Java 通过注解使用 Hibernate UUIDGenerator
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Using Hibernate UUIDGenerator via annotations
提问by Martin
I'm using my uuid as following:
我使用我的 uuid 如下：
@Id
@GeneratedValue(generator = "uuid")
@GenericGenerator(name = "uuid", strategy = "uuid")
@Column(name = "uuid", unique = true)
private String uuid;
but I'm getting a smart Hibernate warning:
但我收到了一个智能的休眠警告：
Using org.hibernate.id.UUIDHexGenerator which does not generate IETF RFC 4122 compliant UUID values; consider using org.hibernate.id.UUIDGenerator instead
使用不生成符合 IETF RFC 4122 的 UUID 值的 org.hibernate.id.UUIDHexGenerator；考虑使用 org.hibernate.id.UUIDGenerator 代替
So I want to switch to org.hibernate.id.UUIDGenerator, now my question is how should I tell it to Hibernate's generator. I saw some guy used it as a "hibernate-uuid" - so this is what I've tried, but with negative result:
所以我想切换到org.hibernate.id.UUIDGenerator，现在我的问题是我应该如何将它告诉 Hibernate 的生成器。我看到有人将它用作“hibernate-uuid” - 所以这是我尝试过的，但结果是负面的：
@Id
@GeneratedValue(generator = "hibernate-uuid")
@GenericGenerator(name = "hibernate-uuid", strategy = "hibernate-uuid")
@Column(name = "uuid", unique = true)
private String uuid;
采纳答案by axtavt
It should be uuid2:
它应该是uuid2：
...
@GenericGenerator(name = "uuid", strategy = "uuid2")
...
回答by CSchulz
HibernateDocsays you can use following:
HibernateDoc说你可以使用以下内容：
@Id
@GeneratedValue(generator="system-uuid")
@GenericGenerator(name="system-uuid", strategy = "uuid")
@Column(name = "uuid", unique = true)
private String uuid;
I hope you are using Hibernate 3.5.
我希望您使用的是 Hibernate 3.5。
回答by kervin
Try...
尝试...
@Id
@GeneratedValue(generator = "uuid2")
@GenericGenerator(name = "uuid2", strategy = "uuid2")
@Column(name = "uuid", columnDefinition = "BINARY(16)")
public UUID getId()
{
return id;
}
public void setId(UUID i)
{
id = i;
}
Note the "uuid2" as opposed to "uuid".
注意“uuid2”而不是“uuid”。
回答by Ahmad R. Nazemi
Unknown Id.generator: hibernate-uuid
未知 Id.generator：hibernate-uuid
@Id
@GeneratedValue(generator = "uuid")
@GenericGenerator(name = "uuid", strategy = "org.hibernate.id.UUIDGenerator")
@Column(name = "id", unique = true)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
回答by Sumit
@Id
@GeneratedValue(generator = "uuid")
@GenericGenerator(name = "uuid", strategy = "uuid")
@Column(name = "UUID_ID")
public String getId(){
return id;
}
This is the proper way to use annotation for uuid generators in Hibernate 5.0.11.FINAL.
这是在 Hibernate 5.0.11.FINAL 中为 uuid 生成器使用注释的正确方法。
Note:IT is deprecated.
注意：IT 已弃用。
回答by senjin.hajrulahovic
As @natan pointed out in a comment, if you are using Hibernate 5 the below code is sufficient:
正如@natan 在评论中指出的那样，如果您使用的是 Hibernate 5，以下代码就足够了：
@Id
@GeneratedValue
private java.util.UUID id;
Define the idcolumn with the type of BINARY(16)in MySQL or it's equivalent in other SQL implementations.
在 MySQL 中定义id类型为的列，BINARY(16)或者在其他 SQL 实现中等价。
回答by Sergey Ponomarev
This will use UUID v4 and the auto generated uuid will be stored in the column as usual varchar(36):
这将使用 UUID v4，自动生成的 uuid 将像往常一样存储在列中varchar(36)：
@Id
@GeneratedValue(generator = "uuid2")
@GenericGenerator(name = "uuid2", strategy = "uuid2")
@Column(length = 36)
private String uuid;
This should have some performance impact:
这应该会对性能产生一些影响：
- consumed size is more than
BINARY(16) - after hydration the
java.lang.Stringinstance consumes more memory thanjava.util.UUID: 112 bytes for UUID as string versus 32 bytes (i.e. two longs + obj header) forUUID.
- 消耗的大小超过
BINARY(16) - 水化后，
java.lang.String实例消耗的内存多于java.util.UUID：UUID 为字符串的 112 字节与UUID.
But it's much more easier to work with string'ed UUID - easier to write queries and you can see the contents of the table.
但是使用字符串 UUID 更容易 - 更容易编写查询并且您可以看到表的内容。
Tested on Hibernate 5.3
在 Hibernate 5.3 上测试
回答by JavierFuentes
With current 5.4.2 Hibernate version,
使用当前的 5.4.2 Hibernate 版本，
if you want a Human-Readablevarchar(36)field in the database table,
but also a SerializableUUIDdata type in your Java Class,
you can use @Type(type = "uuid-char")at the same timeyou declare your field member with java.util.UUIDtype.
如果您想要数据库表中的Human-Readable varchar(36)字段，以及Java 类中
的Serializable UUID数据类型，则
可以@Type(type = "uuid-char")在使用java.util.UUIDtype声明字段成员的同时使用。
Note that @Column(length = 36)is important to reduce from 255 to 36 the field length in MySQL.
请注意，@Column(length = 36)将 MySQL 中的字段长度从 255 减少到 36 很重要。
Note that with PostgreSQL you should use @Type(type = "pg-uuid")instead.
请注意，对于 PostgreSQL，您应该使用它@Type(type = "pg-uuid")。
import org.hibernate.annotations.Type
import java.util.UUID
import javax.persistence.Column
import javax.persistence.GeneratedValue
import javax.persistence.Id
@Id @GeneratedValue
@Type(type = "uuid-char") @Column(length = 36)
private UUID id;
