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全网最全面的Arouter源码解析

2020-03-30 07:15:51来源:阅读:-

前言

相信绝大多数公司项目都做了组件化。为了解耦,组件化势必要解决组件间的通信。其中阿里巴巴开源的Arouter很好的解决了组件间的通信,一直受到开发者的青睐。今天,我们来一步步揭开它的神秘面纱。

首先下载源代码,项目地址:

https://github.com/alibaba/ARouter

来讲一下项目结构

源代码

  • app:项目主工程,演示代码
  • module-java:java演示代码
  • module-kotlin:kotlin演示代码
  • arouter-annotation:所有注解以及注解涉及到的类
  • arouter-compiler:注解处理器,APT
  • arouter-gradle-plugin:路由表自动注册插件
  • arouter-idea-plugin:路由跳转插件,搜索ARouter Helper插件安装即可。
  • arouter-api:所有的api

第一步就是要生成注解类

@Route @Autowired Interceptor Provider都会生成如下面所示的对应注解类,java生成的注解类的位置在build-generated-sourse-apt中,kotlin生成的注解类的位置在build-generated-sourse-kapt

public class ARouter$$Group$$app implements IRouteGroup {
@Override
public void loadInto(Map<String, RouteMeta> atlas) {
atlas.put("/app/degrade1", RouteMeta.build(RouteType.PROVIDER, DegradeServiceImpl.class, "/app/degrade1", "app", null, -1, -2147483648));
atlas.put("/app/main", RouteMeta.build(RouteType.ACTIVITY, MainActivity.class, "/app/main", "app", null, -1, -2147483648));
atlas.put("/app/path", RouteMeta.build(RouteType.PROVIDER, PathReplaceServiceImpl.class, "/app/path", "app", null, -1, -2147483648));
}
}

这里需要重点关注一下RouteMeta这个类,这个类存储了目标对象的所有信息。包括路由类型、目标对象类、path、group、参数、优先级、额外参数。

涉及到的知识点:

  1. apt
  2. javapoet
  3. auto-service

这里是我写的一个AptDemo,仅供参考:

https://github.com/liulingfeng/APT

关于AbstractProcessor的process多次执行可以通过下面方法处理

@Override
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnvironment) {
if (annotations != null && annotations.size() > 0) {

}
}

下面正式讲解api

先整体感受一下整个流程

整体流程

根据官方说明,首先在Application中调用如下api

if(BuildConfig.DEBUG){
ARouter.openLog();//打开日志
ARouter.openDebug();//打开路由调试
}
ARouter.init(this);

进入Arouter.init(this)

public static void init(Application application) {
if (!hasInit) {
logger = _ARouter.logger;
hasInit = _ARouter.init(application);

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

hasInit保证只初始化一次,内部调用了_ARouter.init(application),Arouter是门面, _Arouter是具体实现,有一点装饰模式的感觉。初始化之后调用 _ARouter.afterInit实例化拦截器(这个后面细讲)。继续跟进 _ARouter.init

protected static synchronized boolean init(Application application) {
mContext = application;
LogisticsCenter.init(mContext, executor);
logger.info(Consts.TAG, "ARouter init success!");
hasInit = true;
return true;
}

一眼就看到关键代码在LogisticsCenter.init中,executor是一个自定义的线程池(实现了一种抛出错误的方式)。

public synchronized static void init(Context context, ThreadPoolExecutor tpe) throws HandlerException {
try {
if (registerByPlugin) {
logger.info(TAG, "Load router map by arouter-auto-register plugin.");
} else {
Set<String> routerMap;
if (ARouter.debuggable() || PackageUtils.isNewVersion(context)) {
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);
} else {
for (String className : routerMap) {
if (className.startsWith(ROUTE_ROOT_PAKCAGE + DOT + SDK_NAME + SEPARATOR + SUFFIX_ROOT)) {
((IRouteRoot) (Class.forName(className).getConstructor().newInstance())).loadInto(Warehouse.groupsIndex);
} else if (className.startsWith(ROUTE_ROOT_PAKCAGE + DOT + SDK_NAME + SEPARATOR + SUFFIX_INTERCEPTORS)) {
((IInterceptorGroup) (Class.forName(className).getConstructor().newInstance())).loadInto(Warehouse.interceptorsIndex);
} else if (className.startsWith(ROUTE_ROOT_PAKCAGE + DOT + SDK_NAME + SEPARATOR + SUFFIX_PROVIDERS)) {
((IProviderGroup) (Class.forName(className).getConstructor().newInstance())).loadInto(Warehouse.providersIndex);
}
}
}
} catch (Exception e) {
throw new HandlerException(TAG + "ARouter init logistics center exception! [" + e.getMessage() + "]");
}
}

代码比较长,我把它分解一下

  • 1.判断是不是用插件自动注册路由表,插件注册的方式另说
  • 2.从dex中加载指定路径(com.alibaba.android.arouter.routes)下的所有类名,其实就是注解生成类,然后根据版本号升级版本。非debuggable环境下从SharedPreferences缓存中读取(做的一个优化点)
  • 3.反射调用loadInto把Group、Interceptor、Provider的映射关系添加到集合中

看一下各种类型的注解生成类
Root(这里做了优化先加载各个group,用到的时候再加载各个group下的路由)

public class ARouter$$Root$$app implements IRouteRoot {
@Override
public void loadInto(Map<String, Class<? extends IRouteGroup>> routes) {
routes.put("app", ARouter$$Group$$app.class);
}
}

Interceptor

public class ARouter$$Interceptors$$app implements IInterceptorGroup {
@Override
public void loadInto(Map<Integer, Class<? extends IInterceptor>> interceptors) {
interceptors.put(9, TestInterceptor2.class);
interceptors.put(10, TestInterceptor.class);
}
}

Provider

public class ARouter$$Providers$$app implements IProviderGroup {
@Override
public void loadInto(Map<String, RouteMeta> providers) {
providers.put("com.xls.HelloService", RouteMeta.build(RouteType.PROVIDER, HelloServiceImpl.class, "/yourservicegroupname/hello", "yourservicegroupname", null, -1, -2147483648));
}
}

init工作总结及知识点

  • 1.把Group、Interceptor、Provider注解类的映射添加到Warehouse.groupsIndex、Warehouse.interceptorsIndex、Warehouse.providersIndex集合中
  • 2.实例化所有的Interceptor添加到Warehouse.interceptors中
  • 3.dex分析-多dex怎么查找-热修复的根本原理是什么
  • 4.线程池-线程池各个参数-线程池抛出错误的方法-如何保证线程池线程名字唯一性-原子类

顺便补充一下插件自动注册路由表

首先目光移到PluginLaunch,这是自定义插件的入口。

public class PluginLaunch implements Plugin<Project> {
@Override
public void apply(Project project) {
def android = project.extensions.getByType(AppExtension)
def transformImpl = new RegisterTransform(project)

ArrayList<ScanSetting> list = new ArrayList<>(3)
list.add(new ScanSetting('IRouteRoot'))
list.add(new ScanSetting('IInterceptorGroup'))
list.add(new ScanSetting('IProviderGroup'))
RegisterTransform.registerList = list
android.registerTransform(transformImpl)
}
}
}

这里完成了自定义Transform的注册以及添加需要过滤的接口到ScanSetting,最主要的代码自然是在RegisterTransform中。直奔RegisterTransform的transform方法,首先遍历jar。

inputs.each { TransformInput input ->
input.jarInputs.each {
if (ScanUtil.shouldProcessPreDexJar(src.absolutePath)) {
ScanUtil.scanJar(src, dest)
}
FileUtils.copyFile(src, dest)
}
static void scanJar(File jarFile, File destFile) {
if (jarFile) {
def file = new JarFile(jarFile)
Enumeration enumeration = file.entries()
while (enumeration.hasMoreElements()) {
JarEntry jarEntry = (JarEntry) enumeration.nextElement()
String entryName = jarEntry.getName()
if (entryName.startsWith("com/alibaba/android/arouter/routes/")) {
InputStream inputStream = file.getInputStream(jarEntry)
scanClass(inputStream)
inputStream.close()
} else if ("com/alibaba/android/arouter/core/LogisticsCenter.class" == entryName) {
RegisterTransform.fileContainsInitClass = destFile
}
}
file.close()
}
}

做到两步工作:1.把com/alibaba/android/arouter/routes包名下的交给scanClass处理(这个稍后会分析到) 2.找到LogisticsCenter.class类,对于这个类想必很熟悉吧。

接下来遍历directory

input.directoryInputs.each { DirectoryInput directoryInput ->
directoryInput.file.eachFileRecurse { File file ->
if(file.isFile() && ScanUtil.shouldProcessClass(path)){
ScanUtil.scanClass(file)
}
}
}
static void scanClass(InputStream inputStream) {
ClassReader cr = new ClassReader(inputStream)
ClassWriter cw = new ClassWriter(cr, 0)
ScanClassVisitor cv = new ScanClassVisitor(Opcodes.ASM5, cw)
cr.accept(cv, ClassReader.EXPAND_FRAMES)
inputStream.close()
}

把文件流丢给ScanClassVisitor

static class ScanClassVisitor extends ClassVisitor {

ScanClassVisitor(int api, ClassVisitor cv) {
super(api, cv)
}

void visit(int version, int access, String name, String signature,
String superName, String[] interfaces) {
super.visit(version, access, name, signature, superName, interfaces)
RegisterTransform.registerList.each { ext ->
if (ext.interfaceName && interfaces != null) {
interfaces.each { itName ->
if (itName == ext.interfaceName) {
ext.classList.add(name)
}
}
}
}
}
}

一看就明白,就是把所有实现了IRouteRoot、IInterceptorGroup、IProviderGroup接口的类存到集合中

接着看最后一步做了什么

if (fileContainsInitClass) {
registerList.each { ext ->
if (ext.classList.isEmpty()) {
Logger.e("No class implements found for interface:" + ext.interfaceName)
} else {
RegisterCodeGenerator.insertInitCodeTo(ext)
}
}
}

关键代码都在RegisterCodeGenerator这个类中,我只列关键代码。

private byte[] referHackWhenInit(InputStream inputStream) {
ClassReader cr = new ClassReader(inputStream)
ClassWriter cw = new ClassWriter(cr, 0)
ClassVisitor cv = new MyClassVisitor(Opcodes.ASM5, cw)
cr.accept(cv, ClassReader.EXPAND_FRAMES)
return cw.toByteArray()
}

MethodVisitor visitMethod(int access, String name, String desc,
String signature, String[] exceptions) {
MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions)
if (name == "loadRouterMap") {
mv = new RouteMethodVisitor(Opcodes.ASM5, mv)
}
return mv
}

找到hook点loadRouterMap。hook点的设计特别巧妙,增强了代码的可读性。

void visitInsn(int opcode) {
if ((opcode >= Opcodes.IRETURN && opcode <= Opcodes.RETURN)) {
extension.classList.each { name ->
mv.visitMethodInsn(Opcodes.INVOKESTATIC
, "com/alibaba/android/arouter/core/LogisticsCenter"
, "register"
, "(Ljava/lang/String;)V"
, false)
}
}
super.visitInsn(opcode)
}

调用LogisticsCenter的register方法,我们来看一下register方法做了什么。

 private static void register(String className) {
if (!TextUtils.isEmpty(className)) {
try {
Class<?> clazz = Class.forName(className);
Object obj = clazz.getConstructor().newInstance();
if (obj instanceof IRouteRoot) {
registerRouteRoot((IRouteRoot) obj);
} else if (obj instanceof IProviderGroup) {
registerProvider((IProviderGroup) obj);
} else if (obj instanceof IInterceptorGroup) {
registerInterceptor((IInterceptorGroup) obj);
} else {
logger.info(TAG, "register failed, class name: " + className
+ " should implements one of IRouteRoot/IProviderGroup/IInterceptorGroup.");
}
} catch (Exception e) {
logger.error(TAG,"register class error:" + className);
}
}
}

所有实现了IRouteRoot、IInterceptorGroup、IProviderGroup接口的类都加入了Warehouse相对应的集合中。至此自动注册工作完成。

路由跳转

ARouter.getInstance().build("/home/test").withString("key3", "888")
.withLong("key1", 666L)
.navigation(this)

先看build,new一个Postcard对象并给Postcard设置path和group。Postcard构造方法中new了一个bundler对象。PathReplaceService提供了动态改path的方式,后面细讲。

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);
}
}

.withString("key3", "888").withLong("key1", 666L)把参数设置给当前Postcard的bundle中。

再看navigation方法

protected Object navigation(final Context context, final Postcard postcard, final int requestCode, final NavigationCallback callback) {
try {
LogisticsCenter.completion(postcard);
} catch (NoRouteFoundException ex) {
if (debuggable()) {
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 {
DegradeService degradeService = ARouter.getInstance().navigation(DegradeService.class);
if (null != degradeService) {
degradeService.onLost(context, postcard);
}
}

return null;
}
return null;
}

先看第一部分,重点落在LogisticsCenter.completion(postcard)。内部主要做的是实例化当前group下的具体Route添加到Warehouse.routes,如果没找到就降级处理,两种方式(1.设置NavigationCallback 2.实现DegradeService)

public synchronized static void completion(Postcard postcard) {
RouteMeta routeMeta = Warehouse.routes.get(postcard.getPath());
if (null == routeMeta) {
Class<? extends IRouteGroup> groupMeta = Warehouse.groupsIndex.get(postcard.getGroup());
if (null == groupMeta) {
throw new NoRouteFoundException(TAG + "There is no route match the path [" + postcard.getPath() + "], in group [" + postcard.getGroup() + "]");
} else {
try {
IRouteGroup iGroupInstance = groupMeta.getConstructor().newInstance();
iGroupInstance.loadInto(Warehouse.routes);
Warehouse.groupsIndex.remove(postcard.getGroup());
} catch (Exception e) {
throw new HandlerException(TAG + "Fatal exception when loading group meta. [" + e.getMessage() + "]");
}
completion(postcard);
}
} else {
postcard.setDestination(routeMeta.getDestination());
postcard.setType(routeMeta.getType());
postcard.setPriority(routeMeta.getPriority());
postcard.setExtra(routeMeta.getExtra());

Uri rawUri = postcard.getUri();
if (null != rawUri) {
Map<String, String> resultMap = TextUtils.splitQueryParameters(rawUri);
Map<String, Integer> paramsType = routeMeta.getParamsType();

if (MapUtils.isNotEmpty(paramsType)) {
for (Map.Entry<String, Integer> params : paramsType.entrySet()) {
setValue(postcard,
params.getValue(),
params.getKey(),
resultMap.get(params.getKey()));
}
postcard.getExtras().putStringArray(ARouter.AUTO_INJECT, paramsType.keySet().toArray(new String[]{}));
}

postcard.withString(ARouter.RAW_URI, rawUri.toString());
}

switch (routeMeta.getType()) {
case PROVIDER:
Class<? extends IProvider> providerMeta = (Class<? extends IProvider>) routeMeta.getDestination();
IProvider instance = Warehouse.providers.get(providerMeta);
if (null == instance) {
IProvider provider;
try {
provider = providerMeta.getConstructor().newInstance();
provider.init(mContext);
Warehouse.providers.put(providerMeta, provider);
instance = provider;
} catch (Exception e) {
throw new HandlerException("Init provider failed! " + e.getMessage());
}
}
postcard.setProvider(instance);
postcard.greenChannel();
break;
case FRAGMENT:
postcard.greenChannel();
default:
break;
}
}
}

分析一下这段代码

  • 1.判断Warehouse的routes中对应path的RouteMeta是否为空,看过注解生成类其实我们知道RouteMeta保存了类的具体信息
  • 2.在集合中找到对应的group分组,然后实例化对应分组下的具体Route添加到集合中
  • 3.把RouteMeta的各种信息设置给当前postcard对象
  • 4.uri跳转的处理,uri跳转和普通跳转唯一的区别就是参数的剥离,普通跳转是直接设置的而uri是通过在链接中剥离的,其中参数的数据类型是在Routemeta的paramsType中设置的
  • 5.根据跳转的类型不同做不同处理。如果是服务,直接实例化当前服务调用init方法并设置给postcard。设置绿色通道;如果是fragment,设置绿色通道。所谓绿色通道就是不被拦截器拦截。

第二个部分是处理拦截。我们稍后再讲
先看第三部分

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:
final Intent intent = new Intent(currentContext, postcard.getDestination());
intent.putExtras(postcard.getExtras());

int flags = postcard.getFlags();
if (-1 != flags) {
intent.setFlags(flags);
} else if (!(currentContext instanceof Activity)) {
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
}

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

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;
}

看到这里是不是很亲切,这不就是我们平时常写的startActivity(intent,class)吗?如果是fragment的话反射调用Fragment构造方法返回fragment对象。provider也是返回 Provider对象。至此跳转这一块基本上都搞清楚了。

分析一下拦截器怎么实现的

之前讲了Aroute.init之后会将所有的拦截器实例化。我们看看_ARouter.afterInit()做了什么

static void afterInit() {
interceptorService = (InterceptorService) ARouter.getInstance().build("/arouter/service/interceptor").navigation();
}

使用自己的路由方法初始化interceptorService服务,没毛病。该服务的实现类是InterceptorServiceImpl,从前面的分析可以知道navigation会调用服务的init方法。看看init里面做了什么

@Override
public void init(final Context context) {
LogisticsCenter.executor.execute(new Runnable() {
@Override
public void run() {
if (MapUtils.isNotEmpty(Warehouse.interceptorsIndex)) {
for (Map.Entry<Integer, Class<? extends IInterceptor>> entry : Warehouse.interceptorsIndex.entrySet()) {
Class<? extends IInterceptor> interceptorClass = entry.getValue();
try {
IInterceptor iInterceptor = interceptorClass.getConstructor().newInstance();
iInterceptor.init(context);
Warehouse.interceptors.add(iInterceptor);
} catch (Exception ex) {
throw new HandlerException(TAG + "ARouter init interceptor error! name = [" + interceptorClass.getName() + "], reason = [" + ex.getMessage() + "]");
}
}

interceptorHasInit = true;
}
}
});
}

反射调用所有拦截器的构造函数实例化对象添加到Warehouse.interceptors并调用init方法,这里使用了object.wait和object.notifyAll保证子线程中的所有拦截器实例化完成。拦截的时机在前面已经提到过了,我们来看看具体的代码。

if (!postcard.isGreenChannel()) {
interceptorService.doInterceptions(postcard, new InterceptorCallback() {
@Override
public void onContinue(Postcard postcard) {
_navigation(context, postcard, requestCode, callback);
}

@Override
public void onInterrupt(Throwable exception) {
if (null != callback) {
callback.onInterrupt(postcard);
}
}
});
@Override
public void doInterceptions(final Postcard postcard, final InterceptorCallback callback) {
if (null != Warehouse.interceptors && Warehouse.interceptors.size() > 0) {
LogisticsCenter.executor.execute(new Runnable() {
@Override
public void run() {
CancelableCountDownLatch interceptorCounter = new CancelableCountDownLatch(Warehouse.interceptors.size());
try {
_excute(0, interceptorCounter, postcard);
interceptorCounter.await(postcard.getTimeout(), TimeUnit.SECONDS);
if (interceptorCounter.getCount() > 0) {
callback.onInterrupt(new HandlerException("The interceptor processing timed out."));
} else if (null != postcard.getTag()) {
callback.onInterrupt(new HandlerException(postcard.getTag().toString()));
} else {
callback.onContinue(postcard);
}
} catch (Exception e) {
callback.onInterrupt(e);
}
}
});
} else {
callback.onContinue(postcard);
}
}
private static void _excute(final int index, final CancelableCountDownLatch counter, final Postcard postcard) {
if (index < Warehouse.interceptors.size()) {
IInterceptor iInterceptor = Warehouse.interceptors.get(index);
iInterceptor.process(postcard, new InterceptorCallback() {
@Override
public void onContinue(Postcard postcard) {
counter.countDown();
_excute(index + 1, counter, postcard);
}

@Override
public void onInterrupt(Throwable exception) {
postcard.setTag(null == exception ? new HandlerException("No message.") : exception.getMessage()); // save the exception message for backup.
counter.cancel();
}
});
}
}

使用CountDownLatch.await使得代码阻塞直到所有拦截器执行完成或者超时。拦截器process方法中需要调用callback.onContinue才能调用到counter.countDown()移交到下一个拦截器,这就解释了自定义的拦截器为什么一定要调用counter.countDown()

涉及知识点

  • 1.线程间通信
  • 2.CountDownLatch
  • 3.Object.wait/Object.notify

降级处理

两种方式:1.navigation的时候添加NavigationCallback回调 2.写一个类实现DegradeService别忘了添加@Route path可以随意 第一种比较简单我么不讲,讲一下第二种方式

@Route(path = "/app/degrade1")
class DegradeServiceImpl : DegradeService {
override fun onLost(context: Context?, postcard: Postcard?) {
Log.e("降级处理","自定义降级处理")
}

override fun init(context: Context?) {
}
}

生成的注解类在ARouter$$Providers$$app中,也是init的时候就把映射关系添加到集合中。调用的地方是在navigation中,这段代码也间接的说明了NavigationCallback的优先级高于全局降级处理。

if (null != callback) {
callback.onLost(postcard);
} else {
DegradeService degradeService = ARouter.getInstance().navigation(DegradeService.class);
if (null != degradeService) {
degradeService.onLost(context, postcard);
}
}

关键代码是下面一段代码,诠释了服务的navigation是如何运行的

protected <T> T navigation(Class<? extends T> service) {
try {
Postcard postcard = LogisticsCenter.buildProvider(service.getName());
if (null == postcard) {
postcard = LogisticsCenter.buildProvider(service.getSimpleName());
}

LogisticsCenter.completion(postcard);
return (T) postcard.getProvider();
} catch (NoRouteFoundException ex) {
logger.warning(Consts.TAG, ex.getMessage());
return null;
}
}

buildProvider是根据service的名字从集合中找到对应的RouteMeta并把path和group设置给postcard,接下来也是给postcard设置其他各种参数,和上面分析的大同小异。

path动态改变

调用的方式和降级处理一模一样,时机是在build的时候。

参数自动获取

@Autowired
@JvmField
var key3: String? = null
@Autowired
@JvmField
var key1: Long = 0L

ARouter.getInstance().inject(this)

从文档中可以知道,按照上面的方式就可以自动获取各个参数。关键代码肯定是在inject方法中,调用的还是服务。

static void inject(Object thiz) {
AutowiredService autowiredService = ((AutowiredService) ARouter.getInstance().build("/arouter/service/autowired").navigation());
if (null != autowiredService) {
autowiredService.autowire(thiz);
}
}

看看AutowiredService的autowire方法

@Override
public void autowire(Object instance) {
String className = instance.getClass().getName();
try {
if (!blackList.contains(className)) {
ISyringe autowiredHelper = classCache.get(className);
if (null == autowiredHelper) {
autowiredHelper = (ISyringe) Class.forName(instance.getClass().getName() + SUFFIX_AUTOWIRED).getConstructor().newInstance();
}
autowiredHelper.inject(instance);
classCache.put(className, autowiredHelper);
}
} catch (Exception ex) {
blackList.add(className);
}
}

最关键的方法是XXclass_$$ARouter$$Autowired.inject,其实这个类还是在注解生成类中

public class TestOneActivity$$ARouter$$Autowired implements ISyringe {
private SerializationService serializationService;

@Override
public void inject(Object target) {
serializationService = ARouter.getInstance().navigation(SerializationService.class);
TestOneActivity substitute = (TestOneActivity)target;
substitute.key3 = substitute.getIntent().getStringExtra("girl");
substitute.key1 = substitute.getIntent().getLongExtra("key1", substitute.key1);
}
}

还是通过getIntent().getExtra方法获取的参数,然后把获取的参数设置给当前类。

分析完源码之后扪心自问一下下面问题是否能回答上来

  • 1.openLog和openDebug为什么要在init之前?
  • 2.非Debug环境如何升级路由表——即添加路由?
  • 3.为什么要自定义线程池?线程池抛出错误的方式有哪几种?
  • 4.activity的跳转是怎么实现的?
  • 5.fragment实例是怎么拿到的?为什么不允许拦截?
  • 6.服务是如何调用的?
  • 7.path能动态修改吗?在哪个时机修改的?
  • 8.uri方式是如何跳转的?
  • 9.路由跳转能否在子线程中?
  • 10.拦截器怎么实现的?初始化的时机?为什么要在process调用callback.onContinue()。各个拦截器之间的优先级是如何保证的(是在跳转的时候根据priority判断的吗)
  • 11.全局降级处理怎么实现的,和NavigationCallback谁优先级更高?
  • 12.如何对path进行预处理,让所有路由失效?
  • 13.实现多个类继承PathReplaceService、PretreatmentService实际会用哪个。
  • 个人的一些思考,大家可以讨论一下

  • 1.Fragment未做onActivityResult回调支持,对Fragment的场景还是偏简单了。
  • 2.注解实现类的取名Group和path比较容易混淆。
  • 3.自动注册路由表的plugin考虑做增量和并发编译处理,效率有待商榷。
  • 4.插件化是怎么实现路由表的升级的。
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