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POHandling Threadpools & wait notifyALL()
 

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  1. POHandling Threadpools & wait notifyALL()
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    <p>How to handle the thread pool where one is polling while the other should update new incoming data after processing. The program execution beings in a controller class which has a main method and thread pool:</p> <p>The main class Controller</p> <pre><code> public static void main(String[] args) throws InterruptedException { RunnableController controller = new RunnableController(); Accumulator acque = new Accumulator(); controller.initializeDb(); controller.initialiseThreads(acque); controller.initialUpdate(acque); } </code></pre> <p>The Run method for Polling class:</p> <pre><code> public void run() { int seqId = 0; List&lt;KpiMessage&gt; list = null; while(true) { try{ list = fullPoll(seqId); if (!list.isEmpty()) { accumulator.manageIngoing(list); } } catch (Exception e){ e.printStackTrace(); } } } public List&lt;KpiMessage&gt; fullPoll(int lastSeq) throws Exception { Statement st = dbConnection.createStatement(); System.out.println("Polling"); ResultSet rs = st.executeQuery("Select * from msg_new_to_bde where ACTION = 804 and SEQ &gt;" + lastSeq + "order by SEQ DESC"); return pojoCol; } </code></pre> <p>Run method for processing:</p> <pre><code> public void run() { try { generate(accumulator.outgoingQueue); accumulator.manageOutgoing(accumulator.outgoingQueue, dbConnection); } catch (Exception e) { e.printStackTrace(); } } } </code></pre> <p>Method for updating into Database</p> <pre><code> public void updateDb(Collection&lt;KpiMessage&gt; updatedQueue, Connection dbConnection) throws SQLException{ for(KpiMessage pojoClass : updatedQueue){ Statement stmtupd = dbConnection.createStatement(); System.out.println("Updating"); String query = "UPDATE msg_new_to_bde SET KEYINFO1= 'Processed', KEYINFO2 = 'Updated' WHERE ACTION = 804"; stmtupd.executeUpdate(query);**My Execution stops here** </code></pre> <p>Finally an accumulator class for maintaing all these queues:</p> <pre><code> public boolean isUsed = false; public synchronized void manageIngoing(List&lt;KpiMessage&gt; list){ if(this.isUsed){ try { wait(); System.out.println("first wait"); } catch (Exception e1) { e1.printStackTrace(); } } System.out.println("recived pass after update"); this.getIncomingQueue().addAll(list); //incoming queue copied to outgoing queue this.setOutgoingQueue(this.getIncomingQueue()); System.out.println("waiting"); System.out.println("new incoming message"); this.isUsed = false; notifyAll(); } /** * Method which handles synchronization using wait and notify for outgoing messages after polling * @param outgoingQueue * @param dbConnection */ public synchronized void manageOutgoing(Collection&lt;KpiMessage&gt; outgoingQueue, Connection dbConnection){ if(!this.isUsed) { try { System.out.println("second wait"); wait(); } catch (InterruptedException e) { e.printStackTrace(); } } this.isUsed = true; DBhandler dbhandler = new DBhandler(); try { dbhandler.updateDb(getOutgoingQueue(), dbConnection); } catch (SQLException e) { e.printStackTrace(); } notifyAll(); } } </code></pre> <p><strong>My task and Question is :</strong></p> <p>1.The controller should handle both the threads Poller &amp; processor and accumulator handles the incoming and outgoing queues, finally fed into to updated queue for updating DB after processing</p> <p>2.My class here just does polling once, is not able to update ,execution stops at </p> <p>3.Is my wait(), notifyALL() handle correct here. </p> <p><strong>How to achieve repeated polling and updation here?</strong></p>
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    1. USBabu
    1. USBabu
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    1. COI am sorry, but you need to sumamrize or divide it into different questions separately rather than all at once
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      1. USJatin
    2. CO@JAtin i have updated as you have said...
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      1. USBabu
    3. CO@Jatin My execturtion exactly pauses at the update stament, which does nto return to looping aswell...
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