ARouter源码解析01-编译生成文件

Arouter源码解析

编译时注解

ARouter采用了编译时注解，在IDE编译阶段，即会生成相关文件，以供后续使用。具体实现在arouter-compiler，由于编译时注解的实现原理都大同小异，在这里就不详细说明了。

@AutoService(Processor.class)
@SupportedOptions(KEY_MODULE_NAME)
@SupportedSourceVersion(SourceVersion.RELEASE_7)
@SupportedAnnotationTypes({ANNOTATION_TYPE_ROUTE, ANNOTATION_TYPE_AUTOWIRED})
public class RouteProcessor extends AbstractProcessor {

@Override
public boolean process(Set annotations, RoundEnvironment roundEnv) {
    if (CollectionUtils.isNotEmpty(annotations)) {
        Set routeElements = roundEnv.getElementsAnnotatedWith(Route.class);
        //遍历注解，存储至map集合，再写入到文件中
        this.parseRoutes(routeElements);
        return true;
    }

    return false;
}

主要来看编译之后，ARouter产生的文件。文件的路径在
app/build/generated/source/apt/debug/com.alibaba.android.arouter/文件夹下

ARouter$$Group $ $service: service组的路由清单

public class ARouter$$Group$$service implements IRouteGroup {
  @Override
  public void loadInto(Map atlas) {
    atlas.put("/service/hello", RouteMeta.build(RouteType.PROVIDER, HelloServiceImpl.class, 
        "/service/hello", "service", null, -1, -2147483648));
    atlas.put("/service/json", RouteMeta.build(RouteType.PROVIDER, JsonServiceImpl.class, 
        "/service/json", "service", null, -1, -2147483648));
    atlas.put("/service/single", RouteMeta.build(RouteType.PROVIDER, SingleService.class,
        "/service/single", "service", null, -1, -2147483648));
  }
}  

ARouter$$Group $ $test: test组的路由清单

public class ARouter$$Group$$test implements IRouteGroup {
  @Override
  public void loadInto(Map atlas) {
    atlas.put("/test/activity1", RouteMeta.build(RouteType.ACTIVITY, Test1Activity.class,
        "/test/activity1", "test", new java.util.HashMap(){{put("pac", 9);
        put("url", 8); }}, -1, -2147483648));
    atlas.put("/test/activity2", RouteMeta.build(RouteType.ACTIVITY, Test2Activity.class, 
        "/test/activity2", "test", new java.util.HashMap(){{put("key1", 8); }}
        , -1, -2147483648));
    atlas.put("/test/fragment", RouteMeta.build(RouteType.FRAGMENT, BlankFragment.class, 
        "/test/fragment", "test", null, -1, -2147483648));
    atlas.put("/test/webview", RouteMeta.build(RouteType.ACTIVITY, TestWebview.class, 
        "/test/webview", "test", null, -1, -2147483648));
  }
}  

ARouter$$Root $ $app: 路由清单总表

用于记录组级别的路由清单，所有组级别的路由清单又会在此记录。

public class ARouter$$Root$$app implements IRouteRoot {
  @Override
  public void loadInto(Map> routes) {
    routes.put("service", ARouter$$Group$$service.class);
    routes.put("test", ARouter$$Group$$test.class);
  }
}  

ARouter$$Interceptors $ $app: 拦截器路由清单

可以发现拦截器的put顺序，已在编译阶段，按照优先级排序好了。

public class ARouter$$Interceptors$$app implements IInterceptorGroup {
  @Override
  public void loadInto(Map> interceptors) {
    interceptors.put(3, Test2Interceptor.class);
    interceptors.put(5, Test3Interceptor.class);
    interceptors.put(7, Test1Interceptor.class);
  }
}

ARouter$$Providers $ $app: Provider路由清单

public class ARouter$$Providers$$app implements IProviderGroup {
  @Override
  public void loadInto(Map providers) {
    providers.put("com.alibaba.android.arouter.demo.testservice.HelloService", 
        RouteMeta.build(RouteType.PROVIDER, HelloServiceImpl.class, "/service/hello",
        "service", null, -1, -2147483648));
    providers.put("com.alibaba.android.arouter.facade.service.SerializationService", 
        RouteMeta.build(RouteType.PROVIDER, JsonServiceImpl.class, "/service/json", "service",
        null, -1, -2147483648));
    providers.put("com.alibaba.android.arouter.demo.testservice.SingleService", 
        RouteMeta.build(RouteType.PROVIDER, SingleService.class, "/service/single",
        "service", null, -1, -2147483648));
  }
}  

从ARouter编译的产物，我们可以猜测出，ARouter是通过加载这些路由清单，从而进行跳转等操作的。

下篇文章，我们来验证我们的猜想。