java - 使用 SAP JCo 连接到 SAP BAPI 的两个 Web 应用程序

Question

我在适用于 RHEL6 (x64) 的 WebSphere Application Server 8.5 上部署了两个 Web 应用程序。这两个 Web 应用程序都使用 SAP JCo 库连接到 SAP ECC6 中部署的 BAPI。两个应用程序都需要访问相同的 BAPI 才能创建购买请求。因此，我们使用从 SAP 的 CustomDestinationDataProvider 修改而来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 将其设置为单例。

但是，当应用程序启动时，当 com.sap.conn.jco.ext.Environment.registerDestinationDataProvider(myProvider) 为已执行

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);
        }
    }
}

WebSphere 中 SystemOut.log 的错误如下:

[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.<init>(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 个应用程序无法使用同一提供商，我如何使用相同的服务器/用户/客户端编号访问相同的 BAPI？

本例中的限制是 (1) 我们应该使用 SAP JCo，并且 (2) 我们只有一个 BAPI 函数。如果您认为有问题，可以丢弃 customDestinationDataProvider。

顺便说一句，我为冗长的代码和糟糕的格式表示歉意。

谢谢。

Answer 1

解决您问题的一个简单解决方案是为您的两个应用程序使用不同的目标名称(尽管它们在您的情况下是相同的)。使用两个不同的目标名称，每个应用程序一个。例如PROD_APP1、PROD_APP2

我相信所有其他事情都可以保持不变。

在理想情况下，我更喜欢更强大的解决方案。可能我认为是自定义类加载器等的行

祝你好运!