Problems with a Build_HttpBody() // httpPost.setEn

问题:

I develop AndroidApps with AndroidStudio I start to do a simple HttpPost Request and I had a problems, all post that I could find do this:

private void CheckLoguin_Request(String User, String Pass){

    //Declaration of variables
    HttpClient httpClient = new DefaultHttpClient();
    HttpPost Request = new HttpPost(url_Loguin);
    HttpResponse Response;

    List<NameValuePair> BodyRequest_Elements = new ArrayList<NameValuePair>();
    BodyRequest_Elements.add(new BasicNameValuePair("user_name", User));
    BodyRequest_Elements.add(new BasicNameValuePair("user_passwd", Pass));

    Request.setEntity(new UrlEncodedFormEntity(BodyRequest_Elements));
    Response = httpClient.execute(Request);

    // writing response to log
    Log.d("Http Response:", Response.toString());
}

But when I try to debugg App Android Studio give me a 2 errors in this lines:

 new UrlEncodedFormEntity(BodyRequest_Elements) //Error:(40, 27) error: unreported exception UnsupportedEncodingException; must be caught or declared to be thrown

 Response = httpClient.execute(Request); //Error:(41, 38) error: unreported exception IOException; must be caught or declared to be thrown

It's possible I need install more libraries or support libraries? What I do bad? Anyone can helps me? Thanks in advance and sorry for my English!

PD1: If you need more info or code advise me!

回答1:

Updated 2016

Using HttpURLConnection class we need to open BufferedWritter to insert our entity values as the following code:

//Declaration of variables
private List<NameValuePair> ListOfValues;
...

public Check_Loguin_Request(Context cx,String url, List<NameValuePair> ListOfValues)
{
    this.cx = cx;
    this.Url = url;
    this.ListOfValues= ListOfValues;
}

@Override
protected String doInBackground(String... strings) {

    //Declaration of variables
    InputStream is = null;
    String Result = "";

    URL urll = new URL(url);
    HttpURLConnection conn = (HttpURLConnection) urll.openConnection();
    conn.setReadTimeout(10000);
    conn.setConnectTimeout(15000);
    conn.setRequestMethod("POST");
    conn.setDoInput(true);
    conn.setDoOutput(true);

    OutputStream os = conn.getOutputStream();
    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
    writer.write(Build_HttpBody(ListOfValues));
    writer.flush();
    writer.close();
    os.close();

    // Starts request
    conn.connect();
    int ResponseCode = conn.getResponseCode();

    if (ResponseCode == 200) {
        is = conn.getInputStream();
        String EntityResult = ReadResponse_HttpURLConnection(is);
    } 
    else {
        throw new RuntimeException("Invalid Status Code");
    }
}

---

Attention the DefaultHttpClient class is deprecated (2011)

For more info following this link.

Try to use this following code, remember for this case always use AsyncTask:

 private class Check_Loguin_Request extends AsyncTask <String,Void,String>{

    Context cx;
    String Url;
    List<NameValuePair> BodyRequest_Elements;

    public Check_Loguin_Request(Context cx,String url, List<NameValuePair> ListOfValues)
    {
        this.cx = cx;
        this.Url = url;
        this.BodyRequest_Elements = ListOfValues;
    }

    private String convertStreamToString(InputStream is) {

        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }

    @Override
    protected String doInBackground(String... strings) {

        //Declaration of variables
        DefaultHttpClient httpClient;
        HttpPost Request = new HttpPost(url_Loguin);
        HttpResponse Response;
        HttpParams httpParameters = new BasicHttpParams();
        httpParameters.setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);

        // Set the timeout in milliseconds until a connection is established.
        // The default value is zero, that means the timeout is not used.
        int timeoutConnection = 3000;
        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
        // Set the default socket timeout (SO_TIMEOUT)
        // in milliseconds which is the timeout for waiting for data.
        int timeoutSocket = 5000;
        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
        httpClient = new DefaultHttpClient(httpParameters);


        try {
            HttpEntity entity = new UrlEncodedFormEntity(BodyRequest_Elements);
            Request.setHeader(entity.getContentType());
            Request.setEntity(entity);

            Response = httpClient.execute(Request);

            if(Response.getStatusLine().getStatusCode() == 200){
                String EntityResult = EntityUtils.toString(Response.getEntity());
                //HttpEntity EntityResult = Response.getEntity();
                //InputStream iStream = EntityResult.getContent();
                //JSONObject json = new JSONObject(convertStreamToString(iStream));

                EntityResult = EntityResult.replaceAll("[()]", "");
                JSONObject json = new JSONObject(EntityResult);

                String Result = json.optString("code").toString();
                return Result;
            }
            else{
                throw new RuntimeException("Invalid Status Code");
            }
        }
        catch (Exception ex){
            Log.getStackTraceString(ex);
            return ex.toString();
        }
    }
}

回答2:

You are obviously not handling the IO exceptions being thrown from the constructor:

see: Android docs on UrlEncodedFormEntity

What puzzles me is that your IDE is not reporting this, or how this code even compiles, let alone runs/debugs.

Edit: If you are new at this stuff, maybe it would be worth to take a look at: Android Volley , which is a quite simple yet effective library developed by Google for Android networking.