通用测试
您的JAXB（JSR-222）实现将为每个类创建映射（即
TestGeneric，不是type（即
TestGeneric<Integer>）。因此，它将
value字段视为type
Object。这将导致
xsi:type属性，因为JAXB实现正在添加足够的信息才能解组相同的类型。
@XmlAccessorType(XmlAccessType.NONE)static class TestGeneric<T> { @XmlAttribute public boolean isRequired; @XmlElement public T value; public TestGeneric() { } public TestGeneric(boolean isRequired) { this.isRequired = isRequired; }}演示版
下面是您可以使用的一种方法。我介绍了的子类
TestGeneric来代表不同的可能类型。
package forum11192623;import java.io.PrintWriter;import java.io.StringWriter;import javax.xml.bind.*;import javax.xml.bind.annotation.*;public class Demo { public static void main(String[] args) { try { TestRoot root = new TestRoot(); root.name.value = "bobby"; root.age.value = 102; root.color.value = "blue"; JAXBContext context = JAXBContext.newInstance(root.getClass()); Marshaller marsh = context.createMarshaller(); marsh.setProperty(Marshaller.JAXB_ENCODING,"UTF-8"); marsh.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,Boolean.TRUE); StringWriter sw = new StringWriter(); PrintWriter pw = new PrintWriter(sw); marsh.marshal(root,pw); System.out.println(sw.toString()); } catch(Throwable t) { t.printStackTrace(); } } @XmlRootElement static class TestRoot { @XmlElement public TestString name = new TestString(true); @XmlElement public TestInteger age = new TestInteger(true); @XmlElement public TestString color = new TestString(true); } @XmlAccessorType(XmlAccessType.NONE) @XmlTransient @XmlSeeAlso({TestInteger.class, TestString.class}) static class TestGeneric<T> { @XmlAttribute public boolean isRequired; public T value; public TestGeneric() { } public TestGeneric(boolean isRequired) { this.isRequired = isRequired; } } static class TestInteger extends TestGeneric<Integer> { public TestInteger() { } public TestInteger(boolean b) { super(b); } @XmlElement public Integer getValue() { return value; } public void setValue(Integer value) { this.value = value; } } static class TestString extends TestGeneric<String> { public TestString() { } public TestString(boolean b) { super(b); } @XmlElement public String getValue() { return value; } public void setValue(String value) { this.value = value; } }}
