XmlID (Java EE 5)

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SUMMARY: REQUIRED | OPTIONAL

DETAIL: ELEMENT

javax.xml.bind.annotation Annotation Type XmlID

@Retention(value=RUNTIME) @Target(value={FIELD,METHOD}) public @interface XmlID

Implements: Annotation

@Retention(value=RUNTIME)
@Target(value={FIELD, METHOD})

将 JavaBean 属性映射到 XML ID。

要在 XML 序列化然后反序列化这一过程中保持对象图形的引用完整性，需要通过使用引用或容器适当地对对象引用进行编组。注释 @XmlID 和 @XmlIDREF 一起使用时允许通过容器或引用来实现 JavaBean 属性类型的自定义映射。

用法

@XmlID 注释能够与以下程序元素一起使用：

JavaBean 属性
非 static、非 transient 字段

有关公共信息，请参阅 javax.xml.bind.package javadoc 中的“包规范”。

用法受到以下约束的限制：

只能使用 @XmlID 注释一个类中最多一个字段或属性。
JavaBean 属性的类型必须是 java.lang.String。
能够与 @XmlID 一起使用的其他映射注释只有 @XmlElement 和 @XmlAttribute。

示例：将 JavaBean 属性的类型映射到 xs:ID

    // Example: code fragment
    public class Customer {
        @XmlAttribute
        @XmlID
        public String getCustomerID();
        public void setCustomerID(String id);
        .... other properties not shown 
    }

    <!-- Example: XML Schema fragment -->
    <xs:complexType name="Customer">
      <xs:complexContent>
        <xs:sequence>
          ....
        </xs:sequence>
        <xs:attribute name="customerID" type="xs:ID"/>
      </xs:complexContent>
    </xs:complexType>

since

JAXB2.0

version

$Revision: 1.5 $

See also

javax.xml.bind.annotation.XmlIDREF

英文文档：

Maps a JavaBean property to XML ID.

To preserve referential integrity of an object graph across XML serialization followed by a XML deserialization, requires an object reference to be marshalled by reference or containment appropriately. Annotations @XmlID and @XmlIDREF together allow a customized mapping of a JavaBean property's type by containment or reference.

Usage

The @XmlID annotation can be used with the following program elements:

a JavaBean property
non static, non transient field

See "Package Specification" in javax.xml.bind.package javadoc for additional common information.

The usage is subject to the following constraints:

At most one field or property in a class can be annotated with @XmlID.
The JavaBean property's type must be java.lang.String.
The only other mapping annotations that can be used with @XmlID are:@XmlElement and @XmlAttribute.

Example: Map a JavaBean property's type to xs:ID

    // Example: code fragment
    public class Customer {
        @XmlAttribute
        @XmlID
        public String getCustomerID();
        public void setCustomerID(String id);
        .... other properties not shown 
    }

    <!-- Example: XML Schema fragment -->
    <xs:complexType name="Customer">
      <xs:complexContent>
        <xs:sequence>
          ....
        </xs:sequence>
        <xs:attribute name="customerID" type="xs:ID"/>
      </xs:complexContent>
    </xs:complexType>

Since:: JAXB2.0
Version:: $Revision: 1.5 $
Author:: Sekhar Vajjhala, Sun Microsystems, Inc.
See Also:: XmlIDREF