当我从 XSD 生成 JAXB 类时，具有maxOccurs="unbounded"为它们生成的 getter 方法的元素，但没有 setter 方法，如下所示：
/**
* Gets the value of the element3 property.
*
* <p>
* This accessor method returns a reference to the live list,
* not a snapshot. Therefore any modification you make to the
* returned list will be present inside the JAXB object.
* This is why there is not a <CODE>set</CODE> method for the element3 property.
*
* <p>
* For example, to add a new item, do as follows:
* <pre>
* getElement3().add(newItem);
* </pre>
*
*
* <p>
* Objects of the following type(s) are allowed in the list
* {@link Type }
*
*
*/
public List<Type> getElement3() {
if (element3 == null) {
element3 = new ArrayList<Type>();
}
return this.element3;
}
方法注释清楚地说明了如何使用它，但我的问题如下：
为什么 JAXB 不按照 Java Beans 规则生成一个 setter？我知道我可以自己编写 setter 方法，但是生成的 getter 方法中建议的方法有什么优势吗？
这是我的 XSD：
<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:tns="http://www.example.org/DoTransfer/" targetNamespace="http://www.example.org/DoTransfer/">
<element name="CollectionTest" type="tns:CollectionTest"></element>
<complexType name="CollectionTest">
<sequence>
<element name="element1" type="string" maxOccurs="1" minOccurs="1"></element>
<element name="element2" type="boolean" maxOccurs="1" minOccurs="1"></element>
<element name="element3" type="tns:type" maxOccurs="unbounded" minOccurs="1" nillable="true"></element>
</sequence>
</complexType>
<complexType name="type">
<sequence>
<element name="subelement1" type="string" maxOccurs="1" minOccurs="1"></element>
<element name="subelement2" type="string" maxOccurs="1" minOccurs="0"></element>
</sequence>
</complexType>
</schema>