1.
…

2.
source : http://www.oracle.com/technetwork/java/eol-135779.html

3.
source : http://blog.soat.fr/?p=29705

4.
List<String> datas = Arrays.asList("one", "two", "three");
datas.forEach(new Consumer<String>() {
@Override
public void accept(String elt) {
System.out.println(elt);
}
});

5.
List<String> datas = Arrays.asList("one", "two", "three");
datas.forEach(new Consumer<String>() {
@Override
public void accept(String elt) {
System.out.println(elt);
}
});

6.
List<String> datas = Arrays.asList("one", "two", "three");
datas.forEach(new Consumer<String>() {
@Override
public void accept(String elt) {
System.out.println(elt);
}
});

7.
List<String> datas = Arrays.asList("one", "two", "three");
datas.forEach(elt -> System.out.println(elt));

8.
Resource resource = null;
try {
resource = new Resource();
resource.doJob();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
if (resource != null) {
try {
resource.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

9.
try(Resource resource = new Resource()) {
resource.doJob();
} catch (Exception ex) {
ex.printStackTrace();
}

10.
try(Resource resource = new Resource()) {
resource.doJob();
} catch (Exception ex) {
ex.printStackTrace();
}

11.
public static void doWithResource(Consumer<Resource> lambda)
{
Resource resource = null;
try {
resource = new Resource();
lambda.accept(resource);
} finally {
if(resource != null) {
try {
resource.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

12.
public static void doWithResource(Consumer<Resource> lambda)
{
Resource resource = null;
try {
resource = new Resource();
lambda.accept(resource);
} finally {
if(resource != null) {
try {
resource.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

13.
public static void doWithResource(Consumer<Resource> lambda)
{
Resource resource = null;
try {
resource = new Resource();
lambda.accept(resource);
} finally {
if(resource != null) {
try {
resource.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

14.
doWithResource(resource -> resource.doJob());

15.
Map<String, String> map = new HashMap<>();
String key = "KEY";
if(!map.containsKey(key)) {
map.put(key, key.concat("_COMPUTED"));
}
String result = map.get(key);

16.
Map<String, String> map = new HashMap<>();
String key = "KEY";
if(!map.containsKey(key)) {
map.put(key, key.concat("_COMPUTED"));
}
String result = map.get(key);

17.
Map<String, String> map = new HashMap<>();
String key = "KEY";
String result = map.computeIfAbsent(key,
k -> key + "_COMPUTED");

18.
Map<String, String> map = new HashMap<>();
String key = "KEY";
String result = map.computeIfAbsent(key,
k -> key + "_COMPUTED");

19.
List<String> red = colors.stream()
.filter(c -> "RED".equals(c))
.collect(Collectors.toList());

20.
Registry registry = new Registry();
List<User> users = new ArrayList<>();
for (Group group : registry.getGroups()) {
for (User user : group.getUsers()) {
if(user.getAge() >= 18) {
users.add(user);
}
}
}

21.
Registry registry = new Registry();
List<User> users = new ArrayList<>();
for (Group group : registry.getGroups()) {
for (User user : group.getUsers()) {
if(user.getAge() >= 18) {
users.add(user);
}
}
}

22.
Registry registry = new Registry();
List<User> users = new ArrayList<>();
for (Group group : registry.getGroups()) {
for (User user : group.getUsers()) {
if(user.getAge() >= 18) {
users.add(user);
}
}
}

23.
Registry registry = new Registry();
List<User> users = new ArrayList<>();
for (Group group : registry.getGroups()) {
for (User user : group.getUsers()) {
if(user.getAge() >= 18) {
users.add(user);
}
}
}

24.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

25.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

26.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

27.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

28.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

29.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

30.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

31.
public List<User> filterUsers(Registry registry,
Predicate<User> filter) {
return registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(filter)
.collect(Collectors.toList());
}

32.
public List<User> filterUsers(Registry registry,
Predicate<User> filter) {
return registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(filter)
.collect(Collectors.toList());
}

33.
public List<User> filterUsers(Registry registry,
Predicate<User> filter) {
return registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(filter)
.collect(Collectors.toList());
}

34.
public List<User> filterUsers(Registry registry,
Predicate<User> filter) {
return registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(filter)
.collect(Collectors.toList());
}

35.
Registry registry = new Registry();
filterUsers(registry, u -> u.getAge() >= 18);
filterUsers(registry, u -> u.getName().startsWith("John"));

36.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

37.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> {
return grp.getUsers()
.stream()
.filter(u -> {
return u.getAge() >= 18;
});
})
.collect(Collectors.toList());

38.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

39.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.stream()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

40.
Registry registry = new Registry();
List<User> users = registry.getGroups()
.parallel()
.flatMap(grp -> grp.getUsers().stream())
.filter(u -> u.getAge() >= 18)
.collect(Collectors.toList());

41.
User remoteUser = null;
// NullPointerException
System.out.println("User name : " + remoteUser.getName());

42.
Optional<User> user = Optional.ofNullable(remoteUser);
user.ifPresent(u -> System.out.println("User name : " + u.getName()));

43.
Optional<User> user = Optional.ofNullable(remoteUser);
user.ifPresent(u -> System.out.println("User name : " + u.getName()));

44.
Optional<User> user = Optional.ofNullable(remoteUser);
user.ifPresent(u -> System.out.println("User name : " + u.getName()));

45.
user.flatMap(u -> Optional.ofNullable(u.getName()))
.ifPresent(name -> System.out.println("User name :" + name));

46.
user.flatMap(u -> Optional.ofNullable(u.getName()))
.ifPresent(name -> System.out.println("User name :" + name));

47.
user.flatMap(u -> Optional.ofNullable(u.getName()))
.ifPresent(name -> System.out.println("User name :" + name));

48.
if(user != null) {
if(user.getName() != null) {
System.out.println("User name :" + user.getName());
}
}

49.
Optional<String> birthdate = remoteUser.getBirthdate();

50.
LocalDate newDate = LocalDate.now().plusDays(3)
.plusMonths(2);
LocalDateTime newDateTime = LocalDateTime.now()
.plusMinutes(3)
.plusSeconds(6)
.plusDays(2);

51.
LocalDate newDate = LocalDate.now().plusDays(3)
.plusMonths(2);
LocalDateTime newDateTime = LocalDateTime.now()
.plusMinutes(3)
.plusSeconds(6)
.plusDays(2);

52.
LocalDate newDate = LocalDate.now().plusDays(3)
.plusMonths(2);
LocalDateTime newDateTime = LocalDateTime.now()
.plusMinutes(3)
.plusSeconds(6)
.plusDays(2);

53.
Source : http://www.oracle.com/technetwork/java/javase/8-compatibility-guide-2156366.html

54.
new BigDecimal("0.00").stripTrailingZeros().equals(BigDecimal.ZERO))

55.
new BigDecimal("0.00").stripTrailingZeros().equals(BigDecimal.ZERO))

56.
new BigDecimal("0.00").stripTrailingZeros().equals(BigDecimal.ZERO))

57.
…