私は Android 用の大きなプログラムに取り組んでおり、プログラムの通貨コンバーター部分を機能させようとしています。完全な開示のために: http://firstamong.com/building-android-currency-converter/から見つけました。これは、リアルタイムの通貨コンバーターを構築する方法に関するチュートリアルです。問題のコードに続いて logcat を投稿します。発生するエラーは、ある通貨から別の通貨に変換しようとすると、強制的に停止されたとアプリケーションに表示されます。ただし、「無効」部分は機能します (両方の通貨フィールドが同じ場合)。
コード：
public class currency_converter extends Activity {
public int to;
public int from;
public String [] val;
public String s;
public Handler handler;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_currency_converter);
Spinner s1 = (Spinner) findViewById(R.id.spinner1);
Spinner s2 = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.name, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.select_dialog_singlechoice);
val = getResources().getStringArray(R.array.value);
s1.setAdapter(adapter);
s2.setAdapter(adapter);
s1.setOnItemSelectedListener(new spinOne(1));
s2.setOnItemSelectedListener(new spinOne(2));
Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
TextView t = (TextView) findViewById(R.id.textView4);
if(from == to)
{
Toast.makeText(getApplicationContext(), "Invalid", 4000).show();
}
else
{
try {
s = getJson("http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20in%20(%22"+val[from]+val[to]+"%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=");
JSONObject jObj;
jObj = new JSONObject(s);
String exResult = jObj.getJSONObject("query").getJSONObject("results").getJSONObject("rate").getString("Rate");
t.setText(exResult);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
});
}
public String getJson(String url)throws ClientProtocolException, IOException {
StringBuilder build = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
HttpResponse response = client.execute(httpGet);
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String con;
while ((con = reader.readLine()) != null) {
build.append(con);
}
return build.toString();
}
private class spinOne implements OnItemSelectedListener
{
int ide;
spinOne(int i)
{
ide =i;
}
public void onItemSelected(AdapterView<?> parent, View view,
int index, long id) {
if(ide == 1)
from = index;
else if(ide == 2)
to = index;
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
class GetResponseData extends AsyncTask<String, String, String> {
private ProgressDialog dialog;
private ArrayList<String> titleList;
private TextView textView;
public GetResponseData(TextView textView) {
this.textView = textView;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog = ProgressDialog.show(currency_converter.this, "", "Loading",
false);
}
@Override
protected String doInBackground(String... params) {
try {
String s = getJson("http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20in%20(%22" + val[from] + val[to] + "%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=");
JSONObject jObj;
jObj = new JSONObject(s);
String exResult = jObj.getJSONObject("query").getJSONObject("results").getJSONObject("rate").getString("Rate");
return exResult;
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (dialog != null)
dialog.dismiss();
if (result != null) {
textView.setText(result);
}
}
}
}
}
ログキャット:
10-30 00:59:48.164 20591-20591/com.example.travelapplication E/AndroidRuntime﹕ FATAL EXCEPTION: main
android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1128)
at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
at java.net.InetAddress.getAllByName(InetAddress.java:214)
at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:365)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:587)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:511)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:489)
at com.example.travelapplication.currency_converter.getJson(currency_converter.java:93)
at com.example.travelapplication.currency_converter$1.onClick(currency_converter.java:68)
at android.view.View.performClick(View.java:4222)
at android.view.View$PerformClick.run(View.java:17620)
at android.os.Handler.handleCallback(Handler.java:800)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5391)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)