688 lines
19 KiB
Markdown
688 lines
19 KiB
Markdown
# Mybatis ObjectWrapper
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- Author: [HuiFer](https://github.com/huifer)
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- 源码阅读工程: [SourceHot-Mybatis](https://github.com/SourceHot/mybatis-read.git)
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- 源码位于: `org.apache.ibatis.reflection.wrapper.ObjectWrapper`‘
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类图：
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```java
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public interface ObjectWrapper {
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/**
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* 根据 prop 获取属性值
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*
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* @param prop
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* @return
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*/
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Object get(PropertyTokenizer prop);
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/**
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* 设置属性
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*
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* @param prop 属性值名称
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* @param value 属性值
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*/
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void set(PropertyTokenizer prop, Object value);
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/**
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* 获取属性
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*
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* @param name
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* @param useCamelCaseMapping
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* @return
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*/
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String findProperty(String name, boolean useCamelCaseMapping);
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/**
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* get 方法名,可读方法名
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*
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* @return
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*/
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String[] getGetterNames();
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/**
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* set 方法名,可写方法名
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*
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* @return
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*/
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String[] getSetterNames();
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/**
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* set 数据类型, 获取可写的数据类型
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*
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* @param name
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* @return
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*/
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Class<?> getSetterType(String name);
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/**
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* get 数据类型, 获取可读的数据类型
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*
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* @param name
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* @return
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*/
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Class<?> getGetterType(String name);
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/**
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* 判断是否包含set方法
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*
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* @param name
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* @return
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*/
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boolean hasSetter(String name);
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/**
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* 判断是否包含get方法
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*
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* @param name
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* @return
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*/
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boolean hasGetter(String name);
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/**
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* 初始化数据
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*
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* @param name
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* @param prop
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* @param objectFactory
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* @return
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*/
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MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory);
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/**
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* 判断是不是 list
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*
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* @return
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*/
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boolean isCollection();
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/**
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* list add
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*
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* @param element
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*/
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void add(Object element);
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/**
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* list addAll
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*
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* @param element
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* @param <E>
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*/
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<E> void addAll(List<E> element);
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}
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```
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## BaseWrapper
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```java
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/**
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* @author Clinton Begin
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*/
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public abstract class BaseWrapper implements ObjectWrapper {
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protected static final Object[] NO_ARGUMENTS = new Object[0];
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protected final MetaObject metaObject;
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protected BaseWrapper(MetaObject metaObject) {
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this.metaObject = metaObject;
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}
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/**
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* 处理集合对象
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* @param prop
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* @param object
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* @return
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*/
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protected Object resolveCollection(PropertyTokenizer prop, Object object) {
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if ("".equals(prop.getName())) {
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return object;
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} else {
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return metaObject.getValue(prop.getName());
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}
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}
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/**
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* 对象获取,根据index
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* map.get(index)
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* 数组 array[index]
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* list list.get(index)
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* @param prop
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* @param collection
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* @return
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*/
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protected Object getCollectionValue(PropertyTokenizer prop, Object collection) {
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if (collection instanceof Map) {
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// 如果是Map类型，则index为key
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return ((Map) collection).get(prop.getIndex());
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} else {
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// index 作为下标直接获取
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int i = Integer.parseInt(prop.getIndex());
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if (collection instanceof List) {
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return ((List) collection).get(i);
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} else if (collection instanceof Object[]) {
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return ((Object[]) collection)[i];
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} else if (collection instanceof char[]) {
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return ((char[]) collection)[i];
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} else if (collection instanceof boolean[]) {
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return ((boolean[]) collection)[i];
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} else if (collection instanceof byte[]) {
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return ((byte[]) collection)[i];
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} else if (collection instanceof double[]) {
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return ((double[]) collection)[i];
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} else if (collection instanceof float[]) {
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return ((float[]) collection)[i];
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} else if (collection instanceof int[]) {
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return ((int[]) collection)[i];
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} else if (collection instanceof long[]) {
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return ((long[]) collection)[i];
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} else if (collection instanceof short[]) {
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return ((short[]) collection)[i];
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} else {
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throw new ReflectionException("The '" + prop.getName() + "' property of " + collection + " is not a List or Array.");
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}
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}
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}
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/**
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* 设置属性值 ,List , object[] , char[] boolean byte double float int long short
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* map -> put(index,value)
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* list -> list.set(index,value)
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* array -> array[index] = value
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* @param prop
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* @param collection
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* @param value
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*/
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protected void setCollectionValue(PropertyTokenizer prop, Object collection, Object value) {
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if (collection instanceof Map) {
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// map -> index:value
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((Map) collection).put(prop.getIndex(), value);
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} else {
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// 数组 -> array[index]=value
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int i = Integer.parseInt(prop.getIndex());
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if (collection instanceof List) {
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((List) collection).set(i, value);
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} else if (collection instanceof Object[]) {
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((Object[]) collection)[i] = value;
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} else if (collection instanceof char[]) {
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((char[]) collection)[i] = (Character) value;
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} else if (collection instanceof boolean[]) {
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((boolean[]) collection)[i] = (Boolean) value;
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} else if (collection instanceof byte[]) {
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((byte[]) collection)[i] = (Byte) value;
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} else if (collection instanceof double[]) {
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((double[]) collection)[i] = (Double) value;
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} else if (collection instanceof float[]) {
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((float[]) collection)[i] = (Float) value;
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} else if (collection instanceof int[]) {
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((int[]) collection)[i] = (Integer) value;
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} else if (collection instanceof long[]) {
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((long[]) collection)[i] = (Long) value;
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} else if (collection instanceof short[]) {
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((short[]) collection)[i] = (Short) value;
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} else {
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throw new ReflectionException("The '" + prop.getName() + "' property of " + collection + " is not a List or Array.");
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}
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}
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}
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}
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```
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## BeanWrapper
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```java
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public class BeanWrapper extends BaseWrapper {
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private final Object object;
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private final MetaClass metaClass;
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/**
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* 构造
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* @param metaObject
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* @param object
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*/
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public BeanWrapper(MetaObject metaObject, Object object) {
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super(metaObject);
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this.object = object;
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this.metaClass = MetaClass.forClass(object.getClass(), metaObject.getReflectorFactory());
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}
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@Override
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public Object get(PropertyTokenizer prop) {
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// 索引不为空
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if (prop.getIndex() != null) {
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// 实例化集合对象
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Object collection = resolveCollection(prop, object);
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return getCollectionValue(prop, collection);
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} else {
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// 没有索引
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return getBeanProperty(prop, object);
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}
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}
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@Override
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public void set(PropertyTokenizer prop, Object value) {
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// 是否存在索引
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if (prop.getIndex() != null) {
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Object collection = resolveCollection(prop, object);
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// 向上层调用 BaseWrapper
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setCollectionValue(prop, collection, value);
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} else {
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// 本类方法
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setBeanProperty(prop, object, value);
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}
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}
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@Override
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public String findProperty(String name, boolean useCamelCaseMapping) {
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return metaClass.findProperty(name, useCamelCaseMapping);
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}
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@Override
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public String[] getGetterNames() {
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return metaClass.getGetterNames();
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}
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@Override
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public String[] getSetterNames() {
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return metaClass.getSetterNames();
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}
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@Override
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public Class<?> getSetterType(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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// 是否null
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return metaClass.getSetterType(name);
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} else {
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return metaValue.getSetterType(prop.getChildren());
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}
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} else {
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return metaClass.getSetterType(name);
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}
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}
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@Override
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public Class<?> getGetterType(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return metaClass.getGetterType(name);
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} else {
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return metaValue.getGetterType(prop.getChildren());
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}
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} else {
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return metaClass.getGetterType(name);
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}
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}
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@Override
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public boolean hasSetter(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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if (metaClass.hasSetter(prop.getIndexedName())) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return metaClass.hasSetter(name);
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} else {
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return metaValue.hasSetter(prop.getChildren());
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}
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} else {
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return false;
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}
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} else {
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return metaClass.hasSetter(name);
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}
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}
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/**
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* 是否包含 name 的get 方法
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* @param name
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* @return
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*/
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@Override
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public boolean hasGetter(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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if (metaClass.hasGetter(prop.getIndexedName())) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return metaClass.hasGetter(name);
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} else {
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return metaValue.hasGetter(prop.getChildren());
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}
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} else {
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return false;
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}
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} else {
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return metaClass.hasGetter(name);
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}
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}
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/**
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* 数据嵌套处理 a.b.c 需要处理成 a->b->c
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* @param name
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* @param prop
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* @param objectFactory
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* @return
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*/
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@Override
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public MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory) {
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MetaObject metaValue;
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Class<?> type = getSetterType(prop.getName());
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try {
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Object newObject = objectFactory.create(type);
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// 出现嵌套处理 instantiatePropertyValue->set
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metaValue = MetaObject.forObject(newObject, metaObject.getObjectFactory(), metaObject.getObjectWrapperFactory(), metaObject.getReflectorFactory());
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set(prop, newObject);
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} catch (Exception e) {
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throw new ReflectionException("Cannot set value of property '" + name + "' because '" + name + "' is null and cannot be instantiated on instance of " + type.getName() + ". Cause:" + e.toString(), e);
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}
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return metaValue;
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}
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/**
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* 获取 object 的 prop 属性值
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* @param prop
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* @param object
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* @return
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*/
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private Object getBeanProperty(PropertyTokenizer prop, Object object) {
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try {
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// 获取get 方法
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Invoker method = metaClass.getGetInvoker(prop.getName());
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try {
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// 获取属性值
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return method.invoke(object, NO_ARGUMENTS);
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} catch (Throwable t) {
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throw ExceptionUtil.unwrapThrowable(t);
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}
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} catch (RuntimeException e) {
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throw e;
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} catch (Throwable t) {
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throw new ReflectionException("Could not get property '" + prop.getName() + "' from " + object.getClass() + ". Cause: " + t.toString(), t);
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}
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}
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/**
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* 设置 object 的属性 prop 值为 value
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* @param prop
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* @param object
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* @param value
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*/
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private void setBeanProperty(PropertyTokenizer prop, Object object, Object value) {
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try {
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// 获取set 方法
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Invoker method = metaClass.getSetInvoker(prop.getName());
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Object[] params = {value};
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try {
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// 设置属性
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method.invoke(object, params);
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} catch (Throwable t) {
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throw ExceptionUtil.unwrapThrowable(t);
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}
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} catch (Throwable t) {
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throw new ReflectionException("Could not set property '" + prop.getName() + "' of '" + object.getClass() + "' with value '" + value + "' Cause: " + t.toString(), t);
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}
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}
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@Override
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public boolean isCollection() {
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return false;
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}
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@Override
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public void add(Object element) {
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throw new UnsupportedOperationException();
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}
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@Override
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public <E> void addAll(List<E> list) {
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throw new UnsupportedOperationException();
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}
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}
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```
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## MapWrapper
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```java
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public class MapWrapper extends BaseWrapper {
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private final Map<String, Object> map;
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public MapWrapper(MetaObject metaObject, Map<String, Object> map) {
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super(metaObject);
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this.map = map;
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}
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@Override
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public Object get(PropertyTokenizer prop) {
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// 是否有索引
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if (prop.getIndex() != null) {
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Object collection = resolveCollection(prop, map);
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// 嗲用 BaseWrapper
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return getCollectionValue(prop, collection);
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} else {
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// 获取
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return map.get(prop.getName());
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}
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}
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@Override
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public void set(PropertyTokenizer prop, Object value) {
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if (prop.getIndex() != null) {
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Object collection = resolveCollection(prop, map);
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setCollectionValue(prop, collection, value);
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} else {
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map.put(prop.getName(), value);
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}
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}
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@Override
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public String findProperty(String name, boolean useCamelCaseMapping) {
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return name;
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}
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@Override
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public String[] getGetterNames() {
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return map.keySet().toArray(new String[map.keySet().size()]);
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}
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@Override
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public String[] getSetterNames() {
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return map.keySet().toArray(new String[map.keySet().size()]);
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}
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@Override
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public Class<?> getSetterType(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return Object.class;
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} else {
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return metaValue.getSetterType(prop.getChildren());
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}
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} else {
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if (map.get(name) != null) {
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return map.get(name).getClass();
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} else {
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return Object.class;
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}
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}
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}
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@Override
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public Class<?> getGetterType(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return Object.class;
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} else {
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return metaValue.getGetterType(prop.getChildren());
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}
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} else {
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if (map.get(name) != null) {
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return map.get(name).getClass();
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} else {
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return Object.class;
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}
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}
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}
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@Override
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public boolean hasSetter(String name) {
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return true;
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}
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@Override
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public boolean hasGetter(String name) {
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PropertyTokenizer prop = new PropertyTokenizer(name);
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if (prop.hasNext()) {
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if (map.containsKey(prop.getIndexedName())) {
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MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
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if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
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return true;
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} else {
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return metaValue.hasGetter(prop.getChildren());
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}
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} else {
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return false;
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}
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} else {
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return map.containsKey(prop.getName());
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}
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}
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@Override
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public MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory) {
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HashMap<String, Object> map = new HashMap<>();
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set(prop, map);
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return MetaObject.forObject(map, metaObject.getObjectFactory(), metaObject.getObjectWrapperFactory(), metaObject.getReflectorFactory());
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}
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@Override
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public boolean isCollection() {
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return false;
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}
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@Override
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public void add(Object element) {
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throw new UnsupportedOperationException();
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}
|
||
|
||
@Override
|
||
public <E> void addAll(List<E> element) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
## CollectionWrapper
|
||
|
||
```java
|
||
public class CollectionWrapper implements ObjectWrapper {
|
||
|
||
private final Collection<Object> object;
|
||
|
||
public CollectionWrapper(MetaObject metaObject, Collection<Object> object) {
|
||
this.object = object;
|
||
}
|
||
|
||
@Override
|
||
public Object get(PropertyTokenizer prop) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public void set(PropertyTokenizer prop, Object value) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public String findProperty(String name, boolean useCamelCaseMapping) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public String[] getGetterNames() {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public String[] getSetterNames() {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public Class<?> getSetterType(String name) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public Class<?> getGetterType(String name) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public boolean hasSetter(String name) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public boolean hasGetter(String name) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
@Override
|
||
public MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory) {
|
||
throw new UnsupportedOperationException();
|
||
}
|
||
|
||
/**
|
||
* 是否是list
|
||
*
|
||
* @return true
|
||
*/
|
||
@Override
|
||
public boolean isCollection() {
|
||
return true;
|
||
}
|
||
|
||
/**
|
||
* java {@link Collection#add(Object)}
|
||
*
|
||
* @param element
|
||
*/
|
||
@Override
|
||
public void add(Object element) {
|
||
object.add(element);
|
||
}
|
||
|
||
/**
|
||
* java {@link Collection#addAll(Collection)}
|
||
*
|
||
* @param element
|
||
* @param <E>
|
||
*/
|
||
@Override
|
||
public <E> void addAll(List<E> element) {
|
||
object.addAll(element);
|
||
}
|
||
|
||
}
|
||
```
|