天气预报Dom解析(转）

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DOM是用与平台无关和语言无关的方式表示XML文档的官方W3C标准，DOM是以层次结构组织的节点或信息片段的集合。DOM是基于树的，DOM相对SAX来说简单,耗内存...

本次学习目标：了解DOM解析XML ，并用DOM解析谷歌提供的天气 

谷歌提供的天气接口是 http://www.google.com/ig/api?hl=zh_CN&weather=wuhan   这个接口末尾是wuhan 即 "武汉" 的拼音,依次类推，北京的查询方式是把后面拼音换成beijing就行了，这个接口是查询武汉四天的天气。

根元素(Element)是 xml_api_reply 即树的根 然后往里面扩展。

海蓝网络提供参考网站：http://www.xmhlweb.com/  

我要获取节点forecas_conditions中的数据 

DOM初始工作需要几个函数

DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document document = builder.parse(new InputSource(new InputStreamReader(lianJie(strUrl) )));

然后通过Document对象解析XML，解析XML时会用到节点,并取得他的值 用到类 NodeList  ,Node. 下面开始上我的程序 

 http://www.xmhlweb.com/

package com.study.weather;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class Weather
{

    public InputStream lianJie(String strUrl) throws IOException
    {
        URL url = new URL(strUrl);
        HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
        InputStream is = urlConnection.getInputStream();


        if(is!=null)
        {
            return is;
        }
        return null;
    }

    public void resolutionXML(String strUrl) throws ParserConfigurationException, SAXException, IOException
    {
        WeatherData wd = new WeatherData();
        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = builderFactory.newDocumentBuilder();
        Document document = builder.parse(new InputSource(new InputStreamReader(lianJie(strUrl) )));

        // 得到xml_api_reply
        Element rootElement = document.getDocumentElement();
        System.out.println(rootElement.getNodeName());
        Node weatherNode =  rootElement.getElementsByTagName("weather").item(0);

//      Node weatherNode = rootElement.getFirstChild();
        System.out.println(weatherNode.getNodeName());
        // 得到weather
//      Node nodeWeather = weatherNode.getChildNodes();

        // 得到weather下节点数组
        NodeList nodeForecastWeathers =  weatherNode.getChildNodes();

        // 遍历weather下的节点
        for(int i=0; i<nodeForecastWeathers.getLength(); i++)
        {

            Node nodeForecastWeather = nodeForecastWeathers.item(i);
            // 筛选节点  找名称为 forecast_conditions 节点
            if(nodeForecastWeather.getNodeType()==Node.ELEMENT_NODE
                    &&nodeForecastWeather.getNodeName().equals("forecast_conditions"))
            {
                        // 建立forecast_conditions下节点数组
                        NodeList nodeListForecastConditions =  nodeForecastWeather.getChildNodes();

                        for(int j=0; j<nodeListForecastConditions.getLength(); j++)
                        {
                            //day_of_week low high condition
                            Node data = nodeListForecastConditions.item(j);
                        if(data.getNodeName().equals("day_of_week"))
                        {
                            wd.setDayOfWeek(data.getAttributes().getNamedItem("data").getNodeValue());
                        }
                        else if(data.getNodeName().equals("low"))
                        {
                            wd.setLow(data.getAttributes().item(0).getNodeValue());
                        }
                        else if(data.getNodeName().equals("high"))
                        {
                            wd.setHigh(data.getAttributes().item(0).getNodeValue());
                        }
                        else if(data.getNodeName().equals("condition"))
                        {
                            wd.setConditionData(data.getAttributes().item(0).getNodeValue());
                        }
                        }
                        System.out.println(wd.printWeatheaInfo());

                }
            }

        }





    public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException
    {
        Weather weather = new Weather();
        weather.resolutionXML("http://www.google.com/ig/api?hl=zh_CN&weather=wuhan");

    }
    class WeatherData
    {
        String dayOfWeek;
        String low;
        String high;
        String conditionData;
        public void setDayOfWeek(String dayOfWeek)
        {
            this.dayOfWeek = dayOfWeek;
        }
        public void setLow(String low)
        {
            this.low = low;
        }

        public void setHigh(String high)
        {
            this.high = high;
        }

        public void setConditionData(String conditionData)
        {
            this.conditionData = conditionData;
        }

        public String printWeatheaInfo()
        {
            return dayOfWeek+"\n"+"温度: "+low+"~~"+high+"  \n天气情况: "+conditionData;
        }
    }

}<