bean和DBObject相互转换的方法

package com.iqbon.spider.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;  

public class BeanUtil {  

  /**
   * 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();
    for (Field field : fields) {
      // 获取属性名
      String varName = field.getName();
      // 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();
      Object object = dbObject.get(varName);
      if (object != null) {
        BeanUtils.setProperty(bean, varName, object);
      }
    }
    return bean;
  }
} 

出自：http://iqbon.iteye.com/blog/1756118