{"id":1299,"date":"2020-09-29T14:39:03","date_gmt":"2020-09-29T06:39:03","guid":{"rendered":"http:\/\/admin.evshou.com\/?p=1299"},"modified":"2020-10-15T15:43:40","modified_gmt":"2020-10-15T07:43:40","slug":"java%e6%95%99%e7%a8%8b%ef%bc%9ajava8%e6%96%b0%e7%89%b9%e6%80%a7","status":"publish","type":"post","link":"https:\/\/www.9713job.com\/?p=1299","title":{"rendered":"2020java\u6559\u7a0b\uff1ajava8\u65b0\u7279\u6027"},"content":{"rendered":"

2020java\u6559\u7a0b\uff1ajava8\u65b0\u7279\u6027<\/h3>\n

java8\u65b0\u7279\u6027<\/span><\/strong><\/p>\n

java8\u6982\u8ff0
\njava8\u7b80\u79f0jdk1.8\u662fjava\u8bed\u8a00\u5f00\u53d1\u7684\u4e00\u4e2a\u4e3b\u8981\u7248\u672c\u3002
\noracle\u516c\u53f8\u4e8e14\u5e743\u670818\u65e5\u53d1\u5e03java8<\/p>\n

\u652f\u6301Lambda\u8868\u8fbe\u5f0f
\n\u51fd\u6570\u5f0f\u63a5\u53e3
\n\u65b0\u7684Stream API
\n\u65b0\u7684\u65e5\u671f API
\n\u5176\u4ed6\u7279\u6027<\/p>\n


\nLambda\u8868\u8fbe\u5f0f<\/strong><\/span>
\n\u6982\u8ff0\uff1a\u7279\u6b8a\u7684\u533f\u540d\u5185\u90e8\u7c7b\uff0c\u8bed\u6cd5\u66f4\u7b80\u6d01<\/p>\n

Lambda\u8868\u8fbe\u5f0f\u5141\u8bb8\u628a\u51fd\u6570\u4f5c\u4e3a\u4e00\u4e2a\u65b9\u6cd5\u7684\u53c2\u6570(\u51fd\u6570\u4f5c\u4e3a\u65b9\u6cd5\u53c2\u6570\u4f20\u9012)\uff0c\u5c06\u4ee3\u7801\u50cf\u6570\u636e\u4e00\u6837\u4f20\u9012<\/p>\n

import java.util.Comparator;\r\nimport java.util.TreeSet;\r\n\r\npublic class demos{\r\n    public static void main(String[] args) {\r\n        \/\/\u533f\u540d\u5185\u90e8\u7c7b<\/span><\/strong>\r\n        Runnable runnable=new Runnable() {\r\n            @Override\r\n            public void run() {\r\n                System.out.println(\"\u5b50\u7ebf\u7a0b\u6267\u884c\u4e86\");\r\n            }\r\n        };\r\n        \/\/Lambda\u8868\u8fbe\u5f0f<\/span><\/strong>\r\n        Runnable runnable1=()->System.out.println(\"\u5b50\u7ebf\u7a0b1\u6267\u884c\u4e86\");<\/span><\/strong>\r\n        new Thread(runnable1).start();<\/span><\/strong>\r\n        new Thread(()->System.out.println(\"\u5b50\u7ebf\u7a0b3\u6267\u884c\u4e86\")).start();<\/span><\/strong>\r\n        \/\/\u533f\u540d\u5185\u90e8\u7c7b<\/strong><\/span>\r\n        Comparator<String> com=new Comparator<String>() {\r\n            @Override\r\n            public int compare(String o1, String o2) {\r\n                return o1.length()-o2.length();\r\n            }\r\n        };\r\n        \/\/Lambda\u8868\u8fbe\u5f0f<\/span><\/strong>\r\n        Comparator<String> com2=(String o1, String o2)-> {<\/span><\/strong>\r\n            return o1.length()-o2.length();<\/span><\/strong>\r\n        };<\/span><\/strong>\r\n        Comparator<String> com3=(o1,o2)->o1.length()-o2.length();<\/span><\/strong>\r\n        TreeSet<String> treeSet2=new TreeSet<>(com2);<\/span><\/strong>\r\n        TreeSet<String> treeSet3=new TreeSet<>(com3);<\/span><\/strong>\r\n    }\r\n}<\/pre>\n
\u57fa\u672c\u8bed\u6cd5\uff1a
\n<\u51fd\u6570\u5f0f\u63a5\u53e3><\u53d8\u91cf\u540d>=(\u53c2\u65701\uff0c\u53c2\u65702)->{
\n\/\/\u65b9\u6cd5\u4f53
\n};<\/p>\n
Lambda\u5f15\u5165\u4e86\u65b0\u7684\u64cd\u4f5c\u7b26\uff1a->(\u7bad\u5934\u64cd\u4f5c\u7b26)\uff0c->\u5c06\u8868\u8fbe\u5f0f\u5206\u6210\u4e24\u90e8\u5206
\n\u5de6\u4fa7\uff1a(\u53c2\u65701\uff0c\u53c2\u65702…)\u8868\u793a\u53c2\u6570\u5217\u8868
\n\u53f3\u4fa7\uff1a{}\u5185\u90e8\u662f\u65b9\u6cd5\u4f53<\/p>\n
\u6ce8\u610f\u4e8b\u9879<\/strong><\/span>\uff1a
\n\u5f62\u53c2\u5217\u8868\u7684\u6570\u636e\u7c7b\u578b\u4f1a\u81ea\u52a8\u5224\u65ad<\/span><\/strong>
\n\u5982\u679c\u5f62\u53c2\u5217\u8868\u4e3a\u7a7a\uff0c\u53ea\u9700\u4fdd\u7559()<\/span><\/strong>
\n\u5982\u679c\u5f62\u53c2\u53ea\u6709\u4e00\u4e2a\uff0c()\u53ef\u4ee5\u7701\u7565\uff0c\u53ea\u9700\u8981\u53c2\u6570\u7684\u540d\u79f0\u5373\u53ef<\/span><\/strong>
\n\u5982\u679c\u6267\u884c\u8bed\u53e5\u53ea\u6709\u4e00\u53e5\uff0c\u4e14\u65e0\u8fd4\u56de\u503c\uff0c{}\u53ef\u4ee5\u7701\u7565\uff0c\u82e5\u6709\u8fd4\u56de\u503c\uff0c\u5219\u82e5\u60f3\u7701\u53bb{}<\/span><\/strong>
\n\u5219\u5fc5\u987b\u540c\u65f6\u7701\u7565return\uff0c\u4e14\u6267\u884c\u8bed\u53e5\u4e5f\u4fdd\u8bc1\u53ea\u6709\u4e00\u53e5<\/span><\/strong>
\nLambda\u4e0d\u4f1a\u751f\u6210\u4e00\u4e2a\u5355\u72ec\u7684\u5185\u90e8\u7c7b\u6587\u4ef6<\/span><\/strong>
\n=============================
\n\u51fd\u6570\u5f0f\u63a5\u53e3<\/strong><\/h3>\n
\u5982\u679c\u4e00\u4e2a\u63a5\u53e3\u53ea\u6709\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5\uff0c\u5219\u8be5\u63a5\u53e3\u79f0\u4e4b\u4e3a\u51fd\u6570\u5f0f\u63a5\u53e3\uff0c\u51fd\u6570\u5f0f\u63a5\u53e3\u53ef\u4ee5\u4f7f\u7528
\nLambda\u8868\u8fbe\u5f0f\uff0cLambda\u8868\u8fbe\u5f0f\u4f1a\u88ab\u5339\u914d\u5230\u8fd9\u4e2a\u62bd\u8c61\u65b9\u6cd5\u4e0a\u3002<\/p>\n
@FunctionalInterface \u6ce8\u89e3\u68c0\u6d4b\u63a5\u53e3\u662f\u5426\u7b26\u5408\u51fd\u6570\u5f0f\u63a5\u53e3\u3002<\/span><\/strong><\/p>\n
@FunctionalInterface<\/span><\/strong>\r\npublic interface Usb {<\/span><\/strong>\r\n    void service();<\/span><\/strong>\r\n}<\/span><\/strong><\/pre>\n
\u5e38\u89c1\u51fd\u6570\u5f0f\u63a5\u53e3<\/strong><\/p>\n
\n\n\n\n\n\n\n\n\n
\u5e38\u89c1\u51fd\u6570\u5f0f\u63a5\u53e3<\/caption>\n
\u51fd\u6570\u5f0f\u63a5\u53e3<\/th>\n\u53c2\u6570\u7c7b\u578b<\/th>\n\u8fd4\u56de\u7c7b\u578b<\/th>\n\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n
Consumer <T>\u6d88\u8d39\u578b\u63a5\u53e3<\/td>\nT<\/td>\nvoid<\/td>\nvoid accept(T t);\u5bf9\u7c7b\u578b\u4e3aT \u7684\u5bf9\u8c61\u5e94\u7528\u64cd\u4f5c<\/td>\n<\/tr>\n
Supplier<T>\u4f9b\u7ed9\u578b\u63a5\u53e3<\/td>\n\u65e0<\/td>\nT<\/td>\nT get();\u8fd4\u56de\u7c7b\u578b\u4e3aT\u7684\u5bf9\u8c61<\/td>\n<\/tr>\n
Fuction<T,R>\u51fd\u6570\u578b\u63a5\u53e3<\/td>\nT<\/td>\nR<\/td>\nR apply(T t);\u5bf9\u7c7b\u578b\u4e3aT\u7684\u5bf9\u8c61\u5e94\u7528\u64cd\u4f5c\uff0c\u5e76\u8fd4\u56de\u7c7b\u578b\u4e3aR\u7c7b\u578b\u7684\u5bf9\u8c61<\/td>\n<\/tr>\n
Predicate<T>\u65ad\u8a00\u578b\u63a5\u53e3<\/td>\nT<\/td>\nboolean<\/td>\nboolean test(T t);\u786e\u5b9a\u7c7b\u578b\u4e3aT\u7684\u5bf9\u8c61\u662f\u5426\u6ee1\u8db3\u6761\u4ef6\uff0c\u5e76\u8fd4\u56deBoolean\u7c7b\u578b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\/\/\u6d88\u8d39\u578b\u63a5\u53e3<\/span><\/strong><\/p>\n
import java.util.function.Consumer;\r\n\r\npublic class demos{\r\n    public static void main(String[] args) {\r\n        \/\/\u533f\u540d\u5185\u90e8\u7c7b\r\n        Consumer<Double> con=new Consumer<Double>() {\r\n            @Override\r\n            public void accept(Double aDouble) {\r\n                System.out.println(\"\u6d88\u8d391\\t\"+aDouble);\r\n            }\r\n        };\r\n        \/\/Lambda\u8868\u8fbe\u5f0f\r\n        Consumer<Double> con2=t-> System.out.println(\"\u6d88\u8d392\\t\"+t);\r\n        happy(con,1000);\r\n        happy(con2,2000);\r\n        happy(t-> System.out.println(\"\u6d88\u8d393\\t\"+t),3000);\r\n    }\r\n    public static void happy(Consumer<Double> consumer,double money){\r\n        consumer.accept(money);\r\n    }\r\n}\r\n\/\/\u8fd0\u884c\u7ed3\u679c\r\n\u6d88\u8d391\t1000.0\r\n\u6d88\u8d392\t2000.0\r\n\u6d88\u8d393\t3000.0<\/pre>\n
\/\/\u4f9b\u7ed9\u578b\u51fd\u6570\u5f0f\u63a5\u53e3<\/span><\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.Random;\r\nimport java.util.function.Supplier;\r\n\r\npublic class demos{\r\n    public static void main(String[] args) {\r\n        \/\/\u533f\u540d\u5185\u90e8\u7c7b\r\n        Supplier<Integer> sup=new Supplier<Integer>() {\r\n            @Override\r\n            public Integer get() {\r\n                return new Random().nextInt(100);\r\n            }\r\n        };\r\n        \/\/Lambda\u8868\u8fbe\u5f0f\r\n        int[] nums = getNums(() -> new Random().nextInt(100), 5);\r\n        System.out.println(Arrays.toString(nums));\r\n        System.out.println(\"====\");\r\n        int[] nums1 = getNums(sup, 6);\r\n        System.out.println(Arrays.toString(nums1));\r\n    }\r\n    public static int[] getNums(Supplier<Integer> supplier,int count){\r\n        int[] arr=new int[count];\r\n        for(int i=0;i<count;i++){\r\n            arr[i]=supplier.get();\r\n        }\r\n        return arr;\r\n    }\r\n}<\/pre>\n
\/\/\u7ed3\u679c
\n[80, 20, 60, 23, 52]
\n====
\n[86, 20, 10, 7, 61, 30]<\/p>\n
\/\/\u51fd\u6570\u578b\u63a5\u53e3<\/span><\/strong><\/p>\n
import java.util.function.Function;\r\n\r\npublic class demos{\r\n    public static void main(String[] args) {\r\n        System.out.println(handler(s -> s.toUpperCase(), \"hello\"));\r\n        System.out.println(handler(s ->{return s.toUpperCase();}, \"world\"));\r\n        System.out.println(handler(String::toUpperCase, \"helloworld\"));\r\n    }\r\n    public static String handler(Function<String,String> function,String str){\r\n        return function.apply(str);\r\n    }\r\n}<\/pre>\n
\/\/\u7ed3\u679c
\nHELLO
\nWORLD
\nHELLOWORLD<\/p>\n
\/\/\u65ad\u8a00\u578b\u63a5\u53e3<\/span><\/strong><\/p>\n
import java.util.ArrayList;\r\nimport java.util.List;\r\nimport java.util.function.Predicate;\r\n\r\npublic class demos{\r\n    public static void main(String[] args) {\r\n        List<String> list=new ArrayList<>();\r\n        list.add(\"zhangsan\");\r\n        list.add(\"zhangwuji\");\r\n        list.add(\"lisi\");\r\n        list.add(\"lixiaolong\");\r\n        list.add(\"wangwu\");\r\n        List<String> result = find(s -> s.startsWith(\"zhang\"), list);\r\n        System.out.println(result.toString());\r\n        List<String> result2 = find(s -> s.startsWith(\"li\"), list);\r\n        System.out.println(result2.toString());\r\n        List<String> result3 = find(s -> s.contains(\"i\"), list);\r\n        System.out.println(result3.toString());\r\n        List<String> result4 = find(s -> s.contains(\"a\"), list);\r\n        System.out.println(result4.toString());\r\n    }\r\n    public static List<String> find(Predicate<String> predicate,List<String> list){\r\n        List<String> result=new ArrayList<>();\r\n        for (String s : list) {\r\n            if(predicate.test(s)){\r\n                result.add(s);\r\n            }\r\n        }\r\n        return result;\r\n    }\r\n}<\/pre>\n
\/\/\u7ed3\u679c
\n[zhangsan, zhangwuji]
\n[lisi, lixiaolong]
\n[zhangwuji, lisi, lixiaolong]
\n[zhangsan, zhangwuji, lixiaolong, wangwu]
\n=============================
\n\u65b9\u6cd5\u5f15\u7528<\/p>\n
\u65b9\u6cd5\u5f15\u7528\u662fLambda\u8868\u8fbe\u5f0f\u7684\u4e00\u79cd\u7b80\u5199\u5f62\u5f0f\u3002
\n\u5982\u679cLambda\u8868\u8fbe\u5f0f\u65b9\u6cd5\u4f53\u4e2d\u53ea\u662f\u8c03\u7528\u4e00\u4e2a\u7279\u5b9a\u7684\u5df2\u7ecf\u5b58\u5728\u7684\u65b9\u6cd5\uff0c\u5219\u53ef\u4ee5\u4f7f\u7528\u65b9\u6cd5\u5f15\u7528\u3002<\/p>\n
\u5e38\u89c1\u5f62\u5f0f\uff1a
\n\u5bf9\u8c61::\u5b9e\u4f8b\u65b9\u6cd5
\n\u7c7b::\u9759\u6001\u65b9\u6cd5
\n\u7c7b::\u5b9e\u4f8b\u65b9\u6cd5
\n\u7c7b::new<\/p>\n
public static void main(String[] args) {\r\n    \/\/\u5bf9\u8c61::\u5b9e\u4f8b\u65b9\u6cd5\r\n    Consumer<String> con=System.out::println;\r\n    con.accept(\"hello\");\r\n    \/\/\u7c7b::\u9759\u6001\u65b9\u6cd5\r\n    Comparator<Integer> com=Integer::compare;\r\n    \/\/\u7c7b::\u5b9e\u4f8b\u65b9\u6cd5\r\n    Function<Character,String> function=Character::getName;\r\n    System.out.println(function.apply('a'));\r\n    \/\/\u7c7b::new\r\n    Supplier<Student> sup=Student::new;\r\n    System.out.println(sup.get());\r\n}<\/pre>\n
=============================
\nstream API<\/p>\n
\u4ec0\u4e48\u662fstream\uff1f
\n\u6d41(stream)\u4e2d\u4fdd\u5b58\u5bf9\u96c6\u5408\u6216\u6570\u7ec4\u6570\u636e\u7684\u64cd\u4f5c\u3002\u548c\u96c6\u5408\u7c7b\u4f3c\uff0c\u4f46\u96c6\u5408\u4e2d\u4fdd\u5b58\u7684\u662f\u6570\u636e\u3002<\/p>\n
stream\u7279\u70b9\uff1a
\nstream\u81ea\u5df1\u4e0d\u4f1a\u5b58\u50a8\u5143\u7d20\u3002
\nstream\u4e0d\u4f1a\u6539\u53d8\u5143\u6e90\u5bf9\u8c61\u3002\u76f8\u53cd\uff0c\u4ed6\u4eec\u4f1a\u8fd4\u56de\u4e00\u4e2a\u6301\u6709\u7ed3\u679c\u7684\u65b0Stream
\nstream\u64cd\u4f5c\u662f\u5ef6\u8fdf\u6267\u884c\u7684\u3002\u8fd9\u610f\u5473\u7740\u4ed6\u4eec\u4f1a\u7b49\u5230\u9700\u8981\u7ed3\u679c\u7684\u65f6\u5019\u624d\u6267\u884c\u3002<\/p>\n
Stream\u4f7f\u7528\u6b65\u9aa4
\n\u521b\u5efa\uff1a\u521b\u5efa\u4e00\u4e2a\u6d41
\n\u4e2d\u95f4\u64cd\u4f5c\uff1a\u5728\u4e00\u4e2a\u6216\u591a\u4e2a\u6b65\u9aa4\u4e2d\uff0c\u5c06\u521d\u59cbstream\u8f6c\u5316\u5230\u53e6\u4e00\u4e2astream\u7684\u4e2d\u95f4\u64cd\u4f5c
\n\u7ec8\u6b62\u64cd\u4f5c\uff1a\u4f7f\u7528\u4e00\u4e2a\u7ec8\u6b62\u64cd\u4f5c\u6765\u4ea7\u751f\u4e00\u4e2a\u7ed3\u679c\u3002\u8be5\u64cd\u4f5c\u4f1a\u5f3a\u5236\u5b83\u4e4b\u524d\u7684\u5ef6\u8fdf\u64cd\u4f5c\u7acb\u5373\u6267\u884c\u3002\u5728\u8fd9\u4e4b\u540e\uff0c\u8be5stream\u5c31\u4e0d\u80fd\u4f7f\u7528\u4e86\u3002<\/p>\n
\u521b\u5efastream<\/p>\n
1.\u901a\u8fc7Collection\u5bf9\u8c61\u7684stream()\u6216paralleleStream()<\/p>\n
List<String> list=new ArrayList<>();\r\nlist.add(\"huawei\");\r\nlist.add(\"apple\");\r\nlist.add(\"oppo\");\r\nlist.add(\"vivo\");\r\nStream<String> stream = list.stream();\r\nstream.forEach(System.out::println);\r\nSystem.out.println(\"===\");\r\nStream<String> stream2 = list.parallelStream();\r\nstream2.forEach(System.out::println);<\/pre>\n
2.\u901a\u8fc7Arrays\u7c7b\u7684stream()\u65b9\u6cd5<\/p>\n
String[] s={\"apple\",\"banner\",\"orange\"};\r\nStream<String> stream = Arrays.stream(s);\r\nstream.forEach(System.out::println);<\/pre>\n
3.\u901a\u8fc7Stream\u63a5\u53e3\u7684of()\u3001iterate()\u3001generate()\u65b9\u6cd5<\/p>\n
Stream<Integer> stream = Stream.of(10, 20, 30);\r\nstream.forEach(System.out::println);\r\nSystem.out.println(\"==\u8fed\u4ee3\u6d41==\");\r\nStream<Integer> iterate = Stream.iterate(0, x -> x + 2);\r\niterate.limit(5).forEach(System.out::println);\r\nSystem.out.println(\"==\u751f\u6210\u6d41==\");\r\nStream<Integer> generate = Stream.generate(() -> new Random().nextInt(999));\r\ngenerate.limit(5).forEach(System.out::println);<\/pre>\n
4.\u901a\u8fc7IntStream\u3001LongStream\u3001DoubleStream\u63a5\u53e3\u4e2d\u7684of\u3001range\u3001rangeClosed\u65b9\u6cd5<\/p>\n
IntStream stream=null;\r\nstream=IntStream.of(10,20,30);\r\nstream.forEach(System.out::println);\r\nSystem.out.println(\"====\");\r\nstream=IntStream.range(0,50);\/\/0~49\r\nstream.forEach(System.out::println);\r\nSystem.out.println(\"====\");\r\nstream=IntStream.rangeClosed(0,50);\/\/0~50\r\nstream.forEach(System.out::println);<\/pre>\n
\u4e2d\u95f4\u64cd\u4f5c\u3001\u7ec8\u6b62\u64cd\u4f5c<\/p>\n
\u4e2d\u95f4\u64cd\u4f5c
\nfilter\u8fc7\u6ee4\u3001limit\u9650\u5236\u3001skip\u8df3\u8fc7\u3001distinct\u53bb\u91cd\u3001sorted\u6392\u5e8f<\/span><\/p>\n
public static void main(String[] args) {\r\n    List<Emp> list=new ArrayList<>();\r\n    list.add(new Emp(\"\u5f20\u4e09\",15000));\r\n    list.add(new Emp(\"\u674e\u56db\",17000));\r\n    list.add(new Emp(\"\u8d75\u67f3\",5000));\r\n    list.add(new Emp(\"\u674e\u4e09\",8000));\r\n    list.add(new Emp(\"\u674e\u4e09\",8000));\r\n    \/\/filter\u8fc7\u6ee4\r\n    System.out.println(\"----filter\u8fc7\u6ee4\u5de5\u8d44\u5c0f\u4e8e5000\u7684----\");\r\n    list.stream().filter(e->e.getBalance()>5000).forEach(System.out::println);\r\n    \/\/limit\u9650\u5236\r\n    System.out.println(\"----limit\u9650\u5236\uff0c\u53ea\u663e\u793a3\u6761\u6570\u636e----\");\r\n    list.stream().limit(3).forEach(System.out::println);\r\n    \/\/skip\u8df3\u8fc7\r\n    System.out.println(\"----skip\u8df3\u8fc7\uff0c\u8df3\u8fc7\u5934\u4e24\u6761\u6570\u636e----\");\r\n    list.stream().skip(2).forEach(System.out::println);\r\n    \/\/distinct\u53bb\u91cd\uff0c\u9700\u91cd\u5199hashcode\u548cequals\u65b9\u6cd5\r\n    System.out.println(\"---distinct\u53bb\u91cd---\");\r\n    list.stream().distinct().forEach(System.out::println);\r\n    \/\/sorted\u6392\u5e8f\r\n    System.out.println(\"---sorted\u6392\u5e8f---\");\r\n    list.stream()\r\n            .sorted((e1,e2)->Double.compare(e1.getBalance(),e2.getBalance()))\r\n            .forEach(System.out::println);\r\n}<\/pre>\n
map\u6620\u5c04<\/span><\/p>\n
list.stream().map(Emp::getName).forEach(System.out::println);<\/pre>\n
parallel\u5e76\u884c\u6d41<\/span><\/p>\n
\/\/parallel\u8c03\u7528toString()\u65b9\u6cd5\uff0c\u91c7\u7528\u591a\u7ebf\u7a0b\uff0c\u6548\u7387\u5feb\r\nlist.stream().parallel().forEach(System.out::println);<\/pre>\n
\u5e76\u884c\u6d41\u548c\u4e32\u884c\u6d41\u7684\u533a\u522b<\/span><\/strong><\/h3>\n
List<String> list=new ArrayList<>();\r\nfor(int i=0;i<5000000;i++){\r\n    list.add(UUID.randomUUID().toString());\r\n}\r\nSystem.out.println(\"\u6dfb\u52a0\u5b8c\u6bd5\");\r\nlong s=System.currentTimeMillis();\r\n\/\/\u4e32\u884c\u6d41\uff0c\u5355\u7ebf\u7a0b,\u7528\u65f614\u79d2\r\nlong count = list.stream().sorted().count();\r\n\/\/\u5e76\u884c\u6d41\uff0c\u591a\u7ebf\u7a0b\uff0c\u7528\u65f60.2\u79d2\r\nlong count2 = list.stream().parallel().count();\r\nSystem.out.println(count);\r\nlong e=System.currentTimeMillis();\r\nSystem.out.println(\"\u7528\u65f6\"+(e-s));<\/pre>\n
\u7ec8\u6b62\u64cd\u4f5c<\/p>\n
forEach\u904d\u5386\u3001min\u6c42\u6700\u5c0f\u503c\u3001max\u6c42\u6700\u5927\u503c\u3001count\u83b7\u53d6\u5143\u7d20\u4e2a\u6570<\/span><\/p>\n
\/\/forEach\u904d\u5386\r\nlist.stream().filter(t->t.getSalary()>5000)\r\n        .forEach(System.out::println);\r\n\/\/min\r\nSystem.out.println(\"\u83b7\u53d6\u5de5\u8d44\u6700\u4f4e\u7684\u6570\u636e\");\r\nOptional<Emp> min = list.stream()\r\n        .min((t1, t2) -> Double.compare(t1.getSalary(), t2.getSalary()));\r\nSystem.out.println(min.get());\r\n\/\/max\r\nSystem.out.println(\"\u83b7\u53d6\u5de5\u8d44\u6700\u9ad8\u7684\u6570\u636e\");\r\nOptional<Emp> max = list.stream()\r\n        .max((t1, t2) -> Double.compare(t1.getSalary(), t2.getSalary()));\r\nSystem.out.println(max.get());\r\n\/\/count\r\nSystem.out.println(\"\u83b7\u53d6\u5143\u7d20\u4e2a\u6570\");\r\nSystem.out.println(\"\u6570\u636e\u6709\"+list.stream().count()+\"\u6761\");<\/pre>\n
reduce\u89c4\u7ea6\u6c42\u548c\u3001collect\u6536\u96c6<\/span><\/p>\n
\/\/reduce\u89c4\u7ea6\r\nSystem.out.println(\"\u8ba1\u7b97\u603b\u5de5\u8d44\");\r\nOptional<Double> sum = list.stream().map(Emp::getSalary).reduce(Double::sum);\r\nSystem.out.println(\"\u603b\u5de5\u8d44\u4e3a:\"+sum.get());\r\n\/\/collect\u6536\u96c6\r\nSystem.out.println(\"collect\u6536\u96c6\");\r\nList<String> name = list.stream().map(Emp::getName).collect(Collectors.toList());\r\nfor (String s : name) {\r\n    System.out.println(s);\r\n}<\/pre>\n
=============================
\n\u65b0\u65f6\u95f4API<\/p>\n
\u4e4b\u524d\u65f6\u95f4API\u5b58\u5728\u95ee\u9898\uff0c\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\uff0c\u8bbe\u8ba1\u6df7\u4e71<\/p>\n
\u89e3\u51b3\u65b9\u6848<\/p>\n
public static void main(String[] args)throws Exception {\r\n    DateTimeFormatter dtf=DateTimeFormatter.ofPattern(\"yyyyMMdd\");\r\n    ExecutorService ex = Executors.newFixedThreadPool(10);\r\n    Callable<LocalDate> callable=()->LocalDate.parse(\"20201007\",dtf);\r\n    List<Future<LocalDate>> list=new ArrayList<>();\r\n    for(int i=0;i<10;i++){\r\n        Future<LocalDate> future = ex.submit(callable);\r\n        list.add(future);\r\n    }\r\n    for (Future<LocalDate> f : list) {\r\n        System.out.println(f.get());\r\n    }\r\n    ex.shutdown();\r\n}<\/pre>\n
\u672c\u5730\u5316\u65f6\u95f4API<\/p>\n
LocalDate\u3001LocalTime\u3001LocalDateTime<\/span><\/strong><\/p>\n
public static void main(String[] args) {\r\n    \/\/\u83b7\u53d6\u672c\u5730\u65f6\u95f4\r\n    LocalDateTime ldt=LocalDateTime.now();\r\n    System.out.println(\"\u83b7\u53d6\u5e74\u4efd:\"+ldt.getYear());\r\n    System.out.println(\"\u83b7\u53d6\u6708\u4efd:\"+ldt.getMonthValue());\r\n    System.out.println(\"\u83b7\u53d6\u65e5\u671f:\"+ldt.getDayOfMonth());\r\n    System.out.println(\"\u83b7\u53d6\u661f\u671f:\"+ldt.getDayOfWeek());\r\n    \r\n    \/\/\u4fee\u6539\u65f6\u95f4 plus\u589e\u52a0 min\u51cf\u5c11\r\n    System.out.println(\"\u7a7f\u8d8a\u5230\u660e\u65e9\u5de5\u4f5c\u65f6\u95f4\");\r\n    System.out.println(ldt.plusHours(17));\r\n    System.out.println(\"\u56de\u5230\u5341\u5e74\u524d\");\r\n    System.out.println(ldt.minusYears(10));\r\n}<\/pre>\n
Instant\u65f6\u95f4\u6233\u3001ZoneId\u65f6\u533a<\/span><\/strong><\/p>\n
public static void main(String[] args) {\r\n    \/\/Instant\u65f6\u95f4\u6233\r\n    Instant instant=Instant.now();\r\n    System.out.println(instant.toString());\r\n    System.out.println(instant.toEpochMilli());\r\n    System.out.println(System.currentTimeMillis());\r\n    \/\/\u6dfb\u52a0\u51cf\u5c11\u65f6\u95f4\r\n    Instant instant2=instant.plusSeconds(10);\r\n    System.out.println(Duration.between(instant,instant2).toMillis());\r\n    Instant instant3=instant.minusSeconds(10);\r\n    System.out.println(Duration.between(instant,instant3).toMillis());\r\n    \/\/ZoneId\u65f6\u533a\r\n    Set<String> zoneIds = ZoneId.getAvailableZoneIds();\r\n    for (String str : zoneIds) {\r\n        System.out.println(str);\r\n    }\r\n    System.out.println(\"\u5f53\u524d\u65f6\u533a:\"+ZoneId.systemDefault().toString());\r\n}<\/pre>\n
Date\u3001Instant\u3001LocalDateTime\u7684\u8f6c\u6362<\/span><\/strong><\/p>\n
DateTimeFormatter\uff1a\u683c\u5f0f\u5316\u7c7b<\/span><\/strong><\/p>\n
public static void main(String[] args) {\r\n    \/\/DateTimeFormatter\r\n    DateTimeFormatter dtf=DateTimeFormatter.ofPattern(\"yyyy-MM-dd HH:mm:ss\");\r\n    \/\/\u628a\u65f6\u95f4\u683c\u5f0f\u5316\u6210\u5b57\u7b26\u4e32\r\n    System.out.println(dtf.format(LocalDateTime.now()));\r\n    \/\/\u628a\u5b57\u7b26\u4e32\u89e3\u6790\u6210\u65f6\u95f4\r\n    LocalDateTime localDateTime=LocalDateTime.parse(\"2020-10-07 18:00:47\",dtf);\r\n    System.out.println(localDateTime);\r\n}<\/pre>\n
java8\u603b\u7ed3<\/span><\/h1>\n
Lambda\u8868\u8fbe\u5f0f\uff1a\u5141\u8bb8\u628a\u51fd\u6570\u4f5c\u4e3a\u4e00\u4e2a\u65b9\u6cd5\u7684\u53c2\u6570\u4f20\u9012\u3002<\/p>\n
\u51fd\u6570\u5f0f\u63a5\u53e3\uff1a
\nConsumer\u3001Supplier\u3001Function\u3001predicte<\/p>\n
StreamAPI
\n\u628a\u5bf9\u6570\u636e\u7684\u64cd\u4f5c\u5c01\u88c5\u6210\u4e00\u4e2a\u6d41
\n\u6b65\u9aa4\uff1a\u521b\u5efa\u6d41\u3001\u4e2d\u95f4\u64cd\u4f5c\u3001\u7ec8\u6b62\u64cd\u4f5c<\/p>\n
\u65b0\u65f6\u95f4API<\/p>\n","protected":false},"excerpt":{"rendered":"
2020java\u6559\u7a0b\uff1ajava8\u65b0\u7279\u6027 java8\u65b0\u7279\u6027 java8\u6982\u8ff0 java8\u7b80\u79f0jdk1.8\u662fjava […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-1299","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/1299","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1299"}],"version-history":[{"count":16,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/1299\/revisions"}],"predecessor-version":[{"id":2340,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/1299\/revisions\/2340"}],"wp:attachment":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1299"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1299"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1299"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}