weblogic下的jar包衝突問題

最近工做上遇到一個奇怪的技術問題，記錄下。

咱們服務器是多節點部署的，一共是4臺服務器，是經過apache轉發到每臺服務器的（負載均衡），每臺服務器的架構都是同樣的，都是用weblogic做爲服務器端的，項目應用是用SSH架構。 

問題就出在5,7.8節點的服務器都沒有問題，就6節點的服務器出了問題（假設4臺服務器部署在內網的5,6,7,8節點上）

每次訪問到6節點就掛了，後來查看錯誤日誌，錯誤日誌以下：

2013-09-05 18:47:57,848 ERROR [[ACTIVE] ExecuteThread: '10' for queue: 'weblogic.kernel.Default (self-tuning)'] action.ActionServlet (ActionServlet.java:1034) - Parsing error pr
ocessing resource path 
                                /WEB-INF/struts-cfg/struts-config-user.xml,
                                /WEB-INF/struts-cfg/struts-config-centrex.xml
java.net.UnknownHostException: struts.apache.org
        at java.net.InetAddress.getAllByName0(InetAddress.java:1184)
        at java.net.InetAddress.getAllByName(InetAddress.java:1110)
        at java.net.InetAddress.getAllByName(InetAddress.java:1046)
        at weblogic.net.http.HttpClient.openServer(HttpClient.java:309)
        at weblogic.net.http.HttpClient.openServer(HttpClient.java:425)
        at weblogic.net.http.HttpClient.New(HttpClient.java:252)
        at weblogic.net.http.HttpURLConnection.getHttpClient(HttpURLConnection.java:228)
        at weblogic.net.http.HttpURLConnection.getInputStream(HttpURLConnection.java:450)
        at weblogic.net.http.SOAPHttpURLConnection.getInputStream(SOAPHttpURLConnection.java:37)
        at org.apache.commons.digester.Digester.createInputSourceFromURL(Digester.java:1938)
        at org.apache.commons.digester.Digester.resolveEntity(Digester.java:1615)
        at weblogic.xml.jaxp.ChainingEntityResolver.resolveEntity(ChainingEntityResolver.java:87)
        at weblogic.xml.jaxp.ChainingEntityResolver.resolveEntity(ChainingEntityResolver.java:87)
        at com.sun.org.apache.xerces.internal.util.EntityResolverWrapper.resolveEntity(EntityResolverWrapper.java:107)
        at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.resolveEntityAsPerStax(XMLEntityManager.java:1017)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1189)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1087)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:1000)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:647)
        at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511)
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808)
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
        at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119)
        at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1205)
        at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522)
        at weblogic.xml.jaxp.WebLogicXMLReader.parse(WebLogicXMLReader.java:133)
        at weblogic.xml.jaxp.RegistryXMLReader.parse(RegistryXMLReader.java:173)
        at org.apache.commons.digester.Digester.parse(Digester.java:1745)
        at org.apache.struts.action.ActionServlet.parseModuleConfigFile(ActionServlet.java:1006)
        at org.apache.struts.action.ActionServlet.initModuleConfig(ActionServlet.java:955)
        at org.apache.struts.action.ActionServlet.init(ActionServlet.java:470)
        at javax.servlet.GenericServlet.init(GenericServlet.java:241)
        at weblogic.servlet.internal.StubSecurityHelper$ServletInitAction.run(StubSecurityHelper.java:283)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
        at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
        at weblogic.servlet.internal.StubSecurityHelper.createServlet(StubSecurityHelper.java:64)
        at weblogic.servlet.internal.StubLifecycleHelper.createOneInstance(StubLifecycleHelper.java:58)
        at weblogic.servlet.internal.StubLifecycleHelper.<init>(StubLifecycleHelper.java:48)
        at weblogic.servlet.internal.ServletStubImpl.prepareServlet(ServletStubImpl.java:539)
        at weblogic.servlet.internal.WebAppServletContext.preloadServlet(WebAppServletContext.java:1981)
        at weblogic.servlet.internal.WebAppServletContext.loadServletsOnStartup(WebAppServletContext.java:1955)
        at weblogic.servlet.internal.WebAppServletContext.preloadResources(WebAppServletContext.java:1874)
        at weblogic.servlet.internal.WebAppServletContext.start(WebAppServletContext.java:3154)
        at weblogic.servlet.internal.WebAppModule.startContexts(WebAppModule.java:1518)
        at weblogic.servlet.internal.WebAppModule.start(WebAppModule.java:484)
        at weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:425)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:52)
        at weblogic.application.internal.flow.ModuleStateDriver.start(ModuleStateDriver.java:119)
        at weblogic.application.internal.flow.ScopedModuleDriver.start(ScopedModuleDriver.java:200)
        at weblogic.application.internal.flow.ModuleListenerInvoker.start(ModuleListenerInvoker.java:247)
        at weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:425)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:52)
        at weblogic.application.internal.flow.ModuleStateDriver.start(ModuleStateDriver.java:119)
        at weblogic.application.internal.flow.StartModulesFlow.activate(StartModulesFlow.java:27)
        at weblogic.application.internal.BaseDeployment$2.next(BaseDeployment.java:671)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:52)
        at weblogic.application.internal.BaseDeployment.activate(BaseDeployment.java:212)
        at weblogic.application.internal.SingleModuleDeployment.activate(SingleModuleDeployment.java:44)
        at weblogic.application.internal.DeploymentStateChecker.activate(DeploymentStateChecker.java:161)
        at weblogic.deploy.internal.targetserver.AppContainerInvoker.activate(AppContainerInvoker.java:79)
        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.activate(AbstractOperation.java:569)
        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.activateDeployment(ActivateOperation.java:150)
        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.doCommit(ActivateOperation.java:116)
        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.commit(AbstractOperation.java:323)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentCommit(DeploymentManager.java:844)
        at weblogic.deploy.internal.targetserver.DeploymentManager.activateDeploymentList(DeploymentManager.java:1253)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handleCommit(DeploymentManager.java:440)
        at weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.commit(DeploymentServiceDispatcher.java:163)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doCommitCallback(DeploymentReceiverCallbackDeliverer.java:195)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$100(DeploymentReceiverCallbackDeliverer.java:13)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer$2.run(DeploymentReceiverCallbackDeliverer.java:68)
        at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:545)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)

開始一直覺得是6節點上的服務器解析struts-config.xml配置文件的路徑出錯了（由於它的報錯提示也確實是提示這個錯，誤導啊），換了struts-config.xml配置文件的路徑，仍是這個錯，基本上能夠排除不是路徑問題了。

網上查了下資料，有些說是:

struts-config.xml 的頭聲明不對，說是要把

<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://struts.apache.org/dtds/struts-config_1_2.dtd">

換成

<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN" "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">

就能夠了。

試了一下，仍是不行。

折騰了一天，該排除的都排除了，根據經驗，只能把問題定位在jar包衝突上了，後來看了看lib下的struts包：

-rw-r--r-- 1 weblogic app  438203  8月 19 18:28 struts.jar    
-rw-r--r-- 1 weblogic app  328896  8月 19 18:28 struts-core-1.3.8.jar
-rw-r--r-- 1 weblogic app   39644  8月 19 18:28 struts-extras-1.3.8.jar
-rw-r--r-- 1 weblogic app  251521  8月 19 18:28 struts-taglib-1.3.8.jar
-rw-r--r-- 1 weblogic app  119653  8月 19 18:28 struts-tiles-1.3.8.jar

我記得struts.jar 和 struts-core-1.3.8.jar 包起的做用是同樣了，會不會由於服務器加載jar包的順序不同，致使只加載了一個，而這個卻不能找到struts-config.xml的路徑？  因而把struts.jar重命名了，以下：

-rw-r--r-- 1 weblogic app  438203  8月 19 18:28 struts.jar.zk
-rw-r--r-- 1 weblogic app  328896  8月 19 18:28 struts-core-1.3.8.jar
-rw-r--r-- 1 weblogic app   39644  8月 19 18:28 struts-extras-1.3.8.jar
-rw-r--r-- 1 weblogic app  251521  8月 19 18:28 struts-taglib-1.3.8.jar
-rw-r--r-- 1 weblogic app  119653  8月 19 18:28 struts-tiles-1.3.8.jar

而後重啓了weblogic服務器，不報錯了，瀏覽器訪問也ok了。果真是jar包衝突問題。是由於weblogic加載jar包的順序不同致使的。

可是一直想不明白的是5,7,8節點爲何就能夠？ 四臺服務器的配置都是如出一轍的。待求解。