基于SpringBoot的项目API版本控制

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 {
    /**
     * 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 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：