web学习第三天

Posted 2020-10-09

Sax解析

Xml文档

<?xml version="1.0" encoding="UTF-8"?>

 

<书架> 

  <书> 

    <书名 name="小黄书">Java就业培训教程</书名>  

    <作者>张兆祥</作者>  

    <售价>999元</售价>  

    <售价>59yuan</售价>  

    <售价>1000元</售价> 

  </书>  

  <书> 

    <书名>javascript网页开发</书名>  

    <作者>张兆祥2</作者>  

    <售价>12</售价> 

  </书> 

</书架>

 

 

基本操作

1得到xml文档中所有的文档：

package day3;

 

 

import java.io.IOException;

 

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

 

import org.xml.sax.Attributes;

import org.xml.sax.ContentHandler;

import org.xml.sax.Locator;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

 

public class booksax {

public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {

//1，创建解析工厂

SAXParserFactory factory=SAXParserFactory.newInstance();

//2，得到解析器

SAXParser sp=factory.newSAXParser();

//3，得到读取器

XMLReader reader= sp.getXMLReader();

//4，设置内容处理器

reader.setContentHandler(new ListHandler());

//5，读取xml文档内容

reader.parse("src/day3/book.xml");

}

}

//得到xml文档中所有的文档

class ListHandler implements ContentHandler{

 

@Override

public void setDocumentLocator(Locator locator) {

// TODO Auto-generated method stub

 

}

 

@Override

public void startDocument() throws SAXException {

// TODO Auto-generated method stub

 

}

 

@Override

public void endDocument() throws SAXException {

// TODO Auto-generated method stub

 

}

 

@Override

public void startPrefixMapping(String prefix, String uri) throws SAXException {

// TODO Auto-generated method stub

 

}

 

@Override

public void endPrefixMapping(String prefix) throws SAXException {

// TODO Auto-generated method stub

 

}

 

@Override

public void startElement(String uri, String localName, String name, Attributes atts) throws SAXException {

System.out.println("<"+name+">");

for(int i=0;atts!=null&i<atts.getLength();i++) {

String attname=atts.getQName(i);

String attvalue=atts.getValue(i);

System.out.println(attname+":"+attvalue);

}

 

}

 

@Override

public void endElement(String uri, String localName, String name) throws SAXException {

System.out.println("<"+name+">");

 

}

 

@Override

public void characters(char[] ch, int start, int length) throws SAXException {

System.out.println(new String(ch,start,length));

 

}

 

@Override

public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {

// TODO Auto-generated method stub

 

}

 

@Override

public void processingInstruction(String target, String data) throws SAXException {

// TODO Auto-generated method stub

 

}

 

@Override

public void skippedEntity(String name) throws SAXException {

// TODO Auto-generated method stub

 

}

 

}

2获取指定便签的值

package day3;

 

 

import java.io.IOException;

 

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

 

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

import org.xml.sax.helpers.DefaultHandler;

 

public class booksax2 {

public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {

//1，创建解析工厂

SAXParserFactory factory=SAXParserFactory.newInstance();

//2，得到解析器

SAXParser sp=factory.newSAXParser();

//3，得到读取器

XMLReader reader= sp.getXMLReader();

//4，设置内容处理器

reader.setContentHandler(new  TagValueHandler());

//5，读取xml文档内容

reader.parse("src/day3/book.xml");

}

}

//获取指定便签的值

class TagValueHandler extends DefaultHandler {

private String currentTag;//记住当前解析到的是什么标签

private int needNumber=2; //记住想获取第几个作者标签的值

private int currentNumber=0;//当前解析到第几个

@Override

public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {

currentTag=name;

if(currentTag.equals("作者")) {

currentNumber++;

}

}

 

@Override

public void endElement(String uri, String localName, String name) throws SAXException {

currentTag=null;

}

 

@Override

public void characters(char[] ch, int start, int length) throws SAXException {

if("作者".equals(currentTag)&¤tNumber==needNumber) {

System.out.println(new String(ch,start,length));

}

}

 

}

3Xml->book->list

book对象

package day3;

 

public class Book_booksax3 {

private String name;

private String author;

private String price;

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getAuthor() {

return author;

}

public void setAuthor(String author) {

this.author = author;

}

public String getPrice() {

return price;

}

public void setPrice(String price) {

this.price = price;

}

}

 

操作：

package day3;

 

 

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

 

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

 

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

import org.xml.sax.helpers.DefaultHandler;

 

public class booksax3 {

public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {

//1，创建解析工厂

SAXParserFactory factory=SAXParserFactory.newInstance();

//2，得到解析器

SAXParser sp=factory.newSAXParser();

//3，得到读取器

XMLReader reader= sp.getXMLReader();

//4，设置内容处理器

BeanListHandler handler=new BeanListHandler();

reader.setContentHandler( handler);

//5，读取xml文档内容

reader.parse("src/day3/book.xml");

@SuppressWarnings("unchecked")

List<Book_booksax3> list=handler.getBooks();

System.out.println(list);

}

}

//把xml文档中的每一本书封装到book对象中，并把每一个book对象放在list集合中返回

class BeanListHandler extends DefaultHandler {

private List list=new ArrayList();

private String currentTag;

private Book_booksax3 book;

@Override

public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {

currentTag=name;

if("书".equals(currentTag)) {

 book=new Book_booksax3();

}

}

 

@Override

public void endElement(String uri, String localName, String name) throws SAXException {

currentTag=null;

if(name.equals("书")) {

list.add(book);

book=null;

}

}

 

@Override

public void characters(char[] ch, int start, int length) throws SAXException {

if("书名".equals(currentTag)) {

String name=new String(ch,start,length);

book.setName(name);

}

if("作者".equals(currentTag)) {

String author=new String(ch,start,length);

book.setAuthor(author);

}

if("售价".equals(currentTag)) {

String price=new String(ch,start,length);

book.setPrice(price);

}

}

 

public List getBooks() {

return list;

}

 

 

}

 

 

dom4j

Xml文档

<?xml version="1.0" encoding="UTF-8"?>

 

<书架> 

  <书> 

    <书名 name="小黄书">Java就业培训教程</书名>  

    <作者>张兆祥</作者>  

    <售价>999元</售价>  

    <售价>59yuan</售价>  

    <售价>1000元</售价> 

  </书>  

  <书> 

    <书名>JavaScript网页开发</书名>  

    <作者>张兆祥2</作者>  

    <售价>12</售价> 

  </书> 

 

基本操作

 

package day3_2;

 

import java.io.File;

import java.io.FileOutputStream;

import java.util.List;

 

import org.dom4j.Document;

import org.dom4j.DocumentHelper;

import org.dom4j.Element;

import org.dom4j.io.OutputFormat;

import org.dom4j.io.SAXReader;

import org.dom4j.io.XMLWriter;

import org.junit.Test;

 

public class dom4j {

@Test

//读取第二本书的书名：<书名>JavaScript网页开发</书名>

public void reader()throws Exception {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Elementroot=document.getRootElement();

Elementbook=(Element)root.elements("书").get(1);

Stringvalue=book.element("书名").getText();

System.out.println(value);

 

}

@Test

//读取第一本书的属性：<书名 name="小黄书">Java就业培训教程</书名>

public void readAtt()throws Exception {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Elementroot=document.getRootElement();

Elementbook=(Element)root.elements("书").get(0);

Stringvalue=book.element("书名").attributeValue("name");

System.out.println(value);

 

}

@Test

//在第一本书添加新的售价：<售价>1000元</售价>

public void add()throws Exception {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Elementbook=document.getRootElement().element("书");

book.addElement("售价").setText("1000元");

 

OutputFormatformat = OutputFormat.createPrettyPrint();

format.setEncoding("UTF-8");

 

// XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream( "src/day3_2/book.xml" ),"gb2312"));

XMLWriterwriter =new XMLWriter(new FileOutputStream("src/day3_2/book.xml" ),format);

 writer.write(document);

 writer.close();

 

}

@Test

//在第一本书指定位置添加新的售价：<售价>999元</售价>

public void add2()throws Exception {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Elementbook=document.getRootElement().element("书");

List list=book.elements();//[书名，作者，售价，售价..]

 

Elementprice=DocumentHelper.createElement("售价");

price.setText("999元");

list.add(2,price);

 

OutputFormatformat = OutputFormat.createPrettyPrint();

format.setEncoding("UTF-8");

 

// XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream( "src/day3_2/book.xml" ),"gb2312"));

XMLWriterwriter =new XMLWriter(new FileOutputStream("src/day3_2/book.xml" ),format);

 writer.write(document);

 writer.close();

 

}

 

@Test

//删除上面添加的书售价 节点

public void delete()throws Exception {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Elementprice=document.getRootElement().element("书").element("售价");

price.getParent().remove(price);

 

OutputFormatformat = OutputFormat.createPrettyPrint();

format.setEncoding("UTF-8");

 

// XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream( "src/day3_2/book.xml" ),"gb2312"));

XMLWriterwriter =new XMLWriter(new FileOutputStream("src/day3_2/book.xml" ),format);

writer.write(document);

writer.close();

 

}

@Test

//更新：   <作者>张三</作者>  

public void update()throws Exception {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Elementbook =(Element)document.getRootElement().elements("书").get(1);

book.element("作者").setText("张三");

OutputFormatformat = OutputFormat.createPrettyPrint();

format.setEncoding("UTF-8");

 

// XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream( "src/day3_2/book.xml" ),"gb2312"));

XMLWriterwriter =new XMLWriter(new FileOutputStream("src/day3_2/book.xml" ),format);

writer.write(document);

writer.close();

 

}

}

 

Xpath

Xml文档

<?xml version="1.0" encoding="UTF-8"?>

 

<书架> 

  <书> 

    <书名 name="小黄书" number="123456">Java就业培训教程</书名>  

    <作者>张兆祥</作者>  

    <售价>999元</售价>  

    <售价>59yuan</售价>  

    <售价>1000元</售价> 

  </书>  

  <书> 

    <书名>JavaScript网页开发</书名>  

    <作者>张兆祥2</作者>  

    <售价>12</售价> 

  </书> 

</书架>

 

查找

package day3_2;

 

import java.io.File;

 

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.io.SAXReader;

//应用xpath提取xml文档的数据

public class xpath {

public static void main(String[]args)throws DocumentException {

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Stringvalue =document.selectSingleNode("//作者").getText();

System.out.println(value);

}

}

 

属性对应的标签匹配

package day3_2;

 

import java.io.File;

 

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.Node;

import org.dom4j.io.SAXReader;

 

public class xpath_matching {

 

public static void main(String[]args)throws DocumentException {

Stringname="小黄书1";

Stringnumber="123456";

SAXReaderreader =new SAXReader();

Documentdocument =reader.read(new File("src/day3_2/book.xml"));

 

Nodenode=document.selectSingleNode("//书名[@name=‘"+name+"‘ and @number=‘"+number+"‘]");

if(node==null) {

System.out.println("没有这本书");

}else {

System.out.println("查找成功！");

}

}

 

}

XML Schema

http://www.runoob.com/schema/schema-tutorial.html

二维数组问题

 

package day3_2;

 

/*打印

  3   7  

 2 4 6 8

1   5   9*/

 

 

public class arr {

public static void main(String[] args) {

int num=43;

int height=(num+3)/4;

int width=num;

 

int arr[] []=new int[height][width];

 

int x=height-1,y=0;

boolean order=false;

for(int i=1;i<=width-1;i++) {

arr[x][y]=i;

y++;

if(!order) {

x--;

}

if(order) {

x++;

}

if(x<0) {

order=true;

x=x+2;

}

if(x>(num-1)/4) {

order=false;

x=x-2;

}

}

for(int i=0;i<arr.length;i++) {

for(int j=0;j<arr[i].length;j++) {

if(arr[i][j]==0) {

System.out.print(" ");

}else {

 

System.out.print(arr[i][j]);

}

}

System.out.println();

}

 

 

 

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