java bean转map JavaBean和Map转换封装类的方法

package com.ljq.util;

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


/**
 * Map工具类
 *
 * @author jqlin
 */
public class MapUtils {

  /**
   * 从map集合中获取属性值
   * 
   * @param <E>
   * @param map
   *      map集合
   * @param key
   *      键对
   * @param defaultValue
   *      默认值
   * @return
   * @author jiqinlin
   */
  @SuppressWarnings({ "unchecked", "rawtypes" })
  public final static <E> E get(Map map, Object key, E defaultValue) {
    Object o = map.get(key);
    if (o == null)
      return defaultValue;
    return (E) o;
  }
  
  /**
   * Map集合对象转化成 JavaBean集合对象
   * 
   * @param javaBean JavaBean实例对象
   * @param mapList Map数据集对象
   * @return
   * @author jqlin
   */
  @SuppressWarnings({ "rawtypes" })
  public static <T> List<T> map2Java(T javaBean, List<Map> mapList) {
    if(mapList == null || mapList.isEmpty()){
      return null;
    }
    List<T> objectList = new ArrayList<T>();
    
    T object = null;
    for(Map map : mapList){
      if(map != null){
        object = map2Java(javaBean, map);
        objectList.add(object);
      }
    }
    
    return objectList;
    
  }
  
  /**
   * Map对象转化成 JavaBean对象
   * 
   * @param javaBean JavaBean实例对象
   * @param map Map对象
   * @return
   * @author jqlin
   */
  @SuppressWarnings({ "rawtypes","unchecked", "hiding" })
  public static <T> T map2Java(T javaBean, Map map) {
    try {
      // 获取javaBean属性
      BeanInfo beanInfo = Introspector.getBeanInfo(javaBean.getClass());
      // 创建 JavaBean 对象
      Object obj = javaBean.getClass().newInstance();

      PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
      if (propertyDescriptors != null && propertyDescriptors.length > 0) {
        String propertyName = null; // javaBean属性名
        Object propertyValue = null; // javaBean属性值
        for (PropertyDescriptor pd : propertyDescriptors) {
          propertyName = pd.getName();
          if (map.containsKey(propertyName)) {
            propertyValue = map.get(propertyName);
            pd.getWriteMethod().invoke(obj, new Object[] { propertyValue });
          }
        }
        return (T) obj;
      }
    } catch (Exception e) {
      e.printStackTrace();
    }

    return null;
  }

  /**
   * JavaBean对象转化成Map对象
   * 
   * @param javaBean
   * @return
   * @author jqlin
   */
  @SuppressWarnings({ "rawtypes", "unchecked" })
  public static Map java2Map(Object javaBean) {
    Map map = new HashMap();
     
    try {
      // 获取javaBean属性
      BeanInfo beanInfo = Introspector.getBeanInfo(javaBean.getClass());

      PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
      if (propertyDescriptors != null && propertyDescriptors.length > 0) {
        String propertyName = null; // javaBean属性名
        Object propertyValue = null; // javaBean属性值
        for (PropertyDescriptor pd : propertyDescriptors) {
          propertyName = pd.getName();
          if (!propertyName.equals("class")) {
            Method readMethod = pd.getReadMethod();
            propertyValue = readMethod.invoke(javaBean, new Object[0]);
            map.put(propertyName, propertyValue);
          }
        }
      }
      
    } catch (Exception e) {
      e.printStackTrace();
    } 
    
    return map;
  }
 
}