WebService(WEB服务)--获取网络数据
运用WebService（WEB服务），可以很方便快捷的获取想要的数据。http://www.webxml.com.cn/zh_cn/index.aspx网站提供了很多web服务。下面以获取汇率为例，来说明webservice的用法。这个例子运用到了dom4j操作xml文件，先是从两个web服务中分别获取数据，最后根据具体需求将数据整合在一起，生成一个xml文件。本例中需要用到的webservice有两个：http://webservice.webxml.com.cn/WebServices/ExchangeRateWebService.asmx与http://webservice.webxml.com.cn/WebServices/ForexRmbRateWebService.asmx。完整版代码见附件，精简版代码如下，哈哈
import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileWriter;import java.io.InputStream;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.net.InetSocketAddress;import java.net.Proxy;import java.net.URL;import java.net.URLConnection;import java.text.DecimalFormat;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.Element;import org.dom4j.io.OutputFormat;import org.dom4j.io.SAXReader;import org.dom4j.io.XMLWriter;/** * getExchangeRate *//** * getForexRmbRate *//** * 调用webservice得到汇率服务 * @author gerry * 2010-09-06 */public class ExchangeRateXML{private static String encodeOut = "GBK";private static String encodeIn = "UTF-8";private static Proxy proxy;//代理private static String proxyStr = "10.3.1.93";//代理IP地址 若不用代理请设置proxyStr="";private static int proxyCode = 3128;//代理端口private static int COUNT = 10;//尝试连接次数/** * 单例模式 */private static ExchangeRateXML exchangeRateXML;/** * 私有的构造方法 */private ExchangeRateXML(){}/** * public的获取单例对象的方法 */public static ExchangeRateXML getInstance(){if(exchangeRateXML==null){exchangeRateXML = new ExchangeRateXML();InetSocketAddress isa = new InetSocketAddress(proxyStr, proxyCode);proxy = new Proxy(Proxy.Type.HTTP, isa);}return exchangeRateXML;}/** * 通过dom4j生成xml文件 * @return 成功true 失败false */privateboolean createExchangeRateXMLFile(String fileName){boolean flag = false;Document document=null;SAXReader reader = new SAXReader();Map<String,String> map = new HashMap<String,String>();map.put("xxx", "");reader.getDocumentFactory().setXPathNamespaceURIs(map);try{InputStream is = getSoapInputStream(1);//得到输入流document=reader.read(is);//将输入流转化为documentList<Element> list = document.selectNodes("//xxx:ExchangeRate");Element relativeRootElement = list.get(0).getParent().getParent();//diffgr:diffgram节点相对根节点DecimalFormat df = new DecimalFormat("###0.0000"); //保留小数点后4位Element e = null;for(int i=0; i<=6; i++){e = list.get(i);//先把名称改为"美元Currency"的格式e.element("Currency").setText("美元"+e.element("Currency").getText());e.element("Code").setText("USD-"+e.element("Code").getText());}is = getSoapInputStream(2);//得到输入流Document doc = reader.read(is); //将输入流转化为documentList<Element> l = doc.selectNodes("//xxx:ForexRmbRate");Element ele = null;for (Iterator<Element> it = l.iterator(); it.hasNext();) {ele = it.next();//ele.element("Name").setText(ele.element("Name").getText()+"人民币");ele.element("Name").setText(ele.element("Symbol").getText()); //为了解决在Linux上中文字符的问题ele.element("Symbol").setText(ele.element("Symbol").getText()+"-RMB");}Element element = (Element)doc.selectSingleNode("//xxx:getForexRmbRate");Element elementCopy = element.createCopy();//copy节点relativeRootElement.add(elementCopy);//或relativeRootElement.appendContent(element.getParent());OutputFormat format = OutputFormat.createPrettyPrint();format.setEncoding(encodeOut);format.setIndent(" ");XMLWriter writer = new XMLWriter(new FileWriter(new File(fileName)),format); writer.write(document); writer.close(); flag = true;}catch (Exception e){e.printStackTrace();}return flag;}/** * 从xml文件中获取数据采用XPath * @return */@SuppressWarnings("unchecked")private static void getExchangeRateDataFromXMLFile(String fileName){SAXReader reader = new SAXReader();Map<String,String> map = new HashMap<String,String>();map.put("aaa", "");reader.getDocumentFactory().setXPathNamespaceURIs(map);try {InputStream is = new FileInputStream(fileName);Document document = reader.read(is);//上行代码也可以写成Document document = reader.read(new File(fileName));//找到ForexRmbRate节点List<Element> list = document.selectNodes("//aaa:ForexRmbRate");for (Iterator<Element> it = list.iterator(); it.hasNext();) {Element elm = it.next();String temp = null;temp = elm.element("BasePrice").getText();temp = elm.element("fBuyPrice").getText();temp = elm.element("SellPrice").getText();}} catch (DocumentException e) {e.printStackTrace();} catch (FileNotFoundException e) {e.printStackTrace();}}/** * 用户把SOAP请求发送给服务器端，并返回服务器点返回的输入流 * flag : 为1时代表getExchangeRate，为2时代表getForexRmbRate * @return 服务器端返回的输入流，供客户端读取 */private InputStream getSoapInputStream(int flag) throws Exception {//InputStreamReader isr = null;try {String soap = getSoapRequest(flag);if (soap == null) {return null;}String urlStr = null;String SOAPActionValue = null;if(flag==1){urlStr = "http://webservice.webxml.com.cn/WebServices/ExchangeRateWebService.asmx";SOAPActionValue = "http://webxml.com.cn/getExchangeRate";}else if(flag==2){urlStr = "http://webservice.webxml.com.cn/WebServices/ForexRmbRateWebService.asmx";SOAPActionValue = "http://webxml.com.cn/getForexRmbRate";}URL url = new URL(urlStr);URLConnection conn = null;if (!proxyStr.equals("")) {conn = url.openConnection(proxy);} else {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",SOAPActionValue);OutputStream ops = conn.getOutputStream();OutputStreamWriter osw = new OutputStreamWriter(ops, encodeIn);osw.write(soap);osw.flush();osw.close();InputStream is = conn.getInputStream();//isr = new InputStreamReader(is, encodeIn);//return isr;return is;} catch (Exception e) {e.printStackTrace();return null;}}/** * 获取soap请求头 * flag : 为1时代表getExchangeRate，为2时代表getForexRmbRate * @return 用户将要发送给服务器的soap请求 */private String getSoapRequest(int flag) {StringBuilder sb = new StringBuilder();if(flag==1){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><getExchangeRate xmlns=\"http://webxml.com.cn/\">"+ "<theType>" + "A"+ "</theType></getExchangeRate>"+ "</soap:Body></soap:Envelope>");}else if(flag==2){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><getForexRmbRate xmlns=\"http://webxml.com.cn/\">"+ "</getForexRmbRate>"+ "</soap:Body></soap:Envelope>");}return sb.toString();}/** * 外部可访问的方法，获得汇率数据 */public void getExchangeRate(){for(int i=0; i<COUNT; i++){if(ExchangeRateXML.getInstance().createExchangeRateXMLFile("ExRate.xml")){break;}}getExchangeRateDataFromXMLFile("ExRate.xml");}}
这个链接中有一个简单的webservice例子，是获取天气预报的：http://qinshuwei.com/webservic.html
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