Java. Lang. AbstractMethodError: org apache xerces. Dom. DocumentImpl. SetXmlVersion problem solving method
- 2020-04-01 03:47:25
- OfStack
Read the local XML file and parse it through the DOM. The feature of DOM parsing is to load the entire XML file into memory and form a DOM tree structure, which is convenient for traversal and manipulation.
The feature of DOM parsing is to read an XML file and transform it into a DOM tree structure, traversing through nodes.
This is the W3c concept of nodes
If the XML contains a large amount of data, dom is not suitable for XML parsing with a large amount of data because dom loads the XML into memory at once. When large amounts of XML are included, parsing with SAX saves memory.
Here's an example of parsing an XML file using the DOM:
The structure of the XML file is as follows:
<?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>
The following classes are created to parse XML:
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("-------------------------");
}
}
Analytical results:
Root element: bookstore
Node name: book
----------------------------
book category: cooking
title name: Everyday Italian
author name: Giada De Laurentiis
year :2005
price : 30.00
-------------------------
Node name: book
----------------------------
book category: children
title name: Harry Potter
author name: J K. Rowling
year :2005
price : 29.99
-------------------------
Node name: book
----------------------------
book category: web
title name: XQuery Kick Start
author name: James McGovern
year :2003
price : 49.99
-------------------------
Node name: book
----------------------------
book category: web
title name: Learning XML
author name: Erik T. Ray
year :2003
price : 39.95
-------------------------
So this is the value that we get by name,
The following method USES the output of the loop node:
The code of the output mode of the loop node is as follows:
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());
}
}
}
}
}
The output results are as follows:
Root element: bookstore
------------------------
node name: bookstore
node 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: book
node value:
Everyday Italian
Giada De Laurentiis
2005
30.00
node name category
node value cooking
------------------------
node name: title
node value: Everyday Italian
node name lang
node value en
------------------------
node name: author
node value: Giada De Laurentiis
------------------------
node name: year
node value: 2005
------------------------
node name: price
node value: 30.00
------------------------
node name: book
node value:
Harry Potter
J K. Rowling
2005
29.99
node name category
node value children
------------------------
node name: title
node value: Harry Potter
node name lang
node value en
------------------------
node name: author
node value: J K. Rowling
------------------------
node name: year
node value: 2005
------------------------
node name: price
node value: 29.99
------------------------
node name: book
node value:
XQuery Kick Start
James McGovern
2003
49.99
node name category
node value web
------------------------
node name: title
node value: XQuery Kick Start
node name lang
node value en
------------------------
node name: author
node value: James McGovern
------------------------
node name: year
node value: 2003
------------------------
node name: price
node value: 49.99
------------------------
node name: book
node value:
Learning XML
Erik T. Ray
2003
39.95
node name category
node value web
node name cover
node value paperback
------------------------
node name: title
node value: Learning XML
node name lang
node value en
------------------------
node name: author
node value: Erik T. Ray
------------------------
node name: year
node value: 2003
------------------------
node name: price
node value: 39.95
------------------------
Problems with nodes:
<book category="cooking">
<title lang="en">Everyday Italian</title>
<author>Giada De Laurentiis</author>
<year>2005</year>
<price>30.00</price>
</book>
For the book application: doc.getchildnodes () you get a NodeList with a length of 9
The 9 nodes are as follows:
The title nodes
Lang nodes
Everyday node
The author node
Giada De Laurentiis node
Year node
2005 nodes
Price node
30.00 the node