Java apache commons-collections 库 CollectionUtils 类


#Java Apache Commons 库#


示例: isEmpty、isNotEmpty 判断 List

import org.apache.commons.collections.MapUtils;

import java.util.HashMap;
import java.util.Map;

public class MapUtilsTest {

    public static void main(String[] args) {
        Map<String, String> map = new HashMap<>();
        System.out.println(MapUtils.isEmpty(map));
        System.out.println(MapUtils.isNotEmpty(map));
    }
}

执行结果:

true
false

示例: isEmpty、isNotEmpty 判断 Set

import org.apache.commons.collections.CollectionUtils;

import java.util.HashSet;
import java.util.Set;

public class CollectionUtilsTest {

    public static void main(String[] args) {
        Set<Long> numSet = new HashSet<>();
        System.out.println(CollectionUtils.isEmpty(numSet));
        System.out.println(CollectionUtils.isNotEmpty(numSet));
    }

}

执行结果:

true
false

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