Java Vaadin中的多线程刷新UI_Java_Multithreading_User Interface_Vaadin

Java Vaadin中的多线程刷新UI

java multithreading user-interface vaadin

Java Vaadin中的多线程刷新UI,java,multithreading,user-interface,vaadin,Java,Multithreading,User Interface,Vaadin,我正在尝试在我的Vaadin应用程序中实现一个多线程刷新UI 此UI的一部分是基于容器的dChart。要构建dChartIm遍历容器并按其属性之一计算元素，如下所示： Collection<?> itemIDS = container.getItemIds(); for (Object itemID : itemIDS) { Property property = container.getContainerProperty(

我正在尝试在我的Vaadin应用程序中实现一个多线程刷新UI

此UI的一部分是基于容器的

dChart

。要构建

dChart

Im遍历容器并按其属性之一计算元素，如下所示：

        Collection<?> itemIDS = container.getItemIds();

        for (Object itemID : itemIDS) {
            Property property = container.getContainerProperty(itemID, "status");
            String status = (String) property.getValue();
            if (countMap.containsKey(status)) {
                countMap.put(status, countMap.get(status) + 1);
            } else {
                countMap.put(status, 1);
            }
        }

{
//class with @Push
  void refreshPieDChart(GeneratedPropertyContainer container) {
    new InitializerThread(ui, container).start();
  }

  class InitializerThread extends Thread {
    private LogsUI parentUI;
    private GeneratedPropertyContainer container;

    InitializerThread(LogsUI ui, GeneratedPropertyContainer container) {
        parentUI = ui;
        this.container = container;
    }

    @Override
    public void run() {
        //building dChart etc etc... which takes over 2-3 seconds

        // Init done, update the UI after doing locking
        parentUI.access(new Runnable() {
            @Override
            public void run() {
                chart.setDataSeries(dataSeries).show();
            }
        });
    }
  }
}

但是，如果我刷新页面几次，它就会生成关于

SQLContainer

的错误：

java.lang.IllegalStateException: A trasaction is already active!

countContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

因为在几次刷新之后，我的多个线程使用同一个SQLContainer并行运行

为了解决这个问题，我想停止除最后一个线程之外的所有工作刷新线程，以消除并发问题。我怎么能做到？也许还有别的解决办法

编辑： 我曾经尝试过这样的smth，但问题仍然存在，它是防止并发问题的正确方法吗

{
  private static final Object mutex = new Object();
//class with @Push
  void refreshPieDChart(GeneratedPropertyContainer container) {
    new InitializerThread(ui, container).start();
  }

  class InitializerThread extends Thread {
    private LogsUI parentUI;
    private GeneratedPropertyContainer container;

    InitializerThread(LogsUI ui, GeneratedPropertyContainer container) {
        parentUI = ui;
        this.container = container;
    }

    @Override
    public void run() {
        //is it correct way to prevent concurrent problem? 
        synchronized(mutex){
            //method to refresh/build chart which takes 2-3s.
        }
        // Init done, update the UI after doing locking
        parentUI.access(new Runnable() {
            @Override
            public void run() {
                chart.setDataSeries(dataSeries).show();
            }
        });
    }
  }
}

这就是我所做的：

给我指出了一个非常明显的想法：用SQL进行计数。正如我所说，我正在考虑这个问题，但这意味着我需要为每个可能的过滤器组合准备SQL。这是一个相当复杂的问题，看起来不太好

但这让我意识到，如果我在我的表中使用带有过滤器的SQLContainer，我也可以在计数中使用同样的方法。我只需要用自己的

FreeformQuery

和

freeformstatementdegate

创建第二个

SQLContainer

如果我将创建以上所有内容，我可以将相同的过滤器添加到两个容器中，但是我现在不需要计算元素，因为第二个容器为我保存值。听起来很复杂，但看看我的代码：

FreeformQuery myQuery = new MyFreeformQuery(pool);
FreeformQuery countQuery = new CountMyFreeformQuery(pool);

SQLContainer myContainer = new SQLContainer(myQuery);  //here i hold my all records as in a Question
SQLContainer countContainer = new SQLContainer(countQuery);  //here i hold computed count(*) and status

MyFreeformQuery.java看起来像：

class ProcessFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING = "SELECT request_date, status, id_foo FROM foo";
private static final String COUNT_STRING = "SELECT COUNT(*) FROM foo";
private static final String PK_COLUMN_NAME = "id_foo";

MyFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING, connectionPool, PK_COLUMN_NAME);
    setDelegate(new AbstractFreeformStatementDelegate() {

        protected String getPkColumnName() {
            return PK_COLUMN_NAME;
        }

        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getCountString() {
            return COUNT_STRING;
        }
    });
}

public class CountFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING_GROUP = "SELECT status, count(*) as num FROM foo GROUP BY status";
private static final String QUERY_STRING = "SELECT status, count(*) as num FROM foo";
private static final String GROUP_BY = "foo.status";

public CountFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING_GROUP, connectionPool);
    setDelegate(new CountAbstractFreeformStatementDelegate() {
        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getGroupBy(){
            return GROUP_BY;
        }

    });
}
}

最重要的CountFreeformQuery.java如下所示：

class ProcessFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING = "SELECT request_date, status, id_foo FROM foo";
private static final String COUNT_STRING = "SELECT COUNT(*) FROM foo";
private static final String PK_COLUMN_NAME = "id_foo";

MyFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING, connectionPool, PK_COLUMN_NAME);
    setDelegate(new AbstractFreeformStatementDelegate() {

        protected String getPkColumnName() {
            return PK_COLUMN_NAME;
        }

        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getCountString() {
            return COUNT_STRING;
        }
    });
}

public class CountFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING_GROUP = "SELECT status, count(*) as num FROM foo GROUP BY status";
private static final String QUERY_STRING = "SELECT status, count(*) as num FROM foo";
private static final String GROUP_BY = "foo.status";

public CountFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING_GROUP, connectionPool);
    setDelegate(new CountAbstractFreeformStatementDelegate() {
        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getGroupBy(){
            return GROUP_BY;
        }

    });
}
}

现在，如果我想在smth之后刷新

dChart

，如下所示：

myContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

    Map<String, Long> countMap = new HashMap<String, Long>();
    Collection<?> itemIDS = container.getItemIds();
    for (Object itemID : itemIDS) {
        Property statusProperty = container.getContainerProperty(itemID, "status");
        Property numProperty = container.getContainerProperty(itemID, "num");
        countMap.put((String) statusProperty.getValue(), (Long) numProperty.getValue());
    }

我只是对countContainer做了同样的操作：

java.lang.IllegalStateException: A trasaction is already active!

countContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

并将其传递给不需要计算元素的方法，只需将所有容器添加到map，然后添加到dChart，如下所示：

myContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

    Map<String, Long> countMap = new HashMap<String, Long>();
    Collection<?> itemIDS = container.getItemIds();
    for (Object itemID : itemIDS) {
        Property statusProperty = container.getContainerProperty(itemID, "status");
        Property numProperty = container.getContainerProperty(itemID, "num");
        countMap.put((String) statusProperty.getValue(), (Long) numProperty.getValue());
    }

Map countMap=newhashmap（）；
Collection itemIDS=container.getItemIds（）；
for（对象itemID:itemIDS）{
Property statusProperty=container.getContainerProperty（itemID，“status”）；
属性numProperty=container.getContainerProperty（itemID，“num”）；
countMap.put（（字符串）statusProperty.getValue（），（长）numProperty.getValue（）；
}

现在我已经统计了

status

myContainer中元素的数量，不需要多线程或编写大量sql

谢谢大家的建议。

我就是这么做的：

但这让我意识到，如果我在我的表中使用带有过滤器的SQLContainer，我也可以在计数中使用同样的方法。我只需要用自己的

FreeformQuery

和

freeformstatementdegate

创建第二个

SQLContainer

FreeformQuery myQuery = new MyFreeformQuery(pool);
FreeformQuery countQuery = new CountMyFreeformQuery(pool);

SQLContainer myContainer = new SQLContainer(myQuery);  //here i hold my all records as in a Question
SQLContainer countContainer = new SQLContainer(countQuery);  //here i hold computed count(*) and status

MyFreeformQuery.java看起来像：

class ProcessFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING = "SELECT request_date, status, id_foo FROM foo";
private static final String COUNT_STRING = "SELECT COUNT(*) FROM foo";
private static final String PK_COLUMN_NAME = "id_foo";

MyFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING, connectionPool, PK_COLUMN_NAME);
    setDelegate(new AbstractFreeformStatementDelegate() {

        protected String getPkColumnName() {
            return PK_COLUMN_NAME;
        }

        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getCountString() {
            return COUNT_STRING;
        }
    });
}

public class CountFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING_GROUP = "SELECT status, count(*) as num FROM foo GROUP BY status";
private static final String QUERY_STRING = "SELECT status, count(*) as num FROM foo";
private static final String GROUP_BY = "foo.status";

public CountFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING_GROUP, connectionPool);
    setDelegate(new CountAbstractFreeformStatementDelegate() {
        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getGroupBy(){
            return GROUP_BY;
        }

    });
}
}

最重要的CountFreeformQuery.java如下所示：

class ProcessFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING = "SELECT request_date, status, id_foo FROM foo";
private static final String COUNT_STRING = "SELECT COUNT(*) FROM foo";
private static final String PK_COLUMN_NAME = "id_foo";

MyFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING, connectionPool, PK_COLUMN_NAME);
    setDelegate(new AbstractFreeformStatementDelegate() {

        protected String getPkColumnName() {
            return PK_COLUMN_NAME;
        }

        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getCountString() {
            return COUNT_STRING;
        }
    });
}

public class CountFreeformQuery extends FreeformQuery {

private static final String QUERY_STRING_GROUP = "SELECT status, count(*) as num FROM foo GROUP BY status";
private static final String QUERY_STRING = "SELECT status, count(*) as num FROM foo";
private static final String GROUP_BY = "foo.status";

public CountFreeformQuery(JDBCConnectionPool connectionPool) {
    super(QUERY_STRING_GROUP, connectionPool);
    setDelegate(new CountAbstractFreeformStatementDelegate() {
        protected String getQueryString() {
            return QUERY_STRING;
        }

        protected String getGroupBy(){
            return GROUP_BY;
        }

    });
}
}

现在，如果我想在smth之后刷新

dChart

，如下所示：

myContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

    Map<String, Long> countMap = new HashMap<String, Long>();
    Collection<?> itemIDS = container.getItemIds();
    for (Object itemID : itemIDS) {
        Property statusProperty = container.getContainerProperty(itemID, "status");
        Property numProperty = container.getContainerProperty(itemID, "num");
        countMap.put((String) statusProperty.getValue(), (Long) numProperty.getValue());
    }

我只是对countContainer做了同样的操作：

java.lang.IllegalStateException: A trasaction is already active!

countContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

并将其传递给不需要计算元素的方法，只需将所有容器添加到map，然后添加到dChart，如下所示：

myContainer.addContainerFilter(new Between(DATE_PROPERTY, getTimestamp(currentDate), getOneDayAfter(currentDate)));

    Map<String, Long> countMap = new HashMap<String, Long>();
    Collection<?> itemIDS = container.getItemIds();
    for (Object itemID : itemIDS) {
        Property statusProperty = container.getContainerProperty(itemID, "status");
        Property numProperty = container.getContainerProperty(itemID, "num");
        countMap.put((String) statusProperty.getValue(), (Long) numProperty.getValue());
    }

Map countMap=newhashmap（）；
Collection itemIDS=container.getItemIds（）；
for（对象itemID:itemIDS）{
Property statusProperty=container.getContainerProperty（itemID，“status”）；
属性numProperty=container.getContainerProperty（itemID，“num”）；
countMap.put（（字符串）statusProperty.getValue（），（长）numProperty.getValue（）；
}

现在我已经统计了

status

myContainer中元素的数量，不需要多线程或编写大量sql

谢谢大家的建议。

你有没有考虑为你的数以千计的条目加载懒惰？@ TK12这就是我现在正在做的，不是吗？仅在用户请求时（刷新，输入我的webapp），Im生成UI（图表）。但是，当我想建立一个图表时，我需要在一瞬间获得所有数据（否则我的图表将过时），所有数据是否立即显示在屏幕上？这就是我所说的延迟加载。如果用户一次只看到一部分数据，则可以在数据显示在屏幕上时延迟加载数据，从而提高加载性能。但是如果您想一次使用所有数据，那么我的建议可能不适合您的需要。@tk12如果我的图表正在计算SQLContainer中的元素，您就不能使用延迟加载，因为您需要计算每个元素，这意味着您无论如何都需要加载它。您是对的，延迟加载非常适合加载部分数据，例如：滚动表。但是在这种特殊情况下，我需要获取所有数据。@ilovkatie我认为应该用SQL进行计数，然后应该足够快。那么你没有多线程。你有没有考虑到你的成千上万条条目的懒惰加载？@ TK12这就是我现在正在做的，不是吗？仅在用户请求时（刷新，输入我的webapp），Im生成UI（图表）。但是，当我想建立一个图表时，我需要在一瞬间获得所有数据（否则我的图表将过时），所有数据是否立即显示在屏幕上？这就是我所说的延迟加载。如果用户一次只看到一部分数据，则可以在数据显示在屏幕上时延迟加载数据，从而提高加载性能。但是如果您想一次使用所有数据，那么我的建议可能不适合您的需要。@tk12如果我的图表正在计算SQLContainer中的元素，您就不能使用lazy lo