爲什麼我的代碼會導致編譯器標記「unchecked或unsafe operations」警告？

Question

我的java編譯器抱怨說我的代碼使用「未檢查或不安全的操作」。任何想法哪些行是在兩個代碼片段中造成的？

@SuppressWarnings("unchecked") 
private final void prepareChannelAccountStringsParserImplementedClassConstructor() { 
    try { 
     String channelAccountStringsParserImplementedClassName = channelIdentifier + "AccountStringsParser"; 
     Class channelAccountStringsParserImplementedClass = Class.forName(channelAccountStringsParserImplementedClassName); 
     Class[] channelAccountStringsParserImplementedClassArguments = new Class[1]; 
     channelAccountStringsParserImplementedClassArguments[0] = String.class; 
     channelAccountStringsParserImplementedClassConstructor = channelAccountStringsParserImplementedClass.getConstructor(channelAccountStringsParserImplementedClassArguments); 
     channelAccountStringsParserImplementedParseMethod = channelAccountStringsParserImplementedClass.getMethod("parse", String.class); 
     channelAccountStringsParserGetRequestIDMethod = channelAccountStringsParserImplementedClass.getMethod("getRequestID"); 
    } catch (ClassNotFoundException classNotFoundException) { 
     NotifyMeListenersLogsDB notifyMeListenersLogsDB = DatabaseController.getInstance().getNotifyMeListenersLogsDB(); 
     notifyMeListenersLogsDB.writeDeveloperException(classNotFoundException); 
    } catch (NoSuchMethodException noSuchMethodException) { 
     NotifyMeListenersLogsDB notifyMeListenersLogsDB = DatabaseController.getInstance().getNotifyMeListenersLogsDB(); 
     notifyMeListenersLogsDB.writeDeveloperException(noSuchMethodException); 
    } 
} 

    @SuppressWarnings("unchecked") 
public synchronized final void requestChannelAccountsCompletionSuccess(String responseContent) { 
    Object channelAccountStringsParserImplementedInstance; 
    ArrayList<ChannelAccount> channelAccounts = null; 
    String requestID = null; 
    try { 
     channelAccountStringsParserImplementedInstance = channelAccountStringsParserImplementedClassConstructor.newInstance(responseContent); 
     channelAccounts = (ArrayList<ChannelAccount>) channelAccountStringsParserImplementedParseMethod.invoke(channelAccountStringsParserImplementedInstance, responseContent); 
     requestID = (String) channelAccountStringsParserGetRequestIDMethod.invoke(channelAccountStringsParserImplementedInstance); 
    } catch (InstantiationException instantiationException) { 
     NotifyMeListenersLogsDB notifyMeListenersLogsDB = DatabaseController.getInstance().getNotifyMeListenersLogsDB(); 
     notifyMeListenersLogsDB.writeDeveloperException(instantiationException); 
    } catch (IllegalAccessException illegalAccessException) { 
     NotifyMeListenersLogsDB notifyMeListenersLogsDB = DatabaseController.getInstance().getNotifyMeListenersLogsDB(); 
     notifyMeListenersLogsDB.writeDeveloperException(illegalAccessException); 
    } catch (InvocationTargetException invocationTargetException) { 
     NotifyMeListenersLogsDB notifyMeListenersLogsDB = DatabaseController.getInstance().getNotifyMeListenersLogsDB(); 
     notifyMeListenersLogsDB.writeDeveloperException(invocationTargetException); 
    } 
    channelAccountStringsParserImplementedInstance = null; 
    try { 
     startChannelConnections(channelAccounts); 
     isStarted = true; 
     LoadBalancer.getInstance().sendSuccessAcknowledgement(requestID); 
    } catch (NotifyMeListenersApplicationInitializationException notifyMeListenersApplicationInitializationException) { 
     NotifyMeListenersLogsDB notifyMeListenersLogsDB = DatabaseController.getInstance().getNotifyMeListenersLogsDB(); 
     notifyMeListenersLogsDB.writeNotifyMeListenersException(notifyMeListenersApplicationInitializationException); 
     System.exit(1); 
    } 
} 

當然，我把@SuppressWarnings壓制它，但我想知道原因。任何人都可以幫忙

Answer 1

類是一個參數化類。你應該使用Class<?>（或者如果需要的話可以更具體一些）。當然，編譯器錯誤可能會告訴你確切的問題在哪裏。

而且，這條線是一個未經檢查的演員，但你必須在一個沒有選擇：

channelAccounts = (ArrayList<ChannelAccount>)channelAccountStringsParserImplementedParseMethod.invoke(channelAccountStringsParserImplementedInstance, responseContent);