Android实战之HttpClient

     <p>最近在看Android的开发，其中用到了HttpClient来提交或者获取server端的数据，但是Android自带的API还是有点不好用，所以自己根据自己的需要就做了一个包装，如下：</p>    <p> </p>    <p>HttpConnectionUtil类是一个工具类，其中提供了同步和异步方法，并且目前是支持http的Get和Post方法。</p>    <pre class="brush:java; toolbar: true; auto-links: false;">import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.ArrayList; import java.util.List; import java.util.Map; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import android.os.Handler; import android.util.Log; public class HttpConnectionUtil {  public static enum HttpMethod {GET, POST}    public void asyncConnect(final String url, final HttpMethod method, final HttpConnectionCallback callback) {   asyncConnect(url, null, method, callback);  }    public void syncConnect(final String url, final HttpMethod method, final HttpConnectionCallback callback) {   syncConnect(url, null, method, callback);  }    public void asyncConnect(final String url, final Map<String, String> params,     final HttpMethod method, final HttpConnectionCallback callback) {   Handler handler = new Handler();   Runnable runnable = new Runnable() {    public void run() {     syncConnect(url, params, method, callback);    }   };   handler.post(runnable);  }    public void syncConnect(final String url, final Map<String, String> params,     final HttpMethod method, final HttpConnectionCallback callback) {   String json = null;   BufferedReader reader = null;      try {    HttpClient client = new DefaultHttpClient();    HttpUriRequest request = getRequest(url, params, method);    HttpResponse response = client.execute(request);    if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {     reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));     StringBuilder sb = new StringBuilder();     for (String s = reader.readLine(); s != null; s = reader.readLine()) {      sb.append(s);     }     json = sb.toString();    }   } catch (ClientProtocolException e) {    Log.e("HttpConnectionUtil", e.getMessage(), e);   } catch (IOException e) {    Log.e("HttpConnectionUtil", e.getMessage(), e);   } finally {    try {     if (reader != null) {      reader.close();     }    } catch (IOException e) {     // ignore me    }   }   callback.execute(json);  }    private HttpUriRequest getRequest(String url, Map<String, String> params, HttpMethod method) {   if (method.equals(HttpMethod.POST)) {    List<NameValuePair> listParams = new ArrayList<NameValuePair>();    if (params != null) {     for (String name : params.keySet()) {      listParams.add(new BasicNameValuePair(name, params.get(name)));     }    }    try {     UrlEncodedFormEntity entity = new UrlEncodedFormEntity(listParams);     HttpPost request = new HttpPost(url);     request.setEntity(entity);     return request;    } catch (UnsupportedEncodingException e) {     // Should not come here, ignore me.     throw new java.lang.RuntimeException(e.getMessage(), e);    }   } else {    if (url.indexOf("?") < 0) {     url += "?";    }    if (params != null) {     for (String name : params.keySet()) {      url += "&" + name + "=" + URLEncoder.encode(params.get(name));     }    }    HttpGet request = new HttpGet(url);    return request;   }  } }</pre>HttpConnectionCallback类是一个回调类，用来处理请求完毕后的逻辑。    <pre class="brush:java; toolbar: true; auto-links: false;">public interface HttpConnectionCallback {  /**   * Call back method will be execute after the http request return.   * @param response the response of http request.    * The value will be null if any error occur.   */  void execute(String response); }</pre>    <p></p>