如何获得 XML 响应

Question

How can I get XML response from website? Website is not mine, so I'm going to parse it. I'm using WebView and parse code by JSONP. But there are some needful buttons, when I click them I get XML response. Please help me, I have no idea how to do it

Answer 1

To send a request from your java code use AsyncTask or Android-Async-Http , set the accept header as application/xml and pass it to your webview.

Here an example of a generic request using an Async Http Client :

import com.loopj.android.http.*;
import cz.msebera.android.httpclient.Header;


public class AppConnector {

    private String url;

    private void setUrl(String url){
        this.url = url;
    }

    public ListenableFuture<String> getSomething(){
        Log.d("App", "get something..");
        return launchHttpCall();
    }


    public ListenableFuture<String> launchHttpCall(){

        final SettableFuture<String> future = SettableFuture.create();
        AsyncHttpClient asyncHttpClient = new AsyncHttpClient();

        Log.d("App", "GET request towards: "+url);

        asyncHttpClient
            .get( url, new TextHttpResponseHandler()
            {
                @Override
                public void onSuccess(int statusCode, Header[] headers, String responseBody)
                {
                    Log.d("App", "HTTP CLIENT SUCCESS..");
                    future.set("Response Success. statusCode:"+statusCode+", Response body: "+responseBody);
                }

                @Override
                public void onFailure(int statusCode, Header[] headers, String responseBody, Throwable error){

                    Log.d("MeeRBA", "HTTP CLIENT FAILURE.. ");
                    future.setException(error);
                }

            });
        return future;
    }

And here an example with AsyncTask :

class WebAsyncTask extends AsyncTask<String, Void, String> {

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

        // params comes from the execute() call: params[0] is the url.
        try {
            return goGoConnect(urls[0]);
        } catch (IOException e) {
            return "Unable to retrieve web page. URL may be invalid.";
        }
    }

    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        Log.d("App", "Post execute..");

        // textView.setText(result);
        // or callback
   }

   private String goGoConnect(String myurl) throws IOException {

        InputStream is = null;
        // Only display the first 500 characters of the retrieved web page content.
        int len = 5000;

        try {
            URL url = new URL(myurl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(3000);
            conn.setConnectTimeout(5000); // millis
            conn.setRequestMethod("GET");
            conn.setDoInput(true);

            conn.setRequestProperty("User-Agent", USER_AGENT);
            conn.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
            conn.setRequestProperty("Content-Type", "application/xml");

            // Starts the query
            conn.connect();

            int response = conn.getResponseCode();
            is = conn.getInputStream();

            // Convert the InputStream into a string
            InputStreamReader reader = null;
            reader = new InputStreamReader(is, "UTF-8");        
            char[] buffer = new char[len];
            reader.read(buffer);
            String contentAsString = new String(buffer);

            Log.d("App", "The response content is: "+contentAsString);

            return contentAsString;

        }catch(Exception e){

            Log.d("App", "Exception:"+e);
            return "Eception: >>"+e;

        // Makes sure that the InputStream is closed after the app is finished using it.
        } finally {
            if (is != null) {
                is.close();
            } 
        }
    }
}

If instead you want to send a GET request using javascript within a webview you can use something like:

function httpGetAsync(theUrl, callback)
{
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.onreadystatechange = function() { 
        if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
            callback(xmlHttp.responseText);
    }
    xmlHttp.open("GET", theUrl, true); // true for asynchronous 
    xmlHttp.send(null);
}

or use jquery (or other frameworks like angularJS for more complex webviews). Example using jquery :

$.ajax({
    type: "Get",
    url: "http://domain.com/function?Data=1234567890",
    xhrFields: {withCredentials: true},
    dataType: "JSONP text xml",
    contentType: "application/xml",
    cache: false,
    success: function(xml)
    {
    alert($(this).find('ResponseStatus').text());
    }
});

Anyhow cross domain xml from javascript is a no-no unless you have control over the application that is spitting out the XML and can use a formatting trick to 'fool' the script into parsing it as JSON.