java.lang.AbstractMethodError: org.apache.xerces.dom.DocumentImpl.setXmlVersion問題解決方法

2019-11-26 15:14:30

字體：大中小

來源：轉載

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讀取本地的xml文件，通過DOM進行解析，DOM解析的特點就是把整個xml文件裝載入內存中，形成一顆DOM樹形結構，樹結構是方便遍歷和和操縱。

DOM解析的特性就是讀取xml文件轉換為 dom樹形結構，通過節點進行遍歷。

這是W3c關于節點的概念

如果xml中包含有大量的數據，由于dom一次性把xml裝入內存中的特性，所以dom不適合于包含大量數據的xml解析。當包含有大量xml的時候，用SAX進行解析比較節省內存。

下面是一個運用DOM進行解析xml文件的例子：

xml文件結構如下：

<?xml version="1.0" encoding="ISO-8859-1"?><bookstore> <book category="cooking"> <title lang="en">Everyday Italian</title> <author>Giada De Laurentiis</author> <year>2005</year> <price>30.00</price> </book> <book category="children"> <title lang="en">Harry Potter</title> <author>J K. Rowling</author> <year>2005</year> <price>29.99</price> </book> <book category="web"> <title lang="en">XQuery Kick Start</title> <author>James McGovern</author> <year>2003</year> <price>49.99</price> </book> <book category="web" cover="paperback"> <title lang="en">Learning XML</title> <author>Erik T. Ray</author> <year>2003</year> <price>39.95</price> </book></bookstore>

創建解析xml的類如下：

package xml.dom;import java.io.File;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.Node;import org.w3c.dom.NodeList;public class ReadXmlFile {  public static void main(String[] args) {  try{    File xmlFile = new File("src/resource/book.xml");    DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();    DocumentBuilder builder = builderFactory.newDocumentBuilder();    Document doc = builder.parse(xmlFile);    doc.getDocumentElement().normalize();    System.out.println("Root element: "+doc.getDocumentElement().getNodeName());    NodeList nList = doc.getElementsByTagName("book");    for(int i = 0 ; i<nList.getLength();i++){    Node node = nList.item(i);    System.out.println("Node name: "+ node.getNodeName());  Element ele = (Element)node;    System.out.println("----------------------------");  if(node.getNodeType() == Element.ELEMENT_NODE){    System.out.println("book category: "+ ele.getAttribute("category"));    System.out.println("title name: "+ ele.getElementsByTagName("title").item(0).getTextContent());    System.out.println("author name: "+ele.getElementsByTagName("author").item(0).getTextContent());    System.out.println("year :"+ele.getElementsByTagName("year").item(0).getTextContent());    System.out.println("price : "+ele.getElementsByTagName("price").item(0).getTextContent());    System.out.println("-------------------------");      }      }

解析結果：

Root element: bookstoreNode name: book----------------------------book category: cookingtitle name: Everyday Italianauthor name: Giada De Laurentiisyear :2005price : 30.00-------------------------Node name: book----------------------------book category: childrentitle name: Harry Potterauthor name: J K. Rowlingyear :2005price : 29.99-------------------------Node name: book----------------------------book category: webtitle name: XQuery Kick Startauthor name: James McGovernyear :2003price : 49.99-------------------------Node name: book----------------------------book category: webtitle name: Learning XMLauthor name: Erik T. Rayyear :2003price : 39.95-------------------------

以上是通過name獲得對應的值，
下面利用循環節點的方式輸出：
循環節點輸出方式的代碼如下：

package xml.dom;import java.io.File;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import org.w3c.dom.Document;import org.w3c.dom.NamedNodeMap;import org.w3c.dom.Node;import org.w3c.dom.NodeList;public class ReadXmlFile2 {  public static void main(String[] args) { try{    File xmlFile = new File("src/resource/book.xml");    DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();    DocumentBuilder builder = builderFactory.newDocumentBuilder();    Document doc = builder.parse(xmlFile);    doc.getDocumentElement().normalize();    System.out.println("Root element: "+doc.getDocumentElement().getNodeName());      if(doc.hasChildNodes()){    printNode(doc.getChildNodes());  } }catch(Exception e){  e.printStackTrace();  }  }  public static void printNode(NodeList nodeList){ System.out.println("------------------------"); // System.out.println(nodeList.getLength()); for(int i = 0; i<nodeList.getLength(); i++){  Node node = (Node)nodeList.item(i);   if(node.getNodeType() == Node.ELEMENT_NODE){  System.out.println("node name: "+node.getNodeName());  System.out.println("node value: "+node.getTextContent());  if(node.hasAttributes()){  NamedNodeMap nodeMap = node.getAttributes();    for(int j = 0; j < nodeMap.getLength() ; j++){    Node nodenew = nodeMap.item(j);    System.out.println("node name "+nodenew.getNodeName());  System.out.println("node value "+nodenew.getNodeValue());  } } if(node.hasChildNodes()){  printNode(node.getChildNodes()); } }  }  }}

輸出結果如下：

Root element: bookstore------------------------node name: bookstorenode value:   Everyday Italian Giada De Laurentiis 2005 30.00   Harry Potter J K. Rowling 2005 29.99   XQuery Kick Start James McGovern 2003 49.99   Learning XML Erik T. Ray 2003 39.95 ------------------------node name: booknode value:  Everyday Italian Giada De Laurentiis 2005 30.00 node name categorynode value cooking------------------------node name: titlenode value: Everyday Italiannode name langnode value en------------------------node name: authornode value: Giada De Laurentiis------------------------node name: yearnode value: 2005------------------------node name: pricenode value: 30.00------------------------node name: booknode value:  Harry Potter J K. Rowling 2005 29.99 node name categorynode value children------------------------node name: titlenode value: Harry Potternode name langnode value en------------------------node name: authornode value: J K. Rowling------------------------node name: yearnode value: 2005------------------------node name: pricenode value: 29.99------------------------node name: booknode value:  XQuery Kick Start James McGovern 2003 49.99 node name categorynode value web------------------------node name: titlenode value: XQuery Kick Startnode name langnode value en------------------------node name: authornode value: James McGovern------------------------node name: yearnode value: 2003------------------------node name: pricenode value: 49.99------------------------node name: booknode value:  Learning XML Erik T. Ray 2003 39.95 node name categorynode value webnode name covernode value paperback------------------------node name: titlenode value: Learning XMLnode name langnode value en------------------------node name: authornode value: Erik T. Ray------------------------node name: yearnode value: 2003------------------------node name: pricenode value: 39.95------------------------

關于節點的問題：

 <book category="cooking"> <title lang="en">Everyday Italian</title> <author>Giada De Laurentiis</author> <year>2005</year> <price>30.00</price> </book>

對于 book應用：doc.getChildNodes() 得到一個NodeList其中NodeList的長度為9
9個節點分別如下：
title節點
lang節點
Everyday節點
author節點
Giada De Laurentiis節點
year節點
2005節點
price節點
30.00節點