The Java concurrency API provides a synchronization utility that allows interchange of data between two concurrent tasks. In more detail, the Exchanger class allows you to have a definition of a synchronization point between two threads. When the two threads arrive at this point, they interchange a data structure such that the data structure of the first thread goes to the second one and vice versa.

This class may be very useful in a situation similar to the producer-consumer problem. This is a classic concurrent problem where you have a common buffer of data, one or more producers of data, and one or more consumers of data. As the Exchanger class synchronizes only two threads, you can use it if you have a producer-consumer problem with one producer and one consumer.

In this recipe, you will learn how to use the Exchanger class to solve the producer-consumer problem with one producer and one consumer.