this.id = id; 
  } 
 
  public SysLogsDto(SysLogsDtoId id, String modelname, String content, String inserttime, String remark) { 
    this.id = id; 
    this.modelname = modelname; 
    this.content = content; 
    this.inserttime = inserttime; 
    this.remark = remark; 
  } 
 
  @EmbeddedId 
  public SysLogsDtoId getId() { 
    return this.id; 
  } 
 
  public void setId(SysLogsDtoId id) { 
    this.id = id; 
  } 
 
  @Column(name = "modelname", length = 100) 
  public String getModelname() { 
    return this.modelname; 
  } 
 
  public void setModelname(String modelname) { 
    this.modelname = modelname; 
  } 
 
  @Column(name = "content", length = 500) 
  public String getContent() { 
    return this.content; 
  } 
 
  public void setContent(String content) { 
    this.content = content; 
  } 
 
  @Column(name = "inserttime", length = 20) 
  public String getInserttime() { 
    return this.inserttime; 
  } 
 
  public void setInserttime(String inserttime) { 
    this.inserttime = inserttime; 
  } 
 
  @Column(name = "remark", length = 50) 
  public String getRemark() { 
    return this.remark; 
  } 
 
  public void setRemark(String remark) { 
    this.remark = remark; 
  } 
 
}

三、將類(lèi)注解為@IdClass，并將該實(shí)體中所有屬于主鍵的屬性都注解為@Id

/** 
 * SysLogsDtoId代表主鍵類(lèi) 
 */ 
package com.hibernate.dto; 
 
public class SysLogsDtoId implements java.io.Serializable { 
 
  private static final long serialVersionUID = 1L; 
  private String id; 
  private String yhid; 
 
  public SysLogsDtoId() { 
  } 
 
  public SysLogsDtoId(String id, String yhid) { 
    this.id = id; 
    this.yhid = yhid; 
  } 
 
  public String getId() { 
    return this.id; 
  } 
 
  public void setId(String id) { 
    this.id = id; 
  } 
 
  public String getYhid() { 
    return this.yhid; 
  } 
 
  public void setYhid(String yhid) { 
    this.yhid = yhid; 
  } 
 
  public boolean equals(Object other) { 
    if ((this == other)) 
      return true; 
    if ((other == null)) 
      return false; 
    if (!(other instanceof SysLogsDtoId)) 
      return false; 
    SysLogsDtoId castOther = (SysLogsDtoId) other; 
 
    return ((this.getId() == castOther.getId()) || (this.getId() != null && castOther.getId() != null && this.getId().equals(castOther.getId()))) 
        && ((this.getYhid() == castOther.getYhid()) || (this.getYhid() != null && castOther.getYhid() != null && this.getYhid().equals( 
            castOther.getYhid()))); 
  } 
 
  public int hashCode() { 
    int result = 17; 
 
    result = 37 * result + (getId() == null ? 0 : this.getId().hashCode()); 
    result = 37 * result + (getYhid() == null ? 0 : this.getYhid().hashCode()); 
    return result; 
  } 
 
}

/** 
 * SysLogsDto為表對(duì)象映射類(lèi)，其中主鍵為主鍵類(lèi)SysLogsDtoId 
 */ 
package com.hibernate.dto; 
 
import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.Id; 
import javax.persistence.IdClass; 
import javax.persistence.Table; 
 
@Entity 
@Table(name = "syslogs") 
@IdClass(value=SysLogsDtoId.class) 
public class SysLogsDto implements java.io.Serializable { 
  private static final long serialVersionUID = 1L; 
  private String id; 
  private String yhid; 
  private String modelname; 
  private String content; 
  private String inserttime; 
  private String remark; 
 
  public SysLogsDto() { 
  } 
 
  @Id 
  public String getId() { 
    return id; 
  } 
 
 
  public void setId(String id) { 
    this.id = id; 
  } 
 
  @Id 
  public String getYhid() { 
    return yhid; 
  } 
 
 
  public void setYhid(String yhid) { 
    this.yhid = yhid; 
  } 
 
 
  @Column(name = "modelname", length = 100) 
  public String getModelname() { 
    return this.modelname; 
  } 
 
  public void setModelname(String modelname) { 
    this.modelname = modelname; 
  } 
 
  @Column(name = "content", length = 500) 
  public String getContent() { 
    return this.content; 
  } 
 
  public void setContent(String content) { 
    this.content = content; 
  } 
 
  @Column(name = "inserttime", length = 20) 
  public String getInserttime() { 
    return this.inserttime; 
  } 
 
  public void setInserttime(String inserttime) { 
    this.inserttime = inserttime; 
  } 
 
  @Column(name = "remark", length = 50) 
  public String getRemark() { 
    return this.remark; 
  } 
 
  public void setRemark(String remark) { 
    this.remark = remark; 
  } 
 
}

感謝閱讀，希望能幫助到大家，謝謝大家對(duì)本站的支持！

您可能感興趣的文章: