自己写的一个Java Bean转换为HashMap及ArrayList容器的功能类，支持Hibernate

XStream转换Object生成类结构垃圾数据太多了，影响网络，仿照之前的JSON工具类的写法，自己又写了个转换到仅HashMap和ArrayList容器的类来做一下处理。

思路主要就是把Bean的成员转换到HashMap，而Colecction和数组类型转换到ArrayList。这下除了原始类型外，就只包含HashMap和ArrayList两个JAVA类了。

这样做转换处理后，再用XStream做一下转换成的数据。。。哇，这下世界清洁多了:)


package com.aherp.framework.util;




import java.lang.reflect.Array;


import java.lang.reflect.Method;


import java.util.ArrayList;


import java.util.Collection;


import java.util.HashMap;


import java.util.Iterator;


import java.util.Map;




import org.json.JSONException;






/** *//**


* 转换工具类，支持反射的方式将对象转换为Map，将数组和Collection转换为List供XStrem使用


* @author Jim Wu


*


*/




public class ObjMapListUtil ...{




private static ObjMapListUtil instance = null;






static public Object toHashMap(Object obj) throws JSONException...{


return toHashMap(obj, false);


}






static public Object toHashMap(Object obj, boolean useClassConvert) throws JSONException...{


if(instance == null)


instance = new ObjMapListUtil();


return instance.getMapListObject(obj, useClassConvert);


}






/** *//**


* 代理类是否输出的检查，返回true则允许继续转换


* @param bean


* @return


*/




protected boolean canProxyOutput(Object bean) ...{


return true;


}






/** *//**


* 代理类时做的检查.返回应该检查的对象.


* @param bean


* @return


*/




protected Object proxyConvert(Object bean)...{


return bean;


}






public Object getMapListObject(Object bean, boolean useClassConvert)...{




if(bean == null)


return null;


bean = proxyConvert(bean);


Class clazz = bean.getClass();




if(bean instanceof Number || bean instanceof Boolean || bean instanceof String)...{


return bean;


}




if(clazz.isArray())...{




ArrayList<Object> arrayList = new ArrayList<Object>();




int arrayLength = Array.getLength(bean);




for(int i = 0; i < arrayLength; i ++)...{


Object rowObj = Array.get(bean, i);


if(canProxyOutput(rowObj))


arrayList.add(getMapListObject(rowObj, useClassConvert));


}


return arrayList;


}




if(bean instanceof Collection)...{




ArrayList<Object> arrayList = new ArrayList<Object>();




Iterator iterator = ((Collection)bean).iterator();




while(iterator.hasNext())...{


Object rowObj = iterator.next();


if(canProxyOutput(rowObj))


arrayList.add(getMapListObject(rowObj, useClassConvert));


}


return arrayList;


}




if(bean instanceof Map)...{


HashMap<String, Object> beanMap = new HashMap<String, Object>();




Map map = (Map)bean;


Iterator iterator = map.keySet().iterator();




while(iterator.hasNext())...{


Object key = iterator.next();


Object rowObj = map.get(key);


if(canProxyOutput(rowObj))


beanMap.put(key.toString(), getMapListObject(rowObj, useClassConvert));


}


return beanMap;


}




HashMap<String, Object> beanMap = new HashMap<String, Object>();


Class klass = bean.getClass();


Method[] methods = klass.getMethods();




for (int i = 0; i < methods.length; i ++) ...{




try ...{


Method method = methods[i];


String name = method.getName();


String key = "";




if (name.startsWith("get")) ...{


key = name.substring(3);




} else if (name.startsWith("is")) ...{


key = name.substring(2);


}


if (key.length() > 0 &&


Character.isUpperCase(key.charAt(0)) &&




method.getParameterTypes().length == 0) ...{




if (key.length() == 1) ...{


key = key.toLowerCase();




} else if (!Character.isUpperCase(key.charAt(1))) ...{


key = key.substring(0, 1).toLowerCase() +


key.substring(1);


}


Object elementObj = method.invoke(bean);




if(elementObj instanceof Class)...{


if(useClassConvert)


beanMap.put(key, elementObj.toString());


}




else...{


if(canProxyOutput(elementObj))


beanMap.put(key, getMapListObject(elementObj, useClassConvert));


}


}




} catch (Exception e) ...{




/**//* forget about it */


}


}


return beanMap;


}






}



支持Hibernate的类则继承一下，覆盖proxyConvert和canProxyOutput方法


package com.aherp.framework.util;




import org.hibernate.collection.PersistentSet;


import org.hibernate.proxy.HibernateProxy;


import org.hibernate.proxy.LazyInitializer;


import org.json.JSONException;






/** *//**


* 扩展为支持Hibernate的工具方法.


* @author Jim Wu


*


*/




public class HiObjMapListUtil extends ObjMapListUtil ...{




private static HiObjMapListUtil instance = null;






static public Object toHashMap(Object obj) throws JSONException...{


return toHashMap(obj, false);


}






static public Object toHashMap(Object obj, boolean useClassConvert) throws JSONException...{


if(instance == null)


instance = new HiObjMapListUtil();


return instance.getMapListObject(obj, useClassConvert);


}




@Override




protected Object proxyConvert(Object bean) ...{




if(bean instanceof HibernateProxy)...{


LazyInitializer lazyInitializer = ((HibernateProxy)bean).getHibernateLazyInitializer();




if(lazyInitializer.isUninitialized())...{


return lazyInitializer.getIdentifier();


}else


return lazyInitializer.getImplementation();


}




if(bean instanceof PersistentSet)...{




return new String[]...{}; //忽略hibernate one-to-many


}


return bean;


}




@Override




protected boolean canProxyOutput(Object bean) ...{


return !(bean != null && bean instanceof PersistentSet);


}


}



P.S.发现Hibernate Session的get方法拿到的对象仅填充了一个OID而已，需要Hibernate.initialize才能继续拿到整个实体的数据。这样XStream转换才正确，否则就是一个仅OID的List而已了