TimerService抛出NullPointerException

时间：2016-03-20 19:56:50

标签： java java-ee ejb-3.0 java-ee-7 glassfish-4.1

我正在尝试编写一个服务，该服务将从远程源收集数据并将其保存到数据库中。但是，它会在服务器启动时抛出NullPointerException。 我跟着Oracle's tutorial

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)

我的代码：

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");
    }
}

修改

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());
    }
}

2 个答案:

答案 0 :(得分：1)

所以，经过一番挖掘后，我发现你的应用程序发生的事情已经报告了其他几个问题。

即使您没有直接使用EclipseLink，Glassfish也会在hood下使用它来建立数据库连接。

Glassfish的JIRA中存在一个已报告的问题，修复工作在EclipseLink's 2.6.2 release完成：

另外，我发现Payara（基于Glassfish）有同样的问题：

此外，正如@vempo所述，报告的问题也与其他两个SO问题有关：

作为解决方案，您可以尝试将新的（稳定）版本的EclipseLink（2.6.2）绑定到您的项目并进行部署，如@Tiny建议here。由GlassFish提供的EclipseLink版本将替换为随应用程序打包的版本。

答案 1 :(得分：1)

嗯，花了一些时间，但我终于修好了。正如@aribeiro和@vempo所述，问题可能与2.6.2版本中修复的EclipseLink错误有关。但是，在添加EclipseLink 2.6.2依赖项之后，仍然会抛出异常。我决定切换到WildFly 10服务器，问题已经消失，但服务无论如何都无法启动。 添加了记录服务创建的构造函数，并且工作正常。

正如@Max Fichtelmann所说，minute中的here hour和@Schedule参数默认等于0。声明@Schedule(second = "*/4" , minute="*", hour = "*")修复了所有内容，并且它在WildFly 10.0.0和GlassFish 4.1.1中都有效

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