我有以下代码：
UniqueConstraintViolation violation = new UniqueConstraintViolationImpl();
Set<? extends javax.validation.ConstraintViolation> violations = new HashSet<UniqueConstraintViolation>();
violations.add(violation);
throw new javax.validation.ConstraintViolationException(violations);
其中UniqueConstraintViolation是接口扩展的javax.validation.ConstraintViolation
和UniqueConstraintViolationImpl是类实现的UniqueConstraintViolation
编译时出现以下错误
java：42：错误：找不到适合的方法
添加（UniqueConstraintViolation）
违反。添加（违反）;
^
方法Collection.add（CAP＃1）不适用
（参数不匹配； UniqueConstraintViolation无法转换为CAP＃1）
方法Set.add（CAP＃1）不适用
（参数不匹配；不能将UniqueConstraintViolation转换为CAP＃1），其中CAP＃1是新的类型变量：
CAP＃1从捕获？扩展了ConstraintViolation。扩展ConstraintViolation
C：\ workspace \ zcts-travel \ crud-rest \ src \ main \ java \ ru \ zcts \ crud \ AbstractResource.java：43：错误：类型不兼容：Set无法转换为Set>
抛出新的javax.validation.ConstraintViolationException（violations）;
^ where CAP#1 is a fresh type-variable:
CAP#1 extends ConstraintViolation from capture of ? extends ConstraintViolation
我只想通过我自己的javax.validation.ConstraintViolation实现将javax.validation.ConstraintViolationException构造函数传递给Set。
我该怎么办？
最佳答案
因此，有您的约束：
interface UniqueConstraintViolation extends ConstraintViolation<YourClass> {
}
public class UniqueConstraintViolationImpl implements UniqueConstraintViolation {
/* your impl here */
}
这将编译：
UniqueConstraintViolation violation = new UniqueConstraintViolationImpl();
Set<UniqueConstraintViolation> violations = new HashSet<UniqueConstraintViolation>();
violations.add(violation);
throw new ConstraintViolationException(violations);
关于java - Set中的GenericsAdd(捕获<？extended ConstraintViolation>)不能应用于(ConstraintViolation)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/33668234/