Java通過webService接口擷取天氣預報

import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.net.URLConnection;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class WebService {
    /**
     * 對伺服器端傳回的XML進行解析
     *
     * @param city
     *            使用者輸入的城市名稱
     * @return 字元串 用#分割
     */
    public static String getWeather(String city) {
        try {
            Document doc;
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            dbf.setNamespaceAware(true);
            DocumentBuilder db = dbf.newDocumentBuilder();
            InputStream is = getSoapInputStream(city);
            doc = db.parse(is);
            NodeList nl = doc.getElementsByTagName("string");
            StringBuffer sb = new StringBuffer();
            for (int count = 0; count < nl.getLength(); count++) {
                Node n = nl.item(count);
                if(n.getFirstChild().getNodeValue().equals("查詢結果為空！")) {
                    sb = new StringBuffer("#") ;
                    break ;
                }
                sb.append(n.getFirstChild().getNodeValue() + "#");
            }
            is.close();
            return sb.toString();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 使用者把SOAP請求發送給伺服器端，并傳回伺服器點傳回的輸入流
     *
     * @param city
     *            使用者輸入的城市名稱
     * @return 伺服器端傳回的輸入流，供用戶端讀取
     * @throws Exception
     */
    private static InputStream getSoapInputStream(String city) throws Exception {
        try {
            String soap = getSoapRequest(city);
            if (soap == null) {
                return null;
            }
            URL url = new URL(
                    "http://www.webxml.com.cn/WebServices/WeatherWS.asmx");
            URLConnection conn = url.openConnection();
            conn.setUseCaches(false);
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setRequestProperty("Content-Length", Integer.toString(soap
                    .length()));
            conn.setRequestProperty("Content-Type", "text/xml; charset=utf-8");
            conn.setRequestProperty("SOAPAction",
                    "http://WebXml.com.cn/getWeather");
            OutputStream os = conn.getOutputStream();
            OutputStreamWriter osw = new OutputStreamWriter(os, "utf-8");
            osw.write(soap);
            osw.flush();
            osw.close();
            InputStream is = conn.getInputStream();
            return is;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
    /**
     * 擷取SOAP的請求頭，并替換其中的标志符号為使用者輸入的城市
     *
     * @param city
     *            使用者輸入的城市名稱
     * @return 客戶将要發送給伺服器的SOAP請求
     */
    private static String getSoapRequest(String city) {
        StringBuilder sb = new StringBuilder();
        sb.append("<?xml version=\"1.0\" encoding=\"utf-8\"?>"
                + "<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" "
                + "xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" "
                + "xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">"
                + "<soap:Body>    <getWeather xmlns=\"http://WebXml.com.cn/\">"
                + "<theCityCode>" + city
                + "</theCityCode>    </getWeather>"
                + "</soap:Body></soap:Envelope>");
        return sb.toString();
    }




    /**
     * 測試
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        String weatherInfo = getWeather("北京");
        System.out.println(weatherInfo);
    }
}
           

測試結果