Android開發問題記錄-ARouter init logistics center exception

在Bugly中發現存在偶現的崩潰問題如下：

	#5404 com.alibaba.android.arouter.exception.HandlerException

更詳細的信息如下：

java.lang.RuntimeException:Unable to create application com.xxx: 
com.alibaba.android.arouter.exception.HandlerException: ARouter::ARouter init logistics center exception! 
[com.alibaba.android.arouter.routes.ARouter$$Providers$$yyy]

看了ARouter所有與之相關的Issues，並沒有發現解決方案。

於是查看ARouter源碼，定位到如下代碼，LogisticsCenter::init

    /**
     * LogisticsCenter init, load all metas in memory. Demand initialization
     */
    public synchronized static void init(Context context, ThreadPoolExecutor tpe) throws HandlerException {
        mContext = context;
        executor = tpe;

        try {
            long startInit = System.currentTimeMillis();
            //billy.qi modified at 2017-12-06
            //load by plugin first
            loadRouterMap();
            if (registerByPlugin) {
                logger.info(TAG, "Load router map by arouter-auto-register plugin.");
            } else {
                Set<String> routerMap;

                // It will rebuild router map every times when debuggable.
                if (ARouter.debuggable() || PackageUtils.isNewVersion(context)) {
                    logger.info(TAG, "Run with debug mode or new install, rebuild router map.");
                    // These class was generated by arouter-compiler.
                    routerMap = ClassUtils.getFileNameByPackageName(mContext, ROUTE_ROOT_PAKCAGE);
                    if (!routerMap.isEmpty()) {
                        context.getSharedPreferences(AROUTER_SP_CACHE_KEY, Context.MODE_PRIVATE).edit().putStringSet(AROUTER_SP_KEY_MAP, routerMap).apply();
                    }

                    PackageUtils.updateVersion(context);    // Save new version name when router map update finishes.
                } else {
                    logger.info(TAG, "Load router map from cache.");
                    routerMap = new HashSet<>(context.getSharedPreferences(AROUTER_SP_CACHE_KEY, Context.MODE_PRIVATE).getStringSet(AROUTER_SP_KEY_MAP, new HashSet<String>()));
                }

                logger.info(TAG, "Find router map finished, map size = " + routerMap.size() + ", cost " + (System.currentTimeMillis() - startInit) + " ms.");
                startInit = System.currentTimeMillis();

                for (String className : routerMap) {
                    if (className.startsWith(ROUTE_ROOT_PAKCAGE + DOT + SDK_NAME + SEPARATOR + SUFFIX_ROOT)) {
                        // This one of root elements, load root.
                        ((IRouteRoot) (Class.forName(className).getConstructor().newInstance())).loadInto(Warehouse.groupsIndex);
                    } else if (className.startsWith(ROUTE_ROOT_PAKCAGE + DOT + SDK_NAME + SEPARATOR + SUFFIX_INTERCEPTORS)) {
                        // Load interceptorMeta
                        ((IInterceptorGroup) (Class.forName(className).getConstructor().newInstance())).loadInto(Warehouse.interceptorsIndex);
                    } else if (className.startsWith(ROUTE_ROOT_PAKCAGE + DOT + SDK_NAME + SEPARATOR + SUFFIX_PROVIDERS)) {
                        // Load providerIndex
                        ((IProviderGroup) (Class.forName(className).getConstructor().newInstance())).loadInto(Warehouse.providersIndex);
                    }
                }
            }

            logger.info(TAG, "Load root element finished, cost " + (System.currentTimeMillis() - startInit) + " ms.");

            if (Warehouse.groupsIndex.size() == 0) {
                logger.error(TAG, "No mapping files were found, check your configuration please!");
            }

            if (ARouter.debuggable()) {
                logger.debug(TAG, String.format(Locale.getDefault(), "LogisticsCenter has already been loaded, GroupIndex[%d], InterceptorIndex[%d], ProviderIndex[%d]", Warehouse.groupsIndex.size(), Warehouse.interceptorsIndex.size(), Warehouse.providersIndex.size()));
            }
        } catch (Exception e) {
            throw new HandlerException(TAG + "ARouter init logistics center exception! [" + e.getMessage() + "]");
        }
    }

從代碼可知，如果處於debuggable()或者apk的版本號變更時，ARouter會重新通過指定包名，掃描包下面包含的所有的ClassName。否則，ARouter會從緩存SharedPreferences中讀取這些信息。

由於問題堆棧[com.alibaba.android.arouter.routes.ARouter$$Providers$$yyy]，這裏的yyy模塊，我們在最近移除過，因此，考慮是因爲緩存中有yyy模塊，但是實際新的apk中並沒有。

我們到/data/data/包名/shared_prefs/SP_AROUTER_CACHE.xml下查看，果然ROUTER_MAP中多了<string>com.alibaba.android.arouter.routes.ARouter$$Group$$yyy</string>這個模塊。

確定了問題所在，解決就簡單了：在研發和測試階段，把ARouter.openDebug()打開，而在正式發佈的版本，則不打開。