我有一个包含其他对象列表的json对象，希望在java的HashMap中转换它

这是json，我想转换成HashMap `

ob=”{
“抵达”：“RONGO”，
“价格”：[
{
“id”：“，
“localId”：“，
“localCode”：“”，
“本地名称”：“，
“金额”：[
{
“价值”：950，
“货币”：“Ksh”
}
]
}
]
} ";     
Gson Gson=新的Gson（）；
HashMap result=new ObjectMapper（）.readValue（gson.toJson（ob），HashMap.class）；

` 但我无法访问对象， result.get（“amounts”）的值为空

---

有人可以帮我吗？

使用gson 2.0，您可以将json解析为HashMap和access array：

public static void main(String[] args) throws IOException {
    Gson gson = new Gson();
    HashMap<String, Object> map = gson.fromJson(new FileReader("test.json"), HashMap.class);

    ArrayList<Object> prices = (ArrayList<Object>) map.get("segmentPrices");

    prices.forEach(p -> {

        if (p instanceof LinkedHashMap) {
            System.out.println(((LinkedHashMap)p).get("amounts"));
        }

    });
}

您可以访问金额数组中对象内部的参数，如下所示：

public static void main(String[] args) throws IOException {
    Gson gson = new Gson();
    HashMap<String, Object> map = gson.fromJson(new FileReader("test.json"), HashMap.class);

    ArrayList<Object> prices = (ArrayList<Object>) map.get("segmentPrices");

    prices.forEach(p -> {

        if (p instanceof LinkedHashMap) {

            ArrayList<Object> amounts = (ArrayList<Object>) (((LinkedHashMap)p).get("amounts"));

            amounts.forEach(amount -> {
                System.out.println(((HashMap<String,Object>)amount).get("value"));
            });
        }

    });
}

---

您将需要javason库，如果您需要提取value的值，这就是您可以做的

String ob = "{\n"
                    + "         \"arrival\": \"RONGO\",\n"
                    + "         \"segmentPrices\": [\n"
                    + "          {\n"
                    + "          \"id\": \"\",\n"
                    + "          \"localId\": \"\",\n"
                    + "          \"localCode\": \"\",\n"
                    + "           \"localDesignation\": \"\",\n"
                    + "           \"amounts\": [\n"
                    + "            {\n"
                    + "             \"value\": 950,\n"
                    + "             \"currency\": \"Ksh\"\n"
                    + "            }\n"
                    + "               ]\n"
                    + "            }\n"
                    + "           ]\n"
                    + "          } ";
            JSONObject json = new JSONObject(ob.toString());

            System.out.println(json.getJSONArray("segmentPrices").getJSONObject(0).getJSONArray("amounts").getJSONObject(0).get("value"));

---

您使用什么版本的gson？

public static void main(String[] args) throws IOException {
    Gson gson = new Gson();
    HashMap<String, Object> map = gson.fromJson(new FileReader("test.json"), HashMap.class);

    ArrayList<Object> prices = (ArrayList<Object>) map.get("segmentPrices");

    prices.forEach(p -> {

        if (p instanceof LinkedHashMap) {

            ArrayList<Object> amounts = (ArrayList<Object>) (((LinkedHashMap)p).get("amounts"));

            amounts.forEach(amount -> {
                System.out.println(((HashMap<String,Object>)amount).get("value"));
            });
        }

    });
}

950.0

String ob = "{\n"
                    + "         \"arrival\": \"RONGO\",\n"
                    + "         \"segmentPrices\": [\n"
                    + "          {\n"
                    + "          \"id\": \"\",\n"
                    + "          \"localId\": \"\",\n"
                    + "          \"localCode\": \"\",\n"
                    + "           \"localDesignation\": \"\",\n"
                    + "           \"amounts\": [\n"
                    + "            {\n"
                    + "             \"value\": 950,\n"
                    + "             \"currency\": \"Ksh\"\n"
                    + "            }\n"
                    + "               ]\n"
                    + "            }\n"
                    + "           ]\n"
                    + "          } ";
            JSONObject json = new JSONObject(ob.toString());

            System.out.println(json.getJSONArray("segmentPrices").getJSONObject(0).getJSONArray("amounts").getJSONObject(0).get("value"));