Java使用Predicate过滤集合中的元素的操作方法

Iterator<String> iterator = strings.iterator();
while (iterator.hasNext()) {
    String s = iterator.next();
    if (s == null || s.isEmpty() || s.length() > 5) {
        iterator.remove();
    }
}

import java.util.*;
import java.util.function.Predicate;

public class FilterExample {
    public static void main(String[] args) {
        Predicate<String> isNull = Objects::isNull;
        Predicate<String> isEmpty = String::isEmpty;
        Predicate<String> isTooLong = s -> s.length() > 5;
        
        // 组合多个条件
        Predicate<String> shouldRemove = isNull.or(isEmpty).or(isTooLong);

        Collection<String> strings = new ArrayList<>();
        strings.add(null);
        strings.add("");
        strings.add("one");
        strings.add("two");
        strings.add("");
        strings.add("three"); // 长度大于5
        strings.add("hello"); // 正好5个字符，不会被删
        strings.add(null);

        System.out.println("Before filtering: " + strings);

        strings.removeIf(shouldRemove);

        System.out.println("After filtering: " + strings);
    }
}

Before filtering: [null, , one, two, , three, hello, null]
After filtering: [one, two, hello]

List<Integer> numbers = new ArrayList<>(List.of(1, 2, 3, 4, 5, 6));
numbers.removeIf(n -> n % 2 == 0);
System.out.println(numbers);  // 输出 [1, 3, 5]

List<String> names = new ArrayList<>(List.of("Alice", "Bob", "Charlie", "David"));
names.removeIf(name -> name.startsWith("A"));
System.out.println(names);  // 输出 [Bob, Charlie, David]