Java解析JSON---JSON循环嵌套找key，找到后替换原有key

思路是写一个递归函数

1. 先找key，

2. 找不到的话去value里面找。value里面分三种情况，

• 1.value是json类型就继续找
• 2.如果是数组，就遍历之后递归
• 3，如果是普通类型就continue

    public static String analyseJson(String jsonData, String oldKey, String newKey) {
        JSONObject res = new JSONObject();
        JSONObject jsonObject = JSON.parseObject(jsonData);
        //1. 首先在jsonObject里面找得到key，则直接替换;
        if (jsonObject.containsKey(oldKey)) {
            if (!StringUtils.isEmpty(newKey)) {
                res.put(newKey, jsonObject.get(oldKey));
            }
            return JSON.toJSONString(res);
        }else {
            // 2. 解析value;分三种类型。
            for (Map.Entry entry : jsonObject.entrySet()) {
                Object value = entry.getValue();
                //if:如果value是json类型继续递归解析; else if数组; else基本类型，则continue;
                if (value instanceof JSONObject) {
                    return analyseJson(String.valueOf(value), oldKey, newKey);
                } else if (value instanceof JSONArray) {
                    JSONArray objArray = (JSONArray)value;
                    for (int i = 0; i < objArray.size(); i++) {
                        return analyseJson(String.valueOf(objArray.get(i)),oldKey,newKey);
                    }
                } else {
                    continue;
                }
            }
            return res.toJSONString();
        }
    }

public static void main(String[] args) {
        String test = "{n" +
                "                    "key_as_string": "2022-06-24T08:00:00.000+08:00",n" +
                "                    "key": 1656028800000,n" +
                "                    "doc_count": 13486,n" +
                "                    "avgValue": {n" +
                "                        "value1": 81.9979979237728n" +
                "                    },n" +
                "                    "lastValue": {n" +
                "                        "value2": 19n" +
                "                    }n" +
                "                }n";
        System.out.println("解析前："+test);

        String s = analyseJson(test, "value1", "ycccc");
        System.out.println("解析后："+s);
    }

String test2 = "{n" +
                "    "error": 0,n" +
                "    "status": "success",n" +
                "    "results": [n" +
                "        {n" +
                "            "currentCity": "青岛",n" +
                "            "index": [n" +
                "                {n" +
                "                    "title": "穿衣",n" +
                "                    "zs": "较冷",n" +
                "                    "tipt": "穿衣指数",n" +
                "                    "des": "建议着厚外套加毛衣等服装。年老体弱者宜着大衣、呢外套加羊毛衫。"n" +
                "                },n" +
                "                {n" +
                "                    "title": "紫外线强度",n" +
                "                    "zs": "中等",n" +
                "                    "tipt": "紫外线强度指数",n" +
                "                    "des": "属中等强度紫外线辐射天气，外出时建议涂擦SPF高于15、PA+的防晒护肤品，戴帽子、太阳镜。"n" +
                "                }n" +
                "            ]n" +
                "        }n" +
                "    ]n" +
                "}";
        System.out.println("解析前："+test2);

OK！