1.解决思路：使用一种新的java.util.List实现，来变相的达到列表校验的效果。

package com.xzp.pojo;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

import javax.validation.Valid;

/**
 * 可被校验的List
 * @author xuzhipeng
 * @date 2019-08-30 10:24:08
 * @since 1.0
 */
public class ValidableList<E> implements List<E> {

    @Valid
    private List<E> list;

    public ValidableList() {
        this.list = new ArrayList<>();
    }

    public ValidableList(List<E> list) {
        this.list = list;
    }

    public List<E> getList() {
        return list;
    }

    public void setList(List<E> list) {
        this.list = list;
    }

    @Override
    public int size() {
        return list.size();
    }

    @Override
    public boolean isEmpty() {
        return list.isEmpty();
    }

    @Override
    public boolean contains(Object o) {
        return list.contains(o);
    }

    @Override
    public Iterator<E> iterator() {
        return list.iterator();
    }

    @Override
    public Object[] toArray() {
        return list.toArray();
    }

    @Override
    public <T> T[] toArray(T[] a) {
        return list.toArray(a);
    }

    @Override
    public boolean add(E e) {
        return list.add(e);
    }

    @Override
    public boolean remove(Object o) {
        return list.remove(o);
    }

    @Override
    public boolean containsAll(Collection<?> c) {
        return list.containsAll(c);
    }

    @Override
    public boolean addAll(Collection<? extends E> c) {
        return list.addAll(c);
    }

    @Override
    public boolean addAll(int index, Collection<? extends E> c) {
        return list.addAll(index, c);
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        return list.removeAll(c);
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        return list.retainAll(c);
    }

    @Override
    public void clear() {
        list.clear();
    }

    @Override
    public E get(int index) {
        return list.get(index);
    }

    @Override
    public E set(int index, E element) {
        return list.set(index, element);
    }

    @Override
    public void add(int index, E element) {
        list.add(index, element);
    }

    @Override
    public E remove(int index) {
        return list.remove(index);
    }

    @Override
    public int indexOf(Object o) {
        return list.indexOf(o);
    }

    @Override
    public int lastIndexOf(Object o) {
        return list.lastIndexOf(o);
    }

    @Override
    public ListIterator<E> listIterator() {
        return list.listIterator();
    }

    @Override
    public ListIterator<E> listIterator(int index) {
        return list.listIterator(index);
    }

    @Override
    public List<E> subList(int fromIndex, int toIndex) {
        return list.subList(fromIndex, toIndex);
    }

}

2.可以看到ValidableList具有二象性，ValidableList LIKE-A java.util.List，同时也是个“holder”，对外的方法全部会移交给持有的list处理。也就是说，ValidableList与java.util.List的对外功能完全一致。对于Spring参数绑定来说，JSON转换后也能够绑定到ValidableList对象上（就像能绑定到java.util.ArrayList对象上一样。）实现了上述的效果后，直接在list上声明一个@Valid就解决所有问题了。

@PostMapping
public String test(@Valid @RequestBody ValidableList<User> list) {
    return "SUCCESS";
}

参考：https://blog.csdn.net/wangjiangongchn/article/details/86481729