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;

     }

 }