Android网络编程之Web Service获取天气预报( 获取天气预报信息)

上一篇完成了本应用第一步：下拉列表填充省市信息，本篇完成获取天气预报信息部分：

Activity中的Spinner监听事件:

private class CityChoosedListener implements OnItemSelectedListener {

        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position,
                long id) {
            // 调用工具类的getWeatherMsgByCity静态方法，返回解析后的String字符串
            String weatherMsg = WebServiceUtil.getWeatherMsgByCity(MainActivity.this.citySpinner.getItemAtPosition(position).toString());
            MainActivity.this.weatherInfoText.setText(weatherMsg);
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            
        }
        
    }
}

工具类中的getWeatherMsgByCity()方法通过Post方式获取天气信息:

Post方式详情可见：http://www.cnblogs.com/moka/archive/2013/05/05/3060765.html

/* 使用Post方式根据城市名获取天气数据 */
    public static String getWeatherMsgByCity(String cityName) {
        String result = "";
        String url = "http://webservice.webxml.com.cn/WebServices/WeatherWS.asmx/getWeather";
        HttpPost request = new HttpPost(url);
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("theCityCode", cityName));
        params.add(new BasicNameValuePair("theUserID", ""));                                  
        try {
            request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
            HttpResponse response = new DefaultHttpClient().execute(request);
            // 检测回应状态码
            if (response.getStatusLine().getStatusCode() == 200) {
                String temp = EntityUtils.toString(response.getEntity());
                // 返回数据均为XML格式，要根据具体格式从中提取出所需字符串
                result = parseWeatherInfo(temp);
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }

解析方法与上一篇大同小异，直接提取Xml中的有效文字信息:

    /*解析传回的天气信息xml文件*/
    private static String parseWeatherInfo(String temp) {
        String result = "";
        String[] results = null;
        StringBuffer buffer = new StringBuffer();

        if (temp != null && temp.length() > 0) {
            int start = temp.indexOf("<string>");
            int end = temp.lastIndexOf("</ArrayOfString>");
            result = temp.substring(start, end);
            results = result.split("</string>");
            for (int i = 1; i < results.length - 1; i++) {
                // 因为解析时最后会在String数组中多一项长度为二的空白字符，所以i < results.length - 1
                buffer.append(results[i].substring(12) + "\n");
            }
        }
        return buffer.toString();
    }
}         

运行后效果如图: