{"id":2364,"date":"2022-03-18T11:34:36","date_gmt":"2022-03-18T03:34:36","guid":{"rendered":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2364"},"modified":"2022-03-18T14:14:01","modified_gmt":"2022-03-18T06:14:01","slug":"java8%e4%b9%8bconsumer%e3%80%81supplier%e3%80%81predicate%e5%92%8cfunction%e6%94%bb%e7%95%a5%ef%bf%bc%ef%bf%bc","status":"publish","type":"post","link":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2364","title":{"rendered":"Java8\u4e4bConsumer\u3001Supplier\u3001Predicate\u548cFunction\u653b\u7565\ufffc\ufffc"},"content":{"rendered":"\n<p>\u6458\u81ea\uff1a<a href=\"https:\/\/www.cnblogs.com\/SIHAIloveYAN\/p\/11288064.html\">Java8\u4e4bConsumer\u3001Supplier\u3001Predicate\u548cFunction\u653b\u7565 &#8211; \u516c\u4f17\u53f7\u597d\u597d\u5b66java &#8211; \u535a\u5ba2\u56ed (cnblogs.com)<\/a><\/p>\n\n\n\n<p>\u5206\u522b\u662fConsumer\uff08\u6d88\u8d39\u578b\uff0caccept\uff0c\u63a5\u53d7\u53c2\u6570\uff0c\u4e0d\u8fd4\u56de\uff09\u3001supplier\uff08\u4f9b\u7ed9\u578b\uff0cget\uff0c\u6ca1\u6709\u53c2\u6570\uff0c\u6709\u8fd4\u56de\uff09\u3001predicate\uff08\u8c13\u8bcd\u578b\uff0ctest\uff0c\u4e00\u4e2a\u53c2\u6570\uff0c\u8fd4\u56debool\uff0c\u5224\u65ad\uff09\u3001function\uff08\u529f\u80fd\u6027\uff0c\u8f6c\u6362\uff0c\u4e00\u4e2a\u53c2\u6570\uff0c\u4e00\u4e2a\u8fd4\u56de\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/**\n     * consumer\u63a5\u53e3\u6d4b\u8bd5\n     *\/\n    @Test\n    public void test_Consumer() {\n        \/\/\u2460 \u4f7f\u7528consumer\u63a5\u53e3\u5b9e\u73b0\u65b9\u6cd5\n        Consumer&lt;String> consumer = new Consumer&lt;String>() {\n\n            @Override\n            public void accept(String s) {\n                System.out.println(s);\n            }\n        };\n        Stream&lt;String> stream = Stream.of(\"aaa\", \"bbb\", \"ddd\", \"ccc\", \"fff\");\n        stream.forEach(consumer);\n\n        System.out.println(\"********************\");\n\n        \/\/\u2461 \u4f7f\u7528lambda\u8868\u8fbe\u5f0f\uff0cforEach\u65b9\u6cd5\u9700\u8981\u7684\u5c31\u662f\u4e00\u4e2aConsumer\u63a5\u53e3\n        stream = Stream.of(\"aaa\", \"bbb\", \"ddd\", \"ccc\", \"fff\");\n        Consumer&lt;String> consumer1 = (s) -> System.out.println(s);\/\/lambda\u8868\u8fbe\u5f0f\u8fd4\u56de\u7684\u5c31\u662f\u4e00\u4e2aConsumer\u63a5\u53e3\n        stream.forEach(consumer1);\n        \/\/\u66f4\u76f4\u63a5\u7684\u65b9\u5f0f\n        \/\/stream.forEach((s) -> System.out.println(s));\n        System.out.println(\"********************\");\n\n        \/\/\u2462 \u4f7f\u7528\u65b9\u6cd5\u5f15\u7528\uff0c\u65b9\u6cd5\u5f15\u7528\u4e5f\u662f\u4e00\u4e2aconsumer\n        stream = Stream.of(\"aaa\", \"bbb\", \"ddd\", \"ccc\", \"fff\");\n        Consumer consumer2 = System.out::println;\n        stream.forEach(consumer);\n        \/\/\u66f4\u76f4\u63a5\u7684\u65b9\u5f0f\n        \/\/stream.forEach(System.out::println);\n    }\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>**\n     * Supplier\u63a5\u53e3\u6d4b\u8bd5\uff0csupplier\u76f8\u5f53\u4e00\u4e2a\u5bb9\u5668\u6216\u8005\u53d8\u91cf\uff0c\u53ef\u4ee5\u5b58\u50a8\u503c\n     *\/\n    @Test\n    public void test_Supplier() {\n        \/\/\u2460 \u4f7f\u7528Supplier\u63a5\u53e3\u5b9e\u73b0\u65b9\u6cd5,\u53ea\u6709\u4e00\u4e2aget\u65b9\u6cd5\uff0c\u65e0\u53c2\u6570\uff0c\u8fd4\u56de\u4e00\u4e2a\u503c\n        Supplier&lt;Integer> supplier = new Supplier&lt;Integer>() {\n            @Override\n            public Integer get() {\n                \/\/\u8fd4\u56de\u4e00\u4e2a\u968f\u673a\u503c\n                return new Random().nextInt();\n            }\n        };\n\n        System.out.println(supplier.get());\n\n        System.out.println(\"********************\");\n\n        \/\/\u2461 \u4f7f\u7528lambda\u8868\u8fbe\u5f0f\uff0c\n        supplier = () -> new Random().nextInt();\n        System.out.println(supplier.get());\n        System.out.println(\"********************\");\n\n        \/\/\u2462 \u4f7f\u7528\u65b9\u6cd5\u5f15\u7528\n        Supplier&lt;Double> supplier2 = Math::random;\n        System.out.println(supplier2.get());\n    }\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>\/**\n     * Supplier\u63a5\u53e3\u6d4b\u8bd52\uff0c\u4f7f\u7528\u9700\u8981Supplier\u7684\u63a5\u53e3\u65b9\u6cd5\n     *\/\n    @Test\n    public void test_Supplier2() {\n        Stream&lt;Integer> stream = Stream.of(1, 2, 3, 4, 5);\n        \/\/\u8fd4\u56de\u4e00\u4e2aoptional\u5bf9\u8c61\n        Optional&lt;Integer> first = stream.filter(i -> i > 4)\n                .findFirst();\n\n        \/\/optional\u5bf9\u8c61\u6709\u9700\u8981Supplier\u63a5\u53e3\u7684\u65b9\u6cd5\n        \/\/orElse\uff0c\u5982\u679cfirst\u4e2d\u5b58\u5728\u6570\uff0c\u5c31\u8fd4\u56de\u8fd9\u4e2a\u6570\uff0c\u5982\u679c\u4e0d\u5b58\u5728\uff0c\u5c31\u653e\u56de\u4f20\u5165\u7684\u6570\n        System.out.println(first.orElse(1));\n        System.out.println(first.orElse(7));\n\n        System.out.println(\"********************\");\n\n        Supplier&lt;Integer> supplier = new Supplier&lt;Integer>() {\n            @Override\n            public Integer get() {\n                \/\/\u8fd4\u56de\u4e00\u4e2a\u968f\u673a\u503c\n                return new Random().nextInt();\n            }\n        };\n\n        \/\/orElseGet\uff0c\u5982\u679cfirst\u4e2d\u5b58\u5728\u6570\uff0c\u5c31\u8fd4\u56de\u8fd9\u4e2a\u6570\uff0c\u5982\u679c\u4e0d\u5b58\u5728\uff0c\u5c31\u8fd4\u56desupplier\u8fd4\u56de\u7684\u503c\n        System.out.println(first.orElseGet(supplier));\n    }\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>\/**\n     * Predicate\u8c13\u8bcd\u6d4b\u8bd5\uff0c\u8c13\u8bcd\u5176\u5b9e\u5c31\u662f\u4e00\u4e2a\u5224\u65ad\u7684\u4f5c\u7528\u7c7b\u4f3cbool\u7684\u4f5c\u7528\n     *\/\n    @Test\n    public void test_Predicate() {\n        \/\/\u2460 \u4f7f\u7528Predicate\u63a5\u53e3\u5b9e\u73b0\u65b9\u6cd5,\u53ea\u6709\u4e00\u4e2atest\u65b9\u6cd5\uff0c\u4f20\u5165\u4e00\u4e2a\u53c2\u6570\uff0c\u8fd4\u56de\u4e00\u4e2abool\u503c\n        Predicate&lt;Integer> predicate = new Predicate&lt;Integer>() {\n            @Override\n            public boolean test(Integer integer) {\n                if(integer > 5){\n                    return true;\n                }\n                return false;\n            }\n        };\n\n        System.out.println(predicate.test(6));\n\n        System.out.println(\"********************\");\n\n        \/\/\u2461 \u4f7f\u7528lambda\u8868\u8fbe\u5f0f\uff0c\n        predicate = (t) -> t > 5;\n        System.out.println(predicate.test(1));\n        System.out.println(\"********************\");\n\n    }\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>\/**\n     * Function\u6d4b\u8bd5\uff0cfunction\u7684\u4f5c\u7528\u662f\u8f6c\u6362\uff0c\u5c06\u4e00\u4e2a\u503c\u8f6c\u4e3a\u53e6\u5916\u4e00\u4e2a\u503c\n     *\/\n    @Test\n    public void test_Function() {\n        \/\/\u2460 \u4f7f\u7528map\u65b9\u6cd5\uff0c\u6cdb\u578b\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u8f6c\u6362\u524d\u7684\u7c7b\u578b\uff0c\u7b2c\u4e8c\u4e2a\u662f\u8f6c\u5316\u540e\u7684\u7c7b\u578b\n        Function&lt;String, Integer> function = new Function&lt;String, Integer>() {\n            @Override\n            public Integer apply(String s) {\n                return s.length();\/\/\u83b7\u53d6\u6bcf\u4e2a\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\uff0c\u5e76\u4e14\u8fd4\u56de\n            }\n        };\n\n        Stream&lt;String> stream = Stream.of(\"aaa\", \"bbbbb\", \"ccccccv\");\n        Stream&lt;Integer> stream1 = stream.map(function);\n        stream1.forEach(System.out::println);\n\n        System.out.println(\"********************\");\n\n    }\n<\/code><\/pre>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6458\u81ea\uff1aJava8\u4e4bConsumer\u3001Supplier\u3001Predicate\u548cFunction\u653b\u7565 &#8211; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"_links":{"self":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2364"}],"collection":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2364"}],"version-history":[{"count":13,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2364\/revisions"}],"predecessor-version":[{"id":2377,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2364\/revisions\/2377"}],"wp:attachment":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2364"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2364"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2364"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}