java 获取天气预报实现代码

最简单的办法是申请一个yahoo dev 的key ,然后就可以通过 GeoPlanet api 来查询相应地点的WOEID了。
狼の禅 用的是旧的p 参数传递地点代码，不过最新的api文档里面只对w参数作了说明，因此这里我就用WOEID了。
不想注册申请key,还是自己折腾吧。
下载最新的 GeoPlanet Data ,解压出来有这些个文件：

geoplanet_places_[version].tsv: the WOEID, the placename, and the WOEID of its parent entity
geoplanet_aliases_[version].tsv: alternate names in multiple languages indexed against the WOEID
geoplanet_adjacencies_[version].tsv: the entities neighboring each WOEID
geoplanet_changes_[version].tsv: the list of removed WOEIDs and their replacement WOEID mappings
 这里我只取 geoplanet_places_7.6.0.tsv ，用EmEditor 打开，把 中国 地区的 COPY 出到另外一个文件Chinaplaces.tsv .

这个tsv 文件是用tab分隔字段的，places文件的字段有：

WOE_ID ISO Name Language PlaceType Parent_ID
 
public static HashMap cityCode = new HashMap();
    
/* 初始化城市代号 */
private void initCitys() {
    cityCode.put("北京", "0008");
    cityCode.put("天津", "0133");
    cityCode.put("武汉", "0138");
    cityCode.put("杭州", "0044");
    cityCode.put("合肥 ", "0448");
    cityCode.put("上海 ", "0116");
    cityCode.put("福州 ", "0031");
    cityCode.put("重庆 ", "0017");
    cityCode.put("南昌 ", "0097");
    cityCode.put("香港 ", "0049");
    cityCode.put("济南 ", "0064");
    cityCode.put("澳门 ", "0512");
    cityCode.put("郑州 ", "0165");
    cityCode.put("呼和浩特 ", "0249");
    cityCode.put("乌鲁木齐 ", "0135");
    cityCode.put("长沙 ", "0013");
    cityCode.put("银川 ", "0259");
    cityCode.put("广州 ", "0037");
    cityCode.put("拉萨 ", "0080");
    cityCode.put("海口 ", "0502");
    cityCode.put("南京 ", "0100");
    cityCode.put("成都 ", "0016");
    cityCode.put("石家庄 ", "0122");
    cityCode.put("贵阳 ", "0039");
    cityCode.put("太原 ", "0129");
    cityCode.put("昆明 ", "0076");
    cityCode.put("沈阳 ", "0119");
    cityCode.put("西安 ", "0141");
    cityCode.put("长春 ", "0010");
    cityCode.put("兰州 ", "0079");
    cityCode.put("西宁 ", "0236");
}

　　

接下来我们要创建链接，以获取天气预报的XML文档

private Document getWeatherXML(String cityCode) throws IOException {
        URL url = new URL("http://weather.yahooapis.com/forecastrss?p=CHXX"
                + cityCode + "&u=c");
        URLConnection connection = url.openConnection();
        Document Doc = stringToElement(connection.getInputStream());
        return Doc;
    }

　　

您也可以选择保存获取的天气XML文档

/* 保存获取的天气信息XML文档 */
    private void saveXML(Document Doc, String Path) {
        TransformerFactory transFactory = TransformerFactory.newInstance();
        Transformer transformer;
        try {
            transformer = transFactory.newTransformer();
            DOMSource domSource = new DOMSource(Doc);
            File file = new File(Path);
            FileOutputStream out = new FileOutputStream(file);
            StreamResult xmlResult = new StreamResult(out);
            transformer.transform(domSource, xmlResult);
        } catch (Exception e) {
            System.out.println("保存文件出错！");
        }
    }

　　

本人获取的一份XML保存如下

 
- 
- 
   
  http://us.rd.yahoo.com/dailynews/rss/weather/Wuhan__CH/*http://weather.yahoo.com/forecast/CHXX0138_c.html 
  Yahoo! Weather for Wuhan, CH 
  en-us 
  Sat, 27 Mar 2010 11:00 pm CST 
  60 
   
   
   
   
   
- 
   
  142 
  18 
  http://weather.yahoo.com 
  http://l.yimg.com/a/i/us/nws/th/main_142b.gif 
  
- 
   
  30.58 
  114.27 
  http://us.rd.yahoo.com/dailynews/rss/weather/Wuhan__CH/*http://weather.yahoo.com/forecast/CHXX0138_c.html 
  Sat, 27 Mar 2010 11:00 pm CST 
   
- 
-  
  
   
   
  CHXX0138_2010_03_27_23_00_CST 
  
  
  
- 

　　

好啦，下面就是解析XML了，您看一下XML文档，如果您了解的话很容易获取其中的信息

/* 获取天气信息 */
    public String getWeather(String city) {
        String result = null;
        try {
            Document doc = getWeatherXML(GetWeatherInfo.cityCode.get(city));
            NodeList nodeList = doc.getElementsByTagName("channel");
            for (int i = 0; i < nodeList.getLength(); i++) {
                Node node = nodeList.item(i);
                NodeList nodeList1 = node.getChildNodes();
                for (int j = 0; j < nodeList1.getLength(); j++) {
                    Node node1 = nodeList1.item(j);
                    if (node1.getNodeName().equalsIgnoreCase("item")) {
                        NodeList nodeList2 = node1.getChildNodes();
                        for (int k = 0; k < nodeList2.getLength(); k++) {
                            Node node2 = nodeList2.item(k);
                            if (node2.getNodeName().equalsIgnoreCase(
                                    "yweather:forecast")) {
                                NamedNodeMap nodeMap = node2.getAttributes();
                                Node lowNode = nodeMap.getNamedItem("low");
                                Node highNode = nodeMap.getNamedItem("high");
                                Node codeNode = nodeMap.getNamedItem("code");
                                String day = "今天";
                                if (result == null) {
                                    result = "";
                                } else {
                                    day = "n明天";
                                }
                                result = result
                                        + day
                                        + " "
                                        + dictionaryStrings[Integer
                                                .parseInt(codeNode
                                                        .getNodeValue())]
                                        + "t最低温度：" + lowNode.getNodeValue()
                                        + "℃ t最高温度：" + highNode.getNodeValue()
                                        + "℃ ";
                            }
                        }
                    }
                }
            }
            saveXML(doc, "C:UsersyguiDesktopWeather.xml");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

　　

整个程序的代码如下：

package stwolf.hustbaidu.java.learn.filelist;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashMap;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
class GetWeatherInfo {
    public static HashMap cityCode = new HashMap();
    private final String[] dictionaryStrings = { "龙卷风", "热带风暴", "飓风", "强雷阵雨",
            "雷阵雨", "小雨加雪", "雨加冰雹", "雪加冰雹", "冰雨", "毛毛雨", "冻雨", "阵雨", "阵雨", "小雪",
            "零星小雪", "高吹雪", "雪", "冰雹", "雨夹雪", "尘", "雾", "薄雾", "多烟的", "大风", "有风",
            "寒冷", "阴天", "夜间阴天", "白天阴天", "夜间多云", "白天多云", "夜间清亮", "晴朗", "转晴",
            "转晴", "雨夹冰雹", "热", "雷阵雨", "雷阵雨", "雷阵雨", "雷阵雨", "大雪", "阵雪", "大雪",
            "多云", "雷", "阵雪", "雷雨" };
    public GetWeatherInfo() {
        initCitys();
    }
    /* 初始化城市代号 */
    private void initCitys() {
        cityCode.put("北京", "0008");
        cityCode.put("天津", "0133");
        cityCode.put("武汉", "0138");
        cityCode.put("杭州", "0044");
        cityCode.put("合肥 ", "0448");
        cityCode.put("上海 ", "0116");
        cityCode.put("福州 ", "0031");
        cityCode.put("重庆 ", "0017");
        cityCode.put("南昌 ", "0097");
        cityCode.put("香港 ", "0049");
        cityCode.put("济南 ", "0064");
        cityCode.put("澳门 ", "0512");
        cityCode.put("郑州 ", "0165");
        cityCode.put("呼和浩特 ", "0249");
        cityCode.put("乌鲁木齐 ", "0135");
        cityCode.put("长沙 ", "0013");
        cityCode.put("银川 ", "0259");
        cityCode.put("广州 ", "0037");
        cityCode.put("拉萨 ", "0080");
        cityCode.put("海口 ", "0502");
        cityCode.put("南京 ", "0100");
        cityCode.put("成都 ", "0016");
        cityCode.put("石家庄 ", "0122");
        cityCode.put("贵阳 ", "0039");
        cityCode.put("太原 ", "0129");
        cityCode.put("昆明 ", "0076");
        cityCode.put("沈阳 ", "0119");
        cityCode.put("西安 ", "0141");
        cityCode.put("长春 ", "0010");
        cityCode.put("兰州 ", "0079");
        cityCode.put("西宁 ", "0236");
    }
    private Document getWeatherXML(String cityCode) throws IOException {
        URL url = new URL("http://weather.yahooapis.com/forecastrss?p=CHXX"
                + cityCode + "&u=c");
        URLConnection connection = url.openConnection();
        Document Doc = stringToElement(connection.getInputStream());
        return Doc;
    }
    /* 保存获取的天气信息XML文档 */
    private void saveXML(Document Doc, String Path) {
        TransformerFactory transFactory = TransformerFactory.newInstance();
        Transformer transformer;
        try {
            transformer = transFactory.newTransformer();
            DOMSource domSource = new DOMSource(Doc);
            File file = new File(Path);
            FileOutputStream out = new FileOutputStream(file);
            StreamResult xmlResult = new StreamResult(out);
            transformer.transform(domSource, xmlResult);
        } catch (Exception e) {
            System.out.println("保存文件出错！");
        }
    }
    /* 获取天气信息 */
    public String getWeather(String city) {
        String result = null;
        try {
            Document doc = getWeatherXML(GetWeatherInfo.cityCode.get(city));
            NodeList nodeList = doc.getElementsByTagName("channel");
            for (int i = 0; i < nodeList.getLength(); i++) {
                Node node = nodeList.item(i);
                NodeList nodeList1 = node.getChildNodes();
                for (int j = 0; j < nodeList1.getLength(); j++) {
                    Node node1 = nodeList1.item(j);
                    if (node1.getNodeName().equalsIgnoreCase("item")) {
                        NodeList nodeList2 = node1.getChildNodes();
                        for (int k = 0; k < nodeList2.getLength(); k++) {
                            Node node2 = nodeList2.item(k);
                            if (node2.getNodeName().equalsIgnoreCase(
                                    "yweather:forecast")) {
                                NamedNodeMap nodeMap = node2.getAttributes();
                                Node lowNode = nodeMap.getNamedItem("low");
                                Node highNode = nodeMap.getNamedItem("high");
                                Node codeNode = nodeMap.getNamedItem("code");
                                String day = "今天";
                                if (result == null) {
                                    result = "";
                                } else {
                                    day = "n明天";
                                }
                                result = result
                                        + day
                                        + " "
                                        + dictionaryStrings[Integer
                                                .parseInt(codeNode
                                                        .getNodeValue())]
                                        + "t最低温度：" + lowNode.getNodeValue()
                                        + "℃ t最高温度：" + highNode.getNodeValue()
                                        + "℃ ";
                            }
                        }
                    }
                }
            }
            saveXML(doc, "C:UsersyguiDesktopWeather.xml");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
    public Document stringToElement(InputStream input) {
        try {
            DocumentBuilder db = DocumentBuilderFactory.newInstance()
                    .newDocumentBuilder();
            Document doc = db.parse(input);
            return doc;
        } catch (Exception e) {
            return null;
        }
    }
}
public class Test {
    public static void main(String arg[]) {
        GetWeatherInfo info = new GetWeatherInfo();
        String weather = info.getWeather("武汉");
        System.out.println(weather);
    }
}