java - 将 xml 转换为 java bean

Question

如何将 xml 文件转换为简单的 java bean？ 它是一个没有任何 xsd 的简单 xml 文件，它是从我无权访问的 java bean 生成的。

我尝试使用 xmlbeans 首先从 xml 生成 xmd，然后从 xsd 生成类。我有很多类(class)。我正在寻找单个 java bean 类。

Answer 1

JAXB

JAXB ( JSR-222 ) 提供了一种将对象转换为 XML 的简单方法。该标准有许多开源实现，包括:

• Metro JAXB (Java SE 6 中包含的引用实现)
• EclipseLink JAXB (MOXy) , 我是技术主管
• Apache JaxMe

JAXB 有一个默认的 Java 对象到 XML 的映射。可以通过应用注释来自定义此映射。

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;

}

将对应于以下 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 有一个基于 XPath 的映射扩展。这意味着我们可以采用相同的地址类并将其映射到 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

• XPath Based Mapping - Geocode Example
• Map to Element based on an Attribute Value with EclipseLink JAXB (MOXy)
• XPath Based Mapping