Exception in thread "pool-6-thread-46" java.lang.NullPointerException怎么解决？

Question

Exception in thread "pool-6-thread-1" java.lang.NullPointerException at com.pats.client.cache.VwapBookCache.removeOldVwapBook(VwapBookCache.java:46) at com.pats.client.publish.workingpool.ContentVwapThread.run(ContentVwapThread.java:54) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source)代码：public void run() {        try {            server = new Server(config.getItemInt("SYSTEM", "PORT", 8081));            HandlerList handlerList = new HandlerList();            ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);            //context.setContextPath("/pats");            xmlContext = new XmlWebApplicationContext();            // load spring configration xml            String springXML = "file:"+SYSTEM_PATH + File.separator + "app_all.xml";            xmlContext.setConfigLocations(springXML);            context.addEventListener(new ContextLoaderListener(xmlContext));            context.addServlet(new ServletHolder(new DispatcherServlet(xmlContext)), "/*");            // druid web configure start            context.addServlet(new ServletHolder(new StatViewServlet()), "/druid/*");            FilterHolder filter = new FilterHolder(new WebStatFilter());            FilterHolder myfilter = new FilterHolder(new com.pats.client.cors.CORSFilter());            filter.setInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");            filter.setInitParameter("profileEnable", "true");            filter.setInitParameter("principalCookieName", "USER_COOKIE");            filter.setInitParameter("principalSessionName", "USER_SESSION");            context.addFilter(filter, "/*", EnumSet.of(DispatcherType.REQUEST));            context.addFilter(myfilter, "/*", EnumSet.of(DispatcherType.REQUEST));                        // druid web configure end            // websocket configure            context.addServlet(new ServletHolder(new FxpocServlet()), "/fxpoc");            context.addServlet(new ServletHolder(new CMBCServlet()), "/cmbcsocket");         //   context.addServlet(new ServletHolder(new FxpocServlet()), "/fxpoc");            context.addServlet(new ServletHolder(new BoardServlet()), "/boardsocket");            // context.addServlet(new ServletHolder(new MsgListServlet()), "/msglist");            context.addServlet(new ServletHolder(new PositionServlet()), "/positionsocket");            // Website configure            Properties properties = new Properties(System.getProperties());            String websitePath = SYSTEM_PATH + properties.getProperty("file.separator") + "website";            logger.info("Website path is " + websitePath);            ResourceHandler handler = new ResourceHandler();            handler.setDirectoriesListed(true);            handler.setResourceBase(websitePath);            handler.setMinMemoryMappedContentLength(-1);            handlerList.addHandler(handler);            handlerList.addHandler(context);            handlerList.addHandler(new DefaultHandler());            server.setHandler(handlerList);            server.start();            // ===== ACTIVEMQ start ========            // ActiveMQGetSpotProductDataMsg.getMsg().startread();            // ===== ACTIVEMQ end ========            // init codeSet tenor            initCache();            startMQReaders();            logger.info("pats-publish is ok !");            server.join();        } catch (Exception e) {            logger.error("Sorry, an exception has occurred.", e);        }    }public class ContentVwapThread extends Thread { private VwapBook inputMsg = null; public ContentVwapThread(VwapBook msg) { this.inputMsg = msg; } @Override public void run() { VwapBook vwapBook = inputMsg; Iterator<Map.Entry<Session, String>> sessionObjects = null; ConstructBoardMsg boardMsg = new ConstructBoardMsg(vwapBook); boardMsg.decodeVwapPrice(); Map<String, Object> returnData = boardMsg.getReturnData(); sessionObjects = BoardSocket.sessionlist.entrySet().iterator(); while (sessionObjects.hasNext()) { Map.Entry<Session, String> entry = sessionObjects.next(); Session session = entry.getKey(); String userID = entry.getValue(); ConcurrentHashMap<String, Set<String>> selectedVolumeMap = UserCache.selectedVolumeMap.get(userID); if (selectedVolumeMap != null) { // 获取用户定义的交易量 Set<String> setOfSelectedVolumes = selectedVolumeMap.get(vwapBook.getSymbol()); if (setOfSelectedVolumes != null) { for (String volume : setOfSelectedVolumes) { double currentVolume = Double.parseDouble(ClientUtil.volumeShortToFull(volume)); if (vwapBook.getTargetAskVolume().getRawVolume() == currentVolume) { SendMsgUtil.send(session, returnData); VwapBookCache.vwapBookMap.put(vwapBook.getVwapBookID(), vwapBook); VwapBookCache.removeOldVwapBook(); } } } } } } }public class VwapBookCache { private static VwapBookCache instance; private static byte[] lock = new byte[0]; private static int maxTimetoKeepMills = 100; public static ConcurrentHashMap<String,VwapBook> vwapBookMap = new ConcurrentHashMap<>(); private VwapBookCache(){ } public static VwapBookCache getInstance() { synchronized (lock) { if (instance == null) { instance = new VwapBookCache(); } } return instance; } public ConcurrentHashMap<String, VwapBook> getVwapBookMap() { return vwapBookMap; } public static void removeOldVwapBook() { Iterator<String> iterator = VwapBookCache.vwapBookMap.keySet().iterator(); Date now = new Date(); Long nowTime = new Long(now.getTime() / 1000); while (iterator.hasNext()) { String key = iterator.next(); String priceTimeS = VwapBookCache.vwapBookMap.get(key).getCreateTime(); Long priceTime = Long.parseLong(priceTimeS); if (nowTime - priceTime > maxTimetoKeepMills) { VwapBookCache.vwapBookMap.remove(key); } } } }

Answer 1

从日志上看 应该是VwapBookCache 类的第46行出现空指针异常，你可以将46行所有用到的变量都打印出来 或者直接在debug模式下查看其值