如何从Java列表中过滤空字符串值？
假设我们有一个带有空值的字符串列表。在这里，在Football之前和Squash之后，我们有空的数组元素：
List<String> sports = Arrays.asList("","Football", "Cricket", "Tennis", "Squash","", "Fencing", "Rugby");现在过滤空字符串值。首先，我们使用谓词对值求反：
Stream<String> stream = sports.stream(); Predicate<String> empty = String::isEmpty; Predicate<String> emptyRev = empty.negate(); stream.filter(emptyRev).collect(Collectors.toList()));
以下是从列表中筛选空字符串值的示例：
示例
import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Demo {
public static void main(String[] args) {
List<String> sports = Arrays.asList("","Football", "Cricket", "Tennis", "Squash","", "Fencing", "Rugby");
System.out.println("List with empty elements...");
for (String res : sports)
{
System.out.print(res+" ");
}
Stream<String> stream = sports.stream();
Predicate<String> empty = String::isEmpty;
Predicate<String> emptyRev = empty.negate();
System.out.println("\n\nStrings after removing empty array values = "+stream.filter(emptyRev).collect(Collectors.toList()));
}
}输出结果
List with empty elements... Football Cricket Tennis Squash Fencing Rugby Strings after removing empty array values = [Football, Cricket, Tennis, Squash, Fencing, Rugby]