Gain insights into Java 8's new features: lambdas, Stream API, Functional Interfaces, Collections improvements, Memory Management, and Date & Time API to enhance productivity and code quality.

Java 8 has introduced a ton of features and enhancements to boost developer productivity, while making your code faster, more concise, and more readable. 
In this course, you will learn about lambdas, Java Stream API, Functional Interfaces, as well as lots of other new improvements related to Collections, Memory Management, Date & Time API. 
After completing this course, you’ll be well versed in all the functionality of Java 8 and be ready to utilize these new features in your own code.

Java 8 for Experienced Developers: Lambdas, Stream API & Beyond

In the previous lesson, we looked at `CompletableFuture`. We discussed how to create a `CompletableFuture` object and how to run tasks asynchronously. 

In this lesson, we will look at how to process the result of a `CompletableFuture`.

## Processing the result of CompletableFuture

Suppose we have a `CompletableFuture` and we need to process the result of its execution. Now, the `get()` method of `CompletableFuture` is blocking. This means we need to wait until we get the result of the first task. After getting the result, we can modify the result.

For our system to be truly asynchronous we should be able to attach a callback to the `CompletableFuture`, which should be automatically executed when the `Future` completes. That way, we won’t need to wait for the result, and we can write the logic that needs to be executed after the completion of the `Future` inside our callback function. 

There are a few ways in which we can do this. We will look at each of them one by one.

### 1) `thenApply()`

The `thenApply()` method accepts a `Function<T, R>` instance as parameter. As we have discussed earlier, the `Function<T, R>` interface takes in a parameter of type `T` and returns a result of type `R`. 

The `thenApply()` method uses the `Function<T, R>` instance to process the result and returns a `Future` that holds a value returned by the function, i.e., `CompletableFuture<R>`

In the below example, we have a `CompletableFuture` that returns an `Integer`. Then, we call `thenApply()` method to double the result of `CompletableFuture` and return the final result.


In the previous lesson, we looked at `CompletableFuture`. We discussed how to create a `CompletableFuture` object and how to run tasks asynchronously. 

In this lesson, we will look at how to process the result of a `CompletableFuture`.

# Processing the result of CompletableFuture

Suppose we have a `CompletableFuture` and we need to process the result of its execution. Now, the `get()` method of `CompletableFuture` is blocking. This means we need to wait until we get the result of the first task. After getting the result, we can modify the result.

For our system to be truly asynchronous we should be able to attach a callback to the `CompletableFuture`, which should be automatically executed when the `Future` completes. That way, we won’t need to wait for the result, and we can write the logic that needs to be executed after the completion of the `Future` inside our callback function. 

There are a few ways in which we can do this. We will look at each of them one by one.

## 1) `thenApply()`

The `thenApply()` method accepts a `Function<T, R>` instance as parameter. As we have discussed earlier, the `Function<T, R>` interface takes in a parameter of type `T` and returns a result of type `R`. 

The `thenApply()` method uses the `Function<T, R>` instance to process the result and returns a `Future` that holds a value returned by the function, i.e., `CompletableFuture<R>`

In the below example, we have a `CompletableFuture` that returns an `Integer`. Then, we call `thenApply()` method to double the result of `CompletableFuture` and return the final result.


This lesson discusses, how to process the result of a CompletableFuture.

Let's Begin

Taste of lambdas

Stream API

Java 8 Collections Improvements

Java 8 Concurrency API Improvements

Java Time API

Conclusion

CompletableFuture: Processing Results

Processing the result of CompletableFuture