JAVA8filter对List筛选、排序报nullPointException
1、模糊查询,通过IndexName()!=null 判断防⽌indexName为空报空指针异常
String indexName = "asd";
shardsList = shardsList.stream().filter(ShardsInfoDto -> IndexName()!=null&&IndexName().indexOf(indexName) > -1).co shardsList.stream().forEach(ShardsInfoDto -> {
System.out.IndexName());
});
定冠词the的用法2、如果shardsList集合中有null对象,则加⼊过滤条件Objects::nonNull,这个条件会帮助去除为null的对象
shardsList = shardsList.stream().filter(Objects::nonNull).filter(ShardsInfoDto -> IndexName().indexOf(indexName) > -1).collect(Collectors
3、多个参数联合排序,则加⼊Comparator.nullsFirst()防⽌参数为空导致空指针异常!
String docsFlag = "asc";
String storeFlag = "desc";
//排序
Comparator<ShardsInfoDto> doc = null;
if("asc".equals(docsFlag)){
//docs升序
doc = Comparator.paring(ShardsInfoDto::getDocs, Comparator.nullsFirst(Integer::compareTo)));
}el if("desc".equals(docsFlag)){
//docs降序关于毅力的名言
doc = Comparator.paring(ShardsInfoDto::getDocs, Comparator.nullsFirst(Integer::compareTo)).reverd());
}闺蜜的句子
Comparator<ShardsInfoDto> store = null;
if("asc".equals(storeFlag)){
电话怎么拉黑名单//store升序
store = Comparator.paring(ShardsInfoDto::getStore, Comparator.nullsFirst(Double::compareTo)));
}el if("desc".equals(storeFlag)){
//store降序
store = Comparator.paring(ShardsInfoDto::getStore, Comparator.nullsFirst(Double::compareTo)).reverd());
}
捉泥鳅教案
// 联合排序
Comparator<ShardsInfoDto> finalComparator = doc.thenComparing(store);
shardsList.sort(finalComparator);
金牛女和白羊男for (ShardsInfoDto dto:shardsList) {大水法遗址
System.out.println("doc:"+Docs()+",store:"+Store());
}
>不仅也造句