android开发第七天网络连接的四种方式

HttpURLConnection是java的标准类

HttpClient 是 Apache Jakarta Common 下的子项目，用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。HttpClient 已经应用在很多的项目中，比如 Apache Jakarta 上很著名的另外两个开源项目 Cactus 和 HTMLUnit 都使用了 HttpClient，更多使用 HttpClient 的应用可以参见http://wiki.apache.org/jakarta-httpclient/HttpClientPowered。HttpClient 项目非常活跃，使用的人还是非常多的。目前 HttpClient 版本是在 2005.10.11 发布的 3.0 RC4 。

HttpClient是个很不错的开源框架，封装了访问http的请求头，参数，内容体，响应等等，

HttpURLConnection是java的标准类，什么都没封装，用起来太原始，不方便，比如重访问的自定义，以及一些高级功能等。

1.HttpURLConnection get方式

try {
                URL url = new URL("http://www.baidu.com/img/baidu_sylogo1.gif");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setConnectTimeout(5000);
                conn.setRequestMethod("GET");
                //获得请求的响应码
                int code = conn.getResponseCode();
                if(code == HttpStatus.SC_OK){
                    InputStream inputStream = conn.getInputStream();
                    mIV.setImageBitmap(BitmapFactory.decodeStream(inputStream));
                    Toast.makeText(this, "GET访问成功", Toast.LENGTH_SHORT).show();
                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

2.HttpURLConnection post方式

try {
                URL url = new URL("http://www.baidu.com/img/baidu_sylogo1.gif");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setConnectTimeout(5000);
                conn.setRequestMethod("POST");
                //获得请求的响应码
                int code = conn.getResponseCode();
                if(code == HttpStatus.SC_OK){
                    InputStream inputStream = conn.getInputStream();
                    mIV.setImageBitmap(BitmapFactory.decodeStream(inputStream));
                    Toast.makeText(this, "POST访问成功", Toast.LENGTH_SHORT).show();
                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

3.HttpClient get方式

try {
                DefaultHttpClient httpclient = new DefaultHttpClient();
                HttpParams params = httpclient.getParams();
                HttpGet httpget = new HttpGet("http://www.baidu.com/img/baidu_sylogo1.gif");
                HttpConnectionParams.setConnectionTimeout(params, 5000);
                HttpResponse response = httpclient.execute(httpget);
                if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    byte[] byteArray = EntityUtils.toByteArray(response.getEntity());
                    mIV.setImageBitmap(BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length));
                    Toast.makeText(this, "GET访问成功", Toast.LENGTH_SHORT).show();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

4.HttpClient post方式

try {
                DefaultHttpClient httpclient = new DefaultHttpClient();
                HttpParams params = httpclient.getParams();
                HttpPost httppost = new HttpPost("http://www.baidu.com/img/baidu_sylogo1.gif");
                HttpConnectionParams.setConnectionTimeout(params, 5000);
                HttpResponse response = httpclient.execute(httppost);
                if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    byte[] byteArray = EntityUtils.toByteArray(response.getEntity());
                    mIV.setImageBitmap(BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length));
                    Toast.makeText(this, "POST访问成功", Toast.LENGTH_SHORT).show();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }