postgresql 初始化 c3p0 池期间获取尝试失败
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Acquisition attempt failed during the initializing c3p0 pool
提问by montekristo_07
I am new to J2EE technologies and trying to create a basic web application with JSF, Spring and Hibernate. I also use PostgreSQL. During the server startup, I encounter this exception:
我是 J2EE 技术的新手，正在尝试使用 JSF、Spring 和 Hibernate 创建一个基本的 Web 应用程序。我也使用 PostgreSQL。在服务器启动过程中，我遇到了这个异常：
WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@173b4cf -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.lang.NullPointerException
at sun.jdbc.odbc.JdbcOdbcDriver.getProtocol(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcDriver.knownURL(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcDriver.acceptsURL(Unknown Source)
at java.sql.DriverManager.getDriver(Unknown Source)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:240)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:131)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:156)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:145)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPoolPooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
at com.mchange.v2.resourcepool.BasicResourcePool.access0(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Dec 09, 2015 11:13:21 AM com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask run
WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@173b4cf -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.lang.NullPointerException
at sun.jdbc.odbc.JdbcOdbcDriver.getProtocol(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcDriver.knownURL(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcDriver.acceptsURL(Unknown Source)
at java.sql.DriverManager.getDriver(Unknown Source)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:240)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:131)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:156)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:145)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPoolPooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
at com.mchange.v2.resourcepool.BasicResourcePool.access0(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Dec 09, 2015 11:13:21 AM com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask run
WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@5e53d -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.lang.NullPointerException
at sun.jdbc.odbc.JdbcOdbcDriver.getProtocol(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcDriver.knownURL(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcDriver.acceptsURL(Unknown Source)
at java.sql.DriverManager.getDriver(Unknown Source)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:240)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:131)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:156)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:145)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPoolPooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
at com.mchange.v2.resourcepool.BasicResourcePool.access0(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
I gave my configuration files and related class below:
我在下面给出了我的配置文件和相关类：
application-context.xml:
应用程序上下文.xml：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://localhost:5432/SomeDB" />
<property name="username" value="postgres" />
<property name="password" value="1234" />
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="tr.mypackage" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
<prop key="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
<prop key="hibernate.c3p0.acquire_increment">1</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
<context:annotation-config />
<context:component-scan base-package="tr.mypackage" />
</beans>
web.xml:
网页.xml：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
id="WebApp_ID" version="3.1">
<display-name>Some Display Name</display-name>
<!-- JSF -->
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<!-- SPRING -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/application-context.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>
<!-- OTHER -->
<welcome-file-list>
<welcome-file>index.xhtml</welcome-file>
</welcome-file-list>
</web-app>
Person.java
人.java
package tr.mypackage;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import com.sun.istack.internal.NotNull;
@Entity
@Table(name="person_t")
public class Person {
@Id
@NotNull
@GeneratedValue
private int id;
@Column
private String firstName;
public Person(){
}
public Person(int id, String firstName) {
super();
this.id = id;
this.firstName = firstName;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
}
So, is there any idea about where my error is?
那么，是否知道我的错误在哪里？
回答by Steve Waldman
The immediate cause of your problem is that you haven't actually provided any Connection information to the c3p0 DataSource you have hibernate build with these settings.
您的问题的直接原因是您实际上没有向使用这些设置进行休眠构建的 c3p0 数据源提供任何连接信息。
<prop key="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
<prop key="hibernate.c3p0.acquire_increment">1</prop>
See the Spring docs: The DataSource you have configured in Spring is distinct from the one hibernate's SessionFactory might build internally. You've provided enough configuration to cause hibernate to build a DataSource, but you haven't provided the hibernate.connection.*parameters necessary to properly configure it.
请参阅Spring 文档：您在 Spring 中配置的 DataSource 与可能在内部构建的休眠的 SessionFactory 不同。您已经提供了足够的配置来使 hibernate 构建数据源，但是您还没有提供hibernate.connection.*正确配置它所需的参数。
The easiest thing to do would be to get rid of the DataSource you've configured in Spring and finish configuring your c3p0 DataSource in hibernate. See hibernate docsfor the various Connection parameters you should supply that currently are missing. You can also set c3p0 configuration parametersas hibernate.c3p0.fooBarBlah(where fooBarBlahshould obviously be replaced by real parameter names). [Note that for parameters like max_sizeand maxPoolSizewith both a hibernate name and a c3p0 name, the hibernate name will override c3p0-name settings.]
最简单的方法是去掉你在 Spring 中配置的 DataSource 并在 hibernate 中完成你的 c3p0 DataSource 的配置。有关您应该提供的当前缺少的各种连接参数，请参阅休眠文档。您还可以将c3p0 配置参数设置为hibernate.c3p0.fooBarBlah（其中fooBarBlah显然应该由实际参数名称替换）。[注意，像参数max_size，并maxPoolSize同时具有休眠名称和C3P0名称，休眠名称将覆盖C3P0名设置]
Alternatively, you can get rid of the two hibernate properties above, and supply your own DataSource configured in Spring. If you want Connection pooling, you probably don't your DataSource to be a org.springframework.jdbc.datasource.DriverManagerDataSource. You can configure a com.mchange.v2.c3p0.ComboPooledDataSourcedirectly in Spring, the same way you've configured the unpooled DriverManagerDataSource. See the section "Have Spring Manage the Pool" in this articlefor an example.
或者，您可以去掉上面的两个 hibernate 属性，并提供您自己在 Spring 中配置的 DataSource。如果您想要连接池，您可能不会将 DataSource 设为org.springframework.jdbc.datasource.DriverManagerDataSource. 您可以com.mchange.v2.c3p0.ComboPooledDataSource直接在 Spring 中配置 a ，与配置未合并的 DriverManagerDataSource 的方式相同。请参见“从春季管理池”，在这篇文章中的例子。
回答by Dheeraj
If you are using eclipse and you are facing this error, then you just need to change your mysql connector (which worked totally fine in my case).
如果您正在使用 eclipse 并且遇到此错误，那么您只需要更改您的 mysql 连接器（在我的情况下完全正常）。
The newer versions are using caching_sha2_password.
较新的版本正在使用caching_sha2_password.
