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(parameters) -> expression
(parameters) -> statement
(parameters) -> { statements }
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(intx,inty) -> x + y
() -> System.out.println("hi "+ s);
(String s) -> {intn = s.length();returnn; }
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Runnable r = () -> System.out.println("Hello!");
r.run();
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Callable<Double> pi = () ->3.14;
Double p = pi.call();
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String[] words = {"aaa","b","cc"};
Arrays.sort(words, (s1, s2) -> s1.length() - s2.length());
// 等价于：
Arrays.sort(words, (String s1, String s2) -> s1.length() - s2.length());
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// s是高效的final变量（不会更改）
String s ="foo";
// s可以在lambdas中被引用
Runnable r = () -> System.out.println(s);
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// Class::staticMethod syntax
Arrays.sort(items, Util::compareItems);
// 等价于:
Arrays.sort(items, (a, b) -> Util.compareItems(a, b));
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// instance::instanceMethod syntax
items.forEach(System.out::print);
// 等价于：
items.forEach((x) -> System.out.print(x));
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// Class::instanceMethod syntax
items.forEach(Item::publish);
// 等价于:
items.forEach((x) -> { x.publish(); });
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ConstructorReference cref = Item::new;
Item item = cref.constructor();
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interfaceDescriptive {
defaultString desc() {
return"fantastic";
}
}
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classItemimplementsDescriptive { }
Item x =newItem();
// prints "fantastic"
System.out.println(x.desc());
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List<String> strings = ...;
longn = strings.stream().filter(x -> !x.isEmpty()).count();
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List<Item> items = ...;
String names = items.stream().map((x) -> x.getTitle()).collect(Collectors.joining(", "));
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List<City> cities = ...;
List<Country> countries = cities.stream().map((c) -> c.getCountry()).distinct().collect(Collectors.toList());
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List<Item> items = ...;
IntSummaryStatistics stats = items.stream().mapToInt((x) -> x.getRating()).summaryStatistics();
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原文：http://my.oschina.net/u/1171391/blog/293893