我有一个在两台服务器上运行的应用程序，这两台服务器都通过Hibernate访问同一个数据库。 这里的问题是这两个应用程序处理大量数据并尝试插入同一个表时。发生主键违规。从我注意到的事情来看，hibernate似乎缓冲了一些主键id。例如。如果服务器A将数据插入到id 100中，同时服务器B将插入到id 200左右。我想这个问题与上面提到的情况有关。以下是我的hibernate属性
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/dbtest?autoReconnect=true</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">password</property>
<!-- <property name="hibernate.show_sql">true</property>-->
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<!--
<property name="hibernate.hbm2ddl.auto">update</property>
-->
<property name="hibernate.use_sql_comments">true</property>
<property name="hibernate.format_sql">true</property>
<property name="hibernate.connection.zeroDateTimeBehavior">convertToNull</property>
<property name="hibernate.connection.isolation">2</property>
<property name="hibernate.default_schema">dbtest</property>
<property name="hibernate.jdbc.batch_size">50</property>
<!--c3po connection pooling -->
<property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.max_size">20</property>
<property name="hibernate.c3p0.timeout">300</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.idle_test_period">3000</property>
这是失败的实体
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Sep 3, 2014 4:38:39 PM by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="com.test.dto.AdditionalContacts" table="additional_contacts"
entity-name="additionalcontacts">
<id name="contactId" type="java.lang.Integer" column="contactId">
<generator class="increment" />
</id>
<property name="contactGuid" type="java.lang.String">
<column name="contactGuid" />
</property>
<property name="contactName" type="java.lang.String">
<column name="contactName" />
</property>
<property name="salutation" type="java.lang.String">
<column name="salutation" />
</property>
<property name="EmailAddress" type="java.lang.String">
<column name="email" />
</property>
<property name="includeInEmails" type="java.lang.Boolean">
<column name="includeInEmails" />
</property>
<property name="Website" type="java.lang.String">
<column name="website" />
</property>
<property name="city" type="java.lang.String">
<column name="city" />
</property>
<property name="state" type="java.lang.String">
<column name="state" />
</property>
<property name="postCode" type="java.lang.String">
<column name="postCode" />
</property>
<property name="country" type="java.lang.String">
<column name="country" />
</property>
<property name="street" type="java.lang.String">
<column name="street" />
</property>
<property name="streetLine1" type="java.lang.String">
<column name="streetLine1" />
</property>
<property name="streetLine2" type="java.lang.String">
<column name="streetLine2" />
</property>
<property name="streetLine3" type="java.lang.String">
<column name="streetLine3" />
</property>
<property name="streetLine4" type="java.lang.String">
<column name="streetLine4" />
</property>
<property name="phone1" type="java.lang.String">
<column name="phone1" />
</property>
<property name="phone2" type="java.lang.String">
<column name="phone2" />
</property>
<property name="phone3" type="java.lang.String">
<column name="phone3" />
</property>
<property name="fax" type="java.lang.String">
<column name="fax" />
</property>
<property name="location" type="java.lang.String">
<column name="location" />
</property>
<property access="field" column="createDate" insert="true"
name="createDate" update="false" />
<property access="field" column="modifyDate" insert="true"
name="modifyDate" update="true" />
</class>
</hibernate-mapping>
以下是使用上述实体的实体
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Sep 3, 2014 4:38:39 PM by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="com.test.dto.Contacts" table="contact"
entity-name="contact">
<id name="cGuid" type="java.lang.String">
<column name="contactGuid" />
</id>
<property name="org" type="java.lang.Integer">
<column name="org" />
</property>
<property name="Name" type="java.lang.String">
<column name="name" />
</property>
<property name="FirstName" type="java.lang.String">
<column name="firstName" />
</property>
<property name="LastName" type="java.lang.String">
<column name="lastName" />
</property>
<property name="abn" type="java.lang.String">
<column name="abn" />
</property>
<property name="active" type="java.lang.Boolean">
<column name="active" />
</property>
<property access="field" column="createDate" insert="true"
name="createDate" update="false" />
<property access="field" column="modifyDate" insert="true"
name="modifyDate" update="true" />
<bag name="additionalContactList" table="additional_contact" lazy="false" inverse="true"
cascade="all">
<key>
<column name="contactGuid" not-null="true" />
</key>
<one-to-many entity-name="additionalcontacts"
class="com.test.dto.AdditionalContact" />
</bag>
</class>
</hibernate-mapping>
这个失败
级联=＆＃34;所有＆＃34;
答案 0 :(得分：2)
您需要使用AUTO_INCREMENT。这样MySQL将管理ID的创建，因此服务器不必同步。将数据库列更改为AUTO_INCREMENT。在Hibernate中，将生成器类型更改为native。
其他替代方案是使用UUID作为主键。
较新版本的Hibernate还有其他可以使用的生成器，它们优于native。