一种写法,可以看一下

    public List<AlipayConfigDto> findBillAlipayConfig(){
       return aliPayConfigService.findAll().stream().filter((e) -> {
            return e.getAlipayQueryBillValid() != null && e.getAlipayQueryBillValid() == 1;
        }).map(t -> {
            AlipayConfigDto alipayConfigDto = new AlipayConfigDto();
            BeanUtils.copyProperties(t,alipayConfigDto);
            return alipayConfigDto;
        }).collect(Collectors.toList());
    }

 测试

    public static void main(String[] args) {
        ArrayList<String> arrayList = new ArrayList();
        arrayList.add("123");
        arrayList.add("234");
        arrayList.add("345");
        arrayList.add("456");
        arrayList.add("567");
        List<String> s = arrayList.stream().filter((f) -> {
            return true;
        }).map((e) -> {
            System.out.println("e.toString() = " + e.toString());
            return e.toString();
        }).collect(Collectors.toList());
        System.out.println("s = " + s.toString());
    }
e.toString() = 123
e.toString() = 234
e.toString() = 345
e.toString() = 456
e.toString() = 567
s = [123, 234, 345, 456, 567]
原文地址:https://www.cnblogs.com/zhuxiang1029/p/15606830.html