基于SpringBoot的项目API版本控制

╰半橙微兮° 2022-12-23 07:15 439阅读 0赞

## 第一步：自定义版本号标记注解 ##

@Target({ ElementType.METHOD, ElementType.TYPE})
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    public @interface ApiVersion { 
        /** * 标识版本号，从1开始 */
        int value() default 1;
    }

## 第二步：重写RequestCondition，自定义url匹配逻辑 ##

@Data
    @Slf4j
    public class ApiVersionCondition implements RequestCondition<ApiVersionCondition> { 
        /** * 接口路径中的版本号前缀，如: api/v[1-n]/fun */
        private final static Pattern VERSION_PREFIX = Pattern.compile("/v(\\d+)/");
        private int apiVersion;
    
        ApiVersionCondition(int apiVersion) { 
            this.apiVersion = apiVersion;
        }
        /** * 最近优先原则，方法定义的 @ApiVersion > 类定义的 @ApiVersion */
        @Override
        public ApiVersionCondition combine(ApiVersionCondition other) { 
            return new ApiVersionCondition(other.getApiVersion());
        }
        /** * 获得符合匹配条件的ApiVersionCondition */
        @Override
        public ApiVersionCondition getMatchingCondition(HttpServletRequest request) { 
            Matcher m = VERSION_PREFIX.matcher(request.getRequestURI());
            if (m.find()) { 
                int version = Integer.valueOf(m.group(1));
                if (version >= getApiVersion()) { 
                    return this;
                }
            }
            return null;
        }
        /** * 当出现多个符合匹配条件的ApiVersionCondition，优先匹配版本号较大的 */
        @Override
        public int compareTo(ApiVersionCondition other, HttpServletRequest request) { 
            return other.getApiVersion() - getApiVersion();
        }
    }

说明：

*  getMatchingCondition方法中，控制了只有版本小于等于请求参数中的版本的 ApiCondition 才满足规则
 *  compareTo 指定了当有多个ApiCoondition满足这个请求时，选择最大的版本

## 第三步：重写RequestMappingHandlerMapping，自定义匹配的处理器 ##

public class ApiRequestMappingHandlerMapping extends RequestMappingHandlerMapping { 
        @Override
        protected RequestCondition<?> getCustomTypeCondition(Class<?> handlerType) { 
            // 扫描类上的 @ApiVersion
            ApiVersion apiVersion = AnnotationUtils.findAnnotation(handlerType, ApiVersion.class);
            return createRequestCondition(apiVersion);
        }
        @Override
        protected RequestCondition<?> getCustomMethodCondition(Method method) { 
            // 扫描方法上的 @ApiVersion
            ApiVersion apiVersion = AnnotationUtils.findAnnotation(method, ApiVersion.class);
            return createRequestCondition(apiVersion);
        }
        private RequestCondition<ApiVersionCondition> createRequestCondition(ApiVersion apiVersion) { 
            if (Objects.isNull(apiVersion)) { 
                return null;
            }
            int value = apiVersion.value();
            Assert.isTrue(value >= 1, "Api Version Must be greater than or equal to 1");
            return new ApiVersionCondition(value);
        }
    }

## 第四步：配置注册自定义WebMvcRegistrations ##

@Configuration
    public class WebMvcRegistrationsConfig implements WebMvcRegistrations { 
        @Override
        public RequestMappingHandlerMapping getRequestMappingHandlerMapping() { 
            return new ApiRequestMappingHandlerMapping();
        }
    }

## 第五步：编写测试接口 ##

@RestController
    @RequestMapping("/api/{version}")
    public class ApiControler { 
        @GetMapping("/fun")
        public String fun1() { 
            return "fun 1";
        }
        @ApiVersion(5)
        @GetMapping("/fun")
        public String fun2() { 
            return "fun 2";
        }
        @ApiVersion(9)
        @GetMapping("/fun")
        public String fun3() { 
            return "fun 5";
        }
    }

页面测试效果：  
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