java如何在JPA/Hibernate应用程序中配置连接池（没有Spring）？

Question

持久性。xml

    <properties>
        <property name='javax.persistence.jdbc.driver' value='org.postgresql.Driver' />
        <property name='javax.persistence.jdbc.url'
            value='jdbc:postgresql://192.168.19.66:5432/service1' />
        <property name='javax.persistence.jdbc.user' value='postgres' />
        <property name='javax.persistence.jdbc.password' value='root' />
        <property name='hibernate.dialect' value='org.hibernate.dialect.PostgreSQLDialect' />
        <property name='hibernate.connection.shutdown' value='true' />
        <property name='hibernate.hbm2ddl.auto' value='none' />
        <property name='hibernate.show_sql' value='false' />
        <property name='hibernate.format_sql' value='false' />
                    <!-- Connection Pooling -->
        <property name="hibernate.connection.provider_class"
            value="org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider" />
        <property name="hibernate.c3p0.max_size" value="100" />
        <property name="hibernate.c3p0.min_size" value="5" />
        <property name="hibernate.c3p0.acquire_increment" value="5" />
        <property name="hibernate.c3p0.idle_test_period" value="500" />
        <property name="hibernate.c3p0.max_statements" value="50" />
        <property name="hibernate.c3p0.timeout" value="10000" />
    </properties>

例外情况

[C3P0PooledConnectionPoolManager[identityToken->1hge4qw8wh4gndjoawud4|b81be4]-AdminTaskTimer] DEBUG com.mchange.v2.async.ThreadPoolAsynchronousRunner - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@5d1aef -- Running DeadlockDetector[Exiting. No pending tasks.]
[C3P0PooledConnectionPoolManager[identityToken->1hge4qw8wh4gndjoawud4|b81be4]-AdminTaskTimer] DEBUG com.mchange.v2.resourcepool.BasicResourcePool - Continuing acquisition series. pending_acquires [5],  attempts_remaining: 20
[C3P0PooledConnectionPoolManager[identityToken->1hge4qw8wh4gndjoawud4|b81be4]-AdminTaskTimer] DEBUG com.mchange.v2.async.ThreadPoolAsynchronousRunner - com.mchange.v2.async.ThreadPoolAsynchronousRunner@b66600: Adding task to queue -- com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@934847
[C3P0PooledConnectionPoolManager[identityToken->1hge4qw8wh4gndjoawud4|b81be4]-HelperThread-#0] DEBUG com.mchange.v2.resourcepool.BasicResourcePool - An exception occurred while acquiring a poolable resource. Will retry.
java.sql.SQLException: No suitable driver
    at java.sql.DriverManager.getDriver(DriverManager.java:264)
    at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:240)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
    at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)

获取异常java。sql。SQLException:没有合适的驱动程序

当我查看源代码时，它正在查找属性“hibernate.connection.driver\u class”。我已经在“javax.persistence.jdbc.driver”中提到了驱动程序类

我认为配置连接池的方法不对。该应用程序使用的是Hibernate4.1.11（没有spring）、JPA2、PostgreSQL9.1。没有冬眠。cfg。xml

问题

• 在Hibernate/JPA应用程序中配置连接池的方法是什么
• 我已经用javax提供了。坚持不懈jdbc。驾驶员如果我提供hibernate.connection.driver_class属性，连接池和JPA连接创建的连接是相同还是不同

注意

• Postgresql驱动程序位于类路径中
• 如果我删除<!-- Connection Pooling -->之后的行，它将运行。但是，如果我在连接池的<!-- Connection Pooling -->之后添加行，就会得到这个异常

Answer 1

回到过去，必须使用Class.forName(org.postgresql.Driver.class)构造加载适当的驱动程序类。对于JDBC 4.0驱动程序，不再需要它了——但您可以尝试一下

或者，尝试用-Djdbc.drivers=org.postgresql.Driver启动应用程序，它实际上与Class.forName代码片段相同，但不需要硬编码驱动程序类。希望有帮助

Answer 2

从答案来看

https://stackoverflow.com/a/10899364/112500

我能解决这个问题

在把这行代码发送到c3p0配置之后。xml

<property name="driverClass">org.postgresql.Driver</property>