我也在Hibernate论坛上问了这个问题，并在那里得到了回答。如果有人遇到此问题，我想在这里分享答案。
只需将Collection更改为List即可解决此问题。这是更新的单元测试：
package com.foo;import java.util.ArrayList;import java.util.List;import java.util.Set;import javax.validation.ConstraintViolation;import javax.validation.Valid;import javax.validation.Validation;import javax.validation.Validator;import org.hibernate.validator.constraints.NotEmpty;import org.junit.Test;import org.springframework.util.AutoPopulatingList;public class ValidatorTest { class Person { @NotEmpty private String name; @NotEmpty @Valid private List<Foo> list = new AutoPopulatingList<Foo>(Foo.class); public void setName(String name) { this.name = name; } public String getName() { return name; } public List<Foo> getList() { return list; } public void setList(List<Foo> foos) { this.list = foos; } } class Foo { @NotEmpty private String bar; public void setBar(String bar) { this.bar = bar; } public String getBar() { return bar; } } @Test public void testValidator() throws Exception { Foo foo0 = new Foo(); foo0.setBar(""); Foo foo1 = new Foo(); foo1.setBar(""); List<Foo> list = new ArrayList<ValidatorTest.Foo>(); list.add(foo0); list.add(foo1); Person person = new Person(); person.setName("Test Person"); person.setList(list); Validator validator = Validation.buildDefaultValidatorFactory().getValidator(); Set<ConstraintViolation<Person>> violations = validator.validate(person); for (ConstraintViolation<Person> constraintViolation : violations) { System.out.println(constraintViolation); } }}以上测试的输出（现在包括索引）：
ConstraintViolationImpl{interpolatedMessage='may not be empty', propertyPath=list[1].bar, rootBeanClass=class com.foo.ValidatorTest$Person, messageTemplate='{org.hibernate.validator.constraints.NotEmpty.message}'}ConstraintViolationImpl{interpolatedMessage='may not be empty', propertyPath=list[0].bar, rootBeanClass=class com.foo.ValidatorTest$Person, messageTemplate='{org.hibernate.validator.constraints.NotEmpty.message}'}
