我的问题实际上是这个问题as seen here...的衍生产品，因此在继续之前检查该线程可能会有所帮助。
在我的Spring Boot项目中，我有两个实体Sender和Recipient代表一个Customer并且几乎有相同的字段，所以我让它们扩展基类{{ 1}};
客户基类;
Customer发件人域对象;
@MappedSuperclass
public class Customer extends AuditableEntity {
@Column(name = "firstname")
private String firstname;
@Transient
private CustomerRole role;
public Customer(CustomerRole role) {
this.role = role;
}
//other fields & corresponding getters and setters
}
收件人域对象;
@Entity
@Table(name = "senders")
public class Sender extends Customer {
public Sender(){
super.setRole(CustomerRole.SENDER);
}
}
注意 - @Entity
@Table(name = "recipients")
public class Recipient extends Customer {
public Recipient(){
super.setRole(CustomerRole.RECIPIENT);
}
}
和Sender除了角色外完全相同。通过将Recipient基类作为实体本身，可以轻松地将这些存储在单个客户表中，但我有意将这些实体分开，因为我有义务将每个客户类型保留在单独的数据库表。
现在，我在视图中有一个表单，用于收集Customer和＆amp;的详细信息。 Sender，例如，为了收集名字，我必须以不同方式命名表单字段，如下所示;
表单的发件人部分;
Recipient表单的收件人部分;
<input type="text" id="senderFirstname" name="senderFirstname" value="$!sender.firstname">
但是，客户可用的字段太多了，我正在寻找一种方法，通过this question here中提到的注释将它们映射到pojo。但是，提供的解决方案there意味着我必须为两个域对象创建单独的代理并相应地注释字段，例如
<input type="text" id="recipientFirstname" name="recipientFirstname" value="$!recipient.firstname">
所以我非常好奇并且想知道，有没有办法将这个代理映射到多个@ParamName，以便基类例如可以注释如下？;
public class SenderProxy {
@ParamName("senderFirstname")
private String firstname;
@ParamName("senderLastname")
private String lastname;
//...
}
public class RecipientProxy {
@ParamName("recipientFirstname")
private String firstname;
@ParamName("recipientLastname")
private String lastname;
//...
}
然后可能找到一种基于注释选择字段值的方法??
答案 0 :(得分：0)
所以我这样做
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Alias {
String[] value();
}
public class AliasedBeanInfoFactory implements BeanInfoFactory, Ordered {
@Override
public BeanInfo getBeanInfo(Class<?> beanClass) throws IntrospectionException {
return supports(beanClass) ? new AliasedBeanInfo(Introspector.getBeanInfo(beanClass)) : null;
}
private boolean supports(Class<?> beanClass) {
Class<?> targetClass = beanClass;
do {
Field[] fields = targetClass.getDeclaredFields();
for (Field field : fields) {
if (field.isAnnotationPresent(Alias.class)) {
return true;
}
}
targetClass = targetClass.getSuperclass();
} while (targetClass != null && targetClass != Object.class);
return false;
}
@Override
public int getOrder() {
return Ordered.LOWEST_PRECEDENCE - 100;
}
}
public class AliasedBeanInfo implements BeanInfo {
private static final Logger LOGGER = LoggerFactory.getLogger(AliasedBeanInfo.class);
private final BeanInfo delegate;
private final Set<PropertyDescriptor> propertyDescriptors = new TreeSet<>(new PropertyDescriptorComparator());
AliasedBeanInfo(BeanInfo delegate) {
this.delegate = delegate;
this.propertyDescriptors.addAll(Arrays.asList(delegate.getPropertyDescriptors()));
Class<?> beanClass = delegate.getBeanDescriptor().getBeanClass();
for (Field field : findAliasedFields(beanClass)) {
Optional<PropertyDescriptor> optional = findExistingPropertyDescriptor(field.getName(), field.getType());
if (!optional.isPresent()) {
LOGGER.warn("there is no PropertyDescriptor for field[{}]", field);
continue;
}
Alias alias = field.getAnnotation(Alias.class);
addAliasPropertyDescriptor(alias.value(), optional.get());
}
}
private List<Field> findAliasedFields(Class<?> beanClass) {
List<Field> fields = new ArrayList<>();
ReflectionUtils.doWithFields(beanClass,
fields::add,
field -> field.isAnnotationPresent(Alias.class));
return fields;
}
private Optional<PropertyDescriptor> findExistingPropertyDescriptor(String propertyName, Class<?> propertyType) {
return propertyDescriptors
.stream()
.filter(pd -> pd.getName().equals(propertyName) && pd.getPropertyType().equals(propertyType))
.findAny();
}
private void addAliasPropertyDescriptor(String[] values, PropertyDescriptor propertyDescriptor) {
for (String value : values) {
if (!value.isEmpty()) {
try {
this.propertyDescriptors.add(new PropertyDescriptor(
value, propertyDescriptor.getReadMethod(), propertyDescriptor.getWriteMethod()));
} catch (IntrospectionException e) {
LOGGER.error("add field[{}] alias[{}] property descriptor error", propertyDescriptor.getName(),
value, e);
}
}
}
}
@Override
public BeanDescriptor getBeanDescriptor() {
return this.delegate.getBeanDescriptor();
}
@Override
public EventSetDescriptor[] getEventSetDescriptors() {
return this.delegate.getEventSetDescriptors();
}
@Override
public int getDefaultEventIndex() {
return this.delegate.getDefaultEventIndex();
}
@Override
public PropertyDescriptor[] getPropertyDescriptors() {
return this.propertyDescriptors.toArray(new PropertyDescriptor[0]);
}
@Override
public int getDefaultPropertyIndex() {
return this.delegate.getDefaultPropertyIndex();
}
@Override
public MethodDescriptor[] getMethodDescriptors() {
return this.delegate.getMethodDescriptors();
}
@Override
public BeanInfo[] getAdditionalBeanInfo() {
return this.delegate.getAdditionalBeanInfo();
}
@Override
public Image getIcon(int iconKind) {
return this.delegate.getIcon(iconKind);
}
static class PropertyDescriptorComparator implements Comparator<PropertyDescriptor> {
@Override
public int compare(PropertyDescriptor desc1, PropertyDescriptor desc2) {
String left = desc1.getName();
String right = desc2.getName();
for (int i = 0; i < left.length(); i++) {
if (right.length() == i) {
return 1;
}
int result = left.getBytes()[i] - right.getBytes()[i];
if (result != 0) {
return result;
}
}
return left.length() - right.length();
}
}
}