Question

我在下面的代码中面临线程问题。当线程执行runnable对象的Run方法时，它不会打印我期望的数据。

代码1 - 调用代码

Map<String,Object> logData = CPEMethodData.getLogDataMap();
    CatalogUpdaterLogger.getLogger().info("6 before new splunk logger log data =" + logData);
    CatalogrLogger writer = new CatalogLogger(LogType.INFO,logData,LoggerType.CATALOGUPDATER);
    LogPool.INSTANCE.submitTask(writer);//submitting writer which is a runnable object to the queue

//add one more task/writer to the queue in the same method

logData = CPEMethodData.getLogDataMap();
     CatalogUpdaterLogger.getLogger().info("11 before 3rd writer=logData "+logData);
     CatalogLogger writer2 = new CatalogLogger(LogType.INFO,logData,LoggerType.CATALOGUPDATER);

     LogPool.INSTANCE.submitTask(writer2);

在上面的代码中，我检查过CPEMethodData.getLogDataMap（）返回的logData与我预期的不同。但是当runnable对象实际执行时，它仍然以相同的数据运行...

代码2 - 使用5个线程创建线程池...

public enum LogPool {

    INSTANCE;
    private static final int nThreads = 5;
    final ExecutorService executor = Executors.newFixedThreadPool(nThreads);

    public synchronized void submitTask(Runnable task) {        
        executor.execute(task);     
    }

代码3 - 可运行代码

public class CatalogLogger implements Runnable {
    protected LogType logType;
    protected LoggerType loggerType;
    protected Map<String, Object> logData;
    public CatalogLogger(LogType logType, Map<String, Object> logData,
            LoggerType loggerType) {
        this.logType = logType;
        this.logData = logData;
        this.loggerType = loggerType;
    }

public void run() {
        System.out.println("running with logData " + logData);
        System.out.println(" Thread.currentThread().hashCode()  " +Thread.currentThread().hashCode());
        switch (loggerType) {
        case ORDERPROCESSING:
            logData(Logger.getLogger(ORDER_LOG));
            break;
        case CATALOGUPDATER:
            logData(Logger.getLogger(CATALOGUPDATER_LOG));
            break;
        }
    }

以下是CPEmethoddata.getLogData

public class CPEMethodData {
private static ThreadLocal<Map<String, Object>> logDataMap = new ThreadLocal<Map<String, Object>>();

    public static Map<String,Object> getLogDataMap() {
        return logDataMap.get();
    }
public static void setOppParameters(Map<String, Object> inputParams) {
    Map<String, Object> oppStatus = logDataMap.get();
    if (oppStatus == null) {
        oppStatus = new HashMap<String, Object>();
        logDataMap.set(oppStatus);
    }
    oppStatus.put(INPUT_PARAMS, inputParams);
}

@SuppressWarnings("unchecked")
public static Map<String, Object> getOperationParameters() {
    Map<String, Object> oppStatus = logDataMap.get();
    if (oppStatus != null)
        return (Map<String, Object>) oppStatus.get(INPUT_PARAMS);
    return null;
}

}

当我运行向队列提交两个runnable的代码1时，我希望在run方法的sysout中看到不同的logData内容，但是当我调试它时，我看到两个执行中的数据相同...似乎第二次运行正在干扰第一次......可以请任何人帮我理解这里的问题。我以为我通过2个不同的CatalogLogger实例并且不应该导致任何问题。也可以有人请建议任何解决方案？

Answer 1

正如@ReneLink在我的问题评论中写的那样，CPEMethodData.getLogDataMap返回了相同的hashmap实例...所以当线程的run方法被执行时，hashmap的内容被修改了。我创建了深层副本使用Cloner工具的hashmap并将其传递给线程。感谢@ReneLink向我指出这一点。

使用Executor服务时出现线程问题

1 个答案: