从 Java 类中的@XMLElement获取注释值

Question

我正在尝试从我拥有的java类中获取@XMLElement注释，基本上是尝试在需要注释的地方制作变量映射：true。但是它什么也没打印出来。

我有一个具有以下代码片段的 java 类：

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"subjectCode",
"version",
"messageTitle",
})
@XmlRootElement(name = "CreateMessageRequest", namespace = "mynamespaceblahblah")
public class CreateMessageRequest
extends AbstractRequest
implements Serializable
{
private final static long serialVersionUID = 10007L;
@XmlElement(namespace = "mynamespaceblahblah", required = true)
protected String subjectCode;
@XmlElement(namespace = "mynamespaceblahblah")
protected String version;
@XmlElement(namespace = "mynamespaceblahblah", required = true)
protected String messageTitle;

//Getters and setters
}

我试过这个：

public HashMap<String, String> getRequired(Class<?> c) {
HashMap<String, String> fieldMap = new HashMap<>();
Annotation[] annotations = c.getAnnotations();
for (int i = 0; i < annotations.length; i++) {
Annotation annotation = annotations[i];
if (annotation instanceof XmlElement) {
XmlElement theElement = (XmlElement) annotation;
String name = ((XmlElement) annotation).name();
if (theElement.required()) {
fieldMap.put(name, "true");
} else {
fieldMap.put(name, "false");
}
}
}
return fieldMap;
}

但是当我使用我的方法时：

SchemaBuilder s = new SchemaBuilder();
System.out.println("Required Methods of class:");
HashMap<String, String> fieldMap = s.getRequired(CreateMessageRequest.class);
for (Map.Entry<String, String> entry : fieldMap.entrySet()) {
System.out.println(entry.getKey() + " = " + entry.getValue());
}

它打印出来

Required Methods of class:

对我做错了什么有什么建议吗？我已经考虑过，因为它受到保护，我无法访问它(不幸的是，我无法更改带注释的类(，但我不确定这是问题所在。

Answer 1

解决方案是根据建议查看各个字段:)

为了帮助未来的谷歌用户：

public HashMap<String, String> getRequired(Class<?> c) {
HashMap<String, String> fieldMap = new HashMap<>();
Field[] fields = c.getDeclaredFields();
for (Field f : fields) {
Annotation[] annotations = f.getAnnotationsByType(XmlElement.class);
for (int i = 0; i < annotations.length; i++) {
Annotation annotation = annotations[i];
if (annotation instanceof XmlElement) {
XmlElement theElement = (XmlElement) annotation;
String name = f.getName();
if (theElement.required()) {
fieldMap.put(name, "true");
} else {
fieldMap.put(name, "false");
}
}
}
}
return fieldMap;
}