/**
 * Http工具类
 */
public class HttpUtil {
    // 创建HttpClient对象
    public static HttpClient httpClient = new DefaultHttpClient();
    public static final String BASE_URL = "";
  
    /**
     * get请求
     * 
     * @param url
     *            发送请求的URL
     * @return 服务器响应字符串
     * @throws Exception
     */
    public static String doGet(String url) throws Exception {
        // 创建HttpGet对象。
        HttpGet get = new HttpGet(url);
        // 发送GET请求
        HttpResponse httpResponse = httpClient.execute(get);
        // 如果服务器成功地返回响应
        if (httpResponse.getStatusLine().getStatusCode() == 200) {
            // 获取服务器响应字符串
            HttpEntity entity = httpResponse.getEntity();
            InputStream content = entity.getContent();
            return convertStreamToString(content);
        }
        return null;
    }
  
    /**
     * post请求
     * 
     * @param url
     *            发送请求的URL
     * @param params
     *            请求参数
     * @return 服务器响应字符串
     * @throws Exception
     */
    public static String doPost(String url, Map<String, String> rawParams)
            throws Exception {
        // 创建HttpPost对象。
        HttpPost post = new HttpPost(url);
        // 如果传递参数个数比较多的话可以对传递的参数进行封装
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        for (String key : rawParams.keySet()) {
            // 封装请求参数
            params.add(new BasicNameValuePair(key, rawParams.get(key)));
        }
        // 设置请求参数
        post.setEntity(new UrlEncodedFormEntity(params, "utf-8"));
        // 发送POST请求
        HttpResponse httpResponse = httpClient.execute(post);
        // 如果服务器成功地返回响应
        if (httpResponse.getStatusLine().getStatusCode() == 200) {
            // 获取服务器响应字符串
            HttpEntity entity = httpResponse.getEntity();
            InputStream content = entity.getContent();
            return convertStreamToString(content);
        }
        return null;
    }
  
    /**
     * 获取服务器的响应，转换为字符串
     */
    private static String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();
        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
}