{"id":203075,"date":"2025-05-22T08:27:56","date_gmt":"2025-05-22T00:27:56","guid":{"rendered":"https:\/\/server.hk\/cnblog\/203075\/"},"modified":"2025-05-22T08:27:56","modified_gmt":"2025-05-22T00:27:56","slug":"java%e5%87%bd%e6%95%b0%e5%bc%8f%e6%8e%a5%e5%8f%a3%e5%9c%a8%e6%b5%8b%e8%af%95%e5%92%8c%e6%96%ad%e8%a8%80%e4%b8%ad%e7%9a%84%e4%bd%9c%e7%94%a8%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/203075\/","title":{"rendered":"Java\u51fd\u6570\u5f0f\u63a5\u53e3\u5728\u6d4b\u8bd5\u548c\u65ad\u8a00\u4e2d\u7684\u4f5c\u7528\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

Java\u51fd\u6570\u5f0f\u63a5\u53e3\u5728\u6d4b\u8bd5\u548c\u65ad\u8a00\u4e2d\u7684\u4f5c\u7528\uff1f<\/h1>\n

\u54c8\u55bd\uff01\u4eca\u5929\u5fc3\u8840\u6765\u6f6e\u7ed9\u5927\u5bb6\u5e26\u6765\u4e86\u300aJava\u51fd\u6570\u5f0f\u63a5\u53e3\u5728\u6d4b\u8bd5\u548c\u65ad\u8a00\u4e2d\u7684\u4f5c\u7528\uff1f\u300b<\/span>\uff0c\u60f3\u5fc5\u5927\u5bb6\u5e94\u8be5\u5bf9\u6587\u7ae0<\/span>\u90fd\u4e0d\u964c\u751f\u5427\uff0c\u90a3\u4e48\u9605\u8bfb\u672c\u6587\u5c31\u90fd\u4e0d\u4f1a\u5f88\u56f0\u96be\uff0c\u4ee5\u4e0b\u5185\u5bb9\u4e3b\u8981\u6d89\u53ca\u5230<\/span>\uff0c\u82e5\u662f\u4f60\u6b63\u5728\u5b66\u4e60\u6587\u7ae0<\/span>\uff0c\u5343\u4e07\u522b\u9519\u8fc7\u8fd9\u7bc7\u6587\u7ae0~\u5e0c\u671b\u80fd\u5e2e\u52a9\u5230\u4f60\uff01<\/p>\n

<\/p>\n

Java \u51fd\u6570\u5f0f\u63a5\u53e3\u5728\u6d4b\u8bd5\u548c\u65ad\u8a00\u4e2d\u7684\u4f5c\u7528<\/strong><\/p>\n

\u51fd\u6570\u5f0f\u63a5\u53e3\u5728 Java \u6d4b\u8bd5\u548c\u65ad\u8a00\u4e2d\u626e\u6f14\u7740\u81f3\u5173\u91cd\u8981\u7684\u89d2\u8272\uff0c\u5b83\u63d0\u4f9b\u4e86\u7b80\u6d01\u3001\u53ef\u8bfb\u6027\u5f3a\u7684\u65b9\u5f0f\u6765\u5b9a\u4e49\u548c\u4f7f\u7528\u884c\u4e3a\u4ee3\u7801\u3002<\/p>\n

\u51fd\u6570\u5f0f\u63a5\u53e3<\/strong><\/p>\n

\u51fd\u6570\u5f0f\u63a5\u53e3\u662f\u4e00\u4e2a\u53ea\u5305\u542b\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5\u7684\u63a5\u53e3\u3002\u5728 Java 8 \u4e2d\uff0c\u51fd\u6570\u5f0f\u63a5\u53e3\u88ab\u6807\u8bb0\u4e3a @FunctionalInterface<\/code> \u6ce8\u89e3\u3002<\/p>\n

@FunctionalInterface\npublic interface Predicate<T> {\n    boolean test(T t);\n}<\/pre>\n
\u6d4b\u8bd5\u548c\u65ad\u8a00<\/strong><\/p>\n
\u6d4b\u8bd5\u548c\u65ad\u8a00\u662f\u8f6f\u4ef6\u6d4b\u8bd5\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u90e8\u5206\u3002\u8fd9\u4e9b\u6280\u672f\u5141\u8bb8\u5f00\u53d1\u4eba\u5458\u9a8c\u8bc1\u4ee3\u7801\u7684\u6b63\u786e\u6027\uff0c\u786e\u4fdd\u5176\u6839\u636e\u9884\u671f\u6267\u884c\u3002<\/p>\n
\u4f7f\u7528\u51fd\u6570\u5f0f\u63a5\u53e3\u8fdb\u884c\u6d4b\u8bd5<\/strong><\/p>\n
\u51fd\u6570\u5f0f\u63a5\u53e3\u53ef\u4ee5\u901a\u8fc7\u5c06\u6761\u4ef6\u6216\u884c\u4e3a\u5c01\u88c5\u5230\u4e00\u4e2a\u7b80\u6d01\u7684\u5bf9\u8c61\u4e2d\uff0c\u6765\u7b80\u5316\u6d4b\u8bd5\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528 Predicate<\/code> \u63a5\u53e3\u6765\u6d4b\u8bd5\u4e00\u4e2a\u5bf9\u8c61\u662f\u5426\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\uff1a<\/p>\n
List<String> names = List.of(\"John\", \"Jane\", \"Bob\");\n\nboolean result = names\n    .stream()\n    .anyMatch(Predicate.isEqual(\"Jane\"));\n\nSystem.out.println(result); \/\/ prints \"true\"<\/pre>\n
\u4f7f\u7528\u51fd\u6570\u5f0f\u63a5\u53e3\u8fdb\u884c\u65ad\u8a00<\/strong><\/p>\n
\u65ad\u8a00\u5728\u6d4b\u8bd5\u4e2d\u7528\u4e8e\u9a8c\u8bc1\u9884\u671f\u7ed3\u679c\u4e0e\u5b9e\u9645\u7ed3\u679c\u662f\u5426\u5339\u914d\u3002\u51fd\u6570\u5f0f\u63a5\u53e3\u53ef\u4ee5\u63d0\u4f9b\u4e00\u79cd\u53ef\u8bfb\u6027\u5f3a\u7684\u8bed\u6cd5\u6765\u5b9a\u4e49\u65ad\u8a00\u3002<\/p>\n
import static org.junit.jupiter.api.Assertions.assertEquals;\n\nassertEquals(4, 2 + 2, \"Expected 2 + 2 to be 4\");<\/pre>\n
\u5b9e\u6218\u6848\u4f8b<\/strong><\/p>\n
\u8003\u8651\u4e00\u4e2a\u9700\u8981\u6d4b\u8bd5\u7684\u7c7b\uff0c\u8be5\u7c7b\u63d0\u4f9b\u4e86\u4e00\u4e2a calculate()<\/code> \u65b9\u6cd5\u6765\u8ba1\u7b97\u4e00\u4e2a\u5bf9\u8c61\u7684\u9762\u79ef\u3002<\/p>\n
public class Shape {\n\n    public double calculate(Object object) {\n        if (object instanceof Circle) {\n            return calculateCircleArea((Circle) object);\n        } else if (object instanceof Rectangle) {\n            return calculateRectangleArea((Rectangle) object);\n        } else {\n            throw new IllegalArgumentException(\"Unsupported shape\");\n        }\n    }\n\n    private double calculateCircleArea(Circle circle) {\n        return Math.PI * circle.getRadius() * circle.getRadius();\n    }\n\n    private double calculateRectangleArea(Rectangle rectangle) {\n        return rectangle.getLength() * rectangle.getWidth();\n    }\n}<\/pre>\n
\u4f7f\u7528\u51fd\u6570\u5f0f\u63a5\u53e3\uff0c\u53ef\u4ee5\u8f7b\u677e\u5730\u6d4b\u8bd5 calculate()<\/code> \u65b9\u6cd5\u662f\u5426\u4e3a\u4e0d\u540c\u7684\u5f62\u72b6\u5bf9\u8c61\u8ba1\u7b97\u6b63\u786e\u7684\u9762\u79ef\uff1a<\/p>\n
import org.junit.jupiter.api.Test;\n\npublic class ShapeTest {\n\n    @Test\n    void calculate_circle_returnsCorrectArea() {\n        Shape shape = new Shape();\n\n        double expectedArea = 100 * Math.PI;\n        Circle circle = new Circle(10);\n\n        double actualArea = shape.calculate(circle);\n\n        assertEquals(expectedArea, actualArea, \"Expected area to be \" + expectedArea);\n    }\n\n    @Test\n    void calculate_invalidShape_throwsException() {\n        Shape shape = new Shape();\n\n        assertThrows(IllegalArgumentException.class, () -> shape.calculate(\"Invalid shape\"));\n    }\n}<\/pre>\n
\u51fd\u6570\u5f0f\u63a5\u53e3\u4f7f\u5f97\u6d4b\u8bd5\u548c\u65ad\u8a00\u53d8\u5f97\u66f4\u52a0\u7b80\u6d01\u3001\u53ef\u8bfb\uff0c\u4f7f\u5f00\u53d1\u4eba\u5458\u80fd\u591f\u4e13\u6ce8\u4e8e\u9a8c\u8bc1\u4ee3\u7801\u7684\u6b63\u786e\u6027\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u672c\u6587\u7684\u5168\u90e8\u5185\u5bb9\u4e86\uff0c\u662f\u5426\u6709\u987a\u5229\u5e2e\u52a9\u4f60\u89e3\u51b3\u95ee\u9898\uff1f\u82e5\u662f\u80fd\u7ed9\u4f60\u5e26\u6765\u5b66\u4e60\u4e0a\u7684\u5e2e\u52a9\uff0c\u8bf7\u5927\u5bb6\u591a\u591a\u652f\u6301\uff01\u66f4\u591a\u5173\u4e8e\u6587\u7ae0\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u4e5f\u53ef\u5173\u6ce8\u516c\u4f17\u53f7\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
Java\u51fd\u6570\u5f0f\u63a5\u53e3\u5728\u6d4b\u8bd5\u548c\u65ad\u8a00\u4e2d...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-203075","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203075","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=203075"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203075\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=203075"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=203075"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=203075"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}