Java-实体与集合转换

 import java.beans.BeanInfo;
 import java.beans.IntrospectionException;
 import java.beans.Introspector;
 import java.beans.PropertyDescriptor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 /**
  * 用于对javabean和map之间的相互装换的工具类
  */
 public class BeanMapConvertUtils {

     /**
      * 将Map转为javaBean
      */
     public static <T> T mapToObject(Map<String, Object> map, Class<T> beanClass) {
         if (map == null)
             return null;
         T obj = null;
         BeanInfo beanInfo = null;
         try {
             obj = beanClass.newInstance();
             beanInfo = Introspector.getBeanInfo(obj.getClass());
         } catch (IntrospectionException | InstantiationException | IllegalAccessException e) {
             e.printStackTrace();
             return null; // 如果在创建实例和获取beaninfo出现异常则直接返回null
         }
         PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
         for (PropertyDescriptor property : propertyDescriptors) {
             Method setter = property.getWriteMethod();
             if (setter != null) {
                 String key = property.getName();
                 try {
                     setter.invoke(obj, map.get(key));
                 } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
                 }
             }
         }
         return obj;
     }

     /**
      * @Description: 将Map转为javaBean
      * @param map 要转换的map对象
      * @param beanClass 需要转成的javabean的class
      * @param requiredPropertys 需要转换后包含的属性名集合
      */
     public static <T> T mapToObject(Map<String, Object> map, Class<T> beanClass, Collection<String> requiredPropertys) {
         if (map == null)
             return null;
         T obj = null;
         BeanInfo beanInfo = null;
         try {
             obj = beanClass.newInstance();
             beanInfo = Introspector.getBeanInfo(obj.getClass());
         } catch (IntrospectionException | InstantiationException | IllegalAccessException e) {
             e.printStackTrace();
             return null; // 如果在创建实例和获取beaninfo出现异常则直接返回null
         }
         PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
         for (PropertyDescriptor property : propertyDescriptors) {
             Method setter = property.getWriteMethod();
             if (setter != null) {
                 String key = property.getName();
                 if (requiredPropertys != null && !requiredPropertys.contains(key)) {// 如果不包含需要的属性则跳过
                     continue;
                 }
                 try {
                     setter.invoke(obj, map.get(key));
                 } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
                 }
             }
         }
         return obj;
     }

     /**
      *  将javabean集合转为map集合
      * @param objList avabean集合
      * @param requiredPropertys 需要转换后包含的属性名集合
      */
     public static List<Map<String, Object>> objectsToMaps(Collection<?> objList, Collection<String> requiredPropertys) {
         List<Map<String, Object>> arrayList = new ArrayList<Map<String, Object>>();
         if (objList != null) {
             for (Object obj : objList) {
                 Map<String, Object> objectToMap = objectToMap(obj, requiredPropertys);
                 if (objectToMap != null) {
                     arrayList.add(objectToMap);
                 }
             }
         }
         return arrayList;
     }

     /**
      * 将javaBean转为Map
      */
     public static Map<String, Object> objectToMap(Object obj) {
         if (obj == null)
             return null;
         Map<String, Object> map = new HashMap<String, Object>();
         try {
             BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
             PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
             for (PropertyDescriptor property : propertyDescriptors) {
                 String key = property.getName();
                 if (key.compareToIgnoreCase("class") == 0) {
                     continue;
                 }
                 Method getter = property.getReadMethod();
                 Object value = getter != null ? getter.invoke(obj) : null;
                 map.put(key, value);
             }
         } catch (Exception e) {
             map = null;
             e.printStackTrace();
         }
         return map;
     }

     /**
      *  将Map转为javaBean
      * @param obj 要转换的javabean对象
      * @param requiredPropertys 需要转换后包含的属性名集合
      */
     public static Map<String, Object> objectToMap(Object obj, Collection<String> requiredPropertys) {
         if (obj == null)
             return null;
         Map<String, Object> map = new HashMap<String, Object>();
         try {
             BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
             PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
             for (PropertyDescriptor property : propertyDescriptors) {
                 String key = property.getName();
                 if (key.compareToIgnoreCase("class") == 0) {
                     continue;
                 }
                 if (requiredPropertys != null && !requiredPropertys.contains(key)) {// 如果不包含需要的属性则跳过
                     continue;
                 }
                 Method getter = property.getReadMethod();
                 Object value = getter != null ? getter.invoke(obj) : null;
                 map.put(key, value);
             }
         } catch (Exception e) {
             map = null;
             e.printStackTrace();
         }
         return map;
     }
 }