为什么我的 API 和 JSON 应用程序在 Android Studio 中不起作用

Question

I working on a weather channel app with API and JSON. I wrote all the code but it doesn't work, any help would be appreciated. The API for my app is from https://openweathermap.org/ and I ran it through Postman.

Here is my activity_main.xml :

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/t1_temp"
        android:layout_width="124dp"
        android:layout_height="133dp"
        android:text="30"
        android:textSize="100dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.055"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.17" />

    <TextView
        android:id="@+id/t2_city"
        android:layout_width="130dp"
        android:layout_height="25dp"
        android:text="My City"
        android:textSize="15dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.069" />

    <TextView
        android:id="@+id/t3_description"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Sunny"
        android:textSize="15dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.043"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.33" />

    <TextView
        android:id="@+id/t4_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Date"
        android:textSize="15dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.041"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.075" />

    <TextView
        android:id="@+id/t5_C"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="C"
        android:textSize="30dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.349"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.143" />

</androidx.constraintlayout.widget.ConstraintLayout>

Here is my MainActivity.java :

package com.example.weatherchannel;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.text.SimpleDateFormat;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

    TextView t1_temp,t2_city,t3_description,t4_date;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        t1_temp = findViewById(R.id.t1_temp);
        t2_city = findViewById(R.id.t2_city);
        t3_description = findViewById(R.id.t3_description);
        t4_date = findViewById(R.id.t4_date);

        find_weather();
    }
    public void find_weather() {
        String url = "http://api.openweathermap.org/data/2.5/weather?q=kirkkonummi,finland&appid=48c0eb71736c9d90039d04e5c83581a0&units=metric";

        JsonObjectRequest jor = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    JSONObject main_object = response.getJSONObject("main");
                    JSONArray array = response.getJSONArray("weather");
                    JSONObject object = array.getJSONObject(0);
                    String temp = String.valueOf(main_object.getDouble("temp"));
                    String description = object.getString("description");
                    String city = response.getString("name");


                    //t1_temp.setText(temp);
                    t2_city.setText(city);
                    t3_description.setText(description);

                    Calendar calendar = Calendar.getInstance();
                    SimpleDateFormat sdf = new SimpleDateFormat("EEEE=MM-dd");
                    String formatted_date = sdf.format(calendar.getTime());

                    t4_date.setText(formatted_date);

                    double temp_int = Double.parseDouble(temp);
                    double centi = (temp_int - 32) / 1.8000;
                    centi = Math.round(centi);
                    int i = (int) centi;
                    t1_temp.setText(String.valueOf(i));

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

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        }
        );
        RequestQueue queue = Volley.newRequestQueue(this);
        queue.add(jor);
    }
}

and here is my AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.weatherchannel">
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

If more information is needed just ask.

Answer 1

I found the answer, my API url wasn't working so I changed it to https://samples.openweathermap.org/data/2.5/weather?q=London,uk&appid=48c0eb71736c9d90039d04e5c83581a0

although this is not the correct API, now I just know that my app works correctly, I just have to get the correct API for my location.