【发布时间】：2014-07-03 04:34:59
【问题描述】：
我在 WebSphere Application Server 8.5 for RHEL6 (x64) 上部署了两个 Web 应用程序。两个 Web 应用程序都使用 SAPJCO 库连接到部署在 SAP ECC6 中的 BAPI。两个应用程序都需要访问相同的 BAPI 才能创建采购请求。因此，我们使用从 SAP 的 CustomDestinationDataProvider 修改的相同代码进行连接。为了确保应用程序只注册一次，我们使用 Spring 使其成为单例。
但是，当应用程序启动时，一个应用程序（我们猜测它是在第一个之后加载的）在执行"com.sap.conn.jco.ext.Environment.registerDestinationDataProvider(myProvider)" 时遇到"java.lang.IllegalStateException: DestinationDataProvider already registered"。
CustomDestinationDataProvider 如下：
public class CustomDestinationDataProvider {
public CustomDestinationDataProvider () {
}
public static BapiConfigBean bapiConfigBean;
//The custom destination data provider implements DestinationDataProvider and
//provides an implementation for at least getDestinationProperties(String).
//Whenever possible the implementation should support events and notify the JCo runtime
//if a destination is being created, changed, or deleted. Otherwise JCo runtime
//will check regularly if a cached destination configuration is still valid which incurs
//a performance penalty.
public static class MyDestinationDataProvider implements DestinationDataProvider
{
private DestinationDataEventListener eL;
private HashMap<String, Properties> secureDBStorage = new HashMap<String, Properties>();
public MyDestinationDataProvider () {
}
public Properties getDestinationProperties(String destinationName)
{
try
{
//read the destination from DB
Properties p = secureDBStorage.get(destinationName);
if(p!=null)
{
//check if all is correct, for example
if(p.isEmpty())
throw new DataProviderException(DataProviderException.Reason.INVALID_CONFIGURATION,
"destination configuration is incorrect", null);
return p;
}
return null;
}
catch(RuntimeException re)
{
throw new DataProviderException(DataProviderException.Reason.INTERNAL_ERROR, re);
}
}
//An implementation supporting events has to retain the eventListener instance provided
//by the JCo runtime. This listener instance shall be used to notify the JCo runtime
//about all changes in destination configurations.
public void setDestinationDataEventListener(DestinationDataEventListener eventListener)
{
this.eL = eventListener;
}
public boolean supportsEvents()
{
return true;
}
//implementation that saves the properties in a very secure way
void changeProperties(String destName, Properties properties)
{
synchronized(secureDBStorage)
{
if(properties==null)
{
if(secureDBStorage.remove(destName)!=null)
eL.deleted(destName);
}
else
{
secureDBStorage.put(destName, properties);
eL.updated(destName); // create or updated
}
}
}
public void removeDestination(String destName) {
// TODO Auto-generated method stub
}
public void addDestination(String destName,
MyDestinationDataProvider myProvider) {
// TODO Auto-generated method stub
}
} // end of MyDestinationDataProvider
//business logic
void executeCalls(String destName)
{
JCoDestination dest;
try
{
dest = JCoDestinationManager.getDestination(destName);
dest.ping();
System.out.println("Destination " + destName + " works");
}
catch(JCoException e)
{
e.printStackTrace();
System.out.println("Execution on destination " + destName+ " failed");
}
}
static Properties getDestinationPropertiesFromUI()
{
//adapt parameters in order to configure a valid destination
Properties connectProperties = new Properties();
connectProperties.setProperty(DestinationDataProvider.JCO_ASHOST, getBapiConfigBean().getServerIp());
connectProperties.setProperty(DestinationDataProvider.JCO_SYSNR, getBapiConfigBean().getSystemNumber());
connectProperties.setProperty(DestinationDataProvider.JCO_CLIENT, getBapiConfigBean().getClientId());
connectProperties.setProperty(DestinationDataProvider.JCO_USER, getBapiConfigBean().getUserName());
connectProperties.setProperty(DestinationDataProvider.JCO_PASSWD, getBapiConfigBean().getUserPassword());
connectProperties.setProperty(DestinationDataProvider.JCO_LANG, getBapiConfigBean().getClientLang());
return connectProperties;
}
static MyDestinationDataProvider myProvider = null; //2014-06-30 00:30
public static void initProvider(BapiConfigBean bapiConfigBean) {
CustomDestinationDataProvider.destroy();
setBapiConfigBean(bapiConfigBean);
myProvider = new MyDestinationDataProvider();
String destName = getBapiConfigBean().getSapDestname();
try
{
com.sap.conn.jco.ext.Environment.registerDestinationDataProvider(myProvider);
CustomDestinationDataProvider test = new CustomDestinationDataProvider();
myProvider.changeProperties(destName, getDestinationPropertiesFromUI());
test.executeCalls(destName);
}
catch(IllegalStateException providerAlreadyRegisteredException)
{
try {
JCoDestination jcodest = JCoDestinationManager.getDestination(getBapiConfigBean().getSapDestname());
} catch (JCoException exJCo) {
//TODO: Add exception handling and send friendly message to ui
}
}
}
public static BapiConfigBean getBapiConfigBean() {
return bapiConfigBean;
}
public static void setBapiConfigBean(BapiConfigBean bapiConfigBean) {
CustomDestinationDataProvider.bapiConfigBean = bapiConfigBean;
}
public static void destroy() {
try {
Environment.unregisterDestinationDataProvider(myProvider);
System.out.println("Unregistered connection to SAP");
} catch (IllegalStateException e) {
System.out.println("Failed to unregister connection to SAP: "+ e);
}
}
}
</code></pre>
And the error from SystemOut.log in WebSphere is as follow:
[6/30/14 22:29:15:198 ICT] 00000043 webapp E com.ibm.ws.webcontainer.webapp.WebApp notifyServletContextCreated SRVE0283E: Exception caught while initializing context: {0}
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jdoConnector' defined in ServletContext resource [/WEB-INF/applicationContext-BAPI.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.sps.tmps.bean.bapi.JCOConnector]: Constructor threw exception; nested exception is java.lang.Error: java.lang.IllegalStateException: DestinationDataProvider already registered [com.sps.tmps.bean.bapi.CustomDestinationDataProvider$MyDestinationDataProvider]
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.sps.tmps.bean.bapi.JCOConnector]: Constructor threw exception; nested exception is java.lang.Error: java.lang.IllegalStateException: DestinationDataProvider already registered [com.sps.tmps.bean.bapi.CustomDestinationDataProvider$MyDestinationDataProvider]
Caused by: java.lang.Error: java.lang.IllegalStateException: DestinationDataProvider already registered [com.sps.tmps.bean.bapi.CustomDestinationDataProvider$MyDestinationDataProvider]
at com.sps.tmps.bean.bapi.CustomDestinationDataProvider.initProvider(CustomDestinationDataProvider.java:174)
at com.sps.tmps.bean.bapi.JCOConnector.(JCOConnector.java:41)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:56)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:39)
at java.lang.reflect.Constructor.newInstance(Constructor.java:527)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:85)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:186)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:800)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:720)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:387)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:251)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:156)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:248)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:287)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:244)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:187)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:49)
at com.ibm.ws.webcontainer.webapp.WebApp.notifyServletContextCreated(WebApp.java:1678)
at com.ibm.ws.webcontainer.webapp.WebAppImpl.initialize(WebAppImpl.java:414)
at com.ibm.ws.webcontainer.webapp.WebGroupImpl.addWebApplication(WebGroupImpl.java:88)
at com.ibm.ws.webcontainer.VirtualHostImpl.addWebApplication(VirtualHostImpl.java:169)
at com.ibm.ws.webcontainer.WSWebContainer.addWebApp(WSWebContainer.java:749)
at com.ibm.ws.webcontainer.WSWebContainer.addWebApplication(WSWebContainer.java:634)
at com.ibm.ws.webcontainer.component.WebContainerImpl.install(WebContainerImpl.java:426)
at com.ibm.ws.webcontainer.component.WebContainerImpl.start(WebContainerImpl.java:718)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:1175)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.fireDeployedObjectStart(DeployedApplicationImpl.java:1370)
at com.ibm.ws.runtime.component.DeployedModuleImpl.start(DeployedModuleImpl.java:639)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.start(DeployedApplicationImpl.java:968) at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:774)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:2182)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:445)
at com.ibm.ws.runtime.component.CompositionUnitImpl.start(CompositionUnitImpl.java:123)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:388)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.access$500(CompositionUnitMgrImpl.java:116)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl$CUInitializer.run(CompositionUnitMgrImpl.java:994)
at com.ibm.wsspi.runtime.component.WsComponentImpl$_AsynchInitializer.run(WsComponentImpl.java:502)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1862)
Caused by: java.lang.IllegalStateException: DestinationDataProvider already registered [com.sps.tmps.bean.bapi.CustomDestinationDataProvider$MyDestinationDataProvider]
at com.sap.conn.jco.rt.RuntimeEnvironment.setDestinationDataProvider(RuntimeEnvironment.java:134)
at com.sap.conn.jco.ext.Environment.registerDestinationDataProvider(Environment.java:259)
at com.sps.tmps.bean.bapi.CustomDestinationDataProvider.initProvider(CustomDestinationDataProvider.java:156)
... 41 more
我的问题是：
1) 如何使两个应用程序能够使用相同的 CustomDestinationDataProvider？
2) 如果 2 个应用程序不能使用相同的提供程序，我如何使用相同的服务器/用户/客户端编号访问相同的 BAPI？
这种情况下的限制是（1）我们应该使用 sapjco 和（2）我们只有 BAPI 函数。如果您认为它有问题，可以丢弃 customDestinationDataProvider。
顺便说一句，我为长代码和糟糕的格式道歉。
谢谢。
【问题讨论】：