ARouter源码解析之APT运行时注解

ARouter，可以使用@Route注解来标示路由地址，使用@Autowired给变量实现自动注入值，@Interceptor可以实现拦截功能。

在ARouter中，首先是通过APT在编译时生成了ROOT表，Group表，Interceptor和AutoWired

AutoWired自动注入：

/**
 * DO NOT EDIT THIS FILE!!! IT WAS GENERATED BY AROUTER. */
public class Test2Activity$$ARouter$$Autowired implements ISyringe {
  private SerializationService serializationService;

  @Override
  public void inject(Object target) {
    serializationService = ARouter.getInstance().navigation(SerializationService.class);
    Test2Activity substitute = (Test2Activity)target;
    substitute.key1 = substitute.getIntent().getStringExtra("key1");
  }
}

。

Root表：
/**
 * DO NOT EDIT THIS FILE!!! IT WAS GENERATED BY AROUTER. */
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);
  }
}

Group表：
/**
 * DO NOT EDIT THIS FILE!!! IT WAS GENERATED BY AROUTER. */
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));
  }
}

$$Interceptors表

/**
 * DO NOT EDIT THIS FILE!!! IT WAS GENERATED BY AROUTER. */
public class ARouter$$Interceptors$$app implements IInterceptorGroup {
  @Override
  public void loadInto(Map> interceptors) {
    interceptors.put(7, Test1Interceptor.class);
  }
}

首先讲一下@Route的作用，在编译期间会生成Root表和group表，Root表中用Map进行存储，key为group，value为Root表的class类型，group表也是用Map进行存储，key为Path，value为RouteMeta（存储着类型（Activity|Provider），实现@Route的类，path，group等）。这里找某一个路由类的话只需要在root表中根据path找到相应的路由表，从路由表中找到路由类，不需要全部加在。

 

下面我们来看一下编译期@Route做了什么，他的处理类时 RouteProcessor

在process方法中调用了parseRoutes

    private void parseRoutes(Set routeElements) throws IOException {
        if (CollectionUtils.isNotEmpty(routeElements)) {
            // Perpare the type an so on.

            logger.info(">>> Found routes, size is " + routeElements.size() + " <<<");

            rootMap.clear();

            //TODO 获取
            TypeMirror type_Activity = elements.getTypeElement(ACTIVITY).asType();
            TypeMirror type_Service = elements.getTypeElement(SERVICE).asType();
            TypeMirror fragmentTm = elements.getTypeElement(FRAGMENT).asType();
            TypeMirror fragmentTmV4 = elements.getTypeElement(Consts.FRAGMENT_V4).asType();

            // Interface of ARouter
            TypeElement type_IRouteGroup = elements.getTypeElement(IROUTE_GROUP);
            TypeElement type_IProviderGroup = elements.getTypeElement(IPROVIDER_GROUP);
            ClassName routeMetaCn = ClassName.get(RouteMeta.class);
            ClassName routeTypeCn = ClassName.get(RouteType.class);

            /*
               Build input type, format as :

               ```Map>```
             */
            //TODO javapoet 生成Root参数
            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```
             */
            //TODO javapoet 生成Group参数
            ParameterizedTypeName inputMapTypeOfGroup = ParameterizedTypeName.get(
                    ClassName.get(Map.class),
                    ClassName.get(String.class),
                    ClassName.get(RouteMeta.class)
            );

            /*
              Build input param name.
             */
            //TODO javapoet build出带参数名的参数
            ParameterSpec rootParamSpec = ParameterSpec.builder(inputMapTypeOfRoot, "routes").build();
            ParameterSpec groupParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "atlas").build();
            ParameterSpec providerParamSpec = ParameterSpec.builder(inputMapTypeOfGroup, "providers").build();  // Ps. its param type same as groupParamSpec!

            /*
              Build method : 'loadInto'
             */
            //TODO javapoet 创建方法把参数放进去
            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 = null;
                //TODO @Route节点是属于Activity
                if (types.isSubtype(tm, type_Activity)) {                 // Activity
                    logger.info(">>> Found activity route: " + tm.toString() + " <<<");

                    // Get all fields annotation by @Autowired
                    Map paramsType = 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);
                            //@TODO 获取子节点@AutoWired 添加到Map paramsType中，key：fileName value：类型的标记
                            paramsType.put(StringUtils.isEmpty(paramConfig.name()) ? field.getSimpleName().toString() : paramConfig.name(), typeUtils.typeExchange(field));
                        }
                    }
                    routeMeta = new RouteMeta(route, element, RouteType.ACTIVITY, paramsType);
                } 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 if (types.isSubtype(tm, fragmentTm) || types.isSubtype(tm, fragmentTmV4)) {
                    logger.info(">>> Found fragment route: " + tm.toString() + " <<<");
                    routeMeta = new RouteMeta(route, element, RouteType.parse(FRAGMENT), null);
                } else {
                    throw new RuntimeException("ARouter::Compiler >>> Found unsupported class type, type = [" + types.toString() + "].");
                }
                //TODO groupMap 赋值
                categories(routeMeta);
                // if (StringUtils.isEmpty(moduleName)) {   // Hasn't generate the module name.
                //     moduleName = ModuleUtils.generateModuleName(element, logger);
                // }
            }

            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> entry : groupMap.entrySet()) {
                String groupName = entry.getKey();
                //TODO groupName---group:一个group就需要一个group类
                MethodSpec.Builder loadIntoMethodOfGroupBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
                        .addAnnotation(Override.class)
                        .addModifiers(PUBLIC)
                        .addParameter(groupParamSpec);

                // Build group method body
                Set groupData = entry.getValue();
                // TODO PROVIDER情况addStatement
                for (RouteMeta routeMeta : groupData) {
                    switch (routeMeta.getType()) {
                        case PROVIDER:  // Need cache provider's super class
                            List interfaces = ((TypeElement) routeMeta.getRawType()).getInterfaces();
                            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
                                    loadIntoMethodOfProviderBuilder.addStatement(
                                            "providers.put($S, $T.build($T." + routeMeta.getType() + ", $T.class, $S, $S, null, " + routeMeta.getPriority() + ", " + routeMeta.getExtra() + "))",
                                            (routeMeta.getRawType()).toString(),
                                            routeMetaCn,
                                            routeTypeCn,
                                            ClassName.get((TypeElement) routeMeta.getRawType()),
                                            routeMeta.getPath(),
                                            routeMeta.getGroup());
                                } else if (types.isSubtype(tm, iProvider)) {
                                    // This interface extend the IProvider, so it can be used for mark provider
                                    loadIntoMethodOfProviderBuilder.addStatement(
                                            "providers.put($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.get((TypeElement) routeMeta.getRawType()),
                                            routeMeta.getPath(),
                                            routeMeta.getGroup());
                                }
                            }
                            break;
                        default:
                            break;
                    }

                    // 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("); ");
                        }
                    }
                    //TODO mapBody 实现@AutoWired field以 key、value 以put("pac", 9); put("ch", 5);形式写入
                    String mapBody = mapBodyBuilder.toString();

                    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());
                }
                //Todo 生成group类
                // Generate groups
                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 + "<<<");
                //TODO 生成后添加到rootMap ("service", ARouter$$Group$$service.class)
                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()) {
                    //TODO root表addStatement
                    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.
            //TODO 生成ROOT表
            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 + " <<<");
        }
    }

看一下groupMap赋值

 /**
     * Sort metas in group.
     *groupMap 赋值
     * @param routeMete metas.
     */
    private void categories(RouteMeta routeMete) {
        //验证routeMete合法，path。 path为null截取/赋值group
        if (routeVerify(routeMete)) {
            logger.info(">>> Start categories, group = " + routeMete.getGroup() + ", path = " + routeMete.getPath() + " <<<");
            Set routeMetas = groupMap.get(routeMete.getGroup());
            if (CollectionUtils.isEmpty(routeMetas)) {
                Set routeMetaSet = new TreeSet<>(new Comparator() {
                    @Override
                    public int compare(RouteMeta r1, RouteMeta r2) {
                        try {
                            //set中 path相同替换
                            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() + " <<<");
        }
    }

    /**
     * Verify the route meta
     *
     * @param meta raw meta
     */
    private boolean routeVerify(RouteMeta meta) {
        String path = meta.getPath();

        if (StringUtils.isEmpty(path) || !path.startsWith("/")) {   // The path must be start with '/' and not empty!
            return false;
        }

        if (StringUtils.isEmpty(meta.getGroup())) { // Use default group(the first word in path)
            try {
                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;
    }

通过以上代码，@Route的编译时处理就完了，就会在build/source/apt下生成root表和group表。

 

@AutoWired注解处理器 AutowiredProcessor

    /**
     * Categories field, find his papa.
     *
     * @param elements Field need autowired
     */
    private void categories(Set elements) throws IllegalAccessException {
        if (CollectionUtils.isNotEmpty(elements)) {
            for (Element element : elements) {
                TypeElement enclosingElement = (TypeElement) element.getEnclosingElement();

                if (element.getModifiers().contains(Modifier.PRIVATE)) {
                    throw new IllegalAccessException("The inject fields CAN NOT BE 'private'!!! please check field ["
                            + element.getSimpleName() + "] in class [" + enclosingElement.getQualifiedName() + "]");
                }

                if (parentAndChild.containsKey(enclosingElement)) { // Has categries
                    parentAndChild.get(enclosingElement).add(element);
                } else {
                    List childs = new ArrayList<>();
                    childs.add(element);
                    parentAndChild.put(enclosingElement, childs);
                }
            }

            logger.info("categories finished.");
        }
    }

首先获取到@Autowried节点，不能为private，然后从Map> parentAndChild中根据类节点获取对应的变量节点集合，有直接添加，没有的话就new ArrayList 添加。所有此时的parentAndChild就装有所有的@AutoWired。

private void generateHelper() throws IOException, IllegalAccessException {
        TypeElement type_ISyringe = elements.getTypeElement(ISYRINGE);
        TypeElement type_JsonService = elements.getTypeElement(JSON_SERVICE);
        TypeMirror iProvider = elements.getTypeElement(Consts.IPROVIDER).asType();
        TypeMirror activityTm = elements.getTypeElement(Consts.ACTIVITY).asType();
        TypeMirror fragmentTm = elements.getTypeElement(Consts.FRAGMENT).asType();
        TypeMirror fragmentTmV4 = elements.getTypeElement(Consts.FRAGMENT_V4).asType();

        // Build input param name.
        ParameterSpec objectParamSpec = ParameterSpec.builder(TypeName.OBJECT, "target").build();

        if (MapUtils.isNotEmpty(parentAndChild)) {
            for (Map.Entry> entry : parentAndChild.entrySet()) {
                // Build method : 'inject'
                MethodSpec.Builder injectMethodBuilder = MethodSpec.methodBuilder(METHOD_INJECT)
                        .addAnnotation(Override.class)
                        .addModifiers(PUBLIC)
                        .addParameter(objectParamSpec);

                TypeElement parent = entry.getKey();
                List childs = entry.getValue();

                String qualifiedName = parent.getQualifiedName().toString();
                String packageName = qualifiedName.substring(0, qualifiedName.lastIndexOf("."));
                String fileName = parent.getSimpleName() + NAME_OF_AUTOWIRED;

                logger.info(">>> Start process " + childs.size() + " field in " + parent.getSimpleName() + " ... <<<");

                TypeSpec.Builder helper = TypeSpec.classBuilder(fileName)
                        .addJavadoc(WARNING_TIPS)
                        .addSuperinterface(ClassName.get(type_ISyringe))
                        .addModifiers(PUBLIC);

                //TODO serializationService 用来解析pacelable对象
                FieldSpec jsonServiceField = FieldSpec.builder(TypeName.get(type_JsonService.asType()), "serializationService", Modifier.PRIVATE).build();
                helper.addField(jsonServiceField);
                injectMethodBuilder.addStatement("serializationService = $T.getInstance().navigation($T.class)", ARouterClass, ClassName.get(type_JsonService));
                //TODO 传入的是Object（Activity） 进行强转
                injectMethodBuilder.addStatement("$T substitute = ($T)target", ClassName.get(parent), ClassName.get(parent));

                // Generate method body, start inject.
                for (Element element : childs) {
                    Autowired fieldConfig = element.getAnnotation(Autowired.class);
                    String fieldName = element.getSimpleName().toString();
                    if (types.isSubtype(element.asType(), iProvider)) {  // It's provider
                        if ("".equals(fieldConfig.name())) {    // User has not set service path, then use byType.

                            // Getter
                            injectMethodBuilder.addStatement(
                                    "substitute." + fieldName + " = $T.getInstance().navigation($T.class)",
                                    ARouterClass,
                                    ClassName.get(element.asType())
                            );
                        } else {    // use byName
                            // Getter
                            injectMethodBuilder.addStatement(
                                    "substitute." + fieldName + " = ($T)$T.getInstance().build($S).navigation();",
                                    ClassName.get(element.asType()),
                                    ARouterClass,
                                    fieldConfig.name()
                            );
                        }

                        // Validater
                        if (fieldConfig.required()) {
                            injectMethodBuilder.beginControlFlow("if (substitute." + fieldName + " == null)");
                            injectMethodBuilder.addStatement(
                                    "throw new RuntimeException(\"The field '" + fieldName + "' is null, in class '\" + $T.class.getName() + \"!\")", ClassName.get(parent));
                            injectMethodBuilder.endControlFlow();
                        }
                    } else {    // It's normal intent value
                        String originalValue = "substitute." + fieldName;
                        String statement = "substitute." + fieldName + " = substitute.";
                        boolean isActivity = false;
                        if (types.isSubtype(parent.asType(), activityTm)) {  // Activity, then use getIntent()
                            isActivity = true;
                            statement += "getIntent().";
                        } else if (types.isSubtype(parent.asType(), fragmentTm) || types.isSubtype(parent.asType(), fragmentTmV4)) {   // Fragment, then use getArguments()
                            statement += "getArguments().";
                        } else {
                            throw new IllegalAccessException("The field [" + fieldName + "] need autowired from intent, its parent must be activity or fragment!");
                        }

                        statement = buildStatement(originalValue, statement, typeUtils.typeExchange(element), isActivity);
                        if (statement.startsWith("serializationService.")) {   // Not mortals
                            injectMethodBuilder.beginControlFlow("if (null != serializationService)");
                            injectMethodBuilder.addStatement(
                                    "substitute." + fieldName + " = " + statement,
                                    (StringUtils.isEmpty(fieldConfig.name()) ? fieldName : fieldConfig.name()),
                                    ClassName.get(element.asType())
                            );
                            injectMethodBuilder.nextControlFlow("else");
                            injectMethodBuilder.addStatement(
                                    "$T.e(\"" + Consts.TAG + "\", \"You want automatic inject the field '" + fieldName + "' in class '$T' , then you should implement 'SerializationService' to support object auto inject!\")", AndroidLog, ClassName.get(parent));
                            injectMethodBuilder.endControlFlow();
                        } else {
                            injectMethodBuilder.addStatement(statement, StringUtils.isEmpty(fieldConfig.name()) ? fieldName : fieldConfig.name());
                        }

                        // Validator
                        if (fieldConfig.required() && !element.asType().getKind().isPrimitive()) {  // Primitive wont be check.
                            injectMethodBuilder.beginControlFlow("if (null == substitute." + fieldName + ")");
                            injectMethodBuilder.addStatement(
                                    "$T.e(\"" + Consts.TAG + "\", \"The field '" + fieldName + "' is null, in class '\" + $T.class.getName() + \"!\")", AndroidLog, ClassName.get(parent));
                            injectMethodBuilder.endControlFlow();
                        }
                    }
                }

                helper.addMethod(injectMethodBuilder.build());

                // Generate autowire helper
                JavaFile.builder(packageName, helper.build()).build().writeTo(mFiler);

                logger.info(">>> " + parent.getSimpleName() + " has been processed, " + fileName + " has been generated. <<<");
            }

            logger.info(">>> Autowired processor stop. <<<");
        }
    }

这里需要主要分三部分，第一创建serializationService对象来解析Pacelable对象，第二就是把传入的Object（Context）强转成类，也就是上边的parent，接下来buildStatement来实现,如下：

private String buildStatement(String originalValue, String statement, int type, boolean isActivity) {
        if (type == TypeKind.BOOLEAN.ordinal()) {
            statement += (isActivity ? ("getBooleanExtra($S, " + originalValue + ")") : ("getBoolean($S)"));
        } else if (type == TypeKind.BYTE.ordinal()) {
            statement += (isActivity ? ("getByteExtra($S, " + originalValue + "") : ("getByte($S)"));
        } else if (type == TypeKind.SHORT.ordinal()) {
            statement += (isActivity ? ("getShortExtra($S, " + originalValue + ")") : ("getShort($S)"));
        } else if (type == TypeKind.INT.ordinal()) {
            statement += (isActivity ? ("getIntExtra($S, " + originalValue + ")") : ("getInt($S)"));
        } else if (type == TypeKind.LONG.ordinal()) {
            statement += (isActivity ? ("getLongExtra($S, " + originalValue + ")") : ("getLong($S)"));
        }else if(type == TypeKind.CHAR.ordinal()){
            statement += (isActivity ? ("getCharExtra($S, " + originalValue + ")") : ("getChar($S)"));
        } else if (type == TypeKind.FLOAT.ordinal()) {
            statement += (isActivity ? ("getFloatExtra($S, " + originalValue + ")") : ("getFloat($S)"));
        } else if (type == TypeKind.DOUBLE.ordinal()) {
            statement += (isActivity ? ("getDoubleExtra($S, " + originalValue + ")") : ("getDouble($S)"));
        } else if (type == TypeKind.STRING.ordinal()) {
            statement += (isActivity ? ("getStringExtra($S)") : ("getString($S)"));
        } else if (type == TypeKind.PARCELABLE.ordinal()) {
            statement += (isActivity ? ("getParcelableExtra($S)") : ("getParcelable($S)"));
        } else if (type == TypeKind.OBJECT.ordinal()) {
            statement = "serializationService.parseObject(substitute." + (isActivity ? "getIntent()." : "getArguments().") + (isActivity ? "getStringExtra($S)" : "getString($S)") + ", new com.alibaba.android.arouter.facade.model.TypeWrapper<$T>(){}.getType())";
        }

        return statement;
    }

这样，在时用AutoWired类中只需要inject传入上下文就可以实现注入，不需要自己些getIntent.getString那些方法了。

 

下面就是@Intercept拦截器，比较简单就直接上代码了

 

@AutoService(Processor.class)
@SupportedOptions(KEY_MODULE_NAME)
@SupportedSourceVersion(SourceVersion.RELEASE_7)
@SupportedAnnotationTypes(ANNOTATION_TYPE_INTECEPTOR)
public class InterceptorProcessor extends AbstractProcessor {
    private Map interceptors = new TreeMap<>();
    private Filer mFiler;       // File util, write class file into disk.
    private Logger logger;
    private Elements elementUtil;
    private String moduleName = null;   // Module name, maybe its 'app' or others
    private TypeMirror iInterceptor = null;

    /**
     * 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);

        mFiler = processingEnv.getFiler();                  // Generate class.
        elementUtil = processingEnv.getElementUtils();      // Get class meta.
        logger = new Logger(processingEnv.getMessager());   // Package the log utils.

        // Attempt to get user configuration [moduleName]
        Map options = processingEnv.getOptions();
        if (MapUtils.isNotEmpty(options)) {
            moduleName = options.get(KEY_MODULE_NAME);
        }

        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.");
        }

        iInterceptor = elementUtil.getTypeElement(Consts.IINTERCEPTOR).asType();

        logger.info(">>> InterceptorProcessor init. <<<");
    }

    /**
     * {@inheritDoc}
     *
     * @param annotations
     * @param roundEnv
     */
    @Override
    public boolean process(Set annotations, RoundEnvironment roundEnv) {
        if (CollectionUtils.isNotEmpty(annotations)) {
            Set elements = roundEnv.getElementsAnnotatedWith(Interceptor.class);
            try {
                parseInterceptors(elements);
            } catch (Exception e) {
                logger.error(e);
            }
            return true;
        }

        return false;
    }

    /**
     * Parse tollgate.
     *
     * @param elements elements of tollgate.
     */
    private void parseInterceptors(Set elements) throws IOException {
        if (CollectionUtils.isNotEmpty(elements)) {
            logger.info(">>> Found interceptors, size is " + elements.size() + " <<<");
            
            //TODO 把拦截器放到 TreeMap interceptors中
            
            // Verify and cache, sort incidentally.
            for (Element element : elements) {
                if (verify(element)) {  // Check the interceptor meta
                    logger.info("A interceptor verify over, its " + element.asType());
                    Interceptor interceptor = element.getAnnotation(Interceptor.class);

                    Element lastInterceptor = interceptors.get(interceptor.priority());
                    if (null != lastInterceptor) { // Added, throw exceptions
                        throw new IllegalArgumentException(
                                String.format(Locale.getDefault(), "More than one interceptors use same priority [%d], They are [%s] and [%s].",
                                        interceptor.priority(),
                                        lastInterceptor.getSimpleName(),
                                        element.getSimpleName())
                        );
                    }

                    interceptors.put(interceptor.priority(), element);
                } else {
                    logger.error("A interceptor verify failed, its " + element.asType());
                }
            }

            // Interface of ARouter.
            TypeElement type_ITollgate = elementUtil.getTypeElement(IINTERCEPTOR);
            TypeElement type_ITollgateGroup = elementUtil.getTypeElement(IINTERCEPTOR_GROUP);

            /**
             *  Build input type, format as :
             *
             *  ```Map>```
             */
            ParameterizedTypeName inputMapTypeOfTollgate = ParameterizedTypeName.get(
                    ClassName.get(Map.class),
                    ClassName.get(Integer.class),
                    ParameterizedTypeName.get(
                            ClassName.get(Class.class),
                            WildcardTypeName.subtypeOf(ClassName.get(type_ITollgate))
                    )
            );

            // Build input param name.
            ParameterSpec tollgateParamSpec = ParameterSpec.builder(inputMapTypeOfTollgate, "interceptors").build();

            // Build method : 'loadInto'
            MethodSpec.Builder loadIntoMethodOfTollgateBuilder = MethodSpec.methodBuilder(METHOD_LOAD_INTO)
                    .addAnnotation(Override.class)
                    .addModifiers(PUBLIC)
                    .addParameter(tollgateParamSpec);

            // Generate
            if (null != interceptors && interceptors.size() > 0) {
                // Build method body
                for (Map.Entry entry : interceptors.entrySet()) {
                    //TODO 添加Statement 一个module下只会有一个intercept类
                    loadIntoMethodOfTollgateBuilder.addStatement("interceptors.put(" + entry.getKey() + ", $T.class)", ClassName.get((TypeElement) entry.getValue()));
                }
            }

            // Write to disk(Write file even interceptors is empty.)
            JavaFile.builder(PACKAGE_OF_GENERATE_FILE,
                    TypeSpec.classBuilder(NAME_OF_INTERCEPTOR + SEPARATOR + moduleName)
                            .addModifiers(PUBLIC)
                            .addJavadoc(WARNING_TIPS)
                            .addMethod(loadIntoMethodOfTollgateBuilder.build())
                            .addSuperinterface(ClassName.get(type_ITollgateGroup))
                            .build()
            ).build().writeTo(mFiler);

            logger.info(">>> Interceptor group write over. <<<");
        }
    }

    /**
     * Verify inteceptor meta
     *
     * @param element Interceptor taw type
     * @return verify result
     */
    private boolean verify(Element element) {
        Interceptor interceptor = element.getAnnotation(Interceptor.class);
        // It must be implement the interface IInterceptor and marked with annotation Interceptor.
        return null != interceptor && ((TypeElement) element).getInterfaces().contains(iInterceptor);
    }
}

这里会把所有带有@Intercept并且实现了IIntercept接口的节点都加入到Map interceptors中，key为优先级标记，此不可重复。

loadIntoMethodOfTollgateBuilder.addStatement("interceptors.put(" + entry.getKey() + ", $T.class)", ClassName.get((TypeElement) entry.getValue()));
这样的话使用拦截器的时候也需要初始化，调用loadInto传入Map，所有的拦截器都会保存到Map中，在navigation的时候会把所有的拦截器都过一遍。

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