XML解析

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">XML解析是JAVA中重要的技术之一。下面主要以一个小例子来呈现出JAVA中对XML文档的解析方式，此处以DOM(Document Object Model)解析技术为例。</span>

首先新建一个java项目，取名为corejava。此处例子是为了解析xml文档，那么就要建一个xml标准文档：在corejava目录下新建一个文件夹，取名为res，再在res目录下新建一个文件夹，取名为xml，再在文件夹xml目录下新建一个xml文档，并取名为student.xml。

<?xml version="1.0" encoding="UTF-8"?>
<students>
    <student>
        <name>LiLei</name>
        <age>23</age>
    </student>
    <student>
        <name>HanMei</name>
        <age>22</age>
    </student>
</students>

然后在src目录下新建包与java文件，具体如下所示：

其中，Student文件内容如下所示：

package com.hyc.corejava.bean;

/**
 * Created by huashuncai on 15/9/16.
 */
public class Student {
    public static final String XML_TAG = "student";
    public static final String XML_NAME_TAG = "name";
    public static final String XML_AGE_TAG = "age";

    private String name;
    private String age;

    public Student() {
    }

    public Student(String name, String age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

XMLUtil、Test的文件内容具体如下所示：

package com.hyc.corejava.xml;

import com.hyc.corejava.bean.Student;
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;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by huashuncai on 15/9/16.
 */
public class XMLUtil {
    /**
     * XML文档的根元素
     *
     * @param fileName
     * @return
     */
    public static Element getRootFrom(String fileName) {
        File file = new File(fileName);
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = null;
        Document document = null;
        try {
            builder = factory.newDocumentBuilder();
            document = builder.parse(file);
            return document.getDocumentElement();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 从文件中取出学生列表
     *
     * @param fileName
     * @return
     * @see XMLUtil#getRootFrom(String)
     */
    public static List<Student> getStudentListfrom(String fileName) {
        List<Student> studentList = new ArrayList<>();
        Element root = getRootFrom(fileName);
        NodeList elements = null;
        if (root != null) {
            elements = root.getElementsByTagName(Student.XML_TAG);
            Student stu = null;
            Node node = null;
            for (int i = 0; i < elements.getLength(); i++) {
                stu = new Student();
                node = elements.item(i);
                NodeList childElements = node.getChildNodes();
                for (int j = 0; j < childElements.getLength(); j++) {
                    node = childElements.item(j);
                    if (node instanceof Element) {
                        if (((Element) node).getTagName().equals(Student.XML_NAME_TAG)) {
                            stu.setName(node.getTextContent());
                        } else if (((Element) node).getTagName().equals(Student.XML_AGE_TAG)) {
                            stu.setAge(node.getTextContent());
                        }
                    }
                }
                studentList.add(stu);
            }
            return studentList;
        }
        return null;
    }
}

package com.hyc.corejava;

import com.hyc.corejava.bean.Student;
import com.hyc.corejava.xml.XMLUtil;

import java.io.File;
import java.util.List;

/**
 * Created by huashuncai on 15/9/16.
 */
public class Test {
    public static void main(String[] args) {
        File file = new File("res/xml/student.xml");
        List<Student> studentList = XMLUtil.getStudentListfrom(file.getAbsolutePath());
        if (studentList != null && studentList.size() != 0) {
            for (int i = 0; i < studentList.size(); i++) {
                System.out.println("Name:" + studentList.get(i).getName() + "\tAge:" + studentList.get(i).getAge());
            }
        }
    }
}

亲测成功！