将XML转换为Java Bean

Question

如何将XML文件转换为简单的Java Bean？这是一个没有任何XSD的简单XML文件，它是从一个我无法访问的Java Bean生成的。

我尝试使用xmlbeans先从XML生成xmd，然后从XSD生成类。我得到了一堆类。我正在寻找一个单独的Java Bean类。

- outvir

Answer 1

JAXB

JAXB（JSR-222）提供了一种简单的方法，将对象转换为XML。有许多开源实现了这个标准，包括：

• Metro JAXB（包含在Java SE 6中的参考实现）
• EclipseLink JAXB（MOXy），我是技术领导
• Apache JaxMe

JAXB具有将Java对象映射到XML的默认映射。通过应用注解可以自定义此映射。

import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.Element;

@XmlRootElement
public class Address {

    private String street;

    private String city;

    private String state;

    private String country;

    @XmlElement(name="postal-code")
    private String postalCode;

}

将对应以下XML：

<address>
    <street>123 A Street</street>
    <city>Any Town</city>
    <state>A State</state>
    <postal-code>12345</postal-code>
</address>

EclipseLink JAXB (MOXy)

MOXy具有基于XPath的映射扩展。这意味着我们可以将同一Address类映射到Google的地理编码格式：

import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;

import org.eclipse.persistence.oxm.annotations.XmlPath;

@XmlRootElement(name="kml")
@XmlType(propOrder={"country", "state", "city", "street", "postalCode"})
public class Address {

    @XmlPath("Response/Placemark/ns:AddressDetails/ns:Country/ns:AdministrativeArea/ns:SubAdministrativeArea/ns:Locality/ns:Thoroughfare/ns:ThoroughfareName/text()")
    private String street;

    @XmlPath("Response/Placemark/ns:AddressDetails/ns:Country/ns:AdministrativeArea/ns:SubAdministrativeArea/ns:Locality/ns:LocalityName/text()")
    private String city;

    @XmlPath("Response/Placemark/ns:AddressDetails/ns:Country/ns:AdministrativeArea/ns:AdministrativeAreaName/text()")
    private String state;

    @XmlPath("Response/Placemark/ns:AddressDetails/ns:Country/ns:CountryNameCode/text()")
    private String country;

    @XmlPath("Response/Placemark/ns:AddressDetails/ns:Country/ns:AdministrativeArea/ns:SubAdministrativeArea/ns:Locality/ns:PostalCode/ns:PostalCodeNumber/text()")
    private String postalCode;

}

上述类对应以下XML：

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.0" xmlns:ns="urn:oasis:names:tc:ciq:xsdschema:xAL:2.0">
    <Response>
        <Placemark>
            <ns:AddressDetails>
                <ns:Country>
                    <ns:CountryNameCode>US</ns:CountryNameCode>
                    <ns:AdministrativeArea>
                        <ns:AdministrativeAreaName>CA</ns:AdministrativeAreaName>
                        <ns:SubAdministrativeArea>
                            <ns:Locality>
                                <ns:LocalityName>Mountain View</ns:LocalityName>
                                <ns:Thoroughfare>
                                    <ns:ThoroughfareName>1600 Amphitheatre Pkwy</ns:ThoroughfareName>
                                </ns:Thoroughfare>
                                <ns:PostalCode>
                                    <ns:PostalCodeNumber>94043</ns:PostalCodeNumber>
                                </ns:PostalCode>
                            </ns:Locality>
                        </ns:SubAdministrativeArea>
                    </ns:AdministrativeArea>
                </ns:Country>
            </ns:AddressDetails>
        </Placemark>
    </Response>
</kml> 

获取更多信息

• 基于XPath的映射-地理编码示例
• 基于元素属性值使用EclipseLink JAXB（MOXy）进行映射
• 基于XPath的映射

- bdoughan

Answer 2

尝试使用Castor Mapping。

- Nikunj

Answer 3

您可以使用像Castor或JAXB这样的工具将XML映射到Java类。Castor非常易于使用。

- Rahul