解析Json字符串检索所有字段

I have been trying to parse json with volley , somehow i managed to extract some data but i am unable parse other fields . What i am trying do is checking which user role is doctor and store only that user to a1 arraylist

我一直试图用齐射解析json,不知怎的,我设法提取了一些数据,但我无法解析其他字段。我正在尝试做的是检查哪个用户角色是医生并且仅将该用户存储到a1 arraylist

{"user1":{"password":"******","presence":{"lastSeen":1484695229773,"status":"online"},"role":"Patient"},"user2":{"password":"******","presence":{"lastSeen":1484695229773,"status":"offline"},"role":"Doctor"}}

here is my code :

这是我的代码:

   public class Users extends AppCompatActivity {
    ListView usersList;
    TextView noUsersText;
    ArrayList<String> al = new ArrayList<>();
    int totalUsers = 0;
    ProgressDialog pd;
    private Firebase mRef;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.act_users);

        usersList = (ListView)findViewById(R.id.usersList);
        noUsersText = (TextView)findViewById(R.id.noUsersText);


        pd = new ProgressDialog(Users.this);
        pd.setMessage("Loading...");
        pd.show();

        String url = "https://**********.firebaseio.com/users.json";

        StringRequest request = new StringRequest(Request.Method.GET, url, new Response.Listener<String>(){
            @Override
            public void onResponse(String s) {
                doOnSuccess(s);
            }
        },new Response.ErrorListener(){
            @Override
            public void onErrorResponse(VolleyError volleyError) {
                System.out.println("" + volleyError);
            }
        });

        RequestQueue rQueue = Volley.newRequestQueue(Users.this);
        rQueue.add(request);

        usersList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                UserDetails.chatWith = al.get(position);
                startActivity(new Intent(Users.this, Chat.class));
            }
        });






    }//oncreate ends here




    public void doOnSuccess(String s){
        try {
            JSONObject obj = new JSONObject(s);

            Iterator i = obj.keys();
            String key = "";

            while(i.hasNext()){
                key = i.next().toString();

                if(!key.equals(UserDetails.username)) {
                    al.add(key); /// here want to store only user with doctor role
//currently all users are displaying
                }

                totalUsers++;
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }

        if(totalUsers <=1){
            noUsersText.setVisibility(View.VISIBLE);
            usersList.setVisibility(View.GONE);
        }
        else{
            noUsersText.setVisibility(View.GONE);
            usersList.setVisibility(View.VISIBLE);
            usersList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, al));
        }

        pd.dismiss();
    }
}

i am successfully getting the Root Object "user1" and "user2" but i want to extract all other fields as well

我成功获取根对象“user1”和“user2”,但我想提取所有其他字段

kindly tell how i have to change my code for all fields.

请告诉我如何更改所有字段的代码。

EDITED

 public void doOnSuccess(String s){
        try {
            JSONObject obj = new JSONObject(s);




            Iterator i = obj.keys();
            String key = "";

            while(i.hasNext()){
                key = i.next().toString();
                JSONObject singleUser = (JSONObject) obj.get(key);
                String role = singleUser.get("role").toString();

                if(!key.equals(UserDetails.username)) {
                    if (role.equals("Doctor")) {
                       // doctors.add(keys);
                        al.add(key);
                    }

                }

                totalUsers++;
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }

        if(totalUsers <=1){
            noUsersText.setVisibility(View.VISIBLE);
            usersList.setVisibility(View.GONE);
        }
        else{
            noUsersText.setVisibility(View.GONE);
            usersList.setVisibility(View.VISIBLE);
            usersList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, al));
        }

        pd.dismiss();
    }
}

3 个解决方案

#1

This should give all users with doctor role.

这应该为所有用户提供医生角色。

        JSONParser parser = new JSONParser();

        Object obj = parser.parse(new FileReader(
                "sample.json"));

        JSONObject jsonObject = (JSONObject) obj;

        Set<String> keySet = jsonObject.keySet();
        List<String> doctors = new ArrayList<>();

        for (String keys : keySet) {
            JSONObject singleUser = (JSONObject) jsonObject.get(keys);
            String role = singleUser.get("role").toString();
            if (role.equals("Doctor")) {
                doctors.add(keys);
            }
        }
        System.out.println("Doctor users are --" + doctors);

Output -

Doctor users are --[user2]

医生用户是 - [user2]

#2

You get the values from the User Object as follows

您可以从User Object获取值,如下所示

JSONObject user = obj.getJSONObject("user1");
String role = user.getString("role");
JSONObject presence = user.getJSONObject("presence");
String status = presence.getString("status");

#3

You have embedded JSON objects that can be easily accessed by the JSON object method: (assuming 'userList' is your root JSONObject);

您已经嵌入了可以通过JSON对象方法轻松访问的JSON对象:(假设'userList'是您的根JSONObject);

JSONObject user2 = userList.getJSONObject("user2");

These objects can then have their properties accessed via:

然后,可以通过以下方式访问这些对象:

String user2Password = user2.getString("password");

String user2Password = user2.getString(“password”);

Note the property 'presence' is also an embedded JSONObject, and so will have to be accessed with the JSONObject.getJSONObject() method.

请注意,属性“presence”也是嵌入式JSONObject,因此必须使用JSONObject.getJSONObject()方法进行访问。

So if you want to store these values in an ArrayList, simply create:

因此,如果要将这些值存储在ArrayList中,只需创建:

ArrayList<JSONObject> userArrayList = new ArrayList<JSONObject>();

... and then proceed to store values (probably iteratively) with:

...然后继续存储值(可能是迭代地):

userArrayList.add(user2);