Question

在我的DAO实现中，我正在进行Stripersist.getEntityManager().persist(client);，这似乎没有返回任何错误，但我找不到它持续存在的数据。

我的客户端对象如下所示：

@Entity
public class Client implements Serializable
{

    @Id
    @GeneratedValue
    private Integer id;
    @Column
    private String name;

    //accessors etc here
 ...
 }

我有一个持久性单元，如下所示

<persistence-unit name="stripes" transaction-type="RESOURCE_LOCAL">
      <!-- Tell JPA to use Hibernate -->
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
       <!--Hibernate settings -->
        <properties>
         <!--Autodetect entity classes -->
            <property name="hibernate.archive.autodetection" value="class"/>
         <!--Automatically create the SQL schema -->
            <property name="hibernate.hbm2ddl.auto" value="create"/>
       <!--Tell Hibernate to use HSQLDB -->
            <property name="hibernate.dialect"
        value="org.hibernate.dialect.DerbyDialect" />
            <property name="hibernate.connection.driver_class"
        value="org.apache.derby.jdbc.ClientDriver" />
       <!--Configure the JDBC database connection-->
            <property name="hibernate.connection.url" value="jdbc:derby://localhost:1527/salestracker" />
            <property name="hibernate.connection.username" value="admin"/>
            <property name="hibernate.connection.password" value="admin"/>
            <property name="jdbc.batch_size" value="0"/>
       <!--Configure the connection pool--> 
            <property name="hibernate.c3p0.min_size" value="5"/>
            <property name="hibernate.c3p0.max_size" value="20"/>
            <property name="hibernate.c3p0.timeout" value="300"/>
            <property name="hibernate.c3p0.max_statements" value="50"/>
            <property name="hibernate.c3p0.idle_test_period" value="3000"/>
        </properties>
    </persistence-unit>

就像我说的那样，我在.persist(client);设置了断点，客户端设置了name，null设置了id（否则我' d使用了.merge()），因此我不确定为什么数据不会被保留？

如果我查看表CLIENT，它有0行。

SELECT * FROM ADMIN.CLIENT

Executed successfully in 0.001 s.
Line 1, column 1

Execution finished after 0.001 s, 0 error(s) occurred.

实体是否可能被持久化，但交易未被提交？

由于

编辑：这是一些日志信息

INFO: 09:24:32,002 DEBUG JpaTransactionManager:285 - Found thread-bound EntityManager [org.hibernate.ejb.EntityManagerImpl@4e65ad52] for JPA transaction
INFO: 09:24:32,002 DEBUG JpaTransactionManager:371 - Creating new transaction with name [com.jameselsey.salestracker.service.ClientService.persistClient]: PROPAGATION_REQUIRED,ISOLATION_DEFAULT
INFO: 09:24:32,002 DEBUG JDBCTransaction:82 - begin
INFO: 09:24:32,003 DEBUG ConnectionManager:444 - opening JDBC connection
INFO: 09:24:32,003 DEBUG JDBCTransaction:87 - current autocommit status: true
INFO: 09:24:32,003 DEBUG JDBCTransaction:90 - disabling autocommit
INFO: break
INFO: 09:24:40,960 DEBUG SessionImpl:247 - opened session at timestamp: 12600914809
INFO: 09:24:40,961 DEBUG JDBCTransaction:82 - begin
INFO: 09:24:40,962 DEBUG ConnectionManager:444 - opening JDBC connection
INFO: 09:24:40,965 DEBUG JDBCTransaction:87 - current autocommit status: true
INFO: 09:24:40,966 DEBUG JDBCTransaction:90 - disabling autocommit
INFO: 09:24:40,993 DEBUG AbstractBatcher:585 - opening JDBC connection
INFO: 09:24:40,993 DEBUG DriverManagerConnectionProvider:132 - opening new JDBC connection
INFO: 09:24:40,996 DEBUG DriverManagerConnectionProvider:138 - created connection to: jdbc:derby://localhost:1527/salestracker, Isolation Level: 2
INFO: 09:24:40,997 DEBUG SQL:111 - select next_hi from hibernate_unique_key for read only with rs
INFO: 09:24:41,001 DEBUG SQL:111 - update hibernate_unique_key set next_hi = ? where next_hi = ?
INFO: 09:24:41,006 DEBUG AbstractBatcher:606 - closing JDBC connection (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)
INFO: 09:24:41,007 DEBUG TableHiLoGenerator:87 - new hi value: 0
INFO: 09:24:41,007 DEBUG AbstractSaveEventListener:135 - generated identifier: 1, using strategy: org.hibernate.id.TableHiLoGenerator
INFO: 09:24:41,036 DEBUG JpaTransactionManager:730 - Initiating transaction commit
INFO: 09:24:41,037 DEBUG JpaTransactionManager:451 - Committing JPA transaction on EntityManager [org.hibernate.ejb.EntityManagerImpl@4e65ad52]
INFO: 09:24:41,037 DEBUG JDBCTransaction:134 - commit
INFO: 09:24:41,038 DEBUG JDBCTransaction:227 - re-enabling autocommit
INFO: 09:24:41,038 DEBUG JDBCTransaction:147 - committed JDBC Connection
INFO: 09:24:41,039 DEBUG ConnectionManager:427 - aggressively releasing JDBC connection
INFO: 09:24:41,039 DEBUG ConnectionManager:464 - releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
INFO: 09:24:41,047 DEBUG JpaTransactionManager:539 - Not closing pre-bound JPA EntityManager after transaction
INFO: 09:24:41,047 DEBUG ExecutionContext:183 - Transitioning to lifecycle stage ResolutionExecution
INFO: 09:24:41,048 DEBUG HttpCacheInterceptor:183 - Looking for HttpCache on com.jameselsey.salestracker.action.ViewClientAction.save()
INFO: 09:24:41,160 DEBUG ExecutionContext:183 - Transitioning to lifecycle stage RequestComplete
INFO: 09:24:41,161 DEBUG JDBCTransaction:186 - rollback
INFO: 09:24:41,161 DEBUG JDBCTransaction:227 - re-enabling autocommit
INFO: 09:24:41,162 DEBUG JDBCTransaction:197 - rolled back JDBC Connection
INFO: 09:24:41,162 DEBUG ConnectionManager:427 - aggressively releasing JDBC connection
INFO: 09:24:41,162 DEBUG ConnectionManager:464 - releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
INFO: 09:24:41,163 DEBUG OpenEntityManagerInViewFilter:119 - Closing JPA EntityManager in OpenEntityManagerInViewFilter
INFO: 09:24:41,163 DEBUG EntityManagerFactoryUtils:313 - Closing JPA EntityManager

Answer 1

自由引用Java EE规范，无论何时说em.persist(obj)，都不一定意味着对数据库进行直接SQL查询。这意味着名为obj的实体将具有持久性标识，因此它的状态将在一段时间内保存并刷新到持久性存储，可能就在您persist调用之后，也许在交易之后，它取决于您的JPA提供商。这可能意味着如果您向实体调用persist并使用断点暂停应用程序，则您的持久数据将不会立即存在于数据库中。

如果您希望在保留实体后立即拥有SQL查询，则可以运行em.flush()。

Answer 2

在致电persist()后，您是否这样做了？

Stripersist.getEntityManager().getTransaction().commit();

.persist（）没有返回错误，但我的持久数据在哪里？

2 个答案: