发布于 2016-07-22 12:56:59 | 88 次阅读 | 评论: 1 | 来源: 网友投递

这里有新鲜出炉的Java函数式编程,程序狗速度看过来!

Java程序设计语言

java 是一种可以撰写跨平台应用软件的面向对象的程序设计语言,是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台(即JavaEE(j2ee), JavaME(j2me), JavaSE(j2se))的总称。


这篇文章主要介绍了java.lang.AbstractMethodError: org.apache.xerces.dom.DocumentImpl.setXmlVersion问题解决方法,导致本文问题的原因是缺少一个xerces.jar jar包,需要的朋友可以参考下

读取本地的xml文件,通过DOM进行解析,DOM解析的特点就是把整个xml文件装载入内存中,形成一颗DOM树形结构,树结构是方便遍历和和操纵。

DOM解析的特性就是读取xml文件转换为 dom树形结构,通过节点进行遍历。

这是W3c关于节点的概念

如果xml中包含有大量的数据,由于dom一次性把xml装入内存中的特性,所以dom不适合于包含大量数据的xml解析。当包含有大量xml的时候,用SAX进行解析比较节省内存。

下面是一个运用DOM进行解析xml文件的例子:

xml文件结构如下:


<?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>

创建解析xml的类如下:


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("-------------------------");
  
  
  }
  
  
  }
  

解析结果:


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
-------------------------


以上是通过name获得对应的值,
下面利用循环节点的方式输出:
循环节点输出方式的代码如下:


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());
 }
 }
 
 }
 
 }

}

输出结果如下:


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
------------------------

关于节点的问题:


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

对于 book应用:doc.getChildNodes() 得到一个NodeList其中NodeList的长度为9
9个节点分别如下:
title节点
lang节点 
Everyday节点
 author节点
Giada De Laurentiis节点
 year节点
 2005节点
 price节点
 30.00节点



相关阅读 :
java.lang.AbstractMethodError: org.apache.xerces.dom.DocumentImpl.setXmlVersion问题解决方法
Java中FTPClient上传中文目录、中文文件名乱码问题解决方法
java压缩zip文件中文乱码问题解决方法
java中tomcat的80端口被占用问题解决
java.lang.NoClassDefFoundError: ognl/PropertyAccessor错误解决办法
java.lang.NoClassDefFoundError解决方案
解决Eclipse add external jars运行出现java.lang.NoClassDefFoundError的方法
Java中出现错误:“编码GBK的不可映射字符”的解决方法
安装J2EE的SDK报错:could not find the required version of the Java(TM)2 Runtime Environment in '(null)'的解决方法
运行java弹出Orcale JInitiator 版本太旧该如何解决?
java使用sigar 遇到问题的快速解决方法
java中文乱码之解决URL中文乱码问题的方法
最新网友评论  共有(1)条评论 发布评论 返回顶部
dnoqq 发布于2016-07-30 13:25:57
不顶不行啊,
支持(0)  反对(0)  回复

Copyright © 2007-2017 PHPERZ.COM All Rights Reserved   冀ICP备14009818号  版权声明  广告服务