Java tutorial
//package com.java2s; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; public class Main { public static final Map<String, String> map2Type(Map<String, Object> map) { Map<String, String> resultMap = new HashMap<String, String>(); Iterator<String> iterator = map.keySet().iterator(); while (iterator.hasNext()) { String key = iterator.next(); Object value = map.get(key); resultMap.put(key, Object2String(value)); } return resultMap; } public static final String Object2String(Object obj) { if (null == obj) { return ""; } else if (obj instanceof String) { return (String) obj; } else if (obj instanceof Integer || obj instanceof Double || obj instanceof Float) { return String.valueOf(obj); } else if (obj instanceof String[]) { if (((String[]) obj).length > 0) return String.valueOf(((String[]) obj)[0]); else return ""; } else if (obj instanceof List) { if (((List) obj).size() > 0) return String.valueOf(((List) obj).get(0)); else return ""; } return String.valueOf(obj); } }