Kotlin/Java解析XMl文件的四种方式

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四种解析方式:
DOM
SAX
JDOM
DOM4J

解析目标-books.xml文件



    
        XML深入浅出
        Imooc
        2014
        89
    
    
        Java从入门到精通
        Imooc
        369
    

1. DOM方式解析

package imooc

import org.junit.Test
import org.xml.sax.SAXException
import java.io.IOException
import javax.xml.parsers.DocumentBuilderFactory
import javax.xml.parsers.ParserConfigurationException
import javax.xml.soap.Node

/**
 * @author futao
 * Created on 2017/11/2 - 18:19.
 */
class XML {
    @Test
    fun DOM() {
        //1.创建一个DocumentBuilderFactory对象
        val builderFactory = DocumentBuilderFactory.newInstance()
        try {
            //2.创建一个DocumentBuilder
            val documentBuilder = builderFactory.newDocumentBuilder()
            //通过DocumentBuilder对象的parse方法加载books.xml到当前项目下
            val parse = documentBuilder.parse("D:\\src\\springhibernate\\springshibernate\\src\\test\\kotlin\\imooc\\books.xml")
            //获取节点(book)的集合
            val bookNodeList = parse.getElementsByTagName("book")

            println("book节点个数为${bookNodeList.length}")
            //遍历每一个book节点
            for (i in 0 until bookNodeList.length) {
                //遍历每个book节点的所有属性的集合
                val bookNodeAttributes = bookNodeList.item(i).attributes
                for (j in 0 until bookNodeAttributes.length) {
                    println("第${i + 1} 个book节点公有${bookNodeList.item(i).attributes.length}个属性")
                    println("属性:" + bookNodeAttributes.item(j))
                    println(bookNodeAttributes.item(j).nodeName)
                    println(bookNodeAttributes.item(j).nodeValue)

                    //获取当前book节点的子节点集合
                    val bookNodeChildNodes = bookNodeList.item(i).childNodes
                    //会把空格和换行符也当成节点
                    println("第${i + 1} 本书共有${(bookNodeChildNodes.length - 1) / 2}个子节点")
//                    for (k in 0 until (bookNodeChildNodes.length - 1) / 2) {
                    (0 until bookNodeChildNodes.length - 1)
                            .filter { bookNodeChildNodes.item(it).nodeType == Node.ELEMENT_NODE }
                            .forEach {
                                print("子节点" + bookNodeChildNodes.item(it).nodeName)
                                //null
//                                println(bookNodeChildNodes.item(it).nodeValue)
                                println("   对应的值为   " + bookNodeChildNodes.item(it).firstChild.nodeValue)
//                                println("   对应的值为   " + bookNodeChildNodes.item(it).textContent)
                            }
                }
            }
        } catch (e: ParserConfigurationException) {
            e.printStackTrace()
        } catch (e: IOException) {
            e.printStackTrace()
        } catch (e: SAXException) {
            e.printStackTrace()
        }

    }
}

结果


book节点个数为2
第1 个book节点公有1个属性
属性:id="1"
id
1
第1 本书共有4个子节点
子节点name   对应的值为   XML深入浅出
子节点author   对应的值为   Imooc
子节点year   对应的值为   2014
子节点price   对应的值为   89
第2 个book节点公有1个属性
属性:id="2"
id
2
第2 本书共有3个子节点
子节点name   对应的值为   Java从入门到精通
子节点author   对应的值为   Imooc
子节点price   对应的值为   369


2.SAX方式解析

Book.class


package imooc;

/**
 * @author futao
 * Created on 2017/11/3 - 11:05.
 */
public class Book {
    private int id;
    private String name;
    private String author;
    private String year;
    private String price;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    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 getYear() {
        return year;
    }

    public void setYear(String year) {
        this.year = year;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }
}

    @Test
    fun bySAX() {
        val sAXParserFactory = SAXParserFactory.newInstance()
        val sAXParser = sAXParserFactory.newSAXParser()
        //需要编写处理类MySAXParserHandler
        sAXParser.parse("D:\\src\\springhibernate\\springshibernate\\src\\test\\kotlin\\imooc\\books.xml", MySAXParserHandler())

    }


    
class MySAXParserHandler : DefaultHandler() {
    //遍历xml的book节点的索引
    private var bookIndex = 0
    //保存book对象
    private var bookList = ArrayList()
    //当前的book对象
    var book = Book()
    //当前文本内容
    var trim = ""

    /**
     * 遍历xml的文件开始标签
     */
    override fun startElement(uri: String?, localName: String?, qName: String?, attributes: Attributes?) {
        super.startElement(uri, localName, qName, attributes)
        if (qName!! == "book") {
            book = Book()
            bookList.add(book)
            bookIndex++
            println("开始遍历第$bookIndex 本书")
//            val value = attributes!!.getValue("id")
//            println(value)
            for (i in 0 until attributes!!.length) {
                print("属性名为:" + attributes.getQName(i))
                println("属性值为:" + attributes.getValue(i))
                book.id = attributes.getValue(i).toInt()
            }
        } else if (qName != "book" && qName != "books") {
            print("子节点名字为:   $qName    子节点的值为:     ")
        }
    }

    /**
     * 遍历xml文件的结束标签
     */
    override fun endElement(uri: String?, localName: String?, qName: String?) {
        super.endElement(uri, localName, qName)
        when (qName) {
            "name" -> book.name = trim
            "author" -> book.author = trim
            "year" -> book.year = trim
            "price" -> book.price = trim
        }
        if (qName == "book") {
            println("========================第$bookIndex 本书遍历完成")
        }
    }

    /**
     * 标志解析开始
     */
    override fun startDocument() {
        super.startDocument()
        println("SAX解析开始...")
    }

    /**
     * 标志解析结束
     */
    override fun endDocument() {
        super.endDocument()
        println("SAX解析结束...")
        println(GsonBuilder().serializeNulls().setPrettyPrinting().create().toJson(bookList))
    }

    /**
     * 解析内容,获取文本
     */
    override fun characters(ch: CharArray?, start: Int, length: Int) {
        super.characters(ch, start, length)
        val strings = String(ch!!, start, length)
        trim = strings.trim()
        if (trim != "") {
            println(trim)
        }
    }

结果

SAX解析开始...
开始遍历第1 本书
属性名为:id属性值为:1
子节点名字为:   name    子节点的值为:     XML深入浅出
子节点名字为:   author    子节点的值为:     Imooc
子节点名字为:   year    子节点的值为:     2014
子节点名字为:   price    子节点的值为:     89
========================第1 本书遍历完成
开始遍历第2 本书
属性名为:id属性值为:2
子节点名字为:   name    子节点的值为:     Java从入门到精通
子节点名字为:   author    子节点的值为:     Imooc
子节点名字为:   price    子节点的值为:     369
========================第2 本书遍历完成
SAX解析结束...
[
  {
    "id": 1,
    "name": "XML深入浅出",
    "author": "Imooc",
    "year": "2014",
    "price": "89"
  },
  {
    "id": 2,
    "name": "Java从入门到精通",
    "author": "Imooc",
    "year": null,
    "price": "369"
  }
]

3.JDOM

Maven依赖

       
            
                org.jdom
                jdom
                2.0.2
            

主要代码

package imooc.imooc.jdom

import com.google.gson.GsonBuilder
import imooc.Book
import org.jdom2.input.SAXBuilder
import org.junit.Test
import java.io.FileInputStream
import java.io.InputStreamReader

/**
 * @author futao
 * Created on 2017/11/3 - 13:41.
 */
class Jdom {
    @Test
    fun testJdom() {
        val list = ArrayList()
        var book = Book()
        //1.创建一个SAXBuilder对象
        val saxBuilder = SAXBuilder()
        /*
        * 乱码解决方案
        * 1.修改xml文件的编码格式
        * 2.用InputStreamReader代替FileInputStream,设置编码格式
        * */
        //2.通过输入流的方式加载xml文件到saxBuilder中
//        val document = saxBuilder.build(FileInputStream("D:\\src\\springhibernate\\springshibernate\\src\\test\\resources\\books.xml"))
        val document = saxBuilder.build(InputStreamReader(FileInputStream("D:\\src\\springhibernate\\springshibernate\\src\\test\\resources\\books.xml"), "UTF-8"))
        //3.获取根节点
        val rootElement = document.rootElement
        //4.根节点的子节点集合
        val rootChildElement = rootElement.children
        for (i in rootChildElement) {
            println("==================== 开始解析第${rootChildElement.indexOf(i) + 1}本书==================== ")
            book = Book()
            //解析根节点的所有属性
            for (k in i.attributes) {
                println(k.name + "   :   " + k.value)
                assignment(book, k.name, k.value)
            }
            val children = i.children
            //解析子节点和子节点的内容
            for (j in children) {
                println(j.name + "  :   " + j.value)
                assignment(book, j.name, j.value)
            }
            list.add(book)
        }
        println(GsonBuilder().serializeNulls().setPrettyPrinting().create().toJson(list))
    }

    private fun assignment(book: Book, property: String, value: String): Book {
        when (property) {
            "id" -> book.id = value.toInt()
            "name" -> book.name = value
            "author" -> book.author = value
            "year" -> book.year = value
            "price" -> book.price = value
        }
        return book
    }
}

结果

==================== 开始解析第1本书==================== 
id   :   1
name  :   XML深入浅出
author  :   Imooc
year  :   2014
price  :   89
==================== 开始解析第2本书==================== 
id   :   2
name  :   Java从入门到精通
author  :   Imooc
price  :   369

Disconnected from the target VM, address: '127.0.0.1:59271', transport: 'socket'
[
  {
    "id": 1,
    "name": "XML深入浅出",
    "author": "Imooc",
    "year": "2014",
    "price": "89"
  },
  {
    "id": 2,
    "name": "Java从入门到精通",
    "author": "Imooc",
    "year": null,
    "price": "369"
  }
]

4.DOM4J

maven依赖



    dom4j
    dom4j
    1.6.1


主要代码

package imooc.imooc.dom4j

import com.google.gson.GsonBuilder
import imooc.Book
import org.dom4j.Attribute
import org.dom4j.Element
import org.dom4j.io.SAXReader
import org.junit.Test
import java.io.File

/**
 * @author futao
 * Created on 2017/11/3 - 14:37.
 */
class DOM4JTest {
    @Test
    fun testDOM4J() {
        val list = ArrayList()
        var book = Book()

        val saxReader = SAXReader()
        val document = saxReader.read(File("D:\\src\\springhibernate\\springshibernate\\src\\test\\resources\\books.xml"))
        //根节点
        val rootElement = document.rootElement
        //通过Element的elementIterator()方法获取迭代器
        val elementIterator = rootElement.elementIterator()
        //遍历迭代器,获取根节点的子节点信息
        for ((index, i) in elementIterator.withIndex()) {
            val element = i as Element
//            println(element.name)
            println("===============开始解析第${index + 1}本书===============")
            book = Book()
            //遍历子节点的属性
            i.attributes()
                    .map { it as Attribute }
                    .forEach {
                        println(it.name + "    :   " + it.value)
                        assignment(book, it.name, it.value)
                    }
            //遍历子节点的子节点和内容
            for (k in i.elementIterator()) {
                k as Element
                println(k.name + "    :   " + k.textTrim)
                assignment(book, k.name, k.textTrim)
            }
            list.add(book)
        }
        println(GsonBuilder().serializeNulls().setPrettyPrinting().create().toJson(list))
    }

    private fun assignment(book: Book, property: String, value: String): Book {
        when (property) {
            "id" -> book.id = value.toInt()
            "name" -> book.name = value
            "author" -> book.author = value
            "year" -> book.year = value
            "price" -> book.price = value
        }
        return book
    }
}

结果

===============开始解析第1本书===============
id    :   1
name    :   deep
name    :   XML深入浅出
author    :   Imooc
year    :   2014
price    :   89
===============开始解析第2本书===============
id    :   2
name    :   Java从入门到精通
author    :   Imooc
price    :   369
[
  {
    "id": 1,
    "name": "XML深入浅出",
    "author": "Imooc",
    "year": "2014",
    "price": "89"
  },
  {
    "id": 2,
    "name": "Java从入门到精通",
    "author": "Imooc",
    "year": null,
    "price": "369"
  }
]

读取效率

    @Test
    fun efficiencyCompare() {
        val startTime1 = System.currentTimeMillis()
        testDOM4J()
        println("DOM4J耗时: ${System.currentTimeMillis() - startTime1}")


        val startTime2 = System.currentTimeMillis()
        Jdom().testJdom()
        println("JDOM耗时: ${System.currentTimeMillis() - startTime2}")

        val startTime3 = System.currentTimeMillis()
        XML().byDOM()
        println("DOM耗时: ${System.currentTimeMillis() - startTime3}")



        val startTime4 = System.currentTimeMillis()
        XML().bySAX()
        println("SAX耗时: ${System.currentTimeMillis() - startTime4}")

    }

结果

DOM4J耗时: 379
JDOM耗时: 141
DOM耗时: 52
SAX耗时: 32

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