java读取XML文件的四种方法总结(必看篇)

java操作xml文档主要有四种方式，分别是dom、sax、jdom和dom4j，dom和sax是官方提供的，而jdom和dom4j则是引用第三方库的，其中用的最多的是dom4j方式。运行效率和内存使用方面最优的是sax，但是由于sax是基于事件的方式，所以sax无法在编写xml的过程中对已编写内容进行修改，但对于不用进行频繁修改的需求，还是应该选择使用sax。

下面基于这四种方式来读取xml文件。

第一，以dom的方式实现。

package xmls;
import org.w3c.dom.document;
import org.w3c.dom.element;
import org.w3c.dom.node;
import org.w3c.dom.nodelist;
import org.xml.sax.saxexception;
import javax.xml.parsers.documentbuilder;
import javax.xml.parsers.documentbuilderfactory;
import javax.xml.parsers.parserconfigurationexception;
import java.io.file;
import java.io.ioexception;
/**
 * created by lenovo on 2017-6-3.
 */
public class domreaddemo {
  public static void main(string[] args){
    documentbuilderfactory dbf = documentbuilderfactory.newinstance();
    try{
      documentbuilder db = dbf.newdocumentbuilder();
      document document = db.parse("src/xmls/dom.xml");
      nodelist booklist = document.getelementsbytagname("book");
      for(int i = 0; i < booklist.getlength(); i++){
        system.out.println("--------第" + (i+1) + "本书----------");
        element ele = (element) booklist.item(i);
        nodelist childnodes= ele.getchildnodes();
        for(int j = 0; j < childnodes.getlength(); j++){
          node n = childnodes.item(j);
          if(n.getnodename() != "#text"){
            system.out.println(n.getnodename() + ":" + n.gettextcontent());
          }
        }
        system.out.println("---------------------------------");
      }
    }catch (parserconfigurationexception e){
      e.printstacktrace();
    }catch (ioexception e){
      e.printstacktrace();
    }catch (saxexception e){
      e.printstacktrace();
    }
  }
}

第二，以sax的方式实现。

package xmls;
import javax.xml.parsers.saxparser;
import javax.xml.parsers.saxparserfactory;
/**
 * created by lenovo on 2017-6-1.
 */
public class xmltest2 {
  public static void main(string[] args){
    saxparserfactory spf = saxparserfactory.newinstance();
    try{
      saxparser sp = spf.newsaxparser();
      saxparserhandler handler = new saxparserhandler();
      sp.parse("src\\xmls\\book.xml", handler);
    }catch (exception e){
      e.printstacktrace();
    }
  }
}

package xmls;
import org.xml.sax.attributes;
import org.xml.sax.saxexception;
import org.xml.sax.helpers.defaulthandler;
/**
 * created by lenovo on 2017-6-1.
 */
public class saxparserhandler extends defaulthandler {
  @override
  public void startdocument() throws saxexception {
    super.startdocument();
    system.out.println("sax解析开始");
  }
  @override
  public void enddocument() throws saxexception {
    super.enddocument();
    system.out.println("sax解析结束");
  }
  @override
  public void startelement(string s, string s1, string s2, attributes attributes) throws saxexception {
    super.startelement(s, s1, s2, attributes);
    system.out.println(s2);
    for(int i = 0; i < attributes.getlength(); i++){
      string name = attributes.getqname(i);
      string value = attributes.getvalue(name);
      system.out.println("属性值：" + name + "=" + value);
    }
  }
  @override
  public void endelement(string s, string s1, string s2) throws saxexception {
    super.endelement(s, s1, s2);
    if(s2.equals("book")){
      system.out.println("-----------------------");
    }
  }
  @override
  public void characters(char[] ch, int start, int length) throws saxexception {
    super.characters(ch, start, length);
    string value = new string(ch, start, length);
    if(value.trim().equals("")){
      return;
    }
    system.out.println(value);
  }
}

第三，以jdom的方式实现。

package xmls;
import org.jdom2.attribute;
import org.jdom2.document;
import org.jdom2.element;
import org.jdom2.jdomexception;
import org.jdom2.input.jdomparseexception;
import org.jdom2.input.saxbuilder;
import java.io.*;
import java.util.list;
/**
 * created by lenovo on 2017-6-2.
 */
public class jdomtest {
  public static void main(string[] args){
    saxbuilder saxbuilder = new saxbuilder();
    inputstream in;
    try{
      in = new fileinputstream(new file("src\\xmls\\book.xml"));
      document document = saxbuilder.build(in);
      element rootelement = document.getrootelement();
      list<element> booklist = rootelement.getchildren();
      for(element book: booklist){
        system.out.println("第" + (booklist.indexof(book)+1) + "本书！");
        list<attribute> attrs = book.getattributes();
        for(attribute attr: attrs){
          system.out.println(attr.getname() + "=" + attr.getvalue());
        }
        for(element item: book.getchildren()){
          system.out.println(item.getname() + ":" + item.getvalue());
        }
        system.out.println("------------------------------------");
      }
    }catch (filenotfoundexception e){
      e.printstacktrace();
    }catch (jdomexception e){
      e.printstacktrace();
    }catch (ioexception e){
      e.printstacktrace();
    }
  }
}

第四，以dom4j的方式实现。

package xmls;
import org.dom4j.*;
import org.dom4j.io.outputformat;
import org.dom4j.io.saxreader;
import org.dom4j.io.xmlwriter;
import java.io.file;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.util.iterator;
import java.util.list;
/**
 * created by lenovo on 2017-6-2.
 */
public class dom4jtest {
  public void parsexml(){
    saxreader saxreader = new saxreader();
    try{
      document document = saxreader.read(new file("src\\xmls\\book.xml"));
      element rootelement = document.getrootelement();
      iterator it = rootelement.elementiterator();
      while (it.hasnext()){
        element book = (element)it.next();
        list<attribute> attrs = book.attributes();
        for(attribute attr: attrs){
          system.out.println("属性名：" + attr.getname() + "---- 属性值：" + attr.getvalue() );
        }
        iterator cit = book.elementiterator();
        while (cit.hasnext()){
          element child = (element) cit.next();
          system.out.println("子节点：" + child.getname());
        }
      }
    }catch (documentexception e){
      e.printstacktrace();
    }
  }
  public static void main(string[] args){
    dom4jtest dom4jtest = new dom4jtest();
    dom4jtest.parsexml();
  }
}

以上这篇java读取xml文件的四种方法总结(必看篇)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。