Can we read Tags if we run PlcReadRequest in ExecutorService thread? If I run the below readValues() method in Main Thread, it works fine. Am I missing anything?

[codekundan]

`public class Plc4xConnect2 {
private static final Logger logger = LogManager.getLogger(Plc4xConnect.class.getName());
private static boolean closingFlag = false;

 public static void main(String[] args) throws PlcConnectionException, Exception {
     String connectionString = "opcua:tcp://LAPTOP-A1865M3M:4841?discovery=true&security-policy=Basic128Rsa15&message-security=SIGN_ENCRYPT&key-store-file=D://Plc4x//plc4xConnect//src//test-mxopc-keystore.p12&key-store-password=pass";
     
     try (PlcConnection connection = new DefaultPlcDriverManager().getConnection(connectionString)) {
         
          ExecutorService esVirtual = Executors.newFixedThreadPool(4);
           esVirtual.submit(() -> {
           Plc4xConnect2.readValues(connection);
        });
     }
 }
 
 static void readValues(PlcConnection connection) {
            while (true) {
                
                System.out.println("Thread : ..............................." + Thread.currentThread());
                //Read tags in OPC-UA

                PlcReadRequest readRequest = connection.readRequestBuilder().addTagAddress("readTag", "ns=4;s=Address Space.Dev00.Tag000;BOOL").build();

                // Code is not moving beyond this line
                CompletableFuture<? extends PlcReadResponse> readFuture = readRequest.execute();
                
                readFuture.whenComplete((response, error) -> {
                    try {
                        for (String tag : response.getTagNames()) {
                            if (response.getResponseCode(tag) == PlcResponseCode.OK) {
                                int numValues = response.getNumberOfValues(tag);
                                System.out.println("numValues = "+numValues);
                                if (numValues == 1) {
                                    boolean needReceipe = (boolean) response.getObject(tag);
                                    if (needReceipe) {
                                        try (Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/demo_db", "root", "pass")) {
                                            Statement stmt = con.createStatement();
                                            String query = "select * from table";
                                            ResultSet rs = stmt.executeQuery(query);
                                            
                                            int sno = 0;
                                            String first_name = "";
                                            int flow = 0;
                                            double outer_shaping = 0F;
                                            
                                            while (rs.next()) {
                                                sno = rs.getInt("sno");
                                                first_name = rs.getString("first_name");
                                                flow = rs.getInt("flow");
                                                outer_shaping = rs.getDouble("outer_shaping");
                                                System.out.println(sno + " " + first_name + " " + flow + " " + outer_shaping);
                                            }
                                            
                                        } catch (SQLException ex) {
                                            java.util.logging.Logger.getLogger(Plc4xConnect.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
                                        }
                                    }
                                }
                            } else {
                                System.out.println("Something went wrong ............." + response.getResponseCode(tag));
                            }
                        }
                    } catch (Exception e) {
                        
                    }
                });
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException ex) {
                    java.util.logging.Logger.getLogger(Plc4xConnect.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
                }
            }
    }

}`

[codekundan]

Hi Plc4x Team, I got the answer. I was making the mistake of creating a Connection in Main Thread and running the tags reading task in Executor Service thread. Now, reading tags is happening in Executor Service Thread but at the same time the Main Thread reaches End of Line and terminates the Connection. So, now i created the Connection and reading the tags in Executor Service Thread itself which is working fine.