JAXB @XmlElements使minOccurs = 1

所以我希望有一个列表用@XmlElements注释，如下所示

@XmlElements( { @XmlElement(name = "Apple", type = Apple.class), @XmlElement(name = "Orange", type = Orange.class), @XmlElement(name = "Mango", type = Mango.class) } ) public List getEntries() { return fruitList; } 

我想知道是否有办法强制列表包含至少1个元素，因为现在，xsd看起来像

Answer 1

假设Apple，Orange和Mango是Fruit的子类，您可能希望使用@XmlElementRef注释entries属性，该属性对应于XML模式中的替换组，而不是对应于选择概念的@XmlElements 。

 @XmlElementRef public List getEntries() { return fruitList; } 

这假设Apple，Orange和Mango类扩展了Fruit类，并使用@XmlRootElement进行了注释。

 @XmlRootElement public class Apple extends Fruit { ... } 

了解更多信息

• http://bdoughan.blogspot.com/2010/11/jaxb-and-inheritance-using-substitution.html
• http://bdoughan.blogspot.com/2010/10/jaxb-and-xsd-choice-xmlelements.html

Answer 2

我建议检查一下：

 @XmlElements( { @XmlElement(name = "Apple", type = Apple.class, required = true), @XmlElement(name = "Orange", type = Orange.class, required = true), @XmlElement(name = "Mango", type = Mango.class, required = true) } )