mongodb中Gson和java##Bean对象转化类

此类使用感觉比较繁琐, 每个字段加注解才可以使用, 不如mongoTemplate使用方便, 但如果使用mongo客户端的话, 还是比手动拼接快一点, 所以贴在这儿

package com.iwhere.util;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.Date;

import org.apache.commons.beanutils.BeanUtils;

import com.mongodb.BasicDBObject;
import com.mongodb.DBObject;
/**
 * DBObject 和 javaBean之間轉換
 * @author 231
 */
public class ConvertDBObject {

    /**
     * 把实体bean对象转换成DBObject
     * 
     * @param bean
     * @return
     * @throws IllegalArgumentException
     * @throws IllegalAccessException
     */
    public static <T> DBObject bean2DBObject(T bean) throws IllegalArgumentException, IllegalAccessException {
        if (bean == null) {
            return null;
        }
        
        DBObject dbObject = new BasicDBObject();
        // 获取对象对应类中的所有属性域
        Field[] fields = bean.getClass().getDeclaredFields();

        // 获取所有注解
        for (Field field : fields) {
            org.springframework.data.mongodb.core.mapping.Field anno = field
                    .getAnnotation(org.springframework.data.mongodb.core.mapping.Field.class);
            // 获取属性名
            String varName = field.getName();

            if ("serialVersionUID".equals(varName) || "_id".equals(varName)) {
                continue;
            }

            // 获取注解的值
            varName = anno.value();
            // 修改访问控制权限
            boolean accessFlag = field.isAccessible();
            if (!accessFlag) {
                field.setAccessible(true);
            }
            Object param = field.get(bean);
            if (param == null) {
                continue;
            } else if (param instanceof Integer) {// 判断变量的类型
                int value = ((Integer) param).intValue();
                dbObject.put(varName, value);
            } else if (param instanceof String) {
                String value = (String) param;
                dbObject.put(varName, value);
            } else if (param instanceof Double) {
                double value = ((Double) param).doubleValue();
                dbObject.put(varName, value);
            } else if (param instanceof Float) {
                float value = ((Float) param).floatValue();
                dbObject.put(varName, value);
            } else if (param instanceof Long) {
                long value = ((Long) param).longValue();
                dbObject.put(varName, value);
            } else if (param instanceof Boolean) {
                boolean value = ((Boolean) param).booleanValue();
                dbObject.put(varName, value);
            } else if (param instanceof Date) {
                Date value = (Date) param;
                dbObject.put(varName, value);
            }
            // 恢复访问控制权限
            field.setAccessible(accessFlag);
        }

        return dbObject;
    }

    /**
     * 把DBObject转换成bean对象
     * 
     * @param dbObject
     * @param bean
     * @return
     * @throws IllegalAccessException
     * @throws InvocationTargetException
     * @throws NoSuchMethodException
     */
    public static <T> T dbObject2Bean(DBObject dbObject, T bean)
            throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        if (bean == null) {
            return null;
        }
        Field[] fields = bean.getClass().getDeclaredFields();
        for (Field field : fields) {
            String varName = field.getName();
            org.springframework.data.mongodb.core.mapping.Field anno = field
                    .getAnnotation(org.springframework.data.mongodb.core.mapping.Field.class);
            if ("serialVersionUID".equals(varName) || "_id".equals(varName)) {
                continue;
            }

            String fieldName = anno.value();
            Object object = dbObject.get(fieldName);
            if (object != null) {
                BeanUtils.setProperty(bean, varName, object);
            }
        }
        return bean;
    }
}