Android实战之HttpClient

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：

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

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;
		}
	}
}

HttpConnectionCallback类是一个回调类，用来处理请求完毕后的逻辑。

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);
}