json ，Map转json，全部分了

json 高手救命，Map转json，全部分了
Map<String,List> map=creditTranInfoBusiness.getCountByTime();
//map to array for josn 
Map<String,CreditTranInfoWebBean[]> drawDataMap=new HashMap<String,CreditTranInfoWebBean[]>();
for(String str:map.keySet()){
CreditTranInfoWebBean[] arr=(CreditTranInfoWebBean[])map.get(str).toArray(new CreditTranInfoWebBean[0]);
drawDataMap.put(str, arr);
}
logger.info("******************"+drawDataMap);  

String result ="";
  try {  
  logger.info("***************before**************");
  result = JsonUtil.map2Json(drawDataMap);
  如果声明drawDataMap时不写Map<String,CreditTranInfoWebBean[]> drawDataMap运行时抛出 throw new RuntimeException("Unsupported type: " + o.getClass().getName());这个的异常，但写了的话，报错  
  注：map这传值是没问题的。里面的值类似[{"key":"2","value":[{"id":0,"number":0,"timeOver":1289232300109,"timeStart":1289232000109,"tranCode":"2","tranCodeName":"信用卡"},{"id":0,"number":0,"timeOver":1289232600109,"timeStart":1289232300109,"tranCode":"2","tranCodeName":"信用卡"},{"id":0,"number":0,"timeOver":1289283000109,"timeStart":1289282700109,"tranCode":"2","tranCodeName":"信用卡"}]},{"key":"1","value":[]}]}
JsonUtil.Java
package com.yucheng.ecmp.ecmp4credit.web;

import java.util.Map;
import java.util.Set;

/**
 * Util for converting Java object to JSON string.
 * 
 * @author Xuefeng
 */
public final class JsonUtil {

  /**
  * Convert a Java object to JSON string.
  */
  @SuppressWarnings("unchecked")
  public static String toJson(Object o) {
  if (o==null)
  return "null";
  if (o instanceof String)
  return string2Json((String)o);
  if (o instanceof Boolean)
  return boolean2Json((Boolean)o);
  if (o instanceof Number)
  return number2Json((Number)o);
  if (o instanceof Map)
  return map2Json((Map<String, Object>)o);
  if (o instanceof Object[])
  return array2Json((Object[])o);
  if (o instanceof int[])
  return intArray2Json((int[])o);
  if (o instanceof boolean[])
  return booleanArray2Json((boolean[])o);
  if (o instanceof long[])
  return longArray2Json((long[])o);
  if (o instanceof float[])
  return floatArray2Json((float[])o);
  if (o instanceof double[])
  return doubleArray2Json((double[])o);
  if (o instanceof short[])
  return shortArray2Json((short[])o);
  if (o instanceof byte[])
  return byteArray2Json((byte[])o);
  throw new RuntimeException("Unsupported type: " + o.getClass().getName());
  }

  static String array2Json(Object[] array) {
  if (array.length==0)
  return "[]";
  StringBuilder sb = new StringBuilder(array.length << 4);
  sb.append('[');
  for (Object o : array) {
  sb.append(toJson(o));
  sb.append(',');
  }
  // set last ',' to ']':
  sb.setCharAt(sb.length()-1, ']');
  return sb.toString();