Mybatis MetaObject和ObjectWrapper设计概念

莫问天涯路几重，轻衫侧帽且从容。这篇文章主要讲述Mybatis MetaObject和ObjectWrapper设计概念相关的知识，希望能为你提供帮助。
ObjectWrapper

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该类的作用是对象的包装，对对象属性的操作，其行为有

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BaseWrapper

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具备了MetaObject，对象包装的公共父类，主要处理集合类型

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BeanWrapper具备了储存对象的Object和MetaClass

@Override public Object get(PropertyTokenizer prop) { if (prop.getIndex() != null) { // 使用MetaObject逐级实例化集合对象 Object collection = resolveCollection(prop, object); // 使用MetaObject获得Value return getCollectionValue(prop, collection); } else { return getBeanProperty(prop, object); } }

MetaObject

private final Object originalObject; private final ObjectWrapper objectWrapper; private final ObjectFactory objectFactory; private final ObjectWrapperFactory objectWrapperFactory; private final ReflectorFactory reflectorFactory; private MetaObject(Object object, ObjectFactory objectFactory, ObjectWrapperFactory objectWrapperFactory, ReflectorFactory reflectorFactory) { this.originalObject = object; this.objectFactory = objectFactory; this.objectWrapperFactory = objectWrapperFactory; this.reflectorFactory = reflectorFactory; // 根据originalObject的类型实例化具体的ObjectMapper，将MetaObject自己注入进去，委派模式 if (object instanceof ObjectWrapper) { this.objectWrapper = (ObjectWrapper) object; } else if (objectWrapperFactory.hasWrapperFor(object)) { this.objectWrapper = objectWrapperFactory.getWrapperFor(this, object); } else if (object instanceof Map) { this.objectWrapper = new MapWrapper(this, (Map) object); } else if (object instanceof Collection) { this.objectWrapper = new CollectionWrapper(this, (Collection) object); } else { this.objectWrapper = new BeanWrapper(this, object); } }

获得初始对象的属性值通过ObjectWrapper并可能委派给MetaObject来获得。
【Mybatis MetaObject和ObjectWrapper设计概念】