Java xml内容转对象

在Java中，可以使用DOM、SAX或StAX等库将XML文档解析为Java对象。这里我们介绍一下使用DOM方式将XML内容转换为Java对象。

假设我们有一个XML内容如下：

<person>
    <name>John Doe</name>
    <age>30</age>
    <address>
        <street>123 Main St</street>
        <city>Anytown</city>
        <state>CA</state>
        <zip>12345</zip>
    </address>
</person>

我们可以使用DOM解析器将其解析为以下Java对象：

public class Person {
    private String name;
    private int age;
    private Address address;

    // getters and setters
}

public class Address {
    private String street;
    private String city;
    private String state;
    private String zip;

    // getters and setters
}

我们需要创建一个Document对象，然后使用它获取XML元素并将其映射到Java对象。以下是完整的示例代码：

import org.w3c.dom.*;
import javax.xml.parsers.*;
import java.io.*;

public class XmlToObject {
    public static void main(String[] args) throws Exception {
        String xmlContent = "<person><name>John Doe</name><age>30</age><address><street>123 Main St</street><city>Anytown</city><state>CA</state><zip>12345</zip></address></person>";
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        Document document = builder.parse(new ByteArrayInputStream(xmlContent.getBytes()));
        Element root = document.getDocumentElement();
        Person person = new Person();
        person.setName(getTagValue("name", root));
        person.setAge(Integer.parseInt(getTagValue("age", root)));
        Address address = new Address();
        address.setStreet(getTagValue("street", root));
        address.setCity(getTagValue("city", root));
        address.setState(getTagValue("state", root));
        address.setZip(getTagValue("zip", root));
        person.setAddress(address);
        System.out.println(person.getName());
        System.out.println(person.getAge());
        System.out.println(person.getAddress().getStreet());
        System.out.println(person.getAddress().getCity());
        System.out.println(person.getAddress().getState());
        System.out.println(person.getAddress().getZip());
    }

    private static String getTagValue(String tag, Element element) {
        NodeList nodeList = element.getElementsByTagName(tag).item(0).getChildNodes();
        Node node = nodeList.item(0);
        return node.getNodeValue();
    }
}

运行该程序将输出以下内容：

John Doe
30
123 Main St
Anytown
CA
12345