C3P0 log4j:WARN No appenders could be found for logger (com.mchange.v2.log.MLog) - lazydoggy - ITeye技术网站
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学习SSH的过程中，配置日志，使用SLF4J和LOG4J搭配，数据库连接池使c3p0，启动服务器，会出现如下警告信息：
log4j:WARN No appenders could be found for logger
(com.mchange.v2.log.MLog).
log4j:WARN Please initialize the log4j system
出现原因是，Spring配置监听器先于Log4j配置监听器执行了，解决很简单，把Log4j配置放在Spring配置前就ok了。
下面是我的web.xml配置文件：
&?xml version="1.0" encoding="UTF-8"?&
&web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="/xml/ns/javaee" xmlns:web="/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="/xml/ns/javaee /xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5"&
&display-name&SSHDemo&/display-name&
&welcome-file-list&
&welcome-file&index.html&/welcome-file&
&welcome-file&index.htm&/welcome-file&
&welcome-file&index.jsp&/welcome-file&
&welcome-file&default.html&/welcome-file&
&welcome-file&default.htm&/welcome-file&
&welcome-file&default.jsp&/welcome-file&
&/welcome-file-list&
&!-- Struts2 configuration --&
&filter-name&struts2&/filter-name&
&filter-class&org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter&/filter-class&
&filter-mapping&
&filter-name&struts2&/filter-name&
&url-pattern&/*&/url-pattern&
&/filter-mapping&
&!-- Log4j configuration --&
&context-param&
&param-name&webAppRootKey&/param-name&
&param-value&sshdemo.root&/param-value&
&/context-param&
&context-param&
&param-name&log4jConfigLocation&/param-name&
&param-value&/WEB-INF/log4j.properties&/param-value&
&/context-param&
&listener&
&listener-class&org.springframework.web.util.Log4jConfigListener&/listener-class&
&/listener&
&context-param&
&param-name&contextConfigLocation&/param-name&
&param-value&/WEB-INF/applicationContext.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&
&/web-app&
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没有感觉 动态MBean有什么实际的用处？
的确IDE不全时，没注意啊，org.aspectj.lang ...
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你可能喜欢org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [applicationContext.xml]: Instantiation of nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mchange.boPooledDataSource]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/mchange/v2/log/jdk14logging/ForwardingLogger
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1050)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
at org.springframework.context.support.ClassPathXmlApplicationContext.&init&(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.&init&(ClassPathXmlApplicationContext.java:83)
at test.TestSsh.&init&(TestSsh.java:16)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.junit.runners.BlockJUnit4ClassRunner.createTest(BlockJUnit4ClassRunner.java:217)
at org.junit.runners.BlockJUnit4ClassRunner$1.runReflectiveCall(BlockJUnit4ClassRunner.java:266)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.BlockJUnit4ClassRunner.methodBlock(BlockJUnit4ClassRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mchange.boPooledDataSource]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/mchange/v2/log/jdk14logging/ForwardingLogger
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:154)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098)
... 35 more
Caused by: java.lang.NoClassDefFoundError: com/mchange/v2/log/jdk14logging/ForwardingLogger
at com.mchange.v2.c3p0.impl.PoolBackedDataSourceBase.&init&(PoolBackedDataSourceBase.java:288)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.&init&(AbstractPoolBackedDataSource.java:74)
at com.mchange.v2.c3p0.AbstractComboPooledDataSource.&init&(AbstractComboPooledDataSource.java:142)
at com.mchange.v2.c3p0.AbstractComboPooledDataSource.&init&(AbstractComboPooledDataSource.java:138)
at com.mchange.boPooledDataSource.&init&(ComboPooledDataSource.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142)
... 37 more
Caused by: java.lang.ClassNotFoundException: com.mchange.v2.log.jdk14logging.ForwardingLogger
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 47 more
看上面的cause by
exception is java.lang.NoClassDefFoundError: com/mchange/v2/log/jdk14logging/ForwardingLogger
不得不说c3p0 9.2版本后就分离了这个com/mchange/v2/log/jdk14logging/ForwardingLogger
需要额外添加 mchange-commons-java-XX.jar
问题是c3p0 9.5.2怎么mchange都会出现异常，还是换回车c3
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c3p0.properties
最近由于客户业务量的增长，公司决定使用分布式处理的方式来解决客户反应的处理速度慢的问题。本博主要讲解项目中遇到的问题，如有不对敬请批评指正。废话不多说直接上干货。
首先，我把业务逻辑重新梳理了一遍，抽出了无关的业务和可能产生并发的逻辑，以便考虑分布式（简单分布式）。于是我把能单独运行的一个工程放到一台服务器上在复制一套放到另外一台服务器上。两台服务器同时运行处理报文。结果。。。
org.hibernate.exception.GenericJDBCException: Could not open connection
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:54)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:304)
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:169)
at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.extractPhysicalConnection(ConnectionProxyHandler.java:82)
at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:138)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at com.sun.proxy.$Proxy104.prepareStatement(Unknown Source)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:147)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:166)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:145)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1854)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1831)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1811)
at org.hibernate.loader.Loader.doQuery(Loader.java:899)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:311)
at org.hibernate.loader.Loader.loadEntity(Loader.java:2111)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:82)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:72)
at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:3887)
at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:458)
at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:427)
at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:204)
at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:260)
at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:148)
at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1078)
at org.hibernate.internal.SessionImpl.access$2000(SessionImpl.java:175)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.load(SessionImpl.java:2424)
at org.hibernate.internal.SessionImpl.get(SessionImpl.java:974)
at com.ygjt.bcb.base.AbstractBaseDAO.get(AbstractBaseDAO.java:40)
at com.ygjt.bcb.base.AbstractCommonDAO.findById(AbstractCommonDAO.java:65)
at com.ygjt.bcb.cmn.dao.impl.CustomsDAOImpl.findById(CustomsDAOImpl.java:19)
at com.ygjt.bcb.cmn.dao.impl.CustomsDAOImpl.findById(CustomsDAOImpl.java:1)
at sun.reflect.GeneratedMethodAccessor513.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:80)
at com.google.code.ssm.aop.SingleReadCacheAdvice.cache(SingleReadCacheAdvice.java:78)
at com.google.code.ssm.aop.ReadThroughSingleCacheAdvice.cacheGetSingle(ReadThroughSingleCacheAdvice.java:52)
at sun.reflect.GeneratedMethodAccessor509.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:65)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:161)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at com.sun.proxy.$Proxy46.findById(Unknown Source)
at com.ygjt.bcb.base.BaseBO.findById(BaseBO.java:27)
at sun.reflect.GeneratedMethodAccessor508.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at com.sun.proxy.$Proxy47.findById(Unknown Source)
at com.ygjt.bcb.datainterface.proc.impl.EAutoCheck.check(EAutoCheck.java:172)
at com.ygjt.bcb.datainterface.proc.impl.EAutoCheck.eede(EAutoCheck.java:124)
at com.ygjt.bcb.datainterface.proc.impl.EdeMessageProcessorImpl.process(EdeMessageProcessorImpl.java:116)
at com.ygjt.bcb.datainterface.proc.impl.DataProcessImpl.process(DataProcessImpl.java:19)
at com.ygjt.bcb.datainterface.DataProcThread.run(DataProcThread.java:27)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:65)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:527)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
at org.hibernate.service.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:141)
at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:292)
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:297)
... 70 more
Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@5f927daf -- timeout at awaitAvailable()
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1317)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
... 74 more
```自己在网上google了一下，大部分的同行都说是c3p0的一个bug，大部分认为只要将c3p0.properties中的一个配置项（如下）设置一下：
&div class="se-preview-section-delimiter"&&/div&
The size of c3p0’s global PreparedStatement cache
simple.c3p0.maxStatements=500
&div class="se-preview-section-delimiter"&&/div&
simple.c3p0.maxStatements=0
后来我看了一下c3p0.properties的讲解，贴出以前有问题的配置：
# C3P0 setup
# how many connections at a time c3p0 will try to acquire when the pool is exhausted
simple.c3p0.acquireIncrement=3
# Number of Connections a pool will try to acquire upon startup
simple.c3p0.initialPoolSize=2
#If this is a number greater than 0, c3p0 will test all idle, pooled but unchecked-out connections, every this number of seconds
simple.c3p0.idleConnectionTestPeriod=10
#Minimum number of Connections a pool will maintain at any given time
simple.c3p0.minPoolSize=2
#Maximum number of Connections a pool will maintain at any given time
simple.c3p0.maxPoolSize=200
#c3p0 is very asynchronous. Slow JDBC operations are generally performed by helper threads that don't hold contended locks.
#Spreading these operations over multiple threads can significantly improve performance by allowing multiple operations to be performed simultaneously.
simple.c3p0.numHelperThreads=10
#Seconds a Connection can remain pooled but unused before being discarded. Zero means idle connections never expire
simple.c3p0.maxIdleTime=10
#The size of c3p0's global PreparedStatement cache
simple.c3p0.maxStatements=500
#the max size for every connection
simple.c3p0.maxStatementsPerConnection=20
# how many times c3p0 will try to acquire a new Connection from the database before giving up
simple.c3p0.acquireRetryAttempts=30
# a pooled DataSource will declare itself broken and be permanently closed if a Connection cannot be obtained from the database after making
# to acquire one.
simple.c3p0.breakAfterAcquireFailure=false
#time c3p0 will wait between acquire attempts
simple.c3p0.acquireRetryDelay=1000
#The number of milliseconds a client calling getConnection() will wait for a Connection to be checked-in or acquired when the pool is exhausted
simple.c3p0.checkoutTimeout=10000
#The JDBC spec is unforgivably silent on what should happen to unresolved, pending transactions on Connection close
simple.c3p0.autoCommitOnClose=false
这是后来自己研究以后的配置：
simple.c3p0.acquireIncrement=5
simple.c3p0.initialPoolSize=2
simple.c3p0.idleConnectionTestPeriod=10
simple.c3p0.minPoolSize=2
simple.c3p0.maxPoolSize=200
simple.c3p0.numHelperThreads=20
simple.c3p0.maxIdleTime=10
simple.c3p0.maxStatements=10
simple.c3p0.maxStatementsPerConnection=20
simple.c3p0.acquireRetryAttempts=30
simple.c3p0.breakAfterAcquireFailure=false
simple.c3p0.acquireRetryDelay=1000
simple.c3p0.checkoutTimeout=10000
最大连接数200，maxStatements用以控制数据源内加载的PreparedStatements数量。但由于预缓存的statements属于单个connection而不是整个连接池。所以设置这个参数需要考虑到多方面的因素。配置太大反而会产生文章开始时的异常。
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