== Why is this an issue?

Before Java 8, the only way to partially support closures in Java was by using anonymous inner classes.
Java 8 introduced lambdas, which are significantly more readable and should be used instead.

This rule is automatically disabled when the project's `sonar.java.source` is lower than `8`, as lambda expressions were introduced in Java 8.

=== Code examples

==== Noncompliant code example

[source,java,diff-id=1,diff-type=noncompliant]
----
myCollection.stream().map(new Function<String,String>() { // Noncompliant, use a lambda expression instead
  @Override
  public String apply(String input) {
    return new StringBuilder(input).reverse().toString();
  }
})
  ...
----

==== Compliant solution

[source,java,diff-id=1,diff-type=compliant]
----
myCollection.stream()
  .map(input -> new StringBuilder(input).reverse().toString()) // Compliant
    ...
----

==== Noncompliant code example
[source,java,diff-id=2,diff-type=noncompliant]
----
Predicate<String> isEmpty = new Predicate<String>() { // Noncompliant, use a lambda expression instead
  @Override
  public boolean test(String myString) {
    return myString.isEmpty();
  }
};
----

==== Compliant solution

[source,java,diff-id=2,diff-type=compliant]
----
Predicate<String> isEmpty = myString -> myString.isEmpty(); // Compliant
----

== Resources
* https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html[Lambda Expressions - The Java™ Tutorials]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Make this anonymous inner class a lambda. [(sonar.java.source not set. Assuming 8 or greater.)]


'''
== Comments And Links
(visible only on this page)

=== on 24 Feb 2014, 10:54:33 Freddy Mallet wrote:
Is implemented by \http://jira.codehaus.org/browse/SONARJAVA-455

endif::env-github,rspecator-view[]