Mybatis ObjectWrapper

  • Author: HuiFer
  • 源码阅读工程: SourceHot-Mybatis
  • 源码位于: org.apache.ibatis.reflection.wrapper.ObjectWrapper‘

类图：

image-20191223100956713

  1. public interface ObjectWrapper {
  3.     /**
  4.      * 根据 prop 获取属性值
  5.      *
  6.      * @param prop
  7.      * @return
  8.      */
  9.     Object get(PropertyTokenizer prop);
  11.     /**
  12.      * 设置属性
  13.      *
  14.      * @param prop  属性值名称
  15.      * @param value 属性值
  16.      */
  17.     void set(PropertyTokenizer prop, Object value);
  19.     /**
  20.      * 获取属性
  21.      *
  22.      * @param name
  23.      * @param useCamelCaseMapping
  24.      * @return
  25.      */
  26.     String findProperty(String name, boolean useCamelCaseMapping);
  28.     /**
  29.      * get 方法名,可读方法名
  30.      *
  31.      * @return
  32.      */
  33.     String[] getGetterNames();
  35.     /**
  36.      * set 方法名,可写方法名
  37.      *
  38.      * @return
  39.      */
  40.     String[] getSetterNames();
  42.     /**
  43.      * set 数据类型, 获取可写的数据类型
  44.      *
  45.      * @param name
  46.      * @return
  47.      */
  48.     Class<?> getSetterType(String name);
  50.     /**
  51.      * get 数据类型, 获取可读的数据类型
  52.      *
  53.      * @param name
  54.      * @return
  55.      */
  56.     Class<?> getGetterType(String name);
  58.     /**
  59.      * 判断是否包含set方法
  60.      *
  61.      * @param name
  62.      * @return
  63.      */
  64.     boolean hasSetter(String name);
  66.     /**
  67.      * 判断是否包含get方法
  68.      *
  69.      * @param name
  70.      * @return
  71.      */
  72.     boolean hasGetter(String name);
  74.     /**
  75.      * 初始化数据
  76.      *
  77.      * @param name
  78.      * @param prop
  79.      * @param objectFactory
  80.      * @return
  81.      */
  82.     MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory);
  84.     /**
  85.      * 判断是不是 list
  86.      *
  87.      * @return
  88.      */
  89.     boolean isCollection();
  91.     /**
  92.      * list add
  93.      *
  94.      * @param element
  95.      */
  96.     void add(Object element);
  98.     /**
  99.      * list addAll
  100.      *
  101.      * @param element
  102.      * @param <E>
  103.      */
  104.     <E> void addAll(List<E> element);
  106. }

BaseWrapper

  1. /**
  2.  * @author Clinton Begin
  3.  */
  4. public abstract class BaseWrapper implements ObjectWrapper {
  6.     protected static final Object[] NO_ARGUMENTS = new Object[0];
  7.     protected final MetaObject metaObject;
  9.     protected BaseWrapper(MetaObject metaObject) {
  10.         this.metaObject = metaObject;
  11.     }
  13.     /**
  14.      * 处理集合对象
  15.      * @param prop
  16.      * @param object
  17.      * @return
  18.      */
  19.     protected Object resolveCollection(PropertyTokenizer prop, Object object) {
  20.         if ("".equals(prop.getName())) {
  21.             return object;
  22.         } else {
  23.             return metaObject.getValue(prop.getName());
  24.         }
  25.     }
  27.     /**
  28.      * 对象获取,根据index
  29.      * map.get(index)
  30.      * 数组 array[index]
  31.      * list list.get(index)
  32.      * @param prop
  33.      * @param collection
  34.      * @return
  35.      */
  36.     protected Object getCollectionValue(PropertyTokenizer prop, Object collection) {
  37.         if (collection instanceof Map) {
  38.             // 如果是Map类型，则index为key
  39.             return ((Map) collection).get(prop.getIndex());
  40.         } else {
  41.             // index 作为下标直接获取
  42.             int i = Integer.parseInt(prop.getIndex());
  43.             if (collection instanceof List) {
  44.                 return ((List) collection).get(i);
  45.             } else if (collection instanceof Object[]) {
  46.                 return ((Object[]) collection)[i];
  47.             } else if (collection instanceof char[]) {
  48.                 return ((char[]) collection)[i];
  49.             } else if (collection instanceof boolean[]) {
  50.                 return ((boolean[]) collection)[i];
  51.             } else if (collection instanceof byte[]) {
  52.                 return ((byte[]) collection)[i];
  53.             } else if (collection instanceof double[]) {
  54.                 return ((double[]) collection)[i];
  55.             } else if (collection instanceof float[]) {
  56.                 return ((float[]) collection)[i];
  57.             } else if (collection instanceof int[]) {
  58.                 return ((int[]) collection)[i];
  59.             } else if (collection instanceof long[]) {
  60.                 return ((long[]) collection)[i];
  61.             } else if (collection instanceof short[]) {
  62.                 return ((short[]) collection)[i];
  63.             } else {
  64.                 throw new ReflectionException("The '" + prop.getName() + "' property of " + collection + " is not a List or Array.");
  65.             }
  66.         }
  67.     }
  69.     /**
  70.      * 设置属性值 ,List , object[] , char[] boolean byte double float int long short
  71.      * map -> put(index,value)
  72.      * list -> list.set(index,value)
  73.      * array -> array[index] = value
  74.      * @param prop
  75.      * @param collection
  76.      * @param value
  77.      */
  78.     protected void setCollectionValue(PropertyTokenizer prop, Object collection, Object value) {
  79.         if (collection instanceof Map) {
  80.             // map -> index:value
  81.             ((Map) collection).put(prop.getIndex(), value);
  82.         } else {
  83.             // 数组 -> array[index]=value
  84.             int i = Integer.parseInt(prop.getIndex());
  85.             if (collection instanceof List) {
  86.                 ((List) collection).set(i, value);
  87.             } else if (collection instanceof Object[]) {
  88.                 ((Object[]) collection)[i] = value;
  89.             } else if (collection instanceof char[]) {
  90.                 ((char[]) collection)[i] = (Character) value;
  91.             } else if (collection instanceof boolean[]) {
  92.                 ((boolean[]) collection)[i] = (Boolean) value;
  93.             } else if (collection instanceof byte[]) {
  94.                 ((byte[]) collection)[i] = (Byte) value;
  95.             } else if (collection instanceof double[]) {
  96.                 ((double[]) collection)[i] = (Double) value;
  97.             } else if (collection instanceof float[]) {
  98.                 ((float[]) collection)[i] = (Float) value;
  99.             } else if (collection instanceof int[]) {
  100.                 ((int[]) collection)[i] = (Integer) value;
  101.             } else if (collection instanceof long[]) {
  102.                 ((long[]) collection)[i] = (Long) value;
  103.             } else if (collection instanceof short[]) {
  104.                 ((short[]) collection)[i] = (Short) value;
  105.             } else {
  106.                 throw new ReflectionException("The '" + prop.getName() + "' property of " + collection + " is not a List or Array.");
  107.             }
  108.         }
  109.     }
  111. }

BeanWrapper

  1. public class BeanWrapper extends BaseWrapper {
  3.     private final Object object;
  5.     private final MetaClass metaClass;
  7.     /**
  8.      * 构造
  9.      * @param metaObject
  10.      * @param object
  11.      */
  12.     public BeanWrapper(MetaObject metaObject, Object object) {
  13.         super(metaObject);
  14.         this.object = object;
  15.         this.metaClass = MetaClass.forClass(object.getClass(), metaObject.getReflectorFactory());
  16.     }
  18.     @Override
  19.     public Object get(PropertyTokenizer prop) {
  20.         // 索引不为空
  21.         if (prop.getIndex() != null) {
  22.             // 实例化集合对象
  23.             Object collection = resolveCollection(prop, object);
  24.             return getCollectionValue(prop, collection);
  25.         } else {
  26.             // 没有索引
  27.             return getBeanProperty(prop, object);
  28.         }
  29.     }
  31.     @Override
  32.     public void set(PropertyTokenizer prop, Object value) {
  33.         // 是否存在索引
  34.         if (prop.getIndex() != null) {
  35.             Object collection = resolveCollection(prop, object);
  36.             // 向上层调用 BaseWrapper
  37.             setCollectionValue(prop, collection, value);
  38.         } else {
  39.             // 本类方法
  40.             setBeanProperty(prop, object, value);
  41.         }
  42.     }
  44.     @Override
  45.     public String findProperty(String name, boolean useCamelCaseMapping) {
  46.         return metaClass.findProperty(name, useCamelCaseMapping);
  47.     }
  49.     @Override
  50.     public String[] getGetterNames() {
  51.         return metaClass.getGetterNames();
  52.     }
  54.     @Override
  55.     public String[] getSetterNames() {
  56.         return metaClass.getSetterNames();
  57.     }
  59.     @Override
  60.     public Class<?> getSetterType(String name) {
  61.         PropertyTokenizer prop = new PropertyTokenizer(name);
  62.         if (prop.hasNext()) {
  64.             MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  65.             // 是否null
  66.             if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  67.                 return metaClass.getSetterType(name);
  68.             } else {
  69.                 return metaValue.getSetterType(prop.getChildren());
  70.             }
  71.         } else {
  72.             return metaClass.getSetterType(name);
  73.         }
  74.     }
  76.     @Override
  77.     public Class<?> getGetterType(String name) {
  78.         PropertyTokenizer prop = new PropertyTokenizer(name);
  79.         if (prop.hasNext()) {
  80.             MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  81.             if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  82.                 return metaClass.getGetterType(name);
  83.             } else {
  84.                 return metaValue.getGetterType(prop.getChildren());
  85.             }
  86.         } else {
  87.             return metaClass.getGetterType(name);
  88.         }
  89.     }
  91.     @Override
  92.     public boolean hasSetter(String name) {
  93.         PropertyTokenizer prop = new PropertyTokenizer(name);
  94.         if (prop.hasNext()) {
  95.             if (metaClass.hasSetter(prop.getIndexedName())) {
  96.                 MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  97.                 if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  98.                     return metaClass.hasSetter(name);
  99.                 } else {
  100.                     return metaValue.hasSetter(prop.getChildren());
  101.                 }
  102.             } else {
  103.                 return false;
  104.             }
  105.         } else {
  106.             return metaClass.hasSetter(name);
  107.         }
  108.     }
  110.     /**
  111.      * 是否包含 name 的get 方法
  112.      * @param name
  113.      * @return
  114.      */
  115.     @Override
  116.     public boolean hasGetter(String name) {
  117.         PropertyTokenizer prop = new PropertyTokenizer(name);
  118.         if (prop.hasNext()) {
  119.             if (metaClass.hasGetter(prop.getIndexedName())) {
  120.                 MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  121.                 if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  122.                     return metaClass.hasGetter(name);
  123.                 } else {
  124.                     return metaValue.hasGetter(prop.getChildren());
  125.                 }
  126.             } else {
  127.                 return false;
  128.             }
  129.         } else {
  130.             return metaClass.hasGetter(name);
  131.         }
  132.     }
  134.     /**
  135.      * 数据嵌套处理 a.b.c  需要处理成 a->b->c
  136.      * @param name
  137.      * @param prop
  138.      * @param objectFactory
  139.      * @return
  140.      */
  141.     @Override
  142.     public MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory) {
  143.         MetaObject metaValue;
  144.         Class<?> type = getSetterType(prop.getName());
  145.         try {
  146.             Object newObject = objectFactory.create(type);
  147.             // 出现嵌套处理 instantiatePropertyValue->set
  148.             metaValue = MetaObject.forObject(newObject, metaObject.getObjectFactory(), metaObject.getObjectWrapperFactory(), metaObject.getReflectorFactory());
  149.             set(prop, newObject);
  150.         } catch (Exception e) {
  151.             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);
  152.         }
  153.         return metaValue;
  154.     }
  156.     /**
  157.      * 获取 object 的  prop 属性值
  158.      * @param prop
  159.      * @param object
  160.      * @return
  161.      */
  162.     private Object getBeanProperty(PropertyTokenizer prop, Object object) {
  163.         try {
  164.             // 获取get 方法
  165.             Invoker method = metaClass.getGetInvoker(prop.getName());
  166.             try {
  167.                 // 获取属性值
  168.                 return method.invoke(object, NO_ARGUMENTS);
  169.             } catch (Throwable t) {
  170.                 throw ExceptionUtil.unwrapThrowable(t);
  171.             }
  172.         } catch (RuntimeException e) {
  173.             throw e;
  174.         } catch (Throwable t) {
  175.             throw new ReflectionException("Could not get property '" + prop.getName() + "' from " + object.getClass() + ".  Cause: " + t.toString(), t);
  176.         }
  177.     }
  179.     /**
  180.      * 设置 object 的属性 prop 值为 value
  181.      * @param prop
  182.      * @param object
  183.      * @param value
  184.      */
  185.     private void setBeanProperty(PropertyTokenizer prop, Object object, Object value) {
  186.         try {
  187.             // 获取set 方法
  188.             Invoker method = metaClass.getSetInvoker(prop.getName());
  189.             Object[] params = {value};
  190.             try {
  191.                 // 设置属性
  192.                 method.invoke(object, params);
  193.             } catch (Throwable t) {
  194.                 throw ExceptionUtil.unwrapThrowable(t);
  195.             }
  196.         } catch (Throwable t) {
  197.             throw new ReflectionException("Could not set property '" + prop.getName() + "' of '" + object.getClass() + "' with value '" + value + "' Cause: " + t.toString(), t);
  198.         }
  199.     }
  201.     @Override
  202.     public boolean isCollection() {
  203.         return false;
  204.     }
  206.     @Override
  207.     public void add(Object element) {
  208.         throw new UnsupportedOperationException();
  209.     }
  211.     @Override
  212.     public <E> void addAll(List<E> list) {
  213.         throw new UnsupportedOperationException();
  214.     }
  216. }

MapWrapper

  1. public class MapWrapper extends BaseWrapper {
  3.     private final Map<String, Object> map;
  5.     public MapWrapper(MetaObject metaObject, Map<String, Object> map) {
  6.         super(metaObject);
  7.         this.map = map;
  8.     }
  10.     @Override
  11.     public Object get(PropertyTokenizer prop) {
  12.         // 是否有索引
  13.         if (prop.getIndex() != null) {
  14.             Object collection = resolveCollection(prop, map);
  15.             // 嗲用 BaseWrapper
  16.             return getCollectionValue(prop, collection);
  17.         } else {
  18.             // 获取
  19.             return map.get(prop.getName());
  20.         }
  21.     }
  23.     @Override
  24.     public void set(PropertyTokenizer prop, Object value) {
  25.         if (prop.getIndex() != null) {
  26.             Object collection = resolveCollection(prop, map);
  27.             setCollectionValue(prop, collection, value);
  28.         } else {
  29.             map.put(prop.getName(), value);
  30.         }
  31.     }
  33.     @Override
  34.     public String findProperty(String name, boolean useCamelCaseMapping) {
  35.         return name;
  36.     }
  38.     @Override
  39.     public String[] getGetterNames() {
  40.         return map.keySet().toArray(new String[map.keySet().size()]);
  41.     }
  43.     @Override
  44.     public String[] getSetterNames() {
  45.         return map.keySet().toArray(new String[map.keySet().size()]);
  46.     }
  48.     @Override
  49.     public Class<?> getSetterType(String name) {
  50.         PropertyTokenizer prop = new PropertyTokenizer(name);
  51.         if (prop.hasNext()) {
  52.             MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  53.             if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  54.                 return Object.class;
  55.             } else {
  56.                 return metaValue.getSetterType(prop.getChildren());
  57.             }
  58.         } else {
  59.             if (map.get(name) != null) {
  60.                 return map.get(name).getClass();
  61.             } else {
  62.                 return Object.class;
  63.             }
  64.         }
  65.     }
  67.     @Override
  68.     public Class<?> getGetterType(String name) {
  69.         PropertyTokenizer prop = new PropertyTokenizer(name);
  70.         if (prop.hasNext()) {
  71.             MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  72.             if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  73.                 return Object.class;
  74.             } else {
  75.                 return metaValue.getGetterType(prop.getChildren());
  76.             }
  77.         } else {
  78.             if (map.get(name) != null) {
  79.                 return map.get(name).getClass();
  80.             } else {
  81.                 return Object.class;
  82.             }
  83.         }
  84.     }
  86.     @Override
  87.     public boolean hasSetter(String name) {
  88.         return true;
  89.     }
  91.     @Override
  92.     public boolean hasGetter(String name) {
  93.         PropertyTokenizer prop = new PropertyTokenizer(name);
  94.         if (prop.hasNext()) {
  95.             if (map.containsKey(prop.getIndexedName())) {
  96.                 MetaObject metaValue = metaObject.metaObjectForProperty(prop.getIndexedName());
  97.                 if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
  98.                     return true;
  99.                 } else {
  100.                     return metaValue.hasGetter(prop.getChildren());
  101.                 }
  102.             } else {
  103.                 return false;
  104.             }
  105.         } else {
  106.             return map.containsKey(prop.getName());
  107.         }
  108.     }
  110.     @Override
  111.     public MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory) {
  112.         HashMap<String, Object> map = new HashMap<>();
  113.         set(prop, map);
  114.         return MetaObject.forObject(map, metaObject.getObjectFactory(), metaObject.getObjectWrapperFactory(), metaObject.getReflectorFactory());
  115.     }
  117.     @Override
  118.     public boolean isCollection() {
  119.         return false;
  120.     }
  122.     @Override
  123.     public void add(Object element) {
  124.         throw new UnsupportedOperationException();
  125.     }
  127.     @Override
  128.     public <E> void addAll(List<E> element) {
  129.         throw new UnsupportedOperationException();
  130.     }
  132. }

CollectionWrapper

  1. public class CollectionWrapper implements ObjectWrapper {
  3.     private final Collection<Object> object;
  5.     public CollectionWrapper(MetaObject metaObject, Collection<Object> object) {
  6.         this.object = object;
  7.     }
  9.     @Override
  10.     public Object get(PropertyTokenizer prop) {
  11.         throw new UnsupportedOperationException();
  12.     }
  14.     @Override
  15.     public void set(PropertyTokenizer prop, Object value) {
  16.         throw new UnsupportedOperationException();
  17.     }
  19.     @Override
  20.     public String findProperty(String name, boolean useCamelCaseMapping) {
  21.         throw new UnsupportedOperationException();
  22.     }
  24.     @Override
  25.     public String[] getGetterNames() {
  26.         throw new UnsupportedOperationException();
  27.     }
  29.     @Override
  30.     public String[] getSetterNames() {
  31.         throw new UnsupportedOperationException();
  32.     }
  34.     @Override
  35.     public Class<?> getSetterType(String name) {
  36.         throw new UnsupportedOperationException();
  37.     }
  39.     @Override
  40.     public Class<?> getGetterType(String name) {
  41.         throw new UnsupportedOperationException();
  42.     }
  44.     @Override
  45.     public boolean hasSetter(String name) {
  46.         throw new UnsupportedOperationException();
  47.     }
  49.     @Override
  50.     public boolean hasGetter(String name) {
  51.         throw new UnsupportedOperationException();
  52.     }
  54.     @Override
  55.     public MetaObject instantiatePropertyValue(String name, PropertyTokenizer prop, ObjectFactory objectFactory) {
  56.         throw new UnsupportedOperationException();
  57.     }
  59.     /**
  60.      * 是否是list
  61.      *
  62.      * @return true
  63.      */
  64.     @Override
  65.     public boolean isCollection() {
  66.         return true;
  67.     }
  69.     /**
  70.      * java {@link Collection#add(Object)}
  71.      *
  72.      * @param element
  73.      */
  74.     @Override
  75.     public void add(Object element) {
  76.         object.add(element);
  77.     }
  79.     /**
  80.      * java {@link Collection#addAll(Collection)}
  81.      *
  82.      * @param element
  83.      * @param <E>
  84.      */
  85.     @Override
  86.     public <E> void addAll(List<E> element) {
  87.         object.addAll(element);
  88.     }
  90. }