Question

我有两个jsonobject在列表中。如果我制作新的jsonobject并尝试获取列表，那将给我null。

代码在下面-

    private int isExisting(String pid, List profile, String size) throws JSONException {
       for (int i = 0; i < profile.size(); i++) {
           JSONObject obj = new JSONObject(profile.get(i));
           log.info("--------------" + obj.toString());   //it is giving me an empty object but list contains two objects {"size":"M","id":11} and {"size":8,"id":19}
       }
    }

Answer 1

我尝试了这个方法

private void isExisting(String pid, List profile, String size) throws JSONException {
    for (int i = 0; i < profile.size(); i++) {
        if(profile.get(i)!=null) {
            JSONObject obj = new JSONObject(profile.get(i).toString());
            System.out.print("keys----------" + obj.toString());  
        }
    }
}

public void processList() {
    try {
        JSONObject objA= new JSONObject("{\n" +
                "      \"size\": \"M\",\n" +
                "      \"id\": 11\n" +
                "    }");
        JSONObject objB=new JSONObject("{\n" +
                "      \"size\": 8,\n" +
                "      \"id\": 19\n" +
                "    }");

        List<JSONObject> list=new ArrayList<>();
        list.add(objA);
        list.add(objB);
        isExisting("",list,"");
    } catch (JSONException e) {
        e.printStackTrace();
    }

}

Answer 2

我已经尝试过这种简单的逻辑，并且运行良好-

private int isExisting(String pid, List profile, String size) throws JSONException {
       for (int i = 0; i < profile.size(); i++) {
           JSONObject obj = (JSONObject) profile.get(i);
           log.info("--------------" + obj.toString());   
       }
    }

如何从Java列表中获取Jsonobject？

2 个答案: