一、构建扫描器

1.1 扫描器类型

扫描器类型	解释
new SubTypesScanner()	子类扫描
new TypeAnnotationsScanner()	注解扫描
new MethodAnnotationsScanner()	方法注解扫描
new FieldAnnotationsScanner()	字段注解扫描
new MethodParameterNamesScanner()	方法参数名称扫描
new MethodParameterScanner()	参数类型扫描
new MemberUsageScanner	基本信息扫描

1.2 new SubTypesScanner()子类扫描

 Reflections reflections = new Reflections(new ConfigurationBuilder()
                .setUrls(ClasspathHelper.forPackage("reflect.modle"))
                .setScanners(new SubTypesScanner())
                .filterInputsBy(new FilterBuilder().includePackage("reflect.modle")));
        Set<Class<? extends OtoService>> subTypesOf = reflections.getSubTypesOf(OtoService.class);

1.3 new TypeAnnotationsScanner()注解扫描

1.4 new MethodAnnotationsScanner()方法注解扫描

 Set<Method> resources =
                reflections.getMethodsAnnotatedWith(ApiMapping.class);

1.5 new FieldAnnotationsScanner()字段注解扫描

 Set<Field> fieldsAnnotatedWith = reflections.getFieldsAnnotatedWith(Ignore.class);

1.6 new MethodParameterNamesScanner()方法参数名称扫描

List<String> methodParamNames = reflections.getMethodParamNames(Method method);

1.7 new MethodParameterScanner()参数类型扫描

Set<Method> someMethods =
 reflections.getMethodsMatchParams(String.class, Integer.class);

1.8 new MemberUsageScanner基本信息扫描

Set<Member> methodUsage = reflections.getMethodUsage(x);
            methodUsage.forEach(xx->{
                System.out.println(xx.getDeclaringClass());
            });

二、构建资源路径

2.1过滤器

**包含**
FilterBuilder filter = new FilterBuilder().includePackage("org.reflections", "org.foo");

FilterBuilder filter = new FilterBuilder().includePackage(Reflections.class);

FilterBuilder filter = new FilterBuilder().include("org\\.reflections.*");

**排除**
 FilterBuilder filter = new FilterBuilder().excludePackage("org.reflections");
 
**解释器**
+:开头包含
-:不包含
FilterBuilder filter = FilterBuilder.parsePackages("+org.reflections, -org.reflections.foo");

2.2 网络加载

         final URL[] urls1 = {new URL("file", "foo", 1111, "foo"), new URL("file", "bar", 1111, "bar"),new URL("file", "baz", 1111, "baz")};
        final List<URL> urlsList2 = Arrays.asList(urls1);
        Collections.reverse(urlsList2);
        final URL[] urls2 = urlsList2.toArray(new URL[urlsList2.size()]);

        final URLClassLoader urlClassLoader1 = new URLClassLoader(urls1, null);
       
        //TODO 1.构建扫描器
        ConfigurationBuilder reflectConfig = new ConfigurationBuilder()
                .setUrls(ClasspathHelper.forPackage("reflect"))
                .setScanners(new SubTypesScanner(),
                        new TypeAnnotationsScanner(),
                        new MethodAnnotationsScanner(),
                        new MemberUsageScanner(),
                        new MethodParameterNamesScanner(),
                        new FieldAnnotationsScanner(),
                        new MethodParameterScanner()).addClassLoader(urlClassLoader1);

2.3 ClasspathHelper 工具

三、精确分析

3.1 查询条件

方法	解析
withName("getOrderInfo")	指定方法
withModifier(Modifier.PUBLIC)	指定修饰符
withParametersCount(1)	指定参数个数
withPrefix("")	指定前缀
withReturnType(OrderDo.class)	指定返回值
withParameters(String.class,Integer.class)	指定参数类型
withParametersAssignableTo(Collection.class)	指定参数类型
withTypeAssignableTo(int.class)	限制参数类型(对字段有限)
withAnyParameterAnnotation(TestModel.AM1.class)	方法参数中注解
withName()	指定方法名

  System.out.println("----------------");
        //TODO 查询该类中所有的修饰符为public的方法
  Set<Method> allMethods = getAllMethods(OtoServiceImpl.class, withModifier(Modifier.PUBLIC), withParameters(String.class, Integer.class));
        allMethods.forEach(x -> System.out.println(x));

        //TODO 根据注解和类型查询
  Set<Field> fields = getAllFields(OrderDo.class, withAnnotation(Ignore.class), withTypeAssignableTo(int.class));
        fields.forEach(x->{
            System.out.println(x.getType()+"/"+x.getName());
        });

        //TODO 参数类型是集合，返回值是布尔类型
  Set<Method> listMethodsFromCollectionToBoolean =
                getAllMethods(List.class,
                        withParametersAssignableTo(Collection.class), withReturnType(boolean.class));
        listMethodsFromCollectionToBoolean.forEach(x->{
            System.out.println(x.getName());
        });

3.2获取方法注解

 Set<Method> getOrderInfo = getMethods(OtoServiceImpl.class, withReturnType(OrderDo.class), withName("getOrderInfo"));
        getOrderInfo.forEach(x->{
            ApiMapping annotation = x.getAnnotation(ApiMapping.class);
            System.out.println(annotation);//@reflect.modle.ApiMapping(value=orderInfo)
        });

3.3注解定义

[^Documented 注解]: Documented 注解表明这个注解应该被 javadoc工具记录. 默认情况下,javadoc是不包括注解的. 但如果声明注解时指定了 @Documented,则它会被 javadoc 之类的工具处理, 所以注解类型信息也会被包括在生成的文档中 [^Inherited 注解]: 它指明被注解的类会自动继承. 更具体地说,如果定义注解时使用了 @Inherited 标记,然后用定义的注解来标注另一个父类, 父类又有一个子类(subclass),则父类的所有属性将被继承到它的子类中

• @Target(ElementType.TYPE)   //接口、类、枚举、注解
• @Target(ElementType.FIELD) //字段、枚举的常量
• @Target(ElementType.METHOD) //方法
• @Target(ElementType.PARAMETER) //方法参数
• @Target(ElementType.CONSTRUCTOR)  //构造函数
• @Target(ElementType.LOCAL_VARIABLE)//局部变量
• @Target(ElementType.ANNOTATION_TYPE)//注解
• @Target(ElementType.PACKAGE) ///包   

• 1.RetentionPolicy.SOURCE —— 这种类型的Annotations只在源代码级别保留,编译时就会被忽略
• 2.RetentionPolicy.CLASS —— 这种类型的Annotations编译时被保留,在class文件中存在,但JVM将会忽略
• 3.RetentionPolicy.RUNTIME —— 这种类型的Annotations将被JVM保留,所以他们能在运行时被JVM或其他使用反射机制的代码所读取和使用.