ARouter源码解析 - 1835434698/1835434698.github.io GitHub Wiki

 ARouter.init(this); 

public static void init(Application application) {
        if (!hasInit) {//是否已经初始化
            logger = _ARouter.logger;
            _ARouter.logger.info(Consts.TAG, "ARouter init start.");//日志输出
            hasInit = _ARouter.init(application);//调用 01

            if (hasInit) {
                _ARouter.afterInit();
            }

            _ARouter.logger.info(Consts.TAG, "ARouter init over.");
        }
    }

    private volatile static ThreadPoolExecutor executor = DefaultPoolExecutor.getInstance();//线程池
    private static Handler mHandler;
//01 同步初始化
protected static synchronized boolean init(Application application) {
        mContext = application;
        LogisticsCenter.init(mContext, executor);//调用 02
        logger.info(Consts.TAG, "ARouter init success!");
        hasInit = true;
        mHandler = new Handler(Looper.getMainLooper());//创建主线程的handler

        return true;
    }
// 02 初始化核心模块
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();//加载map，实际就是将registerByPlugin = false
            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);//通过指定包名，扫描包下面包含的所有的ClassName
                    if (!routerMap.isEmpty()) {
                      //数据持久
                        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();
//反射加载所有classname
                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() + "]");
        }
    }

ARouter.getInstance().build("/test/MainActivity")
        .withLong("key1", 666L)
        .withString("key3", "888")
        .withParcelable("key4", dataBean)
        .navigation();

//01获取单例
//02构造目标
//03设置参数
//04开始跳转

//01获取单例
public static ARouter getInstance() {
        if (!hasInit) {//判断是否初始化过
            throw new InitException("ARouter::Init::Invoke init(context) first!");
        } else {
          //双检查单例， 以及 volatile修饰
            if (instance == null) {
                synchronized (ARouter.class) {
                    if (instance == null) {
                        instance = new ARouter();
                    }
                }
            }
            return instance;
        }
    }
//03 参数写入Bundle
public Postcard withLong(@Nullable String key, long value) {
        mBundle.putLong(key, value);
        return this;
    }

public Postcard build(String path) {
        return _ARouter.getInstance().build(path);
    }
protected static _ARouter getInstance() {
        if (!hasInit) {
            throw new InitException("ARouterCore::Init::Invoke init(context) first!");
        } else {
            if (instance == null) {
                synchronized (_ARouter.class) {
                    if (instance == null) {
                        instance = new _ARouter();
                    }
                }
            }
            return instance;
        }
    }
//02构造目标
protected Postcard build(String path) {
        if (TextUtils.isEmpty(path)) {
            throw new HandlerException(Consts.TAG + "Parameter is invalid!");
        } else {
            PathReplaceService pService = ARouter.getInstance().navigation(PathReplaceService.class);
            if (null != pService) {
                path = pService.forString(path);//格式化参数
            }
            return build(path, extractGroup(path));//首先调用201 ，然后调用 202
        }
    }
//201 
private String extractGroup(String path) {
        if (TextUtils.isEmpty(path) || !path.startsWith("/")) {//判断是否以“/”开始
            throw new HandlerException(Consts.TAG + "Extract the default group failed, the path must be start with '/' and contain more than 2 '/'!");
        }

        try {
            String defaultGroup = path.substring(1, path.indexOf("/", 1));//得到最后一个“/”前部分，也就是所属group
            if (TextUtils.isEmpty(defaultGroup)) {
                throw new HandlerException(Consts.TAG + "Extract the default group failed! There's nothing between 2 '/'!");
            } else {
                return defaultGroup;
            }
        } catch (Exception e) {
            logger.warning(Consts.TAG, "Failed to extract default group! " + e.getMessage());
            return null;
        }
    }
//202
protected Postcard build(String path, String group) {
        if (TextUtils.isEmpty(path) || TextUtils.isEmpty(group)) {
            throw new HandlerException(Consts.TAG + "Parameter is invalid!");
        } else {
            PathReplaceService pService = ARouter.getInstance().navigation(PathReplaceService.class);
            if (null != pService) {
                path = pService.forString(path);
            }
            return new Postcard(path, group);
        }
    }
  public Postcard(String path, String group) {
      this(path, group, null, null);
  }
    public Postcard(String path, String group, Uri uri, Bundle bundle) {
        setPath(path);//设置路径
        setGroup(group);//设置group
        setUri(uri);
        this.mBundle = (null == bundle ? new Bundle() : bundle);
    }

//04开始跳转
    public Object navigation() {
        return navigation(null);
    }
    public Object navigation(Context context) {
        return navigation(context, null);
    }
    public Object navigation(Context context, NavigationCallback callback) {
        return ARouter.getInstance().navigation(context, this, -1, callback);
    }
    public Object navigation(Context mContext, Postcard postcard, int requestCode, NavigationCallback callback) {
        return _ARouter.getInstance().navigation(mContext, postcard, requestCode, callback);
    }

    protected Object navigation(final Context context, final Postcard postcard, final int requestCode, final NavigationCallback callback) {
        PretreatmentService pretreatmentService = ARouter.getInstance().navigation(PretreatmentService.class);
        if (null != pretreatmentService && !pretreatmentService.onPretreatment(context, postcard)) {
            // Pretreatment failed, navigation canceled.
            return null;
        }

        try {
            LogisticsCenter.completion(postcard);
        } catch (NoRouteFoundException ex) {
            logger.warning(Consts.TAG, ex.getMessage());

            if (debuggable()) {
                // Show friendly tips for user.
                runInMainThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(mContext, "There's no route matched!\n" +
                                " Path = [" + postcard.getPath() + "]\n" +
                                " Group = [" + postcard.getGroup() + "]", Toast.LENGTH_LONG).show();
                    }
                });
            }

            if (null != callback) {
                callback.onLost(postcard);
            } else {
                // No callback for this invoke, then we use the global degrade service.转化为目标类设置目标intent。
                DegradeService degradeService = ARouter.getInstance().navigation(DegradeService.class);
                if (null != degradeService) {
                    degradeService.onLost(context, postcard);
                }
            }

            return null;
        }

        if (null != callback) {
            callback.onFound(postcard);
        }

        if (!postcard.isGreenChannel()) {   // It must be run in async thread, maybe interceptor cost too mush time made ANR.
            interceptorService.doInterceptions(postcard, new InterceptorCallback() {
                /**
                 * Continue process
                 *
                 * @param postcard route meta
                 */
                @Override
                public void onContinue(Postcard postcard) {
                    _navigation(context, postcard, requestCode, callback);
                }

                /**
                 * Interrupt process, pipeline will be destory when this method called.
                 *
                 * @param exception Reson of interrupt.
                 */
                @Override
                public void onInterrupt(Throwable exception) {
                    if (null != callback) {
                        callback.onInterrupt(postcard);
                    }

                    logger.info(Consts.TAG, "Navigation failed, termination by interceptor : " + exception.getMessage());
                }
            });
        } else {
            return _navigation(context, postcard, requestCode, callback);
        }

        return null;
    }

    private Object _navigation(final Context context, final Postcard postcard, final int requestCode, final NavigationCallback callback) {
        final Context currentContext = null == context ? mContext : context;

        switch (postcard.getType()) {
            case ACTIVITY:
                // Build intent封装参数
                final Intent intent = new Intent(currentContext, postcard.getDestination());
                intent.putExtras(postcard.getExtras());

                // Set flags.
                int flags = postcard.getFlags();
                if (-1 != flags) {
                    intent.setFlags(flags);
                } else if (!(currentContext instanceof Activity)) {    // Non activity, need less one flag.
                    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                }

                // Set Actions
                String action = postcard.getAction();
                if (!TextUtils.isEmpty(action)) {
                    intent.setAction(action);
                }

                // Navigation in main looper.
                runInMainThread(new Runnable() {
                    @Override
                    public void run() {//开始跳转
                        startActivity(requestCode, currentContext, intent, postcard, callback);
                    }
                });

                break;
            case PROVIDER:
                return postcard.getProvider();
            case BOARDCAST:
            case CONTENT_PROVIDER:
            case FRAGMENT:
                Class fragmentMeta = postcard.getDestination();
                try {
                    Object instance = fragmentMeta.getConstructor().newInstance();
                    if (instance instanceof Fragment) {
                        ((Fragment) instance).setArguments(postcard.getExtras());
                    } else if (instance instanceof android.support.v4.app.Fragment) {
                        ((android.support.v4.app.Fragment) instance).setArguments(postcard.getExtras());
                    }

                    return instance;
                } catch (Exception ex) {
                    logger.error(Consts.TAG, "Fetch fragment instance error, " + TextUtils.formatStackTrace(ex.getStackTrace()));
                }
            case METHOD:
            case SERVICE:
            default:
                return null;
        }

        return null;
    }