Android URL Download getJSONResponseFromURL(String url, Hashtable httpGetParams)

Description

get JSON Response From URL

Declaration

public static String getJSONResponseFromURL(String url,
            Hashtable<String, String> httpGetParams) 

Method Source Code

//package com.java2s;
import android.util.Log;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.params.ConnManagerParams;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.List;

public class Main {
    public static HttpClient httpclient;

    public static String getJSONResponseFromURL(String url,
            Hashtable<String, String> httpGetParams) {
        String json_string = "";
        List<NameValuePair> nvps = buildNameValuePair(httpGetParams);
        url = buildGetUrl(nvps, url);//from   w  ww  .  ja  va2  s. c o m
        System.out.println("URL==>" + url);
        InputStream is = null;
        try {
            HttpGet httpget = new HttpGet(url);
            HttpResponse response = getThreadSafeClient().execute(httpget);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(is), 8192);
            String line = null;
            while ((line = reader.readLine()) != null) {
                json_string = json_string + line;
            }
            response.getEntity().consumeContent();
            System.out.println("Json Response==>" + json_string);
        } catch (Exception e) {
            Log.e("log_tag", "Error in http connection" + e.toString());
            return null;
        }
        return json_string;
    }

    private static List<NameValuePair> buildNameValuePair(
            Hashtable<String, String> httpPost) {
        if (httpPost == null)
            return null;
        List<NameValuePair> nvps = new ArrayList<NameValuePair>();
        Enumeration<String> keys = httpPost.keys();
        while (keys.hasMoreElements()) {
            String key = (String) keys.nextElement();
            String value = (String) httpPost.get(key);
            BasicNameValuePair nv = new BasicNameValuePair(key, value);
            nvps.add(nv);
        }
        return nvps;
    }

    private static String buildGetUrl(List<NameValuePair> params, String url) {
        String paramString = URLEncodedUtils.format(params, "utf-8");
        if (!url.endsWith("?")) {
        }
        url += paramString;
        return url;
    }

    public static DefaultHttpClient getThreadSafeClient() {
        if (httpclient != null)
            return (DefaultHttpClient) httpclient;
        HttpParams params = new BasicHttpParams();
        ConnManagerParams.setMaxTotalConnections(params, 100);
        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);

        // Create and initialize scheme registry 
        SchemeRegistry schemeRegistry = new SchemeRegistry();
        schemeRegistry.register(new Scheme("http", PlainSocketFactory
                .getSocketFactory(), 80));

        ClientConnectionManager cm = new ThreadSafeClientConnManager(
                params, schemeRegistry);
        httpclient = new DefaultHttpClient(cm, params);
        return (DefaultHttpClient) httpclient;
    }
}

Related

1. download(String url, String directoryName, String fileName)
2. downloadFile(String downloadUrl, String outputFilePath)
3. downloadFile(URL url, OutputStream output)
4. downloadHtmlPage(String pageUrl)
5. downloadUrl(String urlString)
6. downloadJson(URI uri)
7. getURLString(String urlStr)
8. getBytesFromUrl(String url)
9. getWebContent(String pvUrl)