java JAXB 学习

JAXB（Java Architecture for XML Binding)是JDK的一部分，用于Object <-> XML的转换（有点类似于.NET中的XML序列化）。

1、创建XSD

可以使用任何工具生成XSD工具，比如XMLSPY。eclipse也提供了相关的jaxb插件，File -> New -> XML Schema File

文件命名为order.xsd，eclipse中也提供了xsd可视化编辑工具

当然，你要是很NB，对xsd结构倒背如流的话，完全也可以纯手写。

<?xml version="1.0" encoding="UTF-8"?>
<!-- edited with XMLSpy v2013 (http://www.altova.com) by  () -->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
    <xs:element name="Order">
        <xs:annotation>
            <xs:documentation>Comment describing your root element</xs:documentation>
        </xs:annotation>
        <xs:complexType>
            <xs:sequence>
                <xs:element name="OrderNo" type="xs:string"/>
                <xs:element name="OrderDateTime" type="xs:dateTime"/>
                <xs:element name="CustomerName" type="xs:string"/>
                <xs:element name="OrderItems">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="Produdct" maxOccurs="unbounded">
                                <xs:complexType>
                                    <xs:sequence>
                                        <xs:element name="ProductNo" type="xs:string"/>
                                        <xs:element name="ProductName" type="xs:string"/>
                                        <xs:element name="Price" type="xs:float"/>
                                        <xs:element name="Amount" type="xs:int"/>
                                    </xs:sequence>
                                </xs:complexType>
                            </xs:element>
                        </xs:sequence>
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

上面是Order.xsd的内容

2、根据XSD生成示例Xml

在XSD文件上右击 -> Generate -> XmlFile

会弹出一个框：

Prefix这里，如果不需要，可以参考上图自行清空，如果一些可选节点也需要生成示例数据，上图中的Create optional attributes、Create optional elements这二项也勾选上。

生成的order.xml内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<!--Sample XML file generated by XMLSpy v2013 (http://www.altova.com)-->
<Order xsi:noNamespaceSchemaLocation="order.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <OrderNo>0000001</OrderNo>
    <OrderDateTime>2001-12-17T09:30:47Z</OrderDateTime>
    <CustomerName>jimmy</CustomerName>
    <OrderItems>
        <Produdct>
            <ProductNo>P-01</ProductNo>
            <ProductName>Book</ProductName>
            <Price>1.14159E0</Price>
            <Amount>1</Amount>
        </Produdct>
        <Produdct>
            <ProductNo>P-02</ProductNo>
            <ProductName>iPhone 5C</ProductName>
            <Price>3.14159E0</Price>
            <Amount>2</Amount>
        </Produdct>
    </OrderItems>
</Order>

3、根据xsd生成java类

同样在xsd上右击 -> Generate -> JAXB Classes... 剩下的事情，大家都知道了

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.10 in JDK 6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2014.01.24 at 11:09:15 ���� CST 
//


package model;

import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlSchemaType;
import javax.xml.bind.annotation.XmlType;
import javax.xml.datatype.XMLGregorianCalendar;


/**
 * <p>Java class for anonymous complex type.
 * 
 * <p>The following schema fragment specifies the expected content contained within this class.
 * 
 * <pre>
 * &lt;complexType>
 *   &lt;complexContent>
 *     &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
 *       &lt;sequence>
 *         &lt;element name="OrderNo" type="{http://www.w3.org/2001/XMLSchema}string"/>
 *         &lt;element name="OrderDateTime" type="{http://www.w3.org/2001/XMLSchema}dateTime"/>
 *         &lt;element name="CustomerName" type="{http://www.w3.org/2001/XMLSchema}string"/>
 *         &lt;element name="OrderItems">
 *           &lt;complexType>
 *             &lt;complexContent>
 *               &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
 *                 &lt;sequence>
 *                   &lt;element name="Produdct" maxOccurs="unbounded">
 *                     &lt;complexType>
 *                       &lt;complexContent>
 *                         &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
 *                           &lt;sequence>
 *                             &lt;element name="ProductNo" type="{http://www.w3.org/2001/XMLSchema}string"/>
 *                             &lt;element name="ProductName" type="{http://www.w3.org/2001/XMLSchema}string"/>
 *                             &lt;element name="Price" type="{http://www.w3.org/2001/XMLSchema}float"/>
 *                             &lt;element name="Amount" type="{http://www.w3.org/2001/XMLSchema}int"/>
 *                           &lt;/sequence>
 *                         &lt;/restriction>
 *                       &lt;/complexContent>
 *                     &lt;/complexType>
 *                   &lt;/element>
 *                 &lt;/sequence>
 *               &lt;/restriction>
 *             &lt;/complexContent>
 *           &lt;/complexType>
 *         &lt;/element>
 *       &lt;/sequence>
 *     &lt;/restriction>
 *   &lt;/complexContent>
 * &lt;/complexType>
 * </pre>
 * 
 * 
 */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
    "orderNo",
    "orderDateTime",
    "customerName",
    "orderItems"
})
@XmlRootElement(name = "Order")
public class Order {

    @XmlElement(name = "OrderNo", required = true)
    protected String orderNo;
    @XmlElement(name = "OrderDateTime", required = true)
    @XmlSchemaType(name = "dateTime")
    protected XMLGregorianCalendar orderDateTime;
    @XmlElement(name = "CustomerName", required = true)
    protected String customerName;
    @XmlElement(name = "OrderItems", required = true)
    protected Order.OrderItems orderItems;

    /**
     * Gets the value of the orderNo property.
     * 
     * @return
     *     possible object is
     *     {@link String }
     *     
     */
    public String getOrderNo() {
        return orderNo;
    }

    /**
     * Sets the value of the orderNo property.
     * 
     * @param value
     *     allowed object is
     *     {@link String }
     *     
     */
    public void setOrderNo(String value) {
        this.orderNo = value;
    }

    /**
     * Gets the value of the orderDateTime property.
     * 
     * @return
     *     possible object is
     *     {@link XMLGregorianCalendar }
     *     
     */
    public XMLGregorianCalendar getOrderDateTime() {
        return orderDateTime;
    }

    /**
     * Sets the value of the orderDateTime property.
     * 
     * @param value
     *     allowed object is
     *     {@link XMLGregorianCalendar }
     *     
     */
    public void setOrderDateTime(XMLGregorianCalendar value) {
        this.orderDateTime = value;
    }

    /**
     * Gets the value of the customerName property.
     * 
     * @return
     *     possible object is
     *     {@link String }
     *     
     */
    public String getCustomerName() {
        return customerName;
    }

    /**
     * Sets the value of the customerName property.
     * 
     * @param value
     *     allowed object is
     *     {@link String }
     *     
     */
    public void setCustomerName(String value) {
        this.customerName = value;
    }

    /**
     * Gets the value of the orderItems property.
     * 
     * @return
     *     possible object is
     *     {@link Order.OrderItems }
     *     
     */
    public Order.OrderItems getOrderItems() {
        return orderItems;
    }

    /**
     * Sets the value of the orderItems property.
     * 
     * @param value
     *     allowed object is
     *     {@link Order.OrderItems }
     *     
     */
    public void setOrderItems(Order.OrderItems value) {
        this.orderItems = value;
    }


    /**
     * <p>Java class for anonymous complex type.
     * 
     * <p>The following schema fragment specifies the expected content contained within this class.
     * 
     * <pre>
     * &lt;complexType>
     *   &lt;complexContent>
     *     &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
     *       &lt;sequence>
     *         &lt;element name="Produdct" maxOccurs="unbounded">
     *           &lt;complexType>
     *             &lt;complexContent>
     *               &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
     *                 &lt;sequence>
     *                   &lt;element name="ProductNo" type="{http://www.w3.org/2001/XMLSchema}string"/>
     *                   &lt;element name="ProductName" type="{http://www.w3.org/2001/XMLSchema}string"/>
     *                   &lt;element name="Price" type="{http://www.w3.org/2001/XMLSchema}float"/>
     *                   &lt;element name="Amount" type="{http://www.w3.org/2001/XMLSchema}int"/>
     *                 &lt;/sequence>
     *               &lt;/restriction>
     *             &lt;/complexContent>
     *           &lt;/complexType>
     *         &lt;/element>
     *       &lt;/sequence>
     *     &lt;/restriction>
     *   &lt;/complexContent>
     * &lt;/complexType>
     * </pre>
     * 
     * 
     */
    @XmlAccessorType(XmlAccessType.FIELD)
    @XmlType(name = "", propOrder = {
        "produdct"
    })
    public static class OrderItems {

        @XmlElement(name = "Produdct", required = true)
        protected List<Order.OrderItems.Produdct> produdct;

        /**
         * Gets the value of the produdct property.
         * 
         * <p>
         * This accessor method returns a reference to the live list,
         * not a snapshot. Therefore any modification you make to the
         * returned list will be present inside the JAXB object.
         * This is why there is not a <CODE>set</CODE> method for the produdct property.
         * 
         * <p>
         * For example, to add a new item, do as follows:
         * <pre>
         *    getProdudct().add(newItem);
         * </pre>
         * 
         * 
         * <p>
         * Objects of the following type(s) are allowed in the list
         * {@link Order.OrderItems.Produdct }
         * 
         * 
         */
        public List<Order.OrderItems.Produdct> getProdudct() {
            if (produdct == null) {
                produdct = new ArrayList<Order.OrderItems.Produdct>();
            }
            return this.produdct;
        }


        /**
         * <p>Java class for anonymous complex type.
         * 
         * <p>The following schema fragment specifies the expected content contained within this class.
         * 
         * <pre>
         * &lt;complexType>
         *   &lt;complexContent>
         *     &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
         *       &lt;sequence>
         *         &lt;element name="ProductNo" type="{http://www.w3.org/2001/XMLSchema}string"/>
         *         &lt;element name="ProductName" type="{http://www.w3.org/2001/XMLSchema}string"/>
         *         &lt;element name="Price" type="{http://www.w3.org/2001/XMLSchema}float"/>
         *         &lt;element name="Amount" type="{http://www.w3.org/2001/XMLSchema}int"/>
         *       &lt;/sequence>
         *     &lt;/restriction>
         *   &lt;/complexContent>
         * &lt;/complexType>
         * </pre>
         * 
         * 
         */
        @XmlAccessorType(XmlAccessType.FIELD)
        @XmlType(name = "", propOrder = {
            "productNo",
            "productName",
            "price",
            "amount"
        })
        public static class Produdct {

            @XmlElement(name = "ProductNo", required = true)
            protected String productNo;
            @XmlElement(name = "ProductName", required = true)
            protected String productName;
            @XmlElement(name = "Price")
            protected float price;
            @XmlElement(name = "Amount")
            protected int amount;

            /**
             * Gets the value of the productNo property.
             * 
             * @return
             *     possible object is
             *     {@link String }
             *     
             */
            public String getProductNo() {
                return productNo;
            }

            /**
             * Sets the value of the productNo property.
             * 
             * @param value
             *     allowed object is
             *     {@link String }
             *     
             */
            public void setProductNo(String value) {
                this.productNo = value;
            }

            /**
             * Gets the value of the productName property.
             * 
             * @return
             *     possible object is
             *     {@link String }
             *     
             */
            public String getProductName() {
                return productName;
            }

            /**
             * Sets the value of the productName property.
             * 
             * @param value
             *     allowed object is
             *     {@link String }
             *     
             */
            public void setProductName(String value) {
                this.productName = value;
            }

            /**
             * Gets the value of the price property.
             * 
             */
            public float getPrice() {
                return price;
            }

            /**
             * Sets the value of the price property.
             * 
             */
            public void setPrice(float value) {
                this.price = value;
            }

            /**
             * Gets the value of the amount property.
             * 
             */
            public int getAmount() {
                return amount;
            }

            /**
             * Sets the value of the amount property.
             * 
             */
            public void setAmount(int value) {
                this.amount = value;
            }

        }

    }

}

上面是根据刚才的order.xsd生成的order类，package名称是model（当然生成java class的时候，你可以根据实际情况，设成任何自己需要的package名）

同时还会生成一个ObjectFactory类：

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.10 in JDK 6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2014.01.24 at 11:09:15 ���� CST 
//


package model;

import javax.xml.bind.annotation.XmlRegistry;


/**
 * This object contains factory methods for each 
 * Java content interface and Java element interface 
 * generated in the model package. 
 * <p>An ObjectFactory allows you to programatically 
 * construct new instances of the Java representation 
 * for XML content. The Java representation of XML 
 * content can consist of schema derived interfaces 
 * and classes representing the binding of schema 
 * type definitions, element declarations and model 
 * groups.  Factory methods for each of these are 
 * provided in this class.
 * 
 */
@XmlRegistry
public class ObjectFactory {


    /**
     * Create a new ObjectFactory that can be used to create new instances of schema derived classes for package: model
     * 
     */
    public ObjectFactory() {
    }

    /**
     * Create an instance of {@link Order.OrderItems }
     * 
     */
    public Order.OrderItems createOrderOrderItems() {
        return new Order.OrderItems();
    }

    /**
     * Create an instance of {@link Order }
     * 
     */
    public Order createOrder() {
        return new Order();
    }

    /**
     * Create an instance of {@link Order.OrderItems.Produdct }
     * 
     */
    public Order.OrderItems.Produdct createOrderOrderItemsProdudct() {
        return new Order.OrderItems.Produdct();
    }

}

4、Object <-> XML 的示例代码

    public void testXmlToObj() {
        JAXBContext jc;
        try {
            jc = JAXBContext.newInstance("model");
            Unmarshaller u = jc.createUnmarshaller();
            String xmlFilePath = AppTest.class.getResource("/").getPath()
                    + "order.xml";
            System.out.println(xmlFilePath);
            Order order = (Order) u.unmarshal(new File(xmlFilePath));
            assertTrue(order.getOrderNo().equals("0000001"));
            assertTrue(order.getCustomerName().equals("jimmy"));
            for (int i = 0; i < order.getOrderItems().getProdudct().size(); i++) {
                System.out.println(getProductDesc(order.getOrderItems()
                        .getProdudct().get(i)));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void testObjToXml() {
        try {
            ObjectFactory of = new ObjectFactory();
            Order order = of.createOrder();
            Order.OrderItems orderItems = of.createOrderOrderItems();
            
            Order.OrderItems.Produdct product1 = new Order.OrderItems.Produdct();
            product1.setProductNo("A-01");
            product1.setProductName("Car");
            product1.setPrice(1000000);
            product1.setAmount(1);
            
            orderItems.getProdudct().add(product1);
            
            Order.OrderItems.Produdct product2 = new Order.OrderItems.Produdct();
            product2.setProductNo("B-01");
            product2.setProductName("Book");
            product2.setPrice(200);
            product2.setAmount(2);
            
            orderItems.getProdudct().add(product2);
        
            order.setOrderItems(orderItems);

            JAXBContext jc = JAXBContext.newInstance("model");
            Marshaller ms = jc.createMarshaller();
            ms.setProperty("jaxb.encoding", "UTF-8");
            ms.setProperty("jaxb.formatted.output", true);
            String xmlFilePath = AppTest.class.getResource("/").getPath()
                    + "order_new.xml";
            ms.marshal(order, new File(xmlFilePath));
            
            System.out.println("testObjToXml");
        } catch (Exception e) {
            e.printStackTrace();

        }
    }

示例源代码下载：jaxb-helloworld.zip (注：这是一个maven工程，命令行下直接mvn clean test，就可以测试)