public static void main(String[] args) {
    SingcomUC1SerialRunnableThreadClass t1 = new SingcomUC1SerialRunnableThreadClass("READ_THREAD");
    t1.start1();
    SingcomUC1SerialRunnableThreadClass t2 = new SingcomUC1SerialRunnableThreadClass("Write_THREAD");
    t2.start1();
    System.out.println("active thread count=" + Thread.activeCount());
}

Thread t;
String threadName;

public SingcomUC1SerialRunnableThreadClass(String name) {
    threadName = name;
}

public void start1() {
    if (t == null) {
        t = new Thread(this, threadName);
        t.start();
    }
}

@Override
public void run() {
    System.out.println("run() invokations");
    while (true) {
        if (threadName.equalsIgnoreCase(singcomUC1Readthread)) {
            System.out.println(Thread.currentThread().getName() + "--" + Thread.activeCount());
            try {
                commonSection();
            } catch (InterruptedException ex) {
                Logger.getLogger(SingcomUC1SerialRunnableThreadClass.class.getName()).log(Level.SEVERE, null, ex);
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException ex) {
                Logger.getLogger(SingcomUC1SerialRunnableThreadClass.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        if (threadName.equalsIgnoreCase(singcomUC1Writethread)) {
            System.out.println(Thread.currentThread().getName() + "--" + Thread.activeCount());
            try {
                commonSection();
                Thread.sleep(300);
            } catch (InterruptedException ex) {
                Logger.getLogger(SingcomUC1SerialRunnableThreadClass.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}

public void commonSection() throws InterruptedException {
    InsertValuesIntoUC1DBtable.insertDefaultValueAndStatusIntoUC1DBtable(singcomUC1DeviceId);
    ReadOrUpdateUC1CONTROLtable.insertDefaultValueAndStatusIntoDC1DBtable(singcomUC1DeviceId);
}

public static void insertDefaultValueAndStatusIntoUC1DBtable(int deviceid) {
    try {
        Connection con = null;
        DatabaseConnection databaseConnection_obj = new DatabaseConnection();
        con = databaseConnection_obj.getConnection();
        PreparedStatement pst = con.prepareStatement("select * from uc1db");
        ResultSet rs = pst.executeQuery();
        if (!rs.next()) {
            pst = con.prepareStatement("insert into uc1db(deviceid,frequency,attenuation,transmitterstatus,devicestatus) values(?,?,?,?,?)");
            pst.setInt(1, deviceid);
            pst.setString(2, "0");
            pst.setString(3, "0");
            pst.setString(4, "0");
            pst.setString(5, "online");
            pst.executeUpdate();
        }
        rs.close();
        pst.close();
        con.close();
    } //**
    catch (SQLException ex) {
        Logger.getLogger(InsertValuesIntoUC1DBtable.class.getName()).log(Level.SEVERE, null, ex);
    }
}

public Connection getConnection() {
    Connection con = null;
    try {
        Class.forName("com.mysql.jdbc.Driver");
        con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "admin");
    } catch (Exception e) {
        System.out.println(" Db Exception  " + e);
    }
    return con;
}

output:
active thread count=3
run() invokations
run() invokations
singcomUC1ReadThread--2
singcomUC1WriteThread--2
singcomUC1WriteThread--4
singcomUC1WriteThread--4