格式：<?xml 屬性列表 ?>
	
屬性列表：
	version：版本號(hào)，必須的屬性
	encoding：編碼方式。告知解析引擎當(dāng)前文檔使用的字符集，默認(rèn)值：ISO-8859-1
	standalone：是否獨(dú)立 yes：不依賴(lài)其他文件 no：依賴(lài)其他文件

用于結(jié)合css：<?xml-stylesheet type="text/css" href="xml.css" rel="external nofollow"  ?> 

名稱(chēng)可以包含字母、數(shù)字以及其他的字符 

名稱(chēng)不能以數(shù)字或者標(biāo)點(diǎn)符號(hào)開(kāi)始 

名稱(chēng)不能以字母 xml（或者 XML、Xml 等等）開(kāi)始 

名稱(chēng)不能包含空格 

id屬性值唯一

CDATA區(qū)：在該區(qū)域中的數(shù)據(jù)會(huì)被原樣展示
    格式：  <![CDATA[ 展示數(shù)據(jù)]]>

xml文檔的后綴名 .xml

xml第一行必須定義為文檔聲明，可選部分，如果存在需要放在文檔的第一行

xml文檔中有且僅有一個(gè)根標(biāo)簽，是所有其他元素的父元素

屬性值必須使用引號(hào)(單雙都可)引起來(lái)

標(biāo)簽必須正確關(guān)閉，所有的XML元素都必須有一個(gè)關(guān)閉標(biāo)簽

xml標(biāo)簽名稱(chēng)區(qū)分大小寫(xiě)

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

<students>
    <student id='1'>
        <name>小白</name>
        <age>20</age>
    </student>

    <student id='2'>
        <name>大白</name>
        <age>30</age>
    </student>
</students>

<!ELEMENT students (student+) >
<!ELEMENT student (name,age)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT age (#PCDATA)>
<!ATTLIST student name ID #REQUIRED>

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

<!DOCTYPE students [
        <!ELEMENT students (student+) >
        <!ELEMENT student (name,age)>
        <!ELEMENT name (#PCDATA)>
        <!ELEMENT age (#PCDATA)>
        <!ATTLIST student name ID #REQUIRED>
        ]>
<students>
    <student name="xb">
        <name>小白</name>
        <age>20</age>
    </student>
    <student name="db">
        <name>大白</name>
        <age>30</age>
    </student>
</students>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE students SYSTEM "student.dtd">

<students>
    <student name="xb">
        <name>小白</name>
        <age>20</age>
    </student>
    <student name="db">
        <name>大白</name>
        <age>30</age>
    </student>
</students>

1.填寫(xiě)xml文檔的根元素 <?xml version="1.0" encoding="UTF-8"?>

2.引入xsi前綴  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

3.引入xsd文件命名空間  xsi:schemaLocation="
    http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd"

4.為每一個(gè)xsd約束聲明一個(gè)前綴,作為標(biāo)識(shí) xmlns:mvc="http://www.springframework.org/schema/mvc"

<?xml version="1.0" encoding="UTF-8"?>
<beans 
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">


    <bean></bean>

    <mvc:annotation-driven />

</beans>

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

<students>
    <student id='1'>
        <name>小白</name>
        <age>20</age>
    </student>

    <student id='2'>
        <name>大白</name>
        <age>30</age>
    </student>
</students>

    public static void main(String[] args) throws Exception {
        String path = ApplicationTests.class.getClassLoader().getResource("students.xml").getPath();

        // 創(chuàng)建解析器工廠對(duì)象
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        // 創(chuàng)建解析器對(duì)象
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
        // 解析指定XML文檔返回document
        Document document = documentBuilder.parse(new File(path));
        // 獲得指定標(biāo)簽名的NodeList列表
        NodeList students = document.getElementsByTagName("name");
        // 得到指定角標(biāo)的節(jié)點(diǎn)對(duì)象
        for (int i = 0; i < students.getLength(); i++) {
            Node node = students.item(i);
            // TODO 使用Node接口中的一系列方法對(duì)其進(jìn)行操作
            System.out.println("node name = " + node.getTextContent());
        }
    }

    public static void main(String[] args) throws Exception {
        String path = ApplicationTests.class.getClassLoader().getResource("students.xml").getPath();

        // 創(chuàng)建解析器工廠對(duì)象
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        // 創(chuàng)建解析器對(duì)象
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
        // 解析指定XML文檔返回document
        Document document = documentBuilder.parse(new File(path));

        //創(chuàng)建sex標(biāo)簽
        Node sex = document.createElement("sex");
        //創(chuàng)建文本
        Text text = document.createTextNode("男");
        // sex標(biāo)簽添加text
        sex.appendChild(text);
        Node node = document.getElementsByTagName("student").item(0);
        // student標(biāo)簽添加sex節(jié)點(diǎn)
        node.appendChild(sex);
        // 得到回寫(xiě)轉(zhuǎn)換器對(duì)象工廠
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        // 得到回寫(xiě)轉(zhuǎn)換器對(duì)象
        Transformer transformer = transformerFactory.newTransformer();
        // 將內(nèi)存中內(nèi)容回寫(xiě)入XML文檔
        transformer.transform(new DOMSource(document), new StreamResult(new File(path)));
    }

Document document = DocumentHelper.createDocument();
//其中students是根節(jié)點(diǎn)，可以繼續(xù)添加其他節(jié)點(diǎn)等操作。
Element root = document.addElement("students");

//創(chuàng)建SAXReader對(duì)象
SAXReader reader = new SAXReader();
//讀取文件 轉(zhuǎn)換成Document
Document document = reader.read(new File("XXXX.xml"));

String xmlStr = "<students>......</students>";
Document document = DocumentHelper.parseText(xmlStr);

<!-- https://mvnrepository.com/artifact/org.dom4j/dom4j -->
        <dependency>
            <groupId>org.dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>2.1.3</version>
        </dependency>

public static void main(String[] args) throws Exception {
        String path = XmlTest.class.getClassLoader().getResource("students.xml").getPath();
        //UTF-8編碼
        String filePath = URLDecoder.decode(path, "UTF-8");

        //xml解析器
        SAXReader saxReader = new SAXReader();
        Document read = saxReader.read(filePath);
        //拿到根節(jié)點(diǎn)
        Element rootElement = read.getRootElement();
        //getNodes(rootElement);
        getALLNodes(rootElement);
    }

    static public void getNodes(Element rootElement) {
        System.out.println("節(jié)點(diǎn)名稱(chēng):" + rootElement.getName());

        //拿到節(jié)點(diǎn)屬性
        List<Attribute> attributes = rootElement.attributes();
        for (Attribute attribute : attributes) {
            System.out.println("屬性:" + attribute.getName() + "---" + attribute.getText());
        }

        //節(jié)點(diǎn)名稱(chēng) <name>大白</name>節(jié)點(diǎn)中的值
        if (!rootElement.getTextTrim().equals("")) {
            System.out.println(rootElement.getName() + "---" + rootElement.getText());
        }
        //迭代器遍歷
        Iterator<Element> elementIterator = rootElement.elementIterator();
        while (elementIterator.hasNext()) {
            //獲取當(dāng)前節(jié)點(diǎn)值
            Element next = elementIterator.next();
            getNodes(next);
        }
    }

    static public void getALLNodes(Element rootElement) {
        System.out.println("根節(jié)點(diǎn)名稱(chēng):" + rootElement.getName());
        //根節(jié)點(diǎn)下的節(jié)點(diǎn)
        List<Element> elements = rootElement.elements();
        for (Element element : elements) {
            //拿到節(jié)點(diǎn)屬性
            List<Attribute> attributes = element.attributes();
            for (Attribute attribute : attributes) {
                System.out.println("屬性:" + attribute.getName() + "---" + attribute.getText());
            }
            //根節(jié)點(diǎn)下的節(jié)點(diǎn)的節(jié)點(diǎn)
            List<Element> sonElements = element.elements();
            for (Element sonElement : sonElements) {
                //節(jié)點(diǎn)名稱(chēng) <name>大白</name>節(jié)點(diǎn)中的值
                if (!sonElement.getTextTrim().equals("")) {
                    System.out.println(sonElement.getName() + "---" + sonElement.getText());
                }
            }
        }
    }

public static void main(String[] args) throws Exception {
        String path = ApplicationTests.class.getClassLoader().getResource("students.xml").getPath();
        //UTF-8編碼
        String filePath = URLDecoder.decode(path, "UTF-8");
        //xml解析器
        SAXReader saxReader = new SAXReader();
        Document read = saxReader.read(filePath);
        createStudentNode(read, path);
    }

    /**
     * 創(chuàng)建新的student節(jié)點(diǎn)
     *
     * @param document
     */
    public static void createStudentNode(Document document, String path) {
        try (Writer writer = new OutputStreamWriter(new FileOutputStream(path), "UTF-8")) {
            // 獲取根節(jié)點(diǎn)
            Element root = document.getRootElement();
            // 添加根節(jié)點(diǎn)的子節(jié)點(diǎn)  新的student節(jié)點(diǎn)
            Element b = root.addElement("student");
            // 創(chuàng)建student節(jié)點(diǎn)的各個(gè)子節(jié)點(diǎn)
            // 添加子節(jié)點(diǎn)的屬性
            b.addAttribute("id", "3");//原有長(zhǎng)度+1
            // 添加子節(jié)點(diǎn)的的子節(jié)點(diǎn)name
            b.addElement("name").setText("createNode");
            // 添加子節(jié)點(diǎn)的子節(jié)點(diǎn)age
            b.addElement("age").setText("22");

            // 寫(xiě)入XML
            document.write(writer);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

<!-- https://mvnrepository.com/artifact/org.jsoup/jsoup -->
<dependency>
    <groupId>org.jsoup</groupId>
    <artifactId>jsoup</artifactId>
    <version>1.13.1</version>
</dependency>

//解析xml或html字符串
public static Document parse(String html) {
        return Parser.parse(html, "");
    }

//解析xml或html文件    
public static Document parse(File in, String charsetName) throws IOException {
        return DataUtil.load(in, charsetName, in.getAbsolutePath());
    }

//通過(guò)網(wǎng)絡(luò)路徑獲取指定的html或xml的文檔對(duì)象
public static Document parse(URL url, int timeoutMillis) throws IOException {
        Connection con = HttpConnection.connect(url);
        con.timeout(timeoutMillis);
        return con.get();
    }    

//根據(jù)id屬性值獲取唯一的element對(duì)象
public Element getElementById(String id) {
        Validate.notEmpty(id);
        Elements elements = Collector.collect(new Id(id), this);
        return elements.size() > 0 ? (Element)elements.get(0) : null;
    }

//根據(jù)標(biāo)簽名稱(chēng)獲取元素對(duì)象集合  
public Elements getElementsByTag(String tagName) {
        Validate.notEmpty(tagName);
        tagName = Normalizer.normalize(tagName);
        return Collector.collect(new org.jsoup.select.Evaluator.Tag(tagName), this);
    }

//根據(jù)屬性名稱(chēng)獲取元素對(duì)象集合
 public Elements getElementsByAttribute(String key) {
        Validate.notEmpty(key);
        key = key.trim();
        return Collector.collect(new Attribute(key), this);
    }

//根據(jù)對(duì)應(yīng)的屬性名和屬性值獲取元素對(duì)象集合
   public Elements getElementsByAttributeValue(String key, String value) {
        return Collector.collect(new AttributeWithValue(key, value), this);
    }

//根據(jù)id屬性值獲取唯一的element對(duì)象
    public Element getElementById(String id) {
        Validate.notEmpty(id);
        Elements elements = Collector.collect(new Id(id), this);
        return elements.size() > 0 ? (Element)elements.get(0) : null;
    }
    
//根據(jù)class屬性值獲取elements對(duì)象集合  
 public Elements getElementsByClass(String className) {
        Validate.notEmpty(className);
        return Collector.collect(new Class(className), this);
    }   
    
//根據(jù)標(biāo)簽名稱(chēng)獲取元素對(duì)象集合   
 public Elements getElementsByTag(String tagName) {
        Validate.notEmpty(tagName);
        tagName = Normalizer.normalize(tagName);
        return Collector.collect(new org.jsoup.select.Evaluator.Tag(tagName), this);
    }

//根據(jù)屬性名稱(chēng)獲取元素對(duì)象集合
public Elements getElementsByAttribute(String key) {
        Validate.notEmpty(key);
        key = key.trim();
        return Collector.collect(new Attribute(key), this);
    }

//根據(jù)對(duì)應(yīng)的屬性名和屬性值獲取元素對(duì)象集合
public Elements getElementsByAttributeValue(String key, String value) {
        return Collector.collect(new AttributeWithValue(key, value), this);
    }


//根據(jù)屬性名稱(chēng)獲取屬性值
    public String attr(String attributeKey) {
        Validate.notNull(attributeKey);
        if (!this.hasAttributes()) {
            return "";
        } else {
            String val = this.attributes().getIgnoreCase(attributeKey);
            if (val.length() > 0) {
                return val;
            } else {
                return attributeKey.startsWith("abs:") ? this.absUrl(attributeKey.substring("abs:".length())) : "";
            }
        }
    }
    
//獲取文本內(nèi)容
public String text() {
        StringBuilder sb = new StringBuilder();

        Element element;
        for(Iterator var2 = this.iterator(); var2.hasNext(); sb.append(element.text())) {
            element = (Element)var2.next();
            if (sb.length() != 0) {
                sb.append(" ");
            }
        }

        return sb.toString();
    }
    
//獲取標(biāo)簽體的所有內(nèi)容(包括字標(biāo)簽的字符串內(nèi)容)
    public String html() {
        StringBuilder sb = new StringBuilder();
        Element element;
        for(Iterator var2 = this.iterator(); var2.hasNext(); sb.append(element.html())) {
            element = (Element)var2.next();
            if (sb.length() != 0) {
                sb.append("\n");
            }
        }

        return sb.toString();
    }

    public static void main(String[] args) throws IOException {
        //根據(jù)xml文檔獲取，獲取Document對(duì)象
        String path = JsoupDemo1.class.getClassLoader().getResource("student.xml").getPath();
        //解析xml文檔，加載文檔進(jìn)內(nèi)存
        Document document = Jsoup.parse(new File(path), "utf-8");
        //獲取元素對(duì)象Element
        Elements elements = document.getElementsByTag("name");
        //循環(huán)得到每一個(gè)element對(duì)象
        for (Element element : elements) {
            //獲取數(shù)據(jù)
            String name = element.text();
            System.out.println(name);
        }


        //獲取屬性名為id的元素對(duì)象們
        Elements elements1 = document.getElementsByAttribute("id");
        System.out.println(elements1);

        //獲取id屬性值為2的元素對(duì)象
        Elements elements2 = document.getElementsByAttributeValue("id", "2");
        System.out.println(elements2);

        //獲取id屬性值的元素對(duì)象
        Element elements3 = document.getElementById("2");
        System.out.println(elements3);

        //通過(guò)Element對(duì)象獲取子標(biāo)簽對(duì)象
        Elements ele_name = elements3.getElementsByTag("name");
        System.out.println(ele_name);

        //獲取student對(duì)象的屬性值
        String id = elements3.attr("id");
        System.out.println(id);

        //獲取文本內(nèi)容
        String text = ele_name.text();
        System.out.println(text);
        String html = ele_name.html();
        System.out.println(html);
    }

<!-- https://mvnrepository.com/artifact/cn.wanghaomiao/JsoupXpath -->
<dependency>
    <groupId>cn.wanghaomiao</groupId>
    <artifactId>JsoupXpath</artifactId>
    <version>2.4.3</version>
</dependency>

 public static void main(String[] args) throws IOException, XpathSyntaxErrorException {
        //獲取student.xml的path
        String path = JsoupDemo6.class.getClassLoader().getResource("student.xml").getPath();
        //獲取Document對(duì)象
        Document document = Jsoup.parse(new File(path), "utf-8");

        //根據(jù)document對(duì)象，創(chuàng)建JXDocument對(duì)象
        JXDocument jxDocument = new JXDocument(document);

        //查詢(xún)所有student標(biāo)簽
        List<JXNode> jxNodes = jxDocument.selN("http://student");
        for (JXNode jxNode : jxNodes) {
            System.out.println(jxNode);
        }


        //查詢(xún)所有student標(biāo)簽下的name標(biāo)簽
        List<JXNode> jxNodes2 = jxDocument.selN("http://student/name");
        for (JXNode jxNode : jxNodes2) {
            System.out.println(jxNode);
        }

        //查詢(xún)帶有id屬性的student標(biāo)簽
        List<JXNode> jxNodes3 = jxDocument.selN("http://student[@id]");
        for (JXNode jxNode : jxNodes3) {
            System.out.println(jxNode);
        }

        //查詢(xún)帶有id屬性的student標(biāo)簽并且id屬性值為1
        List<JXNode> jxNodes4 = jxDocument.selN("http://student[@id='1']");
        for (JXNode jxNode : jxNodes4) {
            System.out.println(jxNode);
        }
    }