依赖包
<dependency>
<groupId>org.reflections</groupId>
<artifactId>reflections</artifactId>
<version>0.9.11</version>
</dependency>
<!-- 依赖guava包 -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>21.0</version>
</dependency>
核心方法
Reflections reflections = new Reflections("org.spring.*", new MethodAnnotationsScanner());
//比如可以获取有SupportVersion注解的class
Set<Method> methods = reflections.getMethodsAnnotatedWith(SupportVersion.class);
源码分析
Reflections对象中包含两个属性：
public class Reflections {
protected final transient Configuration configuration;
protected Store store;
}
其中configuration包含扫描方式、扫描位置、classLoader、执行服务、元数据适配器等
扫描方式有如下实现：
org.reflections.scanners.AbstractScanner
org.reflections.scanners.FieldAnnotationsScanner
org.reflections.scanners.MemberUsageScanner
org.reflections.scanners.MethodAnnotationsScanner
org.reflections.scanners.MethodParameterNamesScanner
org.reflections.scanners.MethodParameterScanner
org.reflections.scanners.imgsScanner
org.reflections.scanners.Scanner
org.reflections.scanners.SubTypesScanner
org.reflections.scanners.TypeAnnotationsScanner
org.reflections.scanners.TypeElementsScanner
org.reflections.scanners.TypesScanner
构造器中根据传入scanner不同，会将扫描结果以key为扫描方式，value为扫描结果的Map存入Reflections对象的store中。
public class Store {
private transient boolean concurrent;
private final Map<String, Multimap<String, String>> storeMap;
}
初始化完成后，即可使用reflections类提供的各种筛选方法获取store中扫描结果
注意：
获取扫描结果时，如果获取方式对应的扫描方式为空，会抛出错误如下：
Scanner XXX was not configured