ARouter 源码学习之Compiler
阿里巴巴Arouter github地址如下：
ARouter gitHub 地址
ARouter我的学习注释GitHub地址：
ARouter
Arouter 使用Demo：
Android_Modularization_Demo
对AbstractProcessor不太熟悉的同学，可以参考：
Android中使用AbstractProcessor在编译时生成代码
基础篇：带你从头到尾玩转注解
该文章参考：
阿里路由框架--ARouter 源码解析之Compiler
基础篇：带你从头到尾玩转注解
arouter-compiler 通过AbstractProcessor在编译时生成相关类文件
生成的文件位于以下目录：
Compiler层SDK
- RouteProcessor 路由路径处理器
- InterceptorProcessor 拦截器处理器
- AutowireProcessor 自动装配处理器
上图所示就是ARouter在编译期间生成的类文件。
- 红色标注的是 RouteProcessor 生成的类文件
- 蓝色标注的是 InterceptorProcessor 生成的类文件
- 橙色标书的是 AutowiredProcessor 生成的类文件
RouteProcessor.java
package com.alibaba.android.arouter.compiler.processor;
/**
* A processor used for find route.
*
* @author Alex Contact me.
* @version 1.0
* @since 16/8/15 下午10:08
*/
// 主要的作用是注解 processor 类，并对其生成 META-INF 的配置信息。
@AutoService(Processor.class)
// ??????????????
// 这个注解用来注册可能通过命令行传递给处理器的操作选项
@SupportedOptions(KEY_MODULE_NAME)
// 标识该处理器支持的源码版本
@SupportedSourceVersion(SourceVersion.RELEASE_7)
// 这个 Processor 要处理的 Annotation 名字
// com.alibaba.android.arouter.facade.annotation.Route
// com.alibaba.android.arouter.facade.annotation.Autowired
@SupportedAnnotationTypes({ANNOTATION_TYPE_ROUTE, ANNOTATION_TYPE_AUTOWIRED})
public class RouteProcessor extends AbstractProcessor {
// Filter用来创建新的源文件，class文件以及辅助文件
private Filer mFiler; // File util, write class file into disk.
/**
* 参考：
* http://blog.csdn.net/dd864140130/article/details/53875814
*
* Elements 中包含用于操作Element的工具方法
* element表示一个静态的，语言级别的构件。
* 而任何一个结构化文档都可以看作是由不同的element组成的结构体，比如XML，JSON等。
* 对于java源文件来说，他同样是一种结构化文档：
* package com.closedevice; //PackageElement
* public class Main{ //TypeElement
* private int x; //VariableElement
* private Main(){ //ExecuteableElement
* }
* private void print(String msg){ //其中的参数部分String msg为TypeElement
* }
* }
*/
private Elements elements;
// Types中包含用于操作TypeMirror的工具方法
private Types types;
// TypeMirror代表java语言中的类型.
// Types包括基本类型，声明类型（类类型和接口类型），数组，类型变量和空类型。也代表通配类型参数，可执行文件的签名和返回类型等。
// TypeMirror类中最重要的是getKind()方法，该方法返回TypeKind类型，为了方便大家理解
// Element代表源代码，TypeElement代表的是源码中的类型元素，比如类。
// 虽然我们可以从TypeElement中获取类名，TypeElement中不包含类本身的信息，
// 比如它的父类，要想获取这信息需要借助TypeMirror，可以通过Element中的asType()获取元素对应的TypeMirror
private TypeMirror iProvider = null;
// 判断Element类型
private TypeUtils typeUtils;
//
// ModuleName and routeMeta.
// 例：
// group='test'
// {type=FRAGMENT,
// rawType=com.alibaba.android.arouter.demo.BlankFragment,
// destination=null,
// path='/test/fragment',
// group='test',
// priority=-1,
// extra=-2147483648}
private Map> groupMap = new HashMap<>();
// 例：
// group: test
// group: ARouter$$Group$$test
private Map rootMap = new TreeMap<>(); // Map of root metas, used for generate class file in order.
private String moduleName = null; // Module name, maybe its 'app' or others
// 日志封装
// 通过Messager来报告错误，警告和其他提示信息
private Logger logger;
/**
* Initializes the processor with the processing environment by
* setting the {@code processingEnv} field to the value of the
* {@code processingEnv} argument. An {@code
* IllegalStateException} will be thrown if this method is called
* more than once on the same object.
*
* @param processingEnv environment to access facilities the tool framework
* provides to the processor
* @throws IllegalStateException if this method is called more than once.
*/
@Override
public synchronized void init(ProcessingEnvironment processingEnv) {
super.init(processingEnv);
// Generate class.
// Filter用来创建新的源文件，class文件以及辅助文件
mFiler = processingEnv.getFiler();
// Get class meta.
// Elements 中包含用于操作Element的工具方法
elements = processingEnv.getElementUtils();
// Get type utils.
types = processingEnv.getTypeUtils();
// 判断Element类型
typeUtils = new TypeUtils(types, elements);
// Messager用来报告错误，警告和其他提示信息
logger = new Logger(processingEnv.getMessager()); // Package the log utils.
// Attempt to get user configuration [moduleName]
Map options = processingEnv.getOptions();
logger.info("RouteProcessor options: " + options);
if (MapUtils.isNotEmpty(options)) {
moduleName = options.get(KEY_MODULE_NAME);
}
logger.info("RouteProcessor moduleName: " + moduleName);
if (StringUtils.isNotEmpty(moduleName)) {
moduleName = moduleName.replaceAll("[^0-9a-zA-Z_]+", "");
logger.info("The user has configuration the module name, it was [" + moduleName + "]");
} else {
logger.error("These no module name, at 'build.gradle', like :\n" +
"apt {\n" +
" arguments {\n" +
" moduleName project.getName();\n" +
" }\n" +
"}\n");
throw new RuntimeException("ARouter::Compiler >>> No module name, for more information, look at gradle log.");
}
iProvider = elements.getTypeElement(Consts.IPROVIDER).asType();
logger.info(">>> RouteProcessor init. <<<");
}
/**
* {@inheritDoc}
*
* @param annotations
* @param roundEnv
*/
@Override
public boolean process(Set annotations, RoundEnvironment roundEnv) {
logger.info("RouteProcessor process");
if (CollectionUtils.isNotEmpty(annotations)) {
Set routeElements = roundEnv.getElementsAnnotatedWith(Route.class);
try {
logger.info(">>> Found routes, start... <<<");
this.parseRoutes(routeElements);
} catch (Exception e) {
logger.error(e);
}
return true;
}
return false;
}
/**
* @param routeElements
* @throws IOException
*/
private void parseRoutes(Set routeElements) throws IOException {
logger.info("RouteProcessor parseRoutes");
if (CollectionUtils.isNotEmpty(routeElements)) {
// Perpare the type an so on.
logger.info(">>> Found routes, size is " + routeElements.size() + " <<<");
rootMap.clear();
// 获取ACTIVITY, SERVICE, FRAGMENT, FRAGMENT_V4 这四种 类型镜像
// android.app.Activity
TypeMirror type_Activity = elements.getTypeElement(ACTIVITY).asType();
// android.app.Service
TypeMirror type_Service = elements.getTypeElement(SERVICE).asType();
// android.app.Fragment
TypeMirror fragmentTm = elements.getTypeElement(FRAGMENT).asType();
// android.support.v4.app.Fragment
TypeMirror fragmentTmV4 = elements.getTypeElement(Consts.FRAGMENT_V4).asType();
// ARouter的接口
// Interface of ARouter
// IRouteGroup
TypeElement type_IRouteGroup = elements.getTypeElement(IROUTE_GROUP);
// IProviderGroup
TypeElement type_IProviderGroup = elements.getTypeElement(IPROVIDER_GROUP);
// 下面就是遍历获取的注解信息，通过javapoet来生成类文件了
// RouteMeta
ClassName routeMetaCn = ClassName.get(RouteMeta.class);
// RouteType
ClassName routeTypeCn = ClassName.get(RouteType.class);
/**
*
* 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);
* }
* }
*
*/
/**
* ParameterizedTypeName用来创建类型对象，例如下面
*
* Build input type, format as :
* ```Map>```
*/
ParameterizedTypeName inputMapTypeOfRoot = ParameterizedTypeName.get(
ClassName.get(Map.class),
ClassName.get(String.class),
ParameterizedTypeName.get(
ClassName.get(Class.class),
WildcardTypeName.subtypeOf(ClassName.get(type_IRouteGroup))
)
);
/**
*
* 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("ch", 5); put("fl", 6); put("obj", 10); put("name", 8); put("dou", 7); put("boy", 0); put("objList", 10); put("map", 10); put("age", 3); put("url", 8); put("height", 3); }}, -1, -2147483648));
* atlas.put("/test/activity2", RouteMeta.build(RouteType.ACTIVITY, Test2Activity.class, "/test/activity2", "test", new java.util.HashMap(){{put("key1", 8); }}, -1, -2147483648));
* }
* }
*
*
*/
/**
* RouteMeta封装了路由相关的信息
*
*```Map```
*/
ParameterizedTypeName inputMapTypeOfGroup = ParameterizedTypeName.get(
ClassName.get(Map.class),
ClassName.get(String.class),
ClassName.get(RouteMeta.class)
);
/*
Build input param name.
*/
// 1、生成的参数：Map> routes
ParameterSpec rootParamSpec = ParameterSpec.builder(inputMapTypeOfRoot, "routes").build();
// 2、 Map atlas
ParameterSpec groupParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "atlas").build();
// 3、Map providers
ParameterSpec providerParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "providers").build(); // Ps. its param type same as groupParamSpec!
/**
* Build method : 'loadInto'
*
* @Override
* public void loadInto(Map> routes)
*/
MethodSpec.Builder loadIntoMethodOfRootBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(rootParamSpec);
logger.info("RouteProcessor routeElements.size() " + routeElements.size());
// 接下来的代码就是遍历注解元素，进行分组，进而生成java文件
// Follow a sequence, find out metas of group first, generate java file, then statistics them as root.
for (Element element : routeElements) {
logger.info("element " + element.getSimpleName());
// TypeMirror代表java语言中的类型
TypeMirror tm = element.asType();
//
Route route = element.getAnnotation(Route.class);
//
RouteMeta routeMete = null;
// 判断类型 Activity
if (types.isSubtype(tm, type_Activity)) { // Activity
logger.info(">>> Found activity route: " + tm.toString() + " <<<");
// 遍历查找所有添加 @AutoWired 注解的变量
// Get all fields annotation by @Autowired
Map paramsType = new HashMap<>();
//
for (Element field : element.getEnclosedElements()) {
// 参数 自动装填
// 1. 必须是field
// 2. 必须有注解AutoWired
// 3. 必须不是IProvider类型
if (field.getKind().isField()
&& field.getAnnotation(Autowired.class) != null
&& !types.isSubtype(field.asType(), iProvider)) {
logger.info("Autowired field " + field.getSimpleName());
// 满足上述条件后，获取注解
// It must be field, then it has annotation, but it not be provider.
Autowired paramConfig = field.getAnnotation(Autowired.class);
// Autowired支持写别名，当指定name属性之后，就会以name为准，否则以field的名字为准。
// TypeUtils是自定义工具类，用来判断field的数据类型的，转换成int值。
paramsType.put(
StringUtils.isEmpty(paramConfig.name())
? field.getSimpleName().toString()
: paramConfig.name()
, typeUtils.typeExchange(field));
}
}
logger.info("Autowired route.group " + route.group());
logger.info("Autowired route.name " + route.name());
logger.info("Autowired route.path " + route.path());
logger.info("Autowired route.extras " + route.extras());
logger.info("element " + element.getSimpleName());
logger.info("paramsType " + paramsType);
/**
* route: /test/activity1
* element: Test1Activity
* ACTIVITY(0, "android.app.Activity")
* paramsType 参数 参数对应类型int
*/
routeMete = new RouteMeta(route, element, RouteType.ACTIVITY, paramsType);
}
// 如果是IProvider类型的注解，则直接创建一条PROVIDER类型的路由信息
else if (types.isSubtype(tm, iProvider)) { // IProvider
logger.info(">>> Found provider route: " + tm.toString() + " <<<");
routeMete = new RouteMeta(route, element, RouteType.PROVIDER, null);
}
// 如果是Service类型的注解，则直接创建一条Service类型的路由信息
else if (types.isSubtype(tm, type_Service)) { // Service
logger.info(">>> Found service route: " + tm.toString() + " <<<");
routeMete = new RouteMeta(route, element, RouteType.parse(SERVICE), null);
}
// 如果是fragmentTmV4类型的注解，则直接创建一条Fragment类型的路由信息
else if (types.isSubtype(tm, fragmentTm) || types.isSubtype(tm, fragmentTmV4)) {
logger.info(">>> Found fragment route: " + tm.toString() + " <<<");
routeMete = new RouteMeta(route, element, RouteType.parse(FRAGMENT), null);
} else {
throw new RuntimeException("ARouter::Compiler >>> Found unsupported class type, type = [" + types.toString() + "].");
}
// 将路由信息进行分组，分组信息保存到 groupMap中
categories(routeMete);
}
/**
* @Override
* public void loadInto(Map providers)
*/
MethodSpec.Builder loadIntoMethodOfProviderBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(providerParamSpec);
// 遍历 groupMap
//
// Start generate java source, structure is divided into upper and lower levels, used for demand initialization.
for (Map.Entry> entry : groupMap.entrySet()) {
// 组名称
String groupName = entry.getKey();
/**
* @Override
* public void loadInto(Map atlas)
*/
MethodSpec.Builder loadIntoMethodOfGroupBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
.addAnnotation(Override.class)
.addModifiers(PUBLIC)
.addParameter(groupParamSpec);
// 构建loadInto方法的方法体
// Build group method body
Set groupData = entry.getValue();
// 循环
for (RouteMeta routeMeta : groupData) {
// 类型
switch (routeMeta.getType()) {
// PROVIDER(2, "com.alibaba.android.arouter.facade.template.IProvider")
case PROVIDER:// Need cache provider's super class
//
List interfaces = ((TypeElement) routeMeta.getRawType()).getInterfaces();
// 遍历当前类的接口
for (TypeMirror tm : interfaces) {
// 如果当前类直接实现了IProvider接口
if (types.isSameType(tm, iProvider)) { // Its implements iProvider interface himself.
// This interface extend the IProvider, so it can be used for mark provider
/**
* @Route(path = "/service/single")
* public class SingleService implements IProvider
*
* providers.put("com.alibaba.android.arouter.demo.testservice.SingleService", RouteMeta.build(RouteType.PROVIDER, SingleService.class, "/service/single", "service", null, -1, -2147483648));
*/
loadIntoMethodOfProviderBuilder.addStatement(
"providers.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
(routeMeta.getRawType()).toString(),
routeMetaCn,
routeTypeCn,
ClassName.get((TypeElement) routeMeta.getRawType()),
routeMeta.getPath(),
routeMeta.getGroup());
}
// 如果是接口继承的IProvider
else if (types.isSubtype(tm, iProvider)) {
/**
* @Route(path = "/service/hello")
* public class HelloServiceImpl implements HelloService
* public interface HelloService extends IProvider
* //
* providers.put("com.alibaba.android.arouter.demo.testservice.HelloService", RouteMeta.build(RouteType.PROVIDER, HelloServiceImpl.class, "/service/hello", "service", null, -1, -2147483648));
*/
// This interface extend the IProvider, so it can be used for mark provider
loadIntoMethodOfProviderBuilder.addStatement(
"providers.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
tm.toString(), // So stupid, will duplicate only save class name.
routeMetaCn,
routeTypeCn,
ClassName.get((TypeElement) routeMeta.getRawType()),
routeMeta.getPath(),
routeMeta.getGroup());
}
}
break;
default:
break;
}
// 形式如： put("pac", 9); put("obj", 10);
// Make map body for paramsType
StringBuilder mapBodyBuilder = new StringBuilder();
Map paramsType = routeMeta.getParamsType();
if (MapUtils.isNotEmpty(paramsType)) {
for (Map.Entry types : paramsType.entrySet()) {
mapBodyBuilder.append("put(\"").append(types.getKey()).append("\", ").append(types.getValue()).append("); ");
}
}
String mapBody = mapBodyBuilder.toString();
/**
* atlas.put("/test/activity1", RouteMeta.build(RouteType.ACTIVITY, Test1Activity.class, "/test/activity1", "test", new java.util.HashMap(){{put("pac", 9); put("ch", 5); put("fl", 6); put("obj", 10); put("name", 8); put("dou", 7); put("boy", 0); put("objList", 10); put("map", 10); put("age", 3); put("url", 8); put("height", 3); }}, -1, -2147483648));
*/
loadIntoMethodOfGroupBuilder.addStatement(
"atlas.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, " + (StringUtils.isEmpty(mapBody) ? null : ("new java.util.HashMap(){{" + mapBodyBuilder.toString() + "}}")) + ", " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
routeMeta.getPath(),
routeMetaCn,
routeTypeCn,
ClassName.get((TypeElement) routeMeta.getRawType()),
routeMeta.getPath().toLowerCase(),
routeMeta.getGroup().toLowerCase());
}
// Generate groups
String groupFileName = NAME_OF_GROUP + groupName;
//
JavaFile.builder(
// package 名称 --"com.alibaba.android.arouter.routes"
PACKAGE_OF_GENERATE_FILE,
//java类名
TypeSpec.classBuilder(groupFileName)
// doc
.addJavadoc(WARNING_TIPS)
// 添加继承的接口
.addSuperinterface(ClassName.get(type_IRouteGroup))
// 作用域为public
.addModifiers(PUBLIC)
// 添加函数（包括了函数里面的代码块）
.addMethod(loadIntoMethodOfGroupBuilder.build())
.build()
).build().writeTo(mFiler);
logger.info("---rootMap---");
logger.info(">>> Generated group: " + groupName + "<<<");
logger.info(">>> Generated group: " + groupFileName + "<<<");
rootMap.put(groupName, groupFileName);
}
if (MapUtils.isNotEmpty(rootMap)) {
// Generate root meta by group name, it must be generated before root, then I can find out the class of group.
for (Map.Entry entry : rootMap.entrySet()) {
loadIntoMethodOfRootBuilder.addStatement("routes.put($S, $T.class)", entry.getKey(), ClassName.get(PACKAGE_OF_GENERATE_FILE, entry.getValue()));
}
}
// Wirte 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(elements.getTypeElement(ITROUTE_ROOT)))
.addModifiers(PUBLIC)
.addMethod(loadIntoMethodOfRootBuilder.build())
.build()
).build().writeTo(mFiler);
logger.info(">>> Generated root, name is " + rootFileName + " <<<");
}
}
/**
* Sort metas in group.
*
* 将路由信息进行分组，分组信息保存到 groupMap中
*
* （每个路由信息对象中都保存着它所属的组别信息，在调用categories()函数之前所有的组别信息都是默认值"" ）
*
* @param routeMete metas.
*/
private void categories(RouteMeta routeMete) {
logger.info("---categories---");
// 1、验证路由信息的正确性
// 2、截取路径字符串 获取group
if (routeVerify(routeMete)) {
logger.info(">>> Start categories, group = " + routeMete.getGroup() + ", path = " + routeMete.getPath() + " <<<");
// 尝试从groupMap中通过group名称 获取集合数据
Set routeMetas = groupMap.get(routeMete.getGroup());
// 集合数据为空
if (CollectionUtils.isEmpty(routeMetas)) {
// 创建组
Set routeMetaSet = new TreeSet<>(new Comparator() {
@Override
public int compare(RouteMeta r1, RouteMeta r2) {
try {
return r1.getPath().compareTo(r2.getPath());
} catch (NullPointerException npe) {
logger.error(npe.getMessage());
return 0;
}
}
});
// 添加到新创建的集合中
routeMetaSet.add(routeMete);
// 集合添加到groupMap中
groupMap.put(routeMete.getGroup(), routeMetaSet);
logger.info("routeMete: " + routeMete);
logger.info("routeMete.getGroup(): " + routeMete.getGroup());
} else {
// 添加到组中
routeMetas.add(routeMete);
}
} else {
logger.warning(">>> Route meta verify error, group is " + routeMete.getGroup() + " <<<");
}
}
/**
* 1、验证路由信息的正确性
* 2、截取路径字符串 获取group
*
* Verify the route meta
*
* @param meta raw meta
*/
private boolean routeVerify(RouteMeta meta) {
String path = meta.getPath();
// 合法性判断
if (StringUtils.isEmpty(path) || !path.startsWith("/")) { // The path must be start with '/' and not empty!
return false;
}
// 没有分组时，group为""
if (StringUtils.isEmpty(meta.getGroup())) { // Use default group(the first word in path)
try {
// 截取路径字符串 获取group
String defaultGroup = path.substring(1, path.indexOf("/", 1));
if (StringUtils.isEmpty(defaultGroup)) {
return false;
}
meta.setGroup(defaultGroup);
return true;
} catch (Exception e) {
logger.error("Failed to extract default group! " + e.getMessage());
return false;
}
}
return true;
}
}