Spring配置属性嵌套的自定义验证

Question

我有嵌套的属性类：

@ConfigurationProperties(prefix = "myapp", ignoreUnknownFields = false)
public class MyAppProperties implements Validator {

    @Valid
    private List<Server> servers = new ArrayList();

    public MyAppProperties() {
    }

    public List<Server> getServers() {
        return this.servers;
    }

    public void setServers(List<Server> servers) {
        this.servers = servers;
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return MyAppProperties.class.isAssignableFrom(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        MyAppProperties properties = (MyAppProperties) target;

        if (isEmpty(properties.getServers())) {
            errors.rejectValue("servers", "myapp.servers", "Servers not provided");
        }
    }

    public static class Server implements Validator {

        private String name;
        private String url;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }

        @Override
        public boolean supports(Class<?> clazz) {
            return Server.class.isAssignableFrom(clazz);
        }

        @Override
        public void validate(Object target, Errors errors) {
            Server server = (Server) target;

            if (StringUtils.isBlank(server.getName())) {
                errors.rejectValue("name", "server.name", "Server name not provided");
            }

            if (StringUtils.isBlank(server.getUrl())) {
                errors.rejectValue("url", "server.url", "Server url not provided");
            }
        }
    }
}

现在，我希望对两个类都触发验证，但是当我使用无效值运行时，仅对MyAppProperties触发验证，而对服务器列表不触发。

我做错了什么，我无法完成这项工作。我想同时使用自定义验证器。谁能帮我做这个工作。

我传递的无效值是：

myapp.servers[0].name= 
myapp.servers[0].url=

但这可以正常运行