Polish condition in caching examples

Closes gh-1386

src/docs/asciidoc/integration.adoc

@@ -8304,7 +8304,7 @@ if the argument `name` has a length shorter than 32:
 [source,java,indent=0]
 [subs="verbatim,quotes"]
 ----
-	@Cacheable(cacheNames="book", **condition="#name.length < 32"**)
+	@Cacheable(cacheNames="book", **condition="#name.length() < 32"**)
 	public Book findBook(String name)
 ----
 
@@ -8316,7 +8316,7 @@ only want to cache paperback books:
 [source,java,indent=0]
 [subs="verbatim,quotes"]
 ----
-	@Cacheable(cacheNames="book", condition="#name.length < 32", **unless="#result.hardback"**)
+	@Cacheable(cacheNames="book", condition="#name.length() < 32", **unless="#result.hardback"**)
 	public Book findBook(String name)
 ----
 
@@ -8327,7 +8327,7 @@ supported wrapper so the previous example can be rewritten as follows:
 [source,java,indent=0]
 [subs="verbatim,quotes"]
 ----
-	@Cacheable(cacheNames="book", condition="#name.length < 32", **unless="#result.hardback"**)
+	@Cacheable(cacheNames="book", condition="#name.length() < 32", **unless="#result.hardback"**)
 	public Optional<Book> findBook(String name)
 ----