有一个比较好的实践方式:
首先建立一个父类
/*所有domain类的通用字段*/
@Data
public class BaseDomain implements Serializable {
/*这几个值是公用的,在 INSERT/UPDATE 操作的时候,会去自动更新这几个值,具体实现看 MyMetaObjecthandler*/
@TableField(fill = FieldFill.INSERT_UPDATE)
public Integer yn;
@TableField(fill = FieldFill.INSERT_UPDATE)
public String creator;
@TableField(fill = FieldFill.INSERT_UPDATE)
public String updater;
@TableField(fill = FieldFill.INSERT_UPDATE)
public Date createTime;
@TableField(fill = FieldFill.INSERT_UPDATE)
public Date updateTime;
}
然后我们的实体类都去继承这个类
@TableName(value ="student")
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student extends BaseDomain {
@TableId(type = IdType.AUTO)
private Integer id;
private String studentName;
private String studentPassword;
private String teacheruuid;
private String phone;
private String address;
@TableField(exist = false)
private static final long serialVersionUID = 1L;
@Override
public boolean equals(Object that) {
if (this == that) {
return true;
}
if (that == null) {
return false;
}
if (getClass() != that.getClass()) {
return false;
}
Student other = (Student) that;
return (this.getId() == null ? other.getId() == null : this.getId().equals(other.getId()))
&& (this.getStudentName() == null ? other.getStudentName() == null : this.getStudentName().equals(other.getStudentName()))
&& (this.getStudentPassword() == null ? other.getStudentPassword() == null : this.getStudentPassword().equals(other.getStudentPassword()))
&& (this.getTeacheruuid() == null ? other.getTeacheruuid() == null : this.getTeacheruuid().equals(other.getTeacheruuid()))
&& (this.getPhone() == null ? other.getPhone() == null : this.getPhone().equals(other.getPhone()))
&& (this.getAddress() == null ? other.getAddress() == null : this.getAddress().equals(other.getAddress()))
&& (this.getYn() == null ? other.getYn() == null : this.getYn().equals(other.getYn()))
&& (this.getCreator() == null ? other.getCreator() == null : this.getCreator().equals(other.getCreator()))
&& (this.getUpdater() == null ? other.getUpdater() == null : this.getUpdater().equals(other.getUpdater()))
&& (this.getCreateTime() == null ? other.getCreateTime() == null : this.getCreateTime().equals(other.getCreateTime()))
&& (this.getUpdateTime() == null ? other.getUpdateTime() == null : this.getUpdateTime().equals(other.getUpdateTime()));
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((getId() == null) ? 0 : getId().hashCode());
result = prime * result + ((getStudentName() == null) ? 0 : getStudentName().hashCode());
result = prime * result + ((getStudentPassword() == null) ? 0 : getStudentPassword().hashCode());
result = prime * result + ((getTeacheruuid() == null) ? 0 : getTeacheruuid().hashCode());
result = prime * result + ((getPhone() == null) ? 0 : getPhone().hashCode());
result = prime * result + ((getAddress() == null) ? 0 : getAddress().hashCode());
result = prime * result + ((getYn() == null) ? 0 : getYn().hashCode());
result = prime * result + ((getCreator() == null) ? 0 : getCreator().hashCode());
result = prime * result + ((getUpdater() == null) ? 0 : getUpdater().hashCode());
result = prime * result + ((getCreateTime() == null) ? 0 : getCreateTime().hashCode());
result = prime * result + ((getUpdateTime() == null) ? 0 : getUpdateTime().hashCode());
return result;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(getClass().getSimpleName());
sb.append(" [");
sb.append("Hash = ").append(hashCode());
sb.append(", id=").append(id);
sb.append(", studentName=").append(studentName);
sb.append(", studentPassword=").append(studentPassword);
sb.append(", teacheruuid=").append(teacheruuid);
sb.append(", phone=").append(phone);
sb.append(", address=").append(address);
sb.append(", yn=").append(yn);
sb.append(", creator=").append(creator);
sb.append(", updater=").append(updater);
sb.append(", createTime=").append(createTime);
sb.append(", updateTime=").append(updateTime);
sb.append(", serialVersionUID=").append(serialVersionUID);
sb.append("]");
return sb.toString();
}
}
然后去编写 MetaObjectHandler
/*该类的作用是:
* 为实体类上添加了 INSERT_UPDATE 设置的类的 新增或者是更新操作做自动的属性填充*/
*
@Component //注意这里需要将其放入容器中
public class MyMetaObjecthandler implements MetaObjectHandler {
// 公共的属性有这几个
// public Integer yn;
// public String creator;
// public String updater;
// public Date createTime;
// public Date updateTime;
@Override
public void insertFill(MetaObject metaObject) {
Date now = new Date();
/*如果对象在进行插入操作的时候,对象中的 yn 是没有值的,此时才需要给他进行默认的填充*/
if (metaObject.getValue("yn") == null) {
setFieldValByName("yn", 1, metaObject);
}
if (metaObject.getValue("creator") == null) {
/*这里可以结合 security 的上下文来获取操作人 我这里写的简单了,就直接使用 admin 来赋值*/
setFieldValByName("creator", "admin", metaObject);
}
if (metaObject.getValue("updater") == null) {
/*这里可以结合 security 的上下文来获取操作人 我这里写的简单了,就直接使用 admin 来赋值*/
setFieldValByName("updater", "admin", metaObject);
}
if (metaObject.getValue("createTime") == null) {
setFieldValByName("createTime", now, metaObject);
}
if (metaObject.getValue("updateTime") == null) {
setFieldValByName("updateTime", now, metaObject);
}
}
@Override
public void updateFill(MetaObject metaObject) {
/*更新的时候 逻辑就不太一样了 更新的前提是有一个对象,那么该对象的一些值是不能随便乱动的,
* 就比如yn,而更新人和更新时间则可以变化*/
if (metaObject.getValue("updater") == null) {
/*这里可以结合 security 的上下文来获取操作人 我这里写的简单了,就直接使用 admin 来赋值*/
setFieldValByName("updater", "admin1231231", metaObject);
}
if (metaObject.getValue("updateTime") == null) {
setFieldValByName("updateTime", new Date(), metaObject);
}
}
}
这样就可以了,当然,也可以在里面对某个指定的类做这些操作,比如我只想对 Student这个类的对象在更新和插入的时候做这些操作怎么弄? 使用 metaObject 就可以实现 ,
例如:
if ("com.example.jiubodou.domain.Student".equals( metaObject.getOriginalObject().getClass().getName()) ) {
Date now = new Date();
/*如果对象在进行插入操作的时候,对象中的 yn 是没有值的,此时才需要给他进行默认的填充*/
if (metaObject.getValue("yn") == null) {
setFieldValByName("yn", 1, metaObject);
}
if (metaObject.getValue("creator") == null) {
/*这里可以结合 security 的上下文来获取操作人 我这里写的简单了,就直接使用 admin 来赋值*/
setFieldValByName("creator", "admin", metaObject);
}
if (metaObject.getValue("updater") == null) {
/*这里可以结合 security 的上下文来获取操作人 我这里写的简单了,就直接使用 admin 来赋值*/
setFieldValByName("updater", "admin", metaObject);
}
if (metaObject.getValue("createTime") == null) {
setFieldValByName("createTime", now, metaObject);
}
if (metaObject.getValue("updateTime") == null) {
setFieldValByName("updateTime", now, metaObject);
}
}
经过测试:
studentService.save()
studentService.saveBatch()
studentService.updateBatchById()
都是符合我们的预期的