Route
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.CLASS)
public @interface Route {
String path();
String group() default "";
String name() default "";
int extras() default Integer.MIN_VALUE;
int priority() default -1;
}
- path ：不能为空，而且必须以 “/”开头，
- group ：可以自己设置group的值，默认在path中获取，比如 @Route(path = "/test/activity1")，在构建 RouteMeta 时就会用test作为组名。
- name ：生成文档用的
- extras：可以带一些额外的参数
- priority： 优先级，值越小，优先级越高
概述
通过 Route 的注解，框架会把我们注解的Activity 、Fragment、Service、ContentProvider以及IProvider收集起来
按照不同的Group会生成类似这样的代码，这样框架在初始化的时候，就可以根据这些类把路由信息收集起来。
详情
@Override
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
if (CollectionUtils.isNotEmpty(annotations)) {
// 获取所有被 Route 注解的类
Set<? extends Element> routeElements = roundEnv.getElementsAnnotatedWith(Route.class);
try {=
this.parseRoutes(routeElements);
} catch (Exception e) {
logger.error(e);
}
return true;
}
return false;
}
private void parseRoutes(Set<? extends Element> routeElements) throws IOException {
if (CollectionUtils.isNotEmpty(routeElements)) {
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
// com.alibaba.android.arouter.facade.template.IRouteGroup
TypeElement type_IRouteGroup = elementUtils.getTypeElement(IROUTE_GROUP);
// com.alibaba.android.arouter.facade.template.IProviderGroup
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>>```
*/
// 方法的参数类型
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>```
*/
// 方法的参数类型
ParameterizedTypeName inputMapTypeOfGroup = ParameterizedTypeName.get(
ClassName.get(Map.class),
ClassName.get(String.class),
ClassName.get(RouteMeta.class)
);
/*
Build input param name.
*/
// 方法的参数名
ParameterSpec rootParamSpec = ParameterSpec.builder(inputMapTypeOfRoot, "routes").build();
ParameterSpec groupParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "atlas").build();
ParameterSpec providerParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "providers").build();
/*
Build method : 'loadInto'
*/
// 构建一个方法 public void loadInto(Map<String, Class<? extends IRouteGroup>> routes)
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.
// 遍历被Route注解的类
for (Element element : routeElements) {
TypeMirror tm = element.asType();
Route route = element.getAnnotation(Route.class);
RouteMeta routeMeta;
// 构建 RouteMeta
// 因为Activity 或者 Fragment 是可以传递参数的，getIntent()、getArguments(),就收集该类中被 Autowired 注解的字段
// Activity or Fragment
if (types.isSubtype(tm, type_Activity) || types.isSubtype(tm, fragmentTm) || types.isSubtype(tm, fragmentTmV4)) {
// 当前的类是 Activity 或 Fragment
// Get all fields annotation by @Autowired
// paramsType 与 injectConfig 用来生成文档的，不用关心
Map<String, Integer> paramsType = new HashMap<>();
Map<String, Autowired> injectConfig = new HashMap<>();
//收集类中的被Autowired注解的字段，但字段不能是IProvider类型
injectParamCollector(element, paramsType, injectConfig);
if (types.isSubtype(tm, type_Activity)) {
// Activity
routeMeta = new RouteMeta(route, element, RouteType.ACTIVITY, paramsType);
} else {
// Fragment
routeMeta = new RouteMeta(route, element, RouteType.parse(FRAGMENT), paramsType);
}
routeMeta.setInjectConfig(injectConfig);
} else if (types.isSubtype(tm, iProvider)) { // IProvider
routeMeta = new RouteMeta(route, element, RouteType.PROVIDER, null);
} else if (types.isSubtype(tm, type_Service)) { // Service
routeMeta = new RouteMeta(route, element, RouteType.parse(SERVICE), null);
} else {
throw new RuntimeException("The @Route is marked on unsupported class, look at [" + tm.toString() + "].");
}
// 收集具有相同的group的RouteMeta到 Map<String, Set<RouteMeta>>
categories(routeMeta);
}
// 生成 loadInto 方法
// public void loadInto(Map<Integer, Class<? extends IInterceptor>> interceptors)
MethodSpec.Builder loadIntoMethodOfProviderBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(providerParamSpec);
// 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();
//public void loadInto(Map<String, RouteMeta> atlas)
MethodSpec.Builder loadIntoMethodOfGroupBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(groupParamSpec);
// Build group method body
Set<RouteMeta> groupData = entry.getValue();
for (RouteMeta routeMeta : groupData) {
// 这个ClassName就是被Route注解的类名
ClassName className = ClassName.get((TypeElement) routeMeta.getRawType());
//这是给 IProvider 的类型做了一次特殊服务
switch (routeMeta.getType()) {
case PROVIDER: // Need cache provider's super class
// 注意 routeMeta 返回的是RouteType类型，比如 PROVIDER类型，就是说element是 IProvider 的子类。
// 获取这个TypeElement的直接父接口
// 比如我们一般定义XXXServiceImpl， XXXService ，然后XXXService接口继承自IProvider
List<? extends TypeMirror> interfaces = ((TypeElement) routeMeta.getRawType()).getInterfaces();
// 遍历这个父接口
for (TypeMirror tm : interfaces) {
if (types.isSameType(tm, iProvider)) { // Its implements iProvider interface himself.
// This interface extend the IProvider, so it can be used for mark provider
// 该element是 IProvider的直接子类
// 就会生成类似 providers.put("com.alibaba.android.arouter.demo.module1.testservice.SingleService",
// RouteMeta.build(RouteType.PROVIDER, SingleService.class, "/yourservicegroupname/single", // "yourservicegroupname", null, -1, -2147483648));
loadIntoMethodOfProviderBuilder.addStatement(
"providers.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
(routeMeta.getRawType()).toString(),
routeMetaCn,
routeTypeCn,
className,
routeMeta.getPath(),
routeMeta.getGroup());
} else if (types.isSubtype(tm, iProvider)) {
// This interface extend the IProvider, so it can be used for mark provider
// 类似这样 providers.put("com.alibaba.android.arouter.demo.service.HelloService",
// RouteMeta.build(RouteType.PROVIDER, HelloServiceImpl.class, "/yourservicegroupname/hello",
// "yourservicegroupname", null, -1, -2147483648));
loadIntoMethodOfProviderBuilder.addStatement(
"providers.put($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
....... 省略一部分代码........
}
// Generate groups
// ARouter$$Group$$groupName
// 见图ARouter$$Group$$groupName
String groupFileName = NAME_OF_GROUP + groupName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE, // com.alibaba.android.arouter.routes
TypeSpec.classBuilder(groupFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(type_IRouteGroup))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfGroupBuilder.build())
.build()
).build().writeTo(mFiler);
// 组名和用组名生成的类缓存起来
rootMap.put(groupName, groupFileName);
}
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()) {
// 会生成类似这样的代码
// routes.put("test", ARouter$$Group$$test.class);
// routes.put("yourservicegroupname", ARouter$$Group$$yourservicegroupname.class);
loadIntoMethodOfRootBuilder.addStatement("routes.put($S, $T.class)", entry.getKey(), ClassName.get(PACKAGE_OF_GENERATE_FILE, entry.getValue()));
}
}
// Output route doc
....... 省略一部分代码........
// Write provider into disk
// ARouter$$Providers$$moduleName
// 见图ARouter$$Providers$$moduleName
String providerMapFileName = NAME_OF_PROVIDER + SEPARATOR + moduleName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE, // com.alibaba.android.arouter.routes
TypeSpec.classBuilder(providerMapFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(type_IProviderGroup))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfProviderBuilder.build())
.build()
).build().writeTo(mFiler);
// ARouter$$Root$$moduleName
// 见图 ARouter$$Root$$moduleName
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);
}
}
private void injectParamCollector(Element element, Map<String, Integer> paramsType, Map<String, Autowired> injectConfig) {
for (Element field : element.getEnclosedElements()) {
// 获取 被Route 注解的类中的所有元素，主要是字段
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.
// 是一个带有Autowired注解的字段，但不能是IProvider类型
//
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);
}
}
// 是不是还有父类
TypeMirror parent = ((TypeElement) element).getSuperclass();
if (parent instanceof DeclaredType) {
// 一个类或者接口
Element parentElement = ((DeclaredType) parent).asElement();
if (parentElement instanceof TypeElement && !((TypeElement) parentElement).getQualifiedName().toString().startsWith("android")) {
injectParamCollector(parentElement, paramsType, injectConfig);
}
}
}
// 把具有相同group的 RouteMeta 放在一个Set里
// Map<String, Set<RouteMeta>>
private void categories(RouteMeta routeMete) {
// 设置路由path时必须是"/"开头，如果没有设置 group ，RouteMeta就会自动设置 group
if (routeVerify(routeMete)) {
// 排个序，把相同group的RouteMeta放在一个Set
Set<RouteMeta> routeMetas = groupMap.get(routeMete.getGroup());
if (CollectionUtils.isEmpty(routeMetas)) {
Set<RouteMeta> routeMetaSet = new TreeSet<>(new Comparator<RouteMeta>() {
@Override
public int compare(RouteMeta r1, RouteMeta r2) {
try {
return r1.getPath().compareTo(r2.getPath());
} catch (NullPointerException npe) {
logger.error(npe.getMessage());
return 0;
}
}
});
routeMetaSet.add(routeMete);
groupMap.put(routeMete.getGroup(), routeMetaSet);
} else {
routeMetas.add(routeMete);
}
} else {
logger.warning(">>> Route meta verify error, group is " + routeMete.getGroup() + " <<<");
}
}
// ARouter$$Group$$groupName
String groupFileName = NAME_OF_GROUP + groupName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE, // com.alibaba.android.arouter.routes
TypeSpec.classBuilder(groupFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(type_IRouteGroup))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfGroupBuilder.build())
.build()
).build().writeTo(mFiler);
上面的会生成类似这样的类
// ARouter$$Providers$$moduleName
String providerMapFileName = NAME_OF_PROVIDER + SEPARATOR + moduleName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE, // com.alibaba.android.arouter.routes
TypeSpec.classBuilder(providerMapFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(type_IProviderGroup))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfProviderBuilder.build())
.build()
).build().writeTo(mFiler);
上面的会生成类似这样的类
// ARouter$$Root$$moduleName
String rootFileName = NAME_OF_ROOT + SEPARATOR + moduleName;
JavaFile.builder(PACKAGE_OF_GENERATE_FILE, //com.alibaba.android.arouter.routes
TypeSpec.classBuilder(rootFileName)
.addJavadoc(WARNING_TIPS)
.addSuperinterface(ClassName.get(elementUtils.getTypeElement(ITROUTE_ROOT)))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfRootBuilder.build())
.build()
).build().writeTo(mFiler);
上面的会生成类似这样的类
