JAXB的XmlAttribute注解
- JAXB的XmlAttribute注解,将一个JavaBean属性映射到一个XML属性。
例如,下面的Java代码,将属性currency映射到了XML的属性currency:
package com.thb;
import jakarta.xml.bind.annotation.XmlAttribute;
import jakarta.xml.bind.annotation.XmlRootElement;
import jakarta.xml.bind.annotation.XmlType;
import jakarta.xml.bind.annotation.XmlValue;
@XmlRootElement
@XmlType(name = "", propOrder = {"value"})
public class Price {
@XmlValue
public String value;
@XmlAttribute(name = "currency")
public String currency;
}
生成的XML Schema:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xs:schema version="1.0" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="price">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="currency" type="xs:string"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
</xs:schema>
- XmlAttribute的required属性指定被注解的属性是否必选。
例如下面代码,Java属性currency用@XmlAttribute(name = "currency", required = true)
注解,指明xml属性currency是必选的:
package com.thb;
import jakarta.xml.bind.annotation.XmlAttribute;
import jakarta.xml.bind.annotation.XmlRootElement;
import jakarta.xml.bind.annotation.XmlType;
import jakarta.xml.bind.annotation.XmlValue;
@XmlRootElement
@XmlType(name = "", propOrder = {"value"})
public class Price {
@XmlValue
public String value;
@XmlAttribute(name = "currency", required = true)
public String currency;
}
生成的XML Schema,属性currency中出现了use="required"
:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xs:schema version="1.0" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="price">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="currency" type="xs:string" use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
</xs:schema>