使用dom4j的xPath解析XML

程序员文章站 2022-03-03 16:13:48

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books.xml:

<?xml version="1.0" encoding="UTF-8"?>
<books>
    <!--This is a test for dom4j, jakoes, 2007.7.19-->
    <book show="yes" url="lucene.net">
        <title id="456">Lucene Studing</title>
    </book>
    <book show="yes" url="dom4j.com">
        <title id="123">Dom4j Tutorials</title>
    </book>
    <book show="no" url="spring.org">
        <title id="789">Spring in Action</title>
    </book>
    <owner>O'Reilly</owner>
</books>

下面我们使用dom4j的xPath来解析：

segment of ParseXML.java:

public void parseBooks(){

        SAXReader reader = new SAXReader();
        try {
            Document doc = reader.read("books.xml");
            Node root = doc.selectSingleNode("/books");
            List list = root.selectNodes("book[@url='dom4j.com']");

            for(Object o:list){

                Element e = (Element) o;
                String show=e.attributeValue("show");
                System.out.println("show = " + show);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Document doc = reader.read("books.xml");的意思是加载XML文档，此是可以用doc.asXML()来查看，它将打印整个xml文档。

Node root = doc.selectSingleNode("/books");是读取刚才加载的xml文档内的books节点下的所有内容，对于本例也是整个xml文档。
当然我们也可以加载/books下的某一个节点，如：book节点
Node root = doc.selectSingleNode("/books/book");
或：Node root = doc.selectSingleNode("/books/*");
注意：如果有多个book节点，它只会读取第一个
root.asXML()将打印：
<book show="yes" url="lucene.net">
<title id="456">Lucene Studing</title>
</book>

既然加载了这么多，那我怎么精确的得到我想要的节点呢，别急，看下面：
List list = root.selectNodes("book[@url='dom4j.com']");
它的意思就是读取books节点下的book节点，且book的节点的url属性为dom4j.com
为什么使用list来接收呢，如果有两个book节点，且它们的url属性都为dom4j.com，此时就封闭到list里了。

[color=red]如果想读取books下的所有book节点，可以这样：
List list = root.selectNodes("book");

如果想读取books节点下的book节点下的title节点，可以这样：
List list2 = root.selectNodes("book[@url='dom4j.com']/title[@id='123']");[/color]

注意：selectNodes()参数的格式：
节点名[@属性名='属性值']，如：book[@url='dom4j.com']
如果有多个节点，用“/”分开，如：book[@url='dom4j.com']/title[@id='123']

最后就是读取封闭在List里的内容了，可以用Node来读取，也可以用Element来转换。
attributeValue("属性")是读取该节点的属性值
getText()是读取节点的的内容。

可参考：
[url]http://newbutton.blog.163.com/blog/static/440539462007919115928634/[/url]

下面介绍一个复杂一点的例子，通过请求，从服务器传回一串xml格式的字符串，然后再parse方法中解析，就得到了TermInfo对象实例。
服务器传回的字符串如下：
<?xml version=\"1.0\" encoding=\"utf-8\"?><message><head><messageId>20100707163000062</messageId><result>0000</result><encryptionType>0</encryptionType><md>a4820454be3b0bcc42cb62884a8ef44e</md></head><body><termInfo winTermNo=\"10077\" preTermNo=\"\"><lotteryResult>0607091724|0212</lotteryResult><missCount >10,29,3,4,5,0,0,12,0,2,4,1,12,7,11,1,0,8,1,3,11,11,2,0,5,6,2,7,8,4,14,3,17,9,1|4,0,5,28,2,9,2,8,8,5,4,0</missCount ><limitNumber ></limitNumber ><salesVolume >51385724</salesVolume ><jackpot >68192388.87</jackpot ><winResult><win id=\"1\"><winCount>0</winCount><winMoney>0</winMoney><winAddCount>0</winAddCount><winAddMoney>0</winAddMoney></win><win id=\"2\"><winCount>3</winCount><winMoney>1018831</winMoney><winAddCount>1</winAddCount><winAddMoney>611298</winAddMoney></win><win id=\"3\"><winCount>38</winCount><winMoney>22364</winMoney><winAddCount>5</winAddCount><winAddMoney>13418</winAddMoney></win><win id=\"4\"><winCount>40</winCount><winMoney>3000</winMoney><winAddCount>9</winAddCount><winAddMoney>1500</winAddMoney></win><win id=\"5\"><winCount>1473</winCount><winMoney>600</winMoney><winAddCount>464</winAddCount><winAddMoney>300</winAddMoney></win><win id=\"6\"><winCount>6540</winCount><winMoney>100</winMoney><winAddCount>1573</winAddCount><winAddMoney>50</winAddMoney></win><win id=\"7\"><winCount>69490</winCount><winMoney>10</winMoney><winAddCount>18273</winAddCount><winAddMoney>5</winAddMoney></win><win id=\"8\"><winCount>832924</winCount><winMoney>5</winMoney></win></winResult><term termNo=\"10078\"><termStatus>1</termStatus><winStatus>1</winStatus><saleStatus>1</saleStatus><startTime></startTime><deadLine>20100707193000</deadLine><deadLine2>20100707190000</deadLine2><winLine>20100707220000</winLine><startTime2></startTime2><deadLine3>20100707200000</deadLine3><winLine2>20100707220000</winLine2><changeLine>20100905220000</changeLine><reserve></reserve></term></termInfo></body></message>

解析如下：


import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import com.tlt.app.util.Constants;
/**
 * 当前在售期彩期信息
 * @author Administrator
 *
 */
public class TermInfo extends BaseModel{

	private Head head;
	/*选填，最近一期开奖期号*/
	private String winTermNo;
	/*选填，最近一期预售期号*/
	private String preTermNo;
	/*最近开奖结果*/
	private String lotteryResult;
	/*遗漏信息*/
	private String missCount;
	/*限号信息*/
	private String limitNumber;
	/*上期销量*/
	private String salesVolume;
	/*奖池滚存*/
	private String jackpot;
	/*最近开奖奖级结果*/
	private WinResult winResult;
	/*正在销售彩期信息*/
	private Term term;
	/*保留*/
	private String reserve;
	/*出错信息*/
	private String errorMsg;
	/*球队*/
	private List<GameInfo> gameInfo;
	public List<GameInfo> getGameInfo() {
		return gameInfo;
	}
	public void setGameInfo(List<GameInfo> gameInfo) {
		this.gameInfo = gameInfo;
	}
	public String getWinTermNo() {
		return winTermNo;
	}
	public void setWinTermNo(String winTermNo) {
		this.winTermNo = winTermNo;
	}
	public String getPreTermNo() {
		return preTermNo;
	}
	public void setPreTermNo(String preTermNo) {
		this.preTermNo = preTermNo;
	}
	public String getErrorMsg() {
		return errorMsg;
	}
	public void setErrorMsg(String errorMsg) {
		this.errorMsg = errorMsg;
	}
	public Head getHead() {
		return head;
	}
	public void setHead(Head head) {
		this.head = head;
	}
	public String getLotteryResult() {
		return lotteryResult;
	}
	public void setLotteryResult(String lotteryResult) {
		this.lotteryResult = lotteryResult;
	}
	public String getMissCount() {
		return missCount;
	}
	public void setMissCount(String missCount) {
		this.missCount = missCount;
	}
	public String getLimitNumber() {
		return limitNumber;
	}
	public void setLimitNumber(String limitNumber) {
		this.limitNumber = limitNumber;
	}
	public String getSalesVolume() {
		return salesVolume;
	}
	public void setSalesVolume(String salesVolume) {
		this.salesVolume = salesVolume;
	}
	public String getJackpot() {
		return jackpot;
	}
	public void setJackpot(String jackpot) {
		this.jackpot = jackpot;
	}
	public WinResult getWinResult() {
		return winResult;
	}
	public void setWinResult(WinResult winResult) {
		this.winResult = winResult;
	}
	public Term getTerm() {
		return term;
	}
	public void setTerm(Term term) {
		this.term = term;
	}
	public String getReserve() {
		return reserve;
	}
	public void setReserve(String reserve) {
		this.reserve = reserve;
	}
	@Override
	public boolean parse(String xmlString) {
		// TODO Auto-generated method stub
		try {
			Document document = DocumentHelper.parseText(xmlString);
			Head head=new Head();
			head.setMessageId(document.selectSingleNode("//message/head/messageId").getText());
			head.setResult(document.selectSingleNode("//message/head/result").getText());
			head.setEncryptionType(document.selectSingleNode("//message/head/encryptionType").getText());
			head.setMd(document.selectSingleNode("//message/head/md").getText());
			setHead(head);
			//如果返回失败信息，就没必要继续解析了
			if(!head.getResult().equals(Constants.SUCCESS)){
				setErrorMsg(document.selectSingleNode("//message/head/result").getText()+":"+document.selectSingleNode("//message/body/errorMsg").getText());
				return false;
			}
			setWinTermNo(document.selectSingleNode("//message/body/termInfo/@winTermNo").getText());
			setPreTermNo(document.selectSingleNode("//message/body/termInfo/@preTermNo").getText());
			setLotteryResult(document.selectSingleNode("//message/body/termInfo/lotteryResult").getText());
			setMissCount(document.selectSingleNode("//message/body/termInfo/missCount").getText());
			setLimitNumber(document.selectSingleNode("//message/body/termInfo/limitNumber").getText());
			setSalesVolume(document.selectSingleNode("//message/body/termInfo/salesVolume").getText());
			setJackpot(document.selectSingleNode("//message/body/termInfo/jackpot").getText());
			winResult=new WinResult();
			Map<String,Win> winMap=new TreeMap<String,Win>();//需要排序
			List list = document.selectNodes("//message/body/termInfo/winResult/win");
			for (Iterator iter = list.iterator(); iter.hasNext();) {
				Win win=new Win();
				Element winEle=(Element)iter.next();
				win.setWinCount(winEle.element("winCount").getText());
				win.setWinMoney(winEle.element("winMoney").getText());
				if(winEle.element("winAddCount")!=null){//8等奖没有追加
					win.setWinAddCount(winEle.element("winAddCount").getText());
					win.setWinAddMoney(winEle.element("winAddMoney").getText());
				}else{
					win.setWinAddCount("");
					win.setWinAddMoney("");
				}
				String id=winEle.attribute("id").getValue();
				win.setId(id);
				winMap.put(id,win);
			}
			winResult.setWin(winMap);
			setWinResult(winResult);

			Term term=new Term();
			term.setTermNo(document.selectSingleNode("//message/body/termInfo/term/@termNo").getText());
			term.setTermStatus(document.selectSingleNode("//message/body/termInfo/term/termStatus").getText());
			term.setWinStatus(document.selectSingleNode("//message/body/termInfo/term/winStatus").getText());
			term.setSaleStatus(document.selectSingleNode("//message/body/termInfo/term/saleStatus").getText());
			term.setStartTime(document.selectSingleNode("//message/body/termInfo/term/startTime").getText());
			term.setDeadLine(document.selectSingleNode("//message/body/termInfo/term/deadLine").getText());
			term.setDeadLine2(document.selectSingleNode("//message/body/termInfo/term/deadLine2").getText());
			term.setWinLine(document.selectSingleNode("//message/body/termInfo/term/winLine").getText());
			term.setStartTime2(document.selectSingleNode("//message/body/termInfo/term/startTime2").getText());
			term.setDeadLine3(document.selectSingleNode("//message/body/termInfo/term/deadLine3").getText());
			term.setWinLine2(document.selectSingleNode("//message/body/termInfo/term/winLine2").getText());
			term.setChangeLine(document.selectSingleNode("//message/body/termInfo/term/changeLine").getText());
			term.setReserve(document.selectSingleNode("//message/body/termInfo/term/reserve").getText());
			setTerm(term);

			List list_gameInfo = document.selectNodes("//message/body/termInfo/term/gameInfo/game");
			gameInfo=new ArrayList<GameInfo>();
			for (Iterator iter = list_gameInfo.iterator(); iter.hasNext();) {
				GameInfo info=new GameInfo();
				Element gameInfoEle=(Element)iter.next();
				info.setId(gameInfoEle.attributeValue("id"));
				info.setHomeTeam(gameInfoEle.element("homeTeam").getText());
				info.setAwayTeam(gameInfoEle.element("awayTeam").getText());
				info.setGameDate(gameInfoEle.element("gameDate").getText());
				info.setLeagueMatch(gameInfoEle.element("leagueMatch").getText());//巴甲
				info.setReserve(gameInfoEle.element("reserve").getText());
				gameInfo.add(info);
			}
			setGameInfo(gameInfo);
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
		}
		return true;
	}

}

<![CDATA[你的有特殊字符的内容]]>，比如：
<message><![CDATA[salary<1000]]></message>

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