Java 8 Lambda examples from Simon Ritter's QCon presentation: http://www.infoq.com/presentations/lambda-streams-java-8

java8lambdas.java

// Ex 1: Convert words in list to upper case
List<String> output = wordList.stream()
                              .map(String::toUpperCase)
                              .collect(Collectors.toList());

// Ex 2: Finds words in list with even length
List<String> output = wordList.stream()
                              .filter(w -> w.length() & 1 == 0)
                              .collect(Collectors.toList());

// Ex 3: Count lines in a file
long count = bufferedReader.lines().count();

// Ex 4: Join lines 3-4 into a single string
String output = bufferedReader.lines()
                              .skip(2)
                              .limit(2)
                              .collect(Collectors.joining());

// Ex 5: Find length of longest line in a file
int longest = reader.lines()
                     .mapToInt(String::length)
                     .max()
                     .getAsInt();

// Ex 6: Collect all words in a file into a list
List<String> output = reader.lines()
                            .flatMap(line -> Stream.of(line.split(REGEXP)))
                            .filter(word -> word.length() > 0)
                            .collect(Collectors.toList());
                            
// Ex 7: List of words lowercased, in alphabetical order
List<String> output = reader.lines()
                            .flatMap(line -> Stream.of(line.split(REGEXP)))
                            .filter(word -> word.length() > 0)
                            .map(String::toLowerCase)
                            .sorted()
                            .collect(Collectors.toList());