public interface

HttpClient

org.apache.http.client.HttpClient

HttpClient是Apache提供的Http網(wǎng)絡(luò)訪問接口。 1、創(chuàng)建HttpClient實例 HttpClient是一個接口，無法直接創(chuàng)建實例，通常創(chuàng)建一個DefaultHttpClient（HttpClient 的SubClass）實例。
HttpClient httpClient = new DefaultHttpClient();
2、如果想要發(fā)起一條GET請求 ,可以創(chuàng)建一個HttpGet對象，傳入目標(biāo)地址，之后調(diào)用HttpClient的execute()方法
HttpGet = new HttpClient("http://www.baidu.com"); httpClient.execute(httpGet);
3、執(zhí)行execute()后，會返回一個HttpResponse對象，服務(wù)器返回的所有信息都在這里面，通常都會先取出服務(wù)器返回的狀態(tài)嗎，若等于200則說明請求和相應(yīng)都成功了
if(httpResponse.getStatusLine().getStatusCode() == 200){ }
接下來在這個if判斷內(nèi)部取出服務(wù)返回的具體內(nèi)容，可以調(diào)用httpResponse getEntity()獲得一個HttpEntity實例，再調(diào)用EntityUtils.toString這個靜態(tài)方法將HttpEntity轉(zhuǎn)換成字符串
HttpEntity httpEntity = httpResponse.getEntity(); String responseString = EntityUtils.toString(httpEntity,"utf-8");
由于在子線程中無法對UI操作，最后使用Message，將服務(wù)器返回的數(shù)據(jù)放到Message對象中，用Handler將messge發(fā)送出去，在主線程進(jìn)行UI操作
//將服務(wù)器返回的結(jié)果存放到Message對象中 Message message = Message.obtain(mHandler, SEND_REQUEST, responseString); mHandler.sendMessage(message);
Handler mHandler = new Handler(){@Overridepublic void handleMessage(Message msg){if(msg.what == SEND_REQUEST){String response = (String)msg.obj;responseTextView.setText(response);}}};
主要代碼： public class MainActivity extends ActionBarActivity implements OnClickListener{private Button sendRequestBtn;private TextView responseTextView;private int SEND_REQUEST = 0;Handler mHandler = new Handler(){@Overridepublic void handleMessage(Message msg){if(msg.what == SEND_REQUEST){String response = (String)msg.obj;responseTextView.setText(response);}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendRequestBtn = (Button)findViewById(R.id.requestBtn);responseTextView = (TextView)findViewById(R.id.responseText);sendRequestBtn.setOnClickListener(this);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubif(v.getId() == R.id.requestBtn){sendRequestWithHttpClient();}}private void sendRequestWithHttpClient(){new Thread(new Runnable(){@Overridepublic void run(){try{HttpClient httpClient = new DefaultHttpClient();HttpGet httpGet= new HttpGet("http://www.baidu.com");HttpResponse httpResponse = httpClient.execute(httpGet);if(httpResponse.getStatusLine().getStatusCode() == 200){//獲得消息的響應(yīng)實體HttpEntity httpEntity = httpResponse.getEntity();String responseString = EntityUtils.toString(httpEntity,"utf-8");//將服務(wù)器返回的結(jié)果存放到Message對象中Message message = Message.obtain(mHandler, SEND_REQUEST, responseString);mHandler.sendMessage(message);}}catch(Exception e){e.printStackTrace();}}}).start();}}


?完整代碼在：https://github.com/HiSunny/ComeOnHttpClient.git

總結(jié)

以上是生活随笔為你收集整理的使用Http协议访问网络--HttpClient的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯，歡迎將生活随笔推薦給好友。