前言
當(dāng)我們項(xiàng)目變得龐大的時(shí)候 使用單模塊 就會(huì)變得很臃腫 所以當(dāng)我們使用組件化架構(gòu)的時(shí)候 有一個(gè)需要解決的問(wèn)題就是跨模塊通信問(wèn)題 我們可以使用阿里的ARouter或者美團(tuán)的WMRouter來(lái)實(shí)現(xiàn)
使用方法
使用方法很簡(jiǎn)單 就是使用@Route注解 然后跳轉(zhuǎn)使用ARouter單例來(lái)跳轉(zhuǎn) 具體可以參考官網(wǎng)文檔
編譯階段
我們可以使用AnnotationProcessor 來(lái)對(duì)注解進(jìn)行解析和并且生成代碼 所以我們看一下編譯階段會(huì)做哪些事情
以@Route注解為例 看一下RouteProcessor源碼 下面這段可以跳過(guò) 不怎么想看解析注解的代碼 大致原理就是 獲取所有@Route注解
然后通過(guò)javapoet生成具體的類(lèi)(包名會(huì)固定為com.alibaba.android.arouter.routes)
private void parseRoutes(Set<? extends Element> routeElements) throws IOException {
if (CollectionUtils.isNotEmpty(routeElements)) {
// prepare the type an so on.
logger.info(">>> Found routes, size is " + routeElements.size() + " <<<");
rootMap.clear();
TypeMirror type_Activity = elementUtils.getTypeElement(ACTIVITY).asType();
TypeMirror type_Service = elementUtils.getTypeElement(SERVICE).asType();
TypeMirror fragmentTm = elementUtils.getTypeElement(FRAGMENT).asType();
TypeMirror fragmentTmV4 = elementUtils.getTypeElement(Consts.FRAGMENT_V4).asType();
// Interface of ARouter
TypeElement type_IRouteGroup = elementUtils.getTypeElement(IROUTE_GROUP);
TypeElement type_IProviderGroup = elementUtils.getTypeElement(IPROVIDER_GROUP);
ClassName routeMetaCn = ClassName.get(RouteMeta.class);
ClassName routeTypeCn = ClassName.get(RouteType.class);
/*
Build input type, format as :
```Map<String, Class<? extends IRouteGroup>>```
*/
ParameterizedTypeName inputMapTypeOfRoot = ParameterizedTypeName.get(
ClassName.get(Map.class),
ClassName.get(String.class),
ParameterizedTypeName.get(
ClassName.get(Class.class),
WildcardTypeName.subtypeOf(ClassName.get(type_IRouteGroup))
)
);
/*
```Map<String, RouteMeta>```
*/
ParameterizedTypeName inputMapTypeOfGroup = ParameterizedTypeName.get(
ClassName.get(Map.class),
ClassName.get(String.class),
ClassName.get(RouteMeta.class)
);
/*
Build input param name.
*/
ParameterSpec rootParamSpec = ParameterSpec.builder(inputMapTypeOfRoot, "routes").build();
ParameterSpec groupParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "atlas").build();
ParameterSpec providerParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "providers").build(); // Ps. its param type same as groupParamSpec!
/*
Build method : 'loadInto'
*/
MethodSpec.Builder loadIntoMethodOfRootBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(rootParamSpec);
// Follow a sequence, find out metas of group first, generate java file, then statistics them as root.
for (Element element : routeElements) {
TypeMirror tm = element.asType();
Route route = element.getAnnotation(Route.class);
RouteMeta routeMeta;
// Activity or Fragment
if (types.isSubtype(tm, type_Activity) || types.isSubtype(tm, fragmentTm) || types.isSubtype(tm, fragmentTmV4)) {
// Get all fields annotation by @Autowired
Map<String, Integer> paramsType = new HashMap<>();
Map<String, Autowired> injectConfig = new HashMap<>();
for (Element field : element.getEnclosedElements()) {
if (field.getKind().isField() && field.getAnnotation(Autowired.class) != null && !types.isSubtype(field.asType(), iProvider)) {
// It must be field, then it has annotation, but it not be provider.
Autowired paramConfig = field.getAnnotation(Autowired.class);
String injectName = StringUtils.isEmpty(paramConfig.name()) ? field.getSimpleName().toString() : paramConfig.name();
paramsType.put(injectName, typeUtils.typeExchange(field));
injectConfig.put(injectName, paramConfig);
}
}
if (types.isSubtype(tm, type_Activity)) {
// Activity
logger.info(">>> Found activity route: " + tm.toString() + " <<<");
routeMeta = new RouteMeta(route, element, RouteType.ACTIVITY, paramsType);
} else {
// Fragment
logger.info(">>> Found fragment route: " + tm.toString() + " <<<");
routeMeta = new RouteMeta(route, element, RouteType.parse(FRAGMENT), paramsType);
}
routeMeta.setInjectConfig(injectConfig);
} else if (types.isSubtype(tm, iProvider)) { // IProvider
logger.info(">>> Found provider route: " + tm.toString() + " <<<");
routeMeta = new RouteMeta(route, element, RouteType.PROVIDER, null);
} else if (types.isSubtype(tm, type_Service)) { // Service
logger.info(">>> Found service route: " + tm.toString() + " <<<");
routeMeta = new RouteMeta(route, element, RouteType.parse(SERVICE), null);
} else {
throw new RuntimeException("The @Route is marked on unsupported class, look at [" + tm.toString() + "].");
}
categories(routeMeta);
}
MethodSpec.Builder loadIntoMethodOfProviderBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(providerParamSpec);
Map<String, List<RouteDoc>> docSource = new HashMap<>();
// Start generate java source, structure is divided into upper and lower levels, used for demand initialization.
for (Map.Entry<String, Set<RouteMeta>> entry : groupMap.entrySet()) {
String groupName = entry.getKey();
MethodSpec.Builder loadIntoMethodOfGroupBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(groupParamSpec);
List<RouteDoc> routeDocList = new ArrayList<>();
// Build group method body
Set<RouteMeta> groupData = entry.getValue();
for (RouteMeta routeMeta : groupData) {
RouteDoc routeDoc = extractDocInfo(routeMeta);
ClassName className = ClassName.get((TypeElement) routeMeta.getRawType());
switch (routeMeta.getType()) {
case PROVIDER: // Need cache provider's super class
List<? extends TypeMirror> interfaces = ((TypeElement) routeMeta.getRawType()).getInterfaces();
for (TypeMirror tm : interfaces) {
routeDoc.addPrototype(tm.toString());
if (types.isSameType(tm, iProvider)) { // Its implements iProvider interface himself.
// This interface extend the IProvider, so it can be used for mark provider
loadIntoMethodOfProviderBuilder.addStatement(
"providers.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
(routeMeta.getRawType()).toString(),
routeMetaCn,
routeTypeCn,
className,
routeMeta.getPath(),
routeMeta.getGroup());
} else if (types.isSubtype(tm, iProvider)) {
// This interface extend the IProvider, so it can be used for mark provider
loadIntoMethodOfProviderBuilder.addStatement(
"providers.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
tm.toString(), // So stupid, will duplicate only save class name.
routeMetaCn,
routeTypeCn,
className,
routeMeta.getPath(),
routeMeta.getGroup());
}
}
break;
default:
break;
}
// Make map body for paramsType
StringBuilder mapBodyBuilder = new StringBuilder();
Map<String, Integer> paramsType = routeMeta.getParamsType();
Map<String, Autowired> injectConfigs = routeMeta.getInjectConfig();
if (MapUtils.isNotEmpty(paramsType)) {
List<RouteDoc.Param> paramList = new ArrayList<>();
for (Map.Entry<String, Integer> types : paramsType.entrySet()) {
mapBodyBuilder.append("put(\"").append(types.getKey()).append("\", ").append(types.getValue()).append("); ");
RouteDoc.Param param = new RouteDoc.Param();
Autowired injectConfig = injectConfigs.get(types.getKey());
param.setKey(types.getKey());
param.setType(TypeKind.values()[types.getValue()].name().toLowerCase());
param.setDescription(injectConfig.desc());
param.setRequired(injectConfig.required());
paramList.add(param);
}
routeDoc.setParams(paramList);
}
String mapBody = mapBodyBuilder.toString();
loadIntoMethodOfGroupBuilder.addStatement(
"atlas.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, " + (StringUtils.isEmpty(mapBody) ? null : ("new java.util.HashMap<String, Integer>(){{" + mapBodyBuilder.toString() + "}}")) + ", " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
routeMeta.getPath(),
routeMetaCn,
routeTypeCn,
className,
routeMeta.getPath().toLowerCase(),
routeMeta.getGroup().toLowerCase());
routeDoc.setClassName(className.toString());
routeDocList.add(routeDoc);
}
// Generate groups
String groupFileName = NAME_OF_GROUP + groupName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE,
TypeSpec.classBuilder(groupFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(type_IRouteGroup))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfGroupBuilder.build())
.build()
).build().writeTo(mFiler);
logger.info(">>> Generated group: " + groupName + "<<<");
rootMap.put(groupName, groupFileName);
docSource.put(groupName, routeDocList);
}
if (MapUtils.isNotEmpty(rootMap)) {
// Generate root meta by group name, it must be generated before root, then I can find out the class of group.
for (Map.Entry<String, String> entry : rootMap.entrySet()) {
loadIntoMethodOfRootBuilder.addStatement("routes.put($S, $T.class)", entry.getKey(), ClassName.get(PACKAGE_OF_GENERATE_FILE, entry.getValue()));
}
}
// Output route doc
if (generateDoc) {
docWriter.append(JSON.toJSONString(docSource, SerializerFeature.PrettyFormat));
docWriter.flush();
docWriter.close();
}
// Write provider into disk
String providerMapFileName = NAME_OF_PROVIDER + SEPARATOR + moduleName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE,
TypeSpec.classBuilder(providerMapFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(type_IProviderGroup))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfProviderBuilder.build())
.build()
).build().writeTo(mFiler);
logger.info(">>> Generated provider map, name is " + providerMapFileName + " <<<");
// Write root meta into disk.
String rootFileName = NAME_OF_ROOT + SEPARATOR + moduleName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE,
TypeSpec.classBuilder(rootFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(elementUtils.getTypeElement(ITROUTE_ROOT)))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfRootBuilder.build())
.build()
).build().writeTo(mFiler);
logger.info(">>> Generated root, name is " + rootFileName + " <<<");
}
}
ARouter.init
我們上面講到了 生成的java類(lèi)包名為com.alibaba.android.arouter.routes
ARouter.init方法會(huì)調(diào)用LogisticsCenter.init方法
看一下核心
public synchronized static void init(Context context, ThreadPoolExecutor tpe) throws HandlerException {
try {
......
loadRouterMap();
if (registerByPlugin) {
//autoRegiterPlugin 后面會(huì)講到
logger.info(TAG, "Load router map by arouter-auto-register plugin.");
} else {
Set<String> routerMap;
//如果是debug模式 或者版本有更新 會(huì)重新獲取所有的Route注解類(lèi) 并且保存到SP
// 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.
//根據(jù)我們上面說(shuō)的包名 獲取所有的Class類(lèi)
routerMap = ClassUtils.getFileNameByPackageName(mContext, ROUTE_ROOT_PAKCAGE);
//存在SP中
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 {
routerMap = new HashSet<>(context.getSharedPreferences(AROUTER_SP_CACHE_KEY, Context.MODE_PRIVATE).getStringSet(AROUTER_SP_KEY_MAP, new HashSet<String>()));
}
startInit = System.currentTimeMillis();
//這里會(huì)循環(huán)遍歷所有的Class類(lèi) 然后會(huì)通過(guò)反射 創(chuàng)建所有實(shí)例 并保存到map中
//這里因?yàn)闀?huì)反射創(chuàng)建所有實(shí)例 所以會(huì)比較耗時(shí) 做啟動(dòng)優(yōu)化時(shí) 可以通過(guò)AutoRegister來(lái)優(yōu)化
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);
}
}
}
} catch (Exception e) {
throw new HandlerException(TAG + "ARouter init logistics center exception! [" + e.getMessage() + "]");
}
}
ARouter.init會(huì)將所有注解Class 實(shí)例化并存放在map中 方便調(diào)用
navigation
看一下調(diào)用鏈
Postcard.navigation->
ARouter.navigation->
_ARouter.navigation->
protected Object navigation(final Context context, final Postcard postcard, final int requestCode, final NavigationCallback callback) {
......
try {
//填充postcard
LogisticsCenter.completion(postcard);
} catch (NoRouteFoundException ex) {
if (null != callback) {
callback.onLost(postcard);
} else {
// No callback for this invoke, then we use the global degrade service.
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.
//調(diào)用攔截器
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 {
//繼續(xù)處理
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;
//根據(jù)類(lèi)型跳轉(zhuǎn)
switch (postcard.getType()) {
case ACTIVITY:
// Build intent
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() {
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;
}
AutoRegister插件
調(diào)用ARouter.init方法時(shí) 會(huì)遍歷所有dex文件 并且找到被@Route注解的類(lèi) 并通過(guò)反射生成 這是一個(gè)比較耗時(shí)的操作 之前在啟動(dòng)優(yōu)化的過(guò)程中 發(fā)現(xiàn)ARouter啟動(dòng)占了一半的時(shí)間
ARouter提供了AutoRegister插件 主要核心原理就是將ARouter.init方法的流程 在編譯過(guò)程完成 通過(guò)Transform+ASM的方式 遍歷所有dex文件 并且生成工廠類(lèi) 這樣就避免啟動(dòng)時(shí)遍歷
參考:
自動(dòng)注冊(cè)插件
AutoRegister:一種更高效的組件自動(dòng)注冊(cè)方案(android組件化開(kāi)發(fā))
總結(jié)
我們可以使用ARouter來(lái)方便的進(jìn)行路由管理 核心原理就是掃描所有@Route注解的類(lèi) 然后統(tǒng)一收集 跳轉(zhuǎn)時(shí)取出 并且還有很多像攔截器這種功能
攔截器功能我們得吐槽一下 就是所有的路由跳轉(zhuǎn) 都會(huì)遍歷每一個(gè)攔截器 浪費(fèi)了一部分資源
