获取JSON中所有的KEY

采用递归的方式，遍历JSON中所有的KEY。
JSON格式如下：
{"username":"tom","age":18,"address":[{"province":"上海市"},{"city":"上海市"},{"disrtict":"静安区"}]}
处理后，得到的结果如下:
address|province|city|disrtict|username|age
packageai.advance.until;
importcom.alibaba.fastjson.JSONObject;
importcom.alibaba.fastjson.JSONArray;
public classfastJsonDiff {
    /**
     * 递归读取所有的key
     *
     * @paramjsonObject
     */
    public staticStringBuffer getAllKey(JSONObject jsonObject) {
        StringBuffer stringBuffer = newStringBuffer();
        Iterator<String> keys = jsonObject.keySet().iterator();//jsonObject.keys();
        while(keys.hasNext()) {
            String key =keys.next();
            stringBuffer.append(key.toString()).append("|");
            if (jsonObject.get(key) instanceofJSONObject) {
                JSONObject innerObject =(JSONObject) jsonObject.get(key);
                stringBuffer.append(getAllKey(innerObject));
            } else if (jsonObject.get(key) instanceofJSONArray) {
                JSONArray innerObject =(JSONArray) jsonObject.get(key);
                stringBuffer.append(getAllKey(innerObject));
            }
        }
        returnstringBuffer;
    }
    public staticStringBuffer getAllKey(JSONArray json1) {
        StringBuffer stringBuffer = newStringBuffer();
        if (json1 != null) {
            Iterator i1 =json1.iterator();
            while(i1.hasNext()) {
                Object key =i1.next();
                if (key instanceofJSONObject) {
                    JSONObject innerObject =(JSONObject) key;
                    stringBuffer.append(getAllKey(innerObject));
                } else if (key instanceofJSONArray) {
                    JSONArray innerObject =(JSONArray) key;
                    stringBuffer.append(getAllKey(innerObject));
                }else{
                }
            }
        }
        returnstringBuffer;
    }
    private final static String st1 = "{"username":"tom","age":18,"address":[{"province":"上海市"},{"city":"上海市"},{"disrtict":"静安区"}]}";
    private final static String st2 = "{username:"tom",age:18}";
    public static voidmain(String[] args) {
        System.out.println(st1);
        JSONObject jsonObject1 =JSONObject.parseObject(st1);
        StringBuffer stb =getAllKey(jsonObject1);
        System.err.println(stb);
    }
}