java8-stream根据某个字段去重

java8-stream根据某个字段去重

List rolePermissions = rolePermissionMapper.selectList(wrapper);

rolePermissions = rolePermissions.stream().collect(
                Collectors.collectingAndThen(Collectors.toCollection(() -> new TreeSet<>(
                        Comparator.comparing(RolePermission::getId)
                )), ArrayList::new)
        );