背景

公司最近有一個(gè)項(xiàng)目二期需要對(duì)一些功能進(jìn)行改造耕渴，涉及部分框架內(nèi)置業(yè)務(wù)接口個(gè)性化定制暇咆，兼容老接口功能并且增加一部分新的數(shù)據(jù)返回低零，由于前端調(diào)用這些接口分布較多且較為零碎，修改測(cè)試成本較大水泉，所以打算在框架層面提供路由覆蓋功能善涨，加快項(xiàng)目進(jìn)度減少無技術(shù)含量的修改帶來的系統(tǒng)風(fēng)險(xiǎn)

設(shè)計(jì)

• 提供自定義注解指定需要覆蓋的路由及新路由地址
• 系統(tǒng)啟動(dòng)時(shí)掃描所有注解數(shù)據(jù)并進(jìn)行映射處理
• 注冊(cè)自定義路由映射配置類

實(shí)現(xiàn)

注解定義

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
public @interface CoverRoute {
    String value() default "";
}

注解掃描及管理

在系統(tǒng)啟動(dòng)時(shí)調(diào)用initRoute方法，把原路由和對(duì)應(yīng)的覆蓋路由映射到map鍵值對(duì)中

public class ConverRouteUtil {
    private static HashMap<String, String> mappingRegist = new HashMap<>();

    public static void initRoute(Class runtimeClass, List<String> extraPackageNameList) {
        List<Class<?>> scanClassList = new ArrayList<>();
        if (!runtimeClass.getPackage().getName().equals(Application.class.getPackage().getName())) {
            scanClassList.addAll(ScanUtil.getAllClassByPackageName_Annotation(runtimeClass.getPackage(), CoverRoute.class));
        }
        for (String packageName : extraPackageNameList) {
            scanClassList.addAll(ScanUtil.getAllClassByPackageName_Annotation(packageName, CoverRoute.class));
        }
        for (Class clazz : scanClassList) {
            CoverRoute coverRoute = (CoverRoute) clazz.getAnnotation(CoverRoute.class);
            if (StringUtil.isEmpty(coverRoute.value())) {
                continue;
            }
            RequestMapping requestMapping = (RequestMapping) clazz.getAnnotation(RequestMapping.class);
            String classRoute = "";
            if (requestMapping != null) {
                classRoute = requestMapping.value()[0];
            } else {
                continue;
            }
            List<Method> methodList = Arrays.asList(clazz.getDeclaredMethods());
            for (Method method : methodList) {
                PostMapping postMapping = method.getAnnotation(PostMapping.class);
                String methodRoute = "";
                if (postMapping != null) {
                    methodRoute = postMapping.value()[0];
                } else {
                    GetMapping getMapping = method.getAnnotation(GetMapping.class);
                    if (getMapping != null) {
                        methodRoute = getMapping.value()[0];
                    }
                }
                if (!StringUtil.isEmpty(classRoute) && !StringUtil.isEmpty(methodRoute)) {
                    String orginalRoute = coverRoute.value() + methodRoute;
                    String redirectRoute = classRoute + methodRoute;
                    mappingRegist.put(orginalRoute, redirectRoute);
                }
            }
        }
        if (mappingRegist.size() > 0) {
            System.out.println("掃描路由方法覆蓋：" + mappingRegist.size() + "個(gè)");
        }
    }

    public static boolean checkExistCover(String orginalRoute) {
        return mappingRegist.containsKey(orginalRoute);
    }

    public static String getRedirectRoute(String orginalRoute) {
        return mappingRegist.get(orginalRoute);
    }
}

自定義RequestMappingHandlerMapping

繼承RequestMappingHandlerMapping重寫lookupHandlerMethod方法草则，在spring進(jìn)行路由尋址時(shí)進(jìn)行覆蓋

public class CustomRequestMappingHandlerMapping extends RequestMappingHandlerMapping {
    @Override
    protected HandlerMethod lookupHandlerMethod(String lookupPath, HttpServletRequest request) throws Exception {
        if(ConverRouteUtil.checkExistCover(lookupPath)){
            String redirectRoute = ConverRouteUtil.getRedirectRoute(lookupPath);
            request.setAttribute("redirectTag","1");
            request.setAttribute("redirectRoute",redirectRoute);
            request.setAttribute("lookupPath",lookupPath);
            lookupPath = redirectRoute;
        }else{
            request.setAttribute("redirectTag","0");
        }
        return super.lookupHandlerMethod(lookupPath, request);
    }

    @Override
    protected RequestMappingInfo getMatchingMapping(RequestMappingInfo info, HttpServletRequest request) {
        String redirectTag = ConvertOp.convert2String(request.getAttribute("redirectTag"));
        if(redirectTag.equals("1")){
            String redirectRoute = ConvertOp.convert2String(request.getAttribute("redirectRoute"));
            boolean check = false;
            if( info.getPatternsCondition()!=null){
                Set<String> set =  info.getPatternsCondition().getPatterns();
                if(set.size()>0){
                    String[] array = new String[set.size()];
                    array = set.toArray(array);
                    String pattern = array[0];
                    if(pattern.equals(redirectRoute)){
                        check = true;
                    }
                }
            }
            if(check){
                return info;
            }else{
                return super.getMatchingMapping(info, request);
            }
        }else{
            return super.getMatchingMapping(info, request);
        }
    }
}

注冊(cè)RequestMappingHandlerMapping

@Component
public class WebRequestMappingConfig implements WebMvcRegistrations {
    public RequestMappingHandlerMapping getRequestMappingHandlerMapping() {
        RequestMappingHandlerMapping handlerMapping = new CustomRequestMappingHandlerMapping();
        handlerMapping.setOrder(0);
        return handlerMapping;
    }

}

使用示例

在個(gè)性化接口類增加@CoverRoute注解钢拧，指定需要覆蓋的路由地址，創(chuàng)建相同路由路徑的的方法即可炕横，訪問原來的接口地址會(huì)自動(dòng)轉(zhuǎn)發(fā)到項(xiàng)目個(gè)性化接口地址

• 原接口

@Controller
@RequestMapping("/example/original")
public class RedirectOriginalExampleController {

    @PostMapping("/getConfig")
    @ResponseBody
    @AnonymousAccess
    public Object getConfig(@RequestBody Map<String, Object> params) {
        Result result = Result.okResult();
        result.add("tag","original");
        return result;
    }
}

• 新接口

@Controller
@RequestMapping("/example/redirect")
@CoverRoute("/example/original")
public class RedirectExampleController {

    @PostMapping("/getConfig")
    @ResponseBody
    public Object getConfig(@RequestBody Map<String, Object> params) {
        Result result = Result.okResult();
        String param1 = ConvertOp.convert2String(params.get("param1"));
        result.add("tag","redirect");
        result.add("param1",param1);
        return result;
    }
}