Android 之 HttpClient 網絡請求

1.HttpClient使用流程

①.創建HttpClient對象: HttpClient httpClient = new DefaultHttpClient();
②發送 GET 請求，創建 HttpGet 對象；發送 POST 請求，創建 HttpPost 對象。
③設置請求參數：兩者都可以用setParams（HttpParams）；post 請求還可以用setEntity（HttpEntity）。
④調用httpClient對象的execute（）方法發送請求，會返回一個 HttpResponse。
⑤對返回的HttpResponse調用，getEntity()方法可以獲得HttpEntity對象，該對象包含了服務器響應內容。

1.GET 請求

public class MainActivity extends Activity implements OnClickListener {

    private Button btnGet;
    private WebView wView;
    public static final int SHOW_DATA = 0X123;
    private String detail = "";

    private Handler handler = new Handler() {
        public void handleMessage(Message msg) {
            if(msg.what == SHOW_DATA)
            {
                wView.loadDataWithBaseURL("",detail, "text/html","UTF-8","");
            }
        };
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        setView();
    }

    private void initView() {
        btnGet = (Button) findViewById(R.id.btnGet);
        wView = (WebView) findViewById(R.id.wView);
    }

    private void setView() {
        btnGet.setOnClickListener(this);
        wView.getSettings().setDomStorageEnabled(true);
    }
    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.btnGet) {
            GetByHttpClient();
        }
    }
    private void GetByHttpClient() {
        new Thread()
        {
            public void run() 
            {
                    try {
                        HttpClient httpClient = new DefaultHttpClient();
                        HttpGet httpGet = new HttpGet("http://www.w3cschool.cc/python/python-tutorial.html");
                        HttpResponse httpResponse = httpClient.execute(httpGet);
                        if (httpResponse.getStatusLine().getStatusCode() == 200) {
                            HttpEntity entity = httpResponse.getEntity();
                            detail = EntityUtils.toString(entity, "utf-8");
                            handler.sendEmptyMessage(SHOW_DATA);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
            };
        }.start();
    }

}

另外，如果是帶有參數的GET請求的話，我們可以將參數放到一個List集合中，再對參數進行URL編碼， 最後和URL拼接下就好了：

List<BasicNameValuePair> params = new LinkedList<BasicNameValuePair>();  
params.add(new BasicNameValuePair("user", "豬小弟"));  
params.add(new BasicNameValuePair("pawd", "123"));
String param = URLEncodedUtils.format(params, "UTF-8"); 
HttpGet httpGet = new HttpGet("http://www.baidu.com"+"?"+param);

2.POST 請求

POST請求比GET稍微複雜一點，創建完HttpPost對象後，通過NameValuePair集合來存儲等待提交 的參數，並將參數傳遞到UrlEncodedFormEntity中，最後調用setEntity(entity)完成， HttpClient.execute(HttpPost)即可；

private void PostByHttpClient(final String url)
{
    new Thread()
    {
        public void run() 
        {
            try{
                HttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("user", "豬大哥"));
                params.add(new BasicNameValuePair("pawd", "123"));
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params,"UTF-8");
                httpPost.setEntity(entity);
                HttpResponse httpResponse =  httpClient.execute(httpPost);
                if (httpResponse.getStatusLine().getStatusCode() == 200) {
                    HttpEntity entity2 = httpResponse.getEntity();
                    detail = EntityUtils.toString(entity2, "utf-8");
                    handler.sendEmptyMessage(SHOW_DATA);
                }
            }catch(Exception e){e.printStackTrace();}
        };
    }.start();
}

轉自：http://www.runoob.com/w3cnote/android-tutorial-httpclient.html