java.net.UnknownHostException：无法解析主机“api.themoviedb.org”

Question

I'm getting this error message "java.net.UnknownHostException: Unable to resolve host "api.themoviedb.org": No address associated with hostname". All the stackoverflow posts I read said that the manifest file might be wrong, but I think at this point it's right, so I'm not sure how to continue.

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.flixster">
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<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>

MainActivity.java:

package com.example.flixster;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;

import com.codepath.asynchttpclient.AsyncHttpClient;
import com.codepath.asynchttpclient.callback.JsonHttpResponseHandler;

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

import okhttp3.Headers;

 import static com.facebook.stetho.inspector.network.PrettyPrinterDisplayType.JSON;

 public class MainActivity extends AppCompatActivity {

    public static final String NOW_PLAYING_URL = 
   "https://api.themoviedb.org/3//movie/now_playing?api_key=a07e22bc18f5cb106bfe4cc1f83ad8ed";
    public static final String TAG = "MainActivity";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // make get request on URL to get currently playing movies
    AsyncHttpClient client = new AsyncHttpClient();
    // JSON response handler since API returns JSON- deals with response success/failure
    client.get(NOW_PLAYING_URL, new JsonHttpResponseHandler() {
        @Override
        public void onSuccess(int statusCode, Headers headers, JsonHttpResponseHandler.JSON json) {
            Log.d(TAG, "onSuccess");
            JSONObject  jsonObject = json.jsonObject;

            try {
                JSONArray results = jsonObject.getJSONArray("result");
                Log.i(TAG, "Results: " + results.toString());
            } catch (JSONException e) {
                Log.e(TAG, "Hit json exception", e);
                e.printStackTrace();
            }
        }

        @Override
        public void onFailure(int statusCode, Headers headers, String response, Throwable throwable) {
            Log.d(TAG, "onFailure");
        }
    });
}

}

Answer 1

Looking at your code I found 2 issues:

1. Your NOW_PLAYING_URL has an additional slash ( themoviedb.org/3//movie/ ) after 3 so replace the string as

   public static final String NOW_PLAYING_URL = "https://api.themoviedb.org/3/movie/now_playing?api_key=a07e22bc18f5cb106bfe4cc1f83ad8ed";

That was the reason why your api call returns a failure.

2. Next, the response is success but in your onSuccess() try block you are fetching data for "result" but your API response returns "results" so replace that key as below and you should not be having any issues.

    JSONArray results = jsonObject.getJSONArray("results");

Hope this helps.