由于我们的连接非常不稳定,所以如果查询超时,我们决定切换到本地只读数据库。JPA + MySQL:超时后 - >使用本地连接
但这里是我的问题:当javax.persistence尝试查询我没有得到一个例外:
// Attribute
EntityManagerFactory entityManagerFactory;
EntityManager manager;
entityManagerFactory = Persistence
.createEntityManagerFactory("org.hibernate.tutorial.jpa");
manager = entityManagerFactory.createEntityManager();
try {
Query query = manager.createQuery(String.format(
"SELECT u FROM User u WHERE u.id = '%s'", 116));
User user = (User) query.getSingleResult();
manager.refresh(user);
System.out.println(user.getUsername());
} catch (org.hibernate.QueryTimeoutException ex) {
throw new QueryTimeoutException("timeout");
}
}
这只是一个测试,以证明我的问题。 我错过了什么?
MySQL的:使用mysql-connector-java的5.1.16-bin.jar JPA:javax.persistence_2.0.3.v201010191057.jar 休眠:
115 [main] INFO org.hibernate.annotations.common.Version - Hibernate Commons Annotations 3.2.0.Final
124 [main] INFO org.hibernate.cfg.Environment - Hibernate 3.6.7.Final
126 [main] INFO org.hibernate.cfg.Environment - hibernate.properties not found
129 [main] INFO org.hibernate.cfg.Environment - Bytecode provider name : javassist
132 [main] INFO org.hibernate.cfg.Environment - using JDK 1.4 java.sql.Timestamp handling
208 [main] INFO org.hibernate.ejb.Version - Hibernate EntityManager 3.6.7.Final
persistence.xml:
<properties>
<property name="hibernate.hbm2ddl.auto" value="valide"/>
<property name="hibernate.connection.url" value="jdbc:mysql:///database?zeroDateTimeBehavior=convertToNull"/>
<property name="hibernate.connection.username" value="user"/>
<property name="hibernate.connection.password" value="pass"/>
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.query.timeout" value="1"/>
<property name="dialect" value="org.hibernate.dialect.MySQLDialect"/>
</properties>
谢谢 托比亚斯