Android Studio で Livedoor のお天気Webサービス(JSON) を読み込んで ListView に表示する

Livedoor の お天気Webサービス はこの手のテストに最適な API です。結果は JSON フォーマットで返されるので、 Google Gson を使用します。

※ Google Gson のオンラインドキュメント

読み込んだ後、SharedPreferences で書き込んでいます。

package app.lightbox.winofsql.jp.weather;
 
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
 
import com.google.gson.Gson;
 
public class MainActivity extends Activity {
 
        private ArrayAdapter<PinpointLocation> arrayMyData = null;
        private HttpGet hg = new HttpGet();
 
        @Override
        protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_main);
 
                // WEBアクセス( HttpGet )
                Button button = (Button) this.findViewById(R.id.button);
                button.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                new AsyncTask<String, Void, String>() {
 
                                        // 非同期処理
                                        @Override
                                        protected String doInBackground(String... params) {
                                                String result = null;
                                                HttpGet hg = new HttpGet();
                                                result =
                                                                hg.execute(
                                                                                params[0],
                                                                                params[1],
                                                                                null
                                                                );
 
                                                return result;
                                        }
 
                                        // UI スレッド処理
                                        @Override
                                        protected void onPostExecute(String json) {
                                                super.onPostExecute(json);
 
                                                // ListView のインスタンスを取得
                                                ListView listview = (ListView) MainActivity.this.findViewById(R.id.listView);
                                                // 専用クラス用
                                                arrayMyData = new ArrayAdapter<PinpointLocation>(
                                                                MainActivity.this,
                                                                android.R.layout.simple_list_item_1,
                                                                android.R.id.text1
                                                );
 
                                                Gson gson = new Gson();
                                                Weather weatherData = gson.fromJson(json, Weather.class);
 
                                                // Weather クラス内の配列部分をセット
                                                arrayMyData.addAll(weatherData.pinpointLocations);
                                                listview.setAdapter(arrayMyData);
 
                                                String reJson = gson.toJson(weatherData);
                                                SharedPreferences sp = getSharedPreferences("lightbox", MODE_PRIVATE);
                                                SharedPreferences.Editor editor = sp.edit();
                                                editor.putString("json", reJson);
                                                editor.commit();
 
                                        }
                                }.execute("http://weather.livedoor.com/forecast/webservice/json/v1?city=270000", "utf-8");
                        }
                });
 
                // クリックした時のイベント作成
                ListView listview = (ListView) MainActivity.this.findViewById(R.id.listView);
                listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                        @Override
                        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                                // クリックされたビューの内部データ
                                Object data = (Object) parent.getItemAtPosition(position);
 
                                PinpointLocation myData = (PinpointLocation) data;
                                Log.i("lightbox", "url:" + myData.link);
 
                                // ブラウザの呼び出し
                                callBrowser(myData.link);
 
                        }
                });
        }
 
        private void callBrowser( String url ) {
                // ブラウザの呼び出し
                Uri uri = Uri.parse(url);
                Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                if (intent.resolveActivity(getPackageManager()) != null) {
                        startActivity(intent);
                        return;
                }
 
                // 対応するアプリが無い
                Toast.makeText(
                                MainActivity.this,
                                "ブラウザを呼び出せません",
                                Toast.LENGTH_LONG
                ).show();
                return;
 
        }
 
        public class PinpointLocation {
                String link;
                String name;
 
                @Override
                public String toString() {
                        return name;
                }
        }
 
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
                getMenuInflater().inflate(R.menu.menu_main, menu);
                return true;
        }
 
        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
                int id = item.getItemId();
 
                if (id == R.id.lv_action1) {
                        if ( arrayMyData == null || arrayMyData.getCount() == 0 ) {
                                Toast.makeText(MainActivity.this,"データがありません",Toast.LENGTH_LONG).show();
                                return true;
                        }
 
                        PinpointLocation data = new PinpointLocation();
                        // 久留米市
                        data.name = "\u4e45\u7559\u7c73\u5e02";
                        data.link = "http://weather.livedoor.com/area/forecast/4020300";
                        arrayMyData.insert(data,3);
 
                        return true;
                }
 
                if (id == R.id.lv_action2) {
                        if ( arrayMyData == null || arrayMyData.getCount() == 0 ) {
                                Toast.makeText(MainActivity.this,"データがありません",Toast.LENGTH_LONG).show();
                                return true;
                        }
 
                        PinpointLocation data = null;
                        int count = arrayMyData.getCount();
                        for ( int i = 0; i < count; i++ ) {
                                data = arrayMyData.getItem(i);
                                Log.i("lightbox",data.name + ":" + data.link);
                        }
 
                        return true;
                }
 
 
                return super.onOptionsItemSelected(item);
        }
}

Common Intents ( Web Browser ) | Android Developers

JSON 用 Weather クラス

package app.lightbox.winofsql.jp.weather;
 
 
public class Weather {
 
        class Text {
                String text;
                String publicTime;
        }
 
        class Location {
                String city;
                String area;
                String prefecture;
        }
 
        class IntTest {
                ImageSize image;
        }
 
        class ImageSize {
                int width;
                int height;
        }
 
        MainActivity.PinpointLocation[] pinpointLocations;
        Location location;
        IntTest copyright;
        Text description;
 
        // Getter と Setter で処理する
        private String publicTime;
 
        String getPublicTime() {
                return publicTime.substring(0, 10);
        }
        void setPublicTime(String publicTime) {
                this.publicTime = publicTime;
        }
 
}

HttpGet.java

package app.lightbox.winofsql.jp.weather;
 
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.CookieHandler;
import java.net.CookieManager;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.Map;
 
public class HttpGet {
 
        // **********************************************
        // コンストラクタ
        // **********************************************
        public HttpGet() {
        }
 
        // **********************************************
        // 指定した URL へ 任意の charset で処理
        // **********************************************
        public String execute(String targetUrl,String targetCharset,Map<String,String> params) {
 
                StringBuffer web_data = new StringBuffer();
 
                try {
                        // **********************************************
                        // Query String の作成( 必要無ければ引数を null とする )
                        // **********************************************
                        String data = "";
                        if ( params != null ) {
                                Iterator<String> it =  params.keySet().iterator();
                                String key = null;
                                String value = null;
                                while(it.hasNext()) {
                                        key = it.next().toString();
                                        value = params.get(key);
                                        if ( !data.equals("") ) {
                                                data += "&";
                                        }
                                        data += key + "=" + URLEncoder.encode(value, targetCharset) ;
                                }
                                if ( !data.equals("") ) {
                                        targetUrl = targetUrl + "?" + data;
                                }
                        }
 
                        // **********************************************
                        // インターネットへの接続
                        // **********************************************
                        // 読み込む WEB上のターゲット
                        URL url = new URL(targetUrl);
                        // 接続オブジェクト
                        HttpURLConnection http = (HttpURLConnection)url.openConnection();
                        // GET メソッド
                        http.setRequestMethod("GET");
                        // 接続
                        http.connect();
 
                        // **********************************************
                        // ストリームとして読み込む準備
                        // **********************************************
                        // 以下読み込み３点セット InputStream / InputStreamReader / BufferedReader
                        InputStream input_stream = http.getInputStream();
                        // UTF-8 でリーダーを作成
                        InputStreamReader input_stream_reader = new InputStreamReader(input_stream, targetCharset);
                        // 行単位で読み込む為の準備
                        BufferedReader buffered_reader = new BufferedReader(input_stream_reader);
 
                        // **********************************************
                        // 行の一括読み込み
                        // **********************************************
                        String line_buffer = null;
                        // BufferedReader は、readLine が null を返すと読み込み終了
                        while ( null != (line_buffer = buffered_reader.readLine() ) ) {
                                web_data.append( line_buffer );
                                web_data.append( "\n" );
                        }
 
                        // **********************************************
                        // 接続解除
                        // **********************************************
                        http.disconnect();
                }
                catch(Exception e) {
                        // 失敗
                        System.out.println( e.getMessage());
                }
                return web_data.toString();
        }
}

メニュー定義

<menu xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools"
          tools:context=".MainActivity">
        <item
                android:id="@+id/lv_action1"
                android:title="処理1"
                android:orderInCategory="100"
                android:showAsAction="never"/>
        <item
                android:id="@+id/lv_action2"
                android:title="処理2"
                android:orderInCategory="100"
                android:showAsAction="never"/>
        <item
                android:id="@+id/lv_action3"
                android:title="処理3"
                android:orderInCategory="100"
                android:showAsAction="never"/>
        <item
                android:id="@+id/lv_action4"
                android:title="処理4"
                android:orderInCategory="100"
                android:showAsAction="never"/>
        <item
                android:id="@+id/lv_action5"
                android:title="処理5"
                android:orderInCategory="100"
                android:showAsAction="never"/>
 
</menu>