[已解决]:线程“main”com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException中的异常:3 个IllegalAnnotationExceptions计数

[已解决]:线程“maincom.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException中的异常:3 个IllegalAnnotationExceptions计数

原文: https://howtodoinjava.com/jaxb/solved-exception-in-thread-main-com-sun-xml-internal-bind-v2-runtime-illegalannotationsexception-3-counts-of-illegalannotationexceptions/

当您使用 JAXB 将 Java 对象(集合类型)编组为 xml 格式时,会发生此异常。 栈跟踪如下所示:

Exception in thread "main" com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 1 counts of IllegalAnnotationExceptions
Class has two properties of the same name "employees"
	this problem is related to the following location:
		at public java.util.List com.howtodoinjava.jaxb.examples.list.Employees.getEmployees()
		at com.howtodoinjava.jaxb.examples.list.Employees
	this problem is related to the following location:
		at private java.util.List com.howtodoinjava.jaxb.examples.list.Employees.employees
		at com.howtodoinjava.jaxb.examples.list.Employees

	at com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException$Builder.check(Unknown Source)
	at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(Unknown Source)
	at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(Unknown Source)
	at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(Unknown Source)
	at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(Unknown Source)
	..... more

或者

Exception in thread "main" com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 3 counts of IllegalAnnotationExceptions
java.util.Map is an interface, and JAXB can't handle interfaces.
	this problem is related to the following location:
		at java.util.Map
		at private java.util.Map com.howtodoinjava.jaxb.examples.map.EmployeeMap.employeeMap
		at com.howtodoinjava.jaxb.examples.map.EmployeeMap
java.util.Map does not have a no-arg default constructor.
	this problem is related to the following location:
		at java.util.Map
		at private java.util.Map com.howtodoinjava.jaxb.examples.map.EmployeeMap.employeeMap
		at com.howtodoinjava.jaxb.examples.map.EmployeeMap
Class has two properties of the same name "employeeMap"
	this problem is related to the following location:
		at public java.util.Map com.howtodoinjava.jaxb.examples.map.EmployeeMap.getEmployeeMap()
		at com.howtodoinjava.jaxb.examples.map.EmployeeMap
	this problem is related to the following location:
		at private java.util.Map com.howtodoinjava.jaxb.examples.map.EmployeeMap.employeeMap
		at com.howtodoinjava.jaxb.examples.map.EmployeeMap
	......more

Random exceptions

随机异常

原因

发生上述异常的主要原因是缺少@XmlAccessType注解或对@XmlAccessType@XxmlElement注解的无效使用。 正确的用法是,一个 Java 字段应只包含一个表示其元数据的有效 JAXB 注解。

默认情况下,JAXB 包含所有公开字段和用于整理的获取器。 因此,如果您有一个字段及其获取器,那么它将包含两次。 这是错误,需要通过正确使用注解来解决。

解决方案:使用@XmlAccessType注解

1)@XmlAccessorType(XmlAccessType.FIELD)

如果您使用的是XmlAccessType.FIELD;那么只有所有公开字段(非静态)将被自动包括在内以进行编组。 不会考虑吸气剂。 因此,如果将消除重复的问题。 例如,在下面的代码中,将同时包含employeesize字段。

请注意,“@XmlElement(name="employee")”是可选的; 我用它来重命名输出 xml 中的 xml 节点。 如果删除它; 不会出现任何编组错误或异常。

@XmlRootElement(name = "employees")
@XmlAccessorType (XmlAccessType.FIELD)
public class Employees 
{
	@XmlElement(name="employee")
	private List<Employee> employees = null;

	private Integer size;

	public List<Employee> getEmployees() {
		return employees;
	}
	public void setEmployees(List<Employee> employees) {
		this.employees = employees;
	}
	public Integer getSize() {
		return size;
	}
	public void setSize(Integer size) {
		this.size = size;
	}
}

2)@XmlAccessorType(XmlAccessType.NONE)

如果使用“XmlAccessType.NONE”,则意味着必须在输出 XML 中注解所有要编组的字段。 剩下的任何字段都不会包含在 JAXB 上下文中。 因此,本质上,employeesize字段都需要@XmlElement注解。 如果这两个字段中的任何一个都未使用@XmlElement注解,则不会将其编组。

@XmlRootElement(name = "employees")
@XmlAccessorType (XmlAccessType.NONE)
public class Employees 
{
	@XmlElement(name="employee")
	private List<Employee> employees = null;

	@XmlElement(name="size")
	private Integer size;

	public List<Employee> getEmployees() {
		return employees;
	}
	public void setEmployees(List<Employee> employees) {
		this.employees = employees;
	}
	public Integer getSize() {
		return size;
	}
	public void setSize(Integer size) {
		this.size = size;
	}
}

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