Http通訊（HttpClient）

   HttpURLConnection是java.net.*包提供的類，但java JDK 庫自己功能還不夠豐富和靈活；

Apache HttpClient是一個開源項目，功能更加完善，彌補了java.net.*靈活性不足的缺點。

 

    使用HttpClient接口要加入httpclient-4.3.1.jar相關的jar包

private void getHttpClientConnection(String url){
final String getUrl = url;
new Thread(new Runnable() {//新建一個子線程
        String getUrl2 = getUrl;
@Override
public void run() {
            HttpClient hc = new DefaultHttpClient();//1.建立一個HttpClient,(DefaultHttpClient表示默認屬性)
            HttpGet hg = new HttpGet(getUrl2);//2.HttpGet實例，經過GET方法
            InputStream in = null;
            StringBuffer sb = null;
try{
                HttpResponse hr = hc.execute(hg);//3.HttpResponse Http響應,HttpClient執行HttpGet方法
//鏈接成功
if ((hr.getStatusLine().getStatusCode()) == 200){//4.獲得響應碼，若是==200，鏈接成功
                    in = hr.getEntity().getContent();//5.獲取返回的數據 InPutStream流獲取響應獲得的內容
                    BufferedReader br = new BufferedReader(new InputStreamReader(in));//BufferedReader讀取數據流
char[] buf = new char[1024];
int longth = 0;
                    sb = new StringBuffer();
while((longth = br.read(buf)) != -1){//讀取BufferedReader，放入StringBuffer
                        sb.append(buf,0,longth);
                    }

                }
            }catch(IOException e){
                e.printStackTrace();
            }finally{
if (in != null){
try {
                        in.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

            Message message = new Message();//新建Message
            message.what = CHANGE_TEXT;
            message.obj = sb.toString();//Message.obj獲得StringBuffer的內容
handler.sendMessage(message);//sendMessage

        }
    }).start();
}

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類中建一個Handler接收message

private static final int CHANGE_TEXT = 1;private Handler handler = new Handler(){@Overridepublic void handleMessage(Message msg) {super.handleMessage(msg);if (msg.what == CHANGE_TEXT){textView.setText(msg.obj.toString());        }    }};