Java 17 Recipes

 Solution 3
Thread.join() allows you to wait for a thread to finish executing. The following example 
has a thread for loading the inventory and another thread for loading the orders. Once 
each thread is started, a call to inventoryThread.join() make the main thread wait for 
the inventoryThread to finish executing before continuing.
public static void main(String[] args) {
Recipe10_7_3 recipe = new Recipe10_7_3();
recipe.start();
}
private void start() {
loadItems();
Thread inventoryThread = new Thread(() -> {
System.out.println("Loading Inventory from Database...");
loadInventory();
});
inventoryThread.start();
try {
inventoryThread.join();
} catch (InterruptedException e) {
Chapter 10 ConCurrenCy

---

380
e.printStackTrace();
}
Thread ordersThread = new Thread(() -> {
System.out.println("Loading Orders from XML Web service...");
loadOrders();
});
ordersThread.start();
try {
ordersThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
processOrders();
}
The following is the output.
Loading Inventory from Database...
Loading Orders from XML Web service...
Order # 0 has been fulfilled
Order # 1 has been fulfilled
Order # 2 has been fulfilled
Order # 3 has been fulfilled
Order # 4 has been fulfilled
Order # 5 has been fulfilled
Order # 6 has been fulfilled
Order # 7 has been fulfilled
Order # 8 has been fulfilled
Order # 9 has been fulfilled
Order # 10 has been fulfilled
Order # 11 has been fulfilled
Order # 12 has been fulfilled
Order # 13 has been fulfilled
...
Chapter 10 ConCurrenCy

---

381