Cannot get Mule ESB - Studio Artifacts

Question

I am trying to test a database connection in Mule Studio 3.4. I keep getting errors and I keep noticing this particular error in the error log. What is this trying to tell me? The connection to the database keeps failing and I am not sure what is wrong. I am new to mule and not that experienced with java and spring. Any help is appreciated.

Below is the stack trace for the error.

org.mule.common.MuleArtifactFactoryException: Error initializing
    at org.mule.config.spring.SpringXmlConfigurationMuleArtifactFactory.doGetArtifact(SpringXmlConfigurationMuleArtifactFactory.java:149)
    at org.mule.config.spring.SpringXmlConfigurationMuleArtifactFactory.getArtifact(SpringXmlConfigurationMuleArtifactFactory.java:49)
    at org.mule.config.spring.SpringXmlConfigurationMuleArtifactFactory.getArtifact(SpringXmlConfigurationMuleArtifactFactory.java:39)
    at org.mule.tooling.metadata.api.utils.ConnectionTester.internalTestConnection(ConnectionTester.java:58)
    at org.mule.tooling.metadata.api.utils.ConnectionTester.testConnectionFor(ConnectionTester.java:92)
    at org.mule.tooling.messageflow.action.TestConnectorConnectionFromMuleConfigAction$1$1.run(TestConnectorConnectionFromMuleConfigAction.java:65)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.mule.retry.RetryPolicyExhaustedException: Error trying to load driver: ${osas-jdbc.classname} : ${osas-jdbc.classname} (java.sql.SQLException)
    at org.mule.retry.policies.AbstractPolicyTemplate.execute(AbstractPolicyTemplate.java:105)
    at org.mule.transport.AbstractConnector.connect(AbstractConnector.java:1616)
    at org.mule.transport.AbstractConnector.start(AbstractConnector.java:428)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.mule.lifecycle.phases.DefaultLifecyclePhase.applyLifecycle(DefaultLifecyclePhase.java:225)
    at org.mule.lifecycle.RegistryLifecycleManager$RegistryLifecycleCallback.onTransition(RegistryLifecycleManager.java:276)
    at org.mule.lifecycle.RegistryLifecycleManager.invokePhase(RegistryLifecycleManager.java:155)
    at org.mule.lifecycle.RegistryLifecycleManager.fireLifecycle(RegistryLifecycleManager.java:126)
    at org.mule.registry.AbstractRegistryBroker.fireLifecycle(AbstractRegistryBroker.java:80)
    at org.mule.registry.MuleRegistryHelper.fireLifecycle(MuleRegistryHelper.java:120)
    at org.mule.lifecycle.MuleContextLifecycleManager$MuleContextLifecycleCallback.onTransition(MuleContextLifecycleManager.java:94)
    at org.mule.lifecycle.MuleContextLifecycleManager$MuleContextLifecycleCallback.onTransition(MuleContextLifecycleManager.java:90)
    at org.mule.lifecycle.MuleContextLifecycleManager.invokePhase(MuleContextLifecycleManager.java:72)
    at org.mule.lifecycle.MuleContextLifecycleManager.fireLifecycle(MuleContextLifecycleManager.java:64)
    at org.mule.DefaultMuleContext.start(DefaultMuleContext.java:255)
    at org.mule.config.spring.SpringXmlConfigurationMuleArtifactFactory.doGetArtifact(SpringXmlConfigurationMuleArtifactFactory.java:130)
    ... 6 more
Caused by: org.mule.transport.ConnectException: Error trying to load driver: ${osas-jdbc.classname} : ${osas-jdbc.classname} (java.sql.SQLException)
    at org.mule.transport.jdbc.JdbcConnector.getConnection(JdbcConnector.java:258)
    at org.mule.transport.jdbc.JdbcConnector.doConnect(JdbcConnector.java:377)
    at org.mule.transport.AbstractConnector$5.doWork(AbstractConnector.java:1556)
    at org.mule.retry.policies.AbstractPolicyTemplate.execute(AbstractPolicyTemplate.java:67)
    ... 24 more
Caused by: java.sql.SQLException: Error trying to load driver: ${osas-jdbc.classname} : ${osas-jdbc.classname}
    at org.enhydra.jdbc.standard.StandardDataSource.getConnection(StandardDataSource.java:184)
    at org.enhydra.jdbc.standard.StandardDataSource.getConnection(StandardDataSource.java:144)
    at org.mule.transport.jdbc.JdbcConnector.getConnection(JdbcConnector.java:254)
    ... 27 more

Answer 1

就像您没有通过使用Mule的属性加载机制（即，在类路径的根处名为mule-app.properties的文件）或通过使用Spring的context:property-placeholder来提供${osas-jdbc.classname}的值一样context:property-placeholder 。