ARouter注解处理器分析-RouteProcessor
2020-07-12 本文已影响0人
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简介
- 该篇是ARouter中注解处理器分析的第一篇文章，RouteProcessor的分析
- 我们知道在ARouter中我们可以简单的分成三部分 ,arouter_annotation(自定义注解模块)，arouter_compiler（自定义注解处理器模块），arouter_api（模块）
- 其中我们要分析的注解处理器就是存在于arouter_compiler模块中
怎样自定义注解处理器（通用步骤）
- 通常自定义的注解处理器是处在于新建的Java模块中，因为你如果建Android的module，其中有些api是不存在的。
- 自定义的注解处理器 要 extends AbstractProvessor,还需实现如下几个方法
- init() ---> 初始化方法，在该方法中我们可以获取到很多工具类
- getSupportedSourceVersion() ---> 用于制定Java版本 通常写成 SourceVersion.lastSupported()就可以
- getSupportedAnnotationTypes() ---> 用于制定注解处理器要处理的注解
- process() ----> 很重要的一个方法，用于编写我们在编译期间生成文件的逻辑
- 正常来说，以上是叫做APT技术，通常我们还需要使用的AutoService 和JavaPoet框架
- AutoService的使用 是将注册注解处理器
- JavaPoet是用来便捷的生成文件类 从类到变量和方法都能用此框架来生成。
注解处理器到底是干嘛用的呢？
- 主要是为了在编译期间自动帮我们写代码的功能，对帮我们写代码的功能，我只需要在注解处理器的process()方法中声明好规则，就可以了。
- 那么我们就先看下ARouter在编译期间都生成那些文件了呢？
-
ARouter-Compiler
- 看下ARouter
XX类文件中的代码
public class ARouter$$Group$$test implements IRouteGroup {
@Override
public void loadInto(Map<String, RouteMeta> atlas) {
atlas.put("/test/activity1", RouteMeta.build(RouteType.ACTIVITY, Test1Activity.class, "/test/activity1", "test", new java.util.HashMap<String, Integer>(){{put("ser", 9); put("ch", 5); put("fl", 6); put("dou", 7); put("boy", 0); put("url", 8); put("pac", 10); put("obj", 11); put("name", 8); put("objList", 11); put("map", 11); put("age", 3); put("height", 3); }}, -1, -2147483648));
atlas.put("/test/activity2", RouteMeta.build(RouteType.ACTIVITY, Test2Activity.class, "/test/activity2", "test", new java.util.HashMap<String, Integer>(){{put("key1", 8); }}, -1, -2147483648));
atlas.put("/test/activity3", RouteMeta.build(RouteType.ACTIVITY, Test3Activity.class, "/test/activity3", "test", new java.util.HashMap<String, Integer>(){{put("name", 8); put("boy", 0); put("age", 3); }}, -1, -2147483648));
atlas.put("/test/activity4", RouteMeta.build(RouteType.ACTIVITY, Test4Activity.class, "/test/activity4", "test", null, -1, -2147483648));
atlas.put("/test/fragment", RouteMeta.build(RouteType.FRAGMENT, BlankFragment.class, "/test/fragment", "test", new java.util.HashMap<String, Integer>(){{put("obj", 11); put("name", 8); }}, -1, -2147483648));
atlas.put("/test/webview", RouteMeta.build(RouteType.ACTIVITY, TestWebview.class, "/test/webview", "test", null, -1, -2147483648));
}
}
- 看下ARouter
XX类文件中的代码
public class ARouter$$Root$$app implements IRouteRoot {
@Override
public void loadInto(Map<String, Class<? extends IRouteGroup>> routes) {
routes.put("test", ARouter$$Group$$test.class);
routes.put("yourservicegroupname", ARouter$$Group$$yourservicegroupname.class);
}
}
- 看下Arouter
XX类文件中的代码
public class ARouter$$Providers$$app implements IProviderGroup {
@Override
public void loadInto(Map<String, RouteMeta> providers) {
providers.put("com.alibaba.android.arouter.demo.testservice.HelloService", RouteMeta.build(RouteType.PROVIDER, HelloServiceImpl.class, "/yourservicegroupname/hello", "yourservicegroupname", null, -1, -2147483648));
providers.put("com.alibaba.android.arouter.facade.service.SerializationService", RouteMeta.build(RouteType.PROVIDER, JsonServiceImpl.class, "/yourservicegroupname/json", "yourservicegroupname", null, -1, -2147483648));
providers.put("com.alibaba.android.arouter.demo.testservice.SingleService", RouteMeta.build(RouteType.PROVIDER, SingleService.class, "/yourservicegroupname/single", "yourservicegroupname", null, -1, -2147483648));
}
}
- 以上就是ARouter在编译期间给我们生成的代码文件，其中ARouter
XX，我们该篇文章都会涉及到
- 注明：一般我所指的一级地址就是（"/test/activity"）就是"/test",路由地址就是"/test/activity"
ARouter之 RouteProcessor注解处理器的分析
- 源码如下
//使用了AutoService注解，将注解处理器进行注册
@AutoService(Processor.class)
//使用了注解的方式来指明当前注解处理器要处理的注解
@SupportedAnnotationTypes({ANNOTATION_TYPE_ROUTE, ANNOTATION_TYPE_AUTOWIRED})
// 继承了BaseProcessor，在BaseProcessor中在init方法中我们获取了各种工具类，
//重写了getSupportedSourceVersion() 来指明版本
public class RouteProcessor extends BaseProcessor {
.....
}
process()
@Override
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
if (CollectionUtils.isNotEmpty(annotations)) {
//扫描Route注解 Route注解是作用于类上的
Set<? extends Element> routeElements = roundEnv.getElementsAnnotatedWith(Route.class);
try {
logger.info(">>> Found routes, start... <<<");
// 交给了parseRoutes()方法来处理了
this.parseRoutes(routeElements);
} catch (Exception e) {
logger.error(e);
}
return true;
}
return false;
}
parseRoutes()
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>>```
构造入参参数，用于存储一级路由路径
一级路由路径（组名）
该组对应生成的路由地址清单文件的名字是ARouter$$Root$$Demo
*/
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>```
构造入参参数，用于路由清单中
路由路径全称
RouteMeta 包含目标类的相关信息
用于构建ARouter$$Group$$Demo类中的方法
*/
ParameterizedTypeName inputMapTypeOfGroup = ParameterizedTypeName.get(
ClassName.get(Map.class),
ClassName.get(String.class),
ClassName.get(RouteMeta.class)
);
/*
Build input param name.
构建参数名字
*/
// 生成ARouter$$Root$$Demo 类中 loadInto() 入参的参数名字 routes
ParameterSpec rootParamSpec = ParameterSpec.builder(inputMapTypeOfRoot, "routes").build();
// 生成ARouter$$Group$$Demo 类中 loadInto()方法的入参的参数名字 atlas
ParameterSpec groupParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "atlas").build();
// 生成ARouter$$Provider$$Demo类中loadInto()方法的入参的参数名字 providers
ParameterSpec providerParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "providers").build(); // Ps. its param type same as groupParamSpec!
/*
Build method : 'loadInto'
构建ARouter$$Route$$Demo文件中的方法
@Override
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.
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() + "].");
}
// 对路由节点进行分组
categories(routeMeta);
}
/**
*构建provider类型方法
*也就是ARouter$$Providers$$app类文件中的loadInto的方法
*/
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();
/**
* 构建 ARouter$$Group$$Demo类中的方法 loadInto
*/
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();
// 一个Group中可以有多个路由节点
// 一个Group对应一个路由清单文件
// 一个路由清单文件中loadInto()方法可以存储多个路由节点的映射关系
for (RouteMeta routeMeta : groupData) {
RouteDoc routeDoc = extractDocInfo(routeMeta);
ClassName className = ClassName.get((TypeElement) routeMeta.getRawType());
// 这里做了节点的类别判断 仅仅做了Provider类型的判断
// 这也是为什么Provider不仅出现在 PROVIDER类型的路由节点列表中，也出现在GROUP类型的路由节点中
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());
// 为Provider类型的类文件中的 loadInto()方法中添加方法体的
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, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
tm.toString(), // So stupid, will duplicate only save class name.
routeMetaCn,
routeTypeCn,
className,
routeMeta.getPath(),
routeMeta.getGroup());
}
}
break;
default:
break;
}
// Make map body for paramsType
StringBuilder mapBodyBuilder = new StringBuilder();
Map<String, Integer> paramsType = routeMeta.getParamsType();
Map<String, Autowired> injectConfigs = routeMeta.getInjectConfig();
if (MapUtils.isNotEmpty(paramsType)) {
List<RouteDoc.Param> paramList = new ArrayList<>();
for (Map.Entry<String, Integer> types : paramsType.entrySet()) {
mapBodyBuilder.append("put(\"").append(types.getKey()).append("\", ").append(types.getValue()).append("); ");
RouteDoc.Param param = new RouteDoc.Param();
Autowired injectConfig = injectConfigs.get(types.getKey());
param.setKey(types.getKey());
param.setType(TypeKind.values()[types.getValue()].name().toLowerCase());
param.setDescription(injectConfig.desc());
param.setRequired(injectConfig.required());
paramList.add(param);
}
routeDoc.setParams(paramList);
}
String mapBody = mapBodyBuilder.toString();
// 构建group分组的loadInto的方法体
loadIntoMethodOfGroupBuilder.addStatement(
"atlas.put($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
//完成整个group分组中的loadInto()方法的构建，以及类文件的创建
/**
* public class ARouter$$Group$$xxxx{
* public void loadInto(Map<String,RouteMeta> alts){
* alts.put("/test/test1",RouteMeta.build())
* }
* }
*/
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()) {
// 构建ARouter$$Root$$XXX类文件中的loadInto()方法
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
//创建 ARouter$$Provider$$xxx类文件
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.
// 完成ARouter$$Root$$xxx 类文件的生成
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 + " <<<");
}
}
- 总结
- 在parseRoutes方法中分别生成了 ARouter_Root_XX类文件、ARouter_Group_XX类文件以及ARouter_Provider_XX类文件
- 同时在此方法中为生成文件类中生成了laodInto()方法，和各自对应的方法体
- 对于Providr类型的，不仅存在ARouter_Provider_XX类文件中，也存在于ARouter_Group_XX类文件
- 只不过对于Provider类型，在ARouter_Provider_XX类文件中与在ARouter_Group_XX类文件中存储的形式不同，key是不同的，在ARouter_Provider_XX类文件中是以实现IProvider类型接口的全限定名为key，在ARouter_Group_XX类文件中是以路由地址为key的
categories()
private void categories(RouteMeta routeMete) {
// 校验工作 校验path地址的合法性，并为group属性设置一个具体路径，（默认可以是""，但是在组装的时候拿的是路由地址的一级路径）
if (routeVerify(routeMete)) {
logger.info(">>> Start categories, group = " + routeMete.getGroup() + ", path = " + routeMete.getPath() + " <<<");
// groupMap 是以路由地址的一级路径为key，value是相同的group路由节点集合
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;
}
}
});
//添加路由节点
routeMetaSet.add(routeMete);
groupMap.put(routeMete.getGroup(), routeMetaSet);
} else {
//groupMap中已有对应到的group集合，那么将路由节点直接添加到集合中
routeMetas.add(routeMete);
}
} else {
logger.warning(">>> Route meta verify error, group is " + routeMete.getGroup() + " <<<");
}
}
/**
* Verify the route meta
*
* @param meta raw meta
*/
private boolean routeVerify(RouteMeta meta) {
//获取到路由地址
String path = meta.getPath();
// 检验路由地址
if (StringUtils.isEmpty(path) || !path.startsWith("/")) { // The path must be start with '/' and not empty!
return false;
}
// 当是一个默认分组的话（默认组是一个空的字符串）
if (StringUtils.isEmpty(meta.getGroup())) { // Use default group(the first word in path)
try {
// 获取到路由地址的一级地址
String defaultGroup = path.substring(1, path.indexOf("/", 1));
if (StringUtils.isEmpty(defaultGroup)) {
return false;
}
// 设置一级地址给 RouteMeta对象中的group字段
meta.setGroup(defaultGroup);
return true;
} catch (Exception e) {
logger.error("Failed to extract default group! " + e.getMessage());
return false;
}
}
return true;
}
- 总结
- categories()方法中进行分组的操作，将一级地址与路由地址进行匹配，存在到map中,以及地址作为key，路由地址对应的RouteMeta对象存储到Set集合，Set集合为Value。
- routeVerify()方法是用来校验路由地址的，并且为RouteMeta对象中的group字段赋值（当是""空字符串，把一级地址赋值给group字段）
