android httpurlconnection

public class HttpUrlConnect {
    //get请求
    public String get(String url){
        HttpURLConnection conn = null;
        BufferedReader rd = null ;
        StringBuilder sb = new StringBuilder ();
        String line = null ;
        String response = null;
        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod("GET");
            conn.setDoInput(true);
            conn.setReadTimeout(20000);
            conn.setConnectTimeout(20000);
            conn.setUseCaches(false);
            conn.connect();
            rd  = new BufferedReader( new InputStreamReader(conn.getInputStream(), "UTF-8"));
            while ((line = rd.readLine()) != null ) {
                sb.append(line);
            }
            response = sb.toString();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{      
            try {
                if(rd != null){
                    rd.close();
                }
                if(conn != null){
                    conn.disconnect();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return response;
    }
    //post表单请求
    public String post(String url, Map<String, String> form){
        HttpURLConnection conn = null;
        PrintWriter pw = null ;
        BufferedReader rd = null ;
        StringBuilder out = new StringBuilder();
        StringBuilder sb = new StringBuilder();
        String line = null ;
        String response = null;
        for (String key : form.keySet()) {
            if(out.length()!=0){
                out.append("&");
            }
            out.append(key).append("=").append(form.get(key));
        }
        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setReadTimeout(20000);
            conn.setConnectTimeout(20000);
            conn.setUseCaches(false);
            conn.connect();
            pw = new PrintWriter(conn.getOutputStream());
            pw.print(out.toString());
            pw.flush();
            rd  = new BufferedReader( new InputStreamReader(conn.getInputStream(), "UTF-8"));
            while ((line = rd.readLine()) != null ) {
                sb.append(line);
            }
            response = sb.toString();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{      
            try {
                if(pw != null){
                    pw.close();
                }
                if(rd != null){
                    rd.close();
                }
                if(conn != null){
                    conn.disconnect();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return response;
    }
    //post字符串请求
    public String post(String url, String rawBody){
        HttpURLConnection conn = null;
        PrintWriter pw = null ;
        BufferedReader rd = null ;
        StringBuilder sb = new StringBuilder ();
        String line = null ;
        String response = null;
        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setReadTimeout(20000);
            conn.setConnectTimeout(20000);
            conn.setUseCaches(false);
            conn.connect();
            pw = new PrintWriter(conn.getOutputStream());
            pw.print(rawBody);
            pw.flush();
            rd  = new BufferedReader( new InputStreamReader(conn.getInputStream(), "UTF-8"));
            while ((line = rd.readLine()) != null ) {
                sb.append(line);
            }
            response = sb.toString();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{      
            try {
                if(pw != null){
                    pw.close();
                }
                if(rd != null){
                    rd.close();
                }
                if(conn != null){
                    conn.disconnect();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return response;
    }

    public static void main(String[] args) {
        HttpUrlConnect h = new HttpUrlConnect();
        System.out.println(h.get(""));
        Map<String, String> form = new HashMap<String, String>();
        form.put("test", "test");
        System.out.println(h.post("", form));
    }

}