Spring cache: custom key generator (#4166)

spring-mvc-java/src/main/java/com/baeldung/cache/BookService.java

@@ -0,0 +1,21 @@
+package com.baeldung.cache;
+
+import com.baeldung.model.Book;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Component
+public class BookService {
+
+    @Cacheable(value="books", keyGenerator="customKeyGenerator")
+    public List<Book> getBooks() {
+        List<Book> books = new ArrayList<Book>();
+        books.add(new Book(1, "The Counterfeiters", "André Gide"));
+        books.add(new Book(2, "Peer Gynt and Hedda Gabler", "Henrik Ibsen"));
+        return books;
+    }
+
+}