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问TimerService抛出NullPointerException
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Stack Overflow用户

提问于 2016-03-20 19:56:49

回答 2查看 1.7K关注 0票数 0

我正在编写一个服务，它将从远程源收集数据并将其保存到DB中。但是，它在服务器启动时抛出一个NullPointerException。我跟着甲骨文教程

这是日志：

java.lang.NullPointerException
    at org.eclipse.persistence.platform.server.ServerPlatformUtils.createServerPlatform(ServerPlatformUtils.java:99)
    at org.eclipse.persistence.sessions.factories.SessionManager.init(SessionManager.java:77)
    at org.eclipse.persistence.sessions.factories.SessionManager.<clinit>(SessionManager.java:71)
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.addSessionToGlobalSessionManager(EntityManagerSetupImpl.java:907)
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.initSession(EntityManagerSetupImpl.java:2671)
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:675)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:205)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.createEntityManagerImpl(EntityManagerFactoryDelegate.java:305)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:337)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:318)
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper._getDelegate(EntityManagerWrapper.java:197)
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper.createNamedQuery(EntityManagerWrapper.java:521)
    at org.glassfish.ejb.persistent.timer.TimerBean.findTimersByOwnerAndState(TimerBean.java:209)
    at org.glassfish.ejb.persistent.timer.TimerBean.findActiveTimersOwnedByThisServer(TimerBean.java:523)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
    at com.sun.proxy.$Proxy166.findActiveTimersOwnedByThisServer(Unknown Source)
    at org.glassfish.ejb.persistent.timer.PersistentEJBTimerService.restoreEJBTimers(PersistentEJBTimerService.java:369)
    at org.glassfish.ejb.persistent.timer.PersistentEJBTimerService.resetEJBTimers(PersistentEJBTimerService.java:1400)
    at com.sun.ejb.containers.EJBTimerService.initEJBTimerService(EJBTimerService.java:236)
    at com.sun.ejb.containers.EJBTimerService.getEJBTimerService(EJBTimerService.java:205)
    at com.sun.ejb.containers.EJBTimerService.getEJBTimerService(EJBTimerService.java:187)
    at com.sun.ejb.containers.BaseContainer.<init>(BaseContainer.java:825)
    at com.sun.ejb.containers.AbstractSingletonContainer.<init>(AbstractSingletonContainer.java:127)
    at com.sun.ejb.containers.CMCSingletonContainer.<init>(CMCSingletonContainer.java:76)
    at com.sun.ejb.containers.SingletonContainerFactory.createContainer(SingletonContainerFactory.java:68)
    at org.glassfish.ejb.startup.EjbApplication.loadContainers(EjbApplication.java:221)
    at org.glassfish.ejb.startup.EjbDeployer.load(EjbDeployer.java:291)
    at org.glassfish.ejb.startup.EjbDeployer.load(EjbDeployer.java:99)

我的密码是：

package db;

import sun.net.www.protocol.http.HttpURLConnection;

import javax.annotation.Resource;
import javax.ejb.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;

@Singleton
@Startup
public class DataCollector{

    @Resource
    TimerService timerService;

    private DBController db = new DBController();

    private static final Logger logger = Logger.getLogger("db.DataCollector");

    @Schedule(second = "*/4")
    public void collectData(Timer timer){
        String URL = "...";
        try{
            java.net.URL url = new URL(URL);

            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            InputStream is = connection.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            String line;
            String [] columns;

            while((line = reader.readLine()) != null){
                if(line.contains("Err")) {
                    logger.log(Level.WARNING, "[SENSORS]: {s}", line);
                    continue;
                }
                columns = parseData(line);
                if(columns.length != 10) {
                    logger.log(Level.WARNING, "[SENSORS]: BAD DATA");
                    continue;
                }

                db.insertToProcessingCollection(columns);
            }
        } catch (IOException e) {
            logger.log(Level.SEVERE, e.getLocalizedMessage());
        }
    }

    private String [] parseData(String data){
        return data.split("\t");
    }
}

编辑：

DBController.java：

public class DBController {
    private MongoDatabase db;

    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH);
    private static final Logger logger = Logger.getLogger("db.DBController");

    public DBController(){
        MongoClient client = new MongoClient();
        db = client.getDatabase("master");
    }

    public boolean insertToProcessingCollection(String [] data){
        MongoCollection<Document> collection = db.getCollection("newData");

        try {
            Document doc = new Document()...

            collection.insertOne(doc);

            return true;
        } catch (ParseException e) {
            logger.log(Level.SEVERE, e.getMessage());
            return false;
        }
    }

    public void pushDataToHistoryCollection(){
        try {
            MongoCollection<Document> historyCollection = db.getCollection("oldData");
            MongoCollection<Document> processingCollection = db.getCollection("newData");

            processingCollection.find().forEach((Block<Document>) historyCollection::insertOne);

            processingCollection.deleteMany(new Document());
        } catch (Exception e) {
            logger.log(Level.SEVERE, e.getMessage());
        }
    }

    public JSONArray getNewData(){
        try {
            MongoCollection<Document> collection = db.getCollection("newData");

            FindIterable<Document> newData = collection.find();

            JSONArray result = convertToJSON(newData);

            pushDataToHistoryCollection();

            return result;
        } catch (Exception e) {
            logger.severe(e.getMessage());
            return null;
        }
    }

    public JSONArray convertToJSON(FindIterable<Document> data){
        JSONArray result = new JSONArray();

        data.forEach((Block<Document>) document -> {
            JSONObject object = new JSONObject(document.toJson());
            object.put("dateTime", dateFormat.format(document.get("dateTime")));
            result.put(object);
        });

        return result;
    }

    public void removeOldData(){
        MongoCollection<Document> collection = db.getCollection("oldData");
        collection.deleteMany(new Document());
    }
}

java

jakarta-ee

ejb-3.0

java-ee-7

glassfish-4.1

回答 2

Stack Overflow用户

回答已采纳

发布于 2016-03-21 15:48:53

嗯，花了些时间，但我终于修好了。正如@aribeiro和@vempo所指出的，这个问题可能与2.6.2版本中的EclipseLink错误有关。但是，在添加EclipseLink 2.6.2依赖项后，仍然会引发异常。我决定切换到WildFly 10服务器，问题已经解决了，但是服务还是不会启动。添加了一个构造函数，该构造函数记录了服务的创建并使其工作。

正如@Max所说，默认情况下，这里、minute和@Schedule中的hour参数等于0。声明@Schedule(second = "*/4" , minute="*", hour = "*")修复了所有问题，它在WildFly 10.0.0和GlassFish 4.1.1中都有效

票数 1

Stack Overflow用户

发布于 2016-03-21 13:06:32

因此，在深入研究之后，我发现您的应用程序所发生的事情已经在其他几个问题上得到了报道。

即使您没有直接使用EclipseLink，Glassfish也在胡德下使用它来建立数据库连接。

报告的问题之一出现在玻璃鱼的JIRA上，fix正在EclipseLink的2.6.2版本上完成

https://java.net/jira/browse/GLASSFISH-21468

此外，我发现Payara (基于Glassfish)也有同样的问题：

https://github.com/payara/Payara/issues/509

此外，正如@vempo所述，所报告的问题也与这两个问题有关：

作为解决方案，您可以尝试将新的(稳定的) EclipseLink (2.6.2)版本绑定到您的项目并部署它，就像@ 这里建议的那样。由EclipseLink提供的GlassFish版本将被您的应用程序打包的版本所取代。

票数 1

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/36118768

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