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;
    }
}