Обработка исключений Android

Question

1. Приведенный ниже код при выполнении в Android вызывает IOException, но не выполняется как Java-проект.
2. Также я не могу просмотреть исключение в консоли, которое произошлоесли я использую e.printstacktrace.

   Просьба ответить как можно скорее

public String convert(String from, String to,int amt){
    String result= null;
    URL url = null;
    HttpURLConnection urlConnection = null;
    try {
        url = new URL("http://www.exchangerate-api.com/"+from+"/"+to+"/"+amt+"?k=ZTKOy-28yPI-g2cQd");
        System.out.println("hai");
        urlConnection = (HttpURLConnection) url.openConnection();
        InputStream in = new BufferedInputStream(urlConnection.getInputStream());
        result = readStream(in);
        System.out.println(result);
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return result;
}
public static String readStream(InputStream in) throws IOException {
    StringBuilder sb = new StringBuilder();
    BufferedReader r = new BufferedReader(new InputStreamReader(in),1000);
    for (String line = r.readLine(); line != null; line =r.readLine()){
        sb.append(line);
    }
    in.close();
    return sb.toString();
} 

---

08-17 12:30:31.356: WARN/System.err(946): java.net.UnknownHostException: www.exchangerate-api.com
08-17 12:30:31.416: WARN/System.err(946):     at java.net.InetAddress.lookupHostByName(InetAddress.java:506)
08-17 12:30:31.447: WARN/System.err(946):     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:294)
08-17 12:30:31.468: WARN/System.err(946):     at java.net.InetAddress.getAllByName(InetAddress.java:256)
08-17 12:30:31.496: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:68)
08-17 12:30:31.517: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:48)
08-17 12:30:31.537: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:298)
08-17 12:30:31.557: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89)
08-17 12:30:31.586: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:285)
08-17 12:30:31.606: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:267)
08-17 12:30:31.626: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.retrieveResponse(HttpURLConnectionImpl.java:1018)
08-17 12:30:31.649: WARN/System.err(946):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:510)
08-17 12:30:31.679: WARN/System.err(946):     at com.CurrencyConverterActivity.ConverterCurrency.convert(ConverterCurrency.java:110)
08-17 12:30:31.697: WARN/System.err(946):     at com.CurrencyConverterActivity.ConverterCurrency.onClick(ConverterCurrency.java:67)
08-17 12:30:31.716: WARN/System.err(946):     at android.view.View.performClick(View.java:2485)
08-17 12:30:31.736: WARN/System.err(946):     at android.view.View$PerformClick.run(View.java:9080)
08-17 12:30:31.746: WARN/System.err(946):     at android.os.Handler.handleCallback(Handler.java:587)
08-17 12:30:31.766: WARN/System.err(946):     at android.os.Handler.dispatchMessage(Handler.java:92)
08-17 12:30:31.786: WARN/System.err(946):     at android.os.Looper.loop(Looper.java:123)
08-17 12:30:31.806: WARN/System.err(946):     at android.app.ActivityThread.main(ActivityThread.java:3647)
08-17 12:30:31.826: WARN/System.err(946):     at java.lang.reflect.Method.invokeNative(Native Method)
08-17 12:30:31.836: WARN/System.err(946):     at java.lang.reflect.Method.invoke(Method.java:507)
08-17 12:30:31.856: WARN/System.err(946):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-17 12:30:31.876: WARN/System.err(946):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-17 12:30:31.896: WARN/System.err(946):     at dalvik.system.NativeStart.main(Native Method)

это исключение, которое происходит ..

Answer 1

предоставить доступ в Интернет

 <uses-permission android:name="android.permission.INTERNET"></uses-permission>. In android-manifest

А если вы уже предоставили, тогда опубликуйте свой журнал cat

Попробуйте код ниже

HttpsURLConnection con = (HttpsURLConnection) new URL(newUrl).openConnection(); 
            con.setRequestMethod("POST"); 
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
            con.setRequestProperty("Content-Length", ""+Integer.toString(newUrl.getBytes().length)); 
            con.setRequestProperty("Content-Language", "en-US"); 
            con.setRequestProperty("Connection", "close"); 
            con.setUseCaches (false); 
            con.setDoOutput(true); 
            con.setDoInput(true); 
            InputStream in =con.getInputStream();
            InputStreamReader is=new InputStreamReader(in);
            BufferedReader br=new BufferedReader(is);
            String read=br.readLine();
            String line;
              while((line=br.readLine())!=null){
               System.out.println(read);
               read+=line;
             }