集合的常用操作类CollectionUtils

亦凉 2022-09-06 15:27 161阅读 0赞

转：[http://www.blogjava.net/jakin/archive/2009/05/14/270634.html][http_www.blogjava.net_jakin_archive_2009_05_14_270634.html]

package com.jakin.util;
    
    import java.util.ArrayList;
    import java.util.Collection;
    import java.util.Collections;
    import java.util.List;
    
    import org.apache.commons.collections.CollectionUtils;
    import org.apache.commons.lang.ArrayUtils;
    
    public class CollectionUtilsTest {
    
        @SuppressWarnings("unchecked")
        public static void main(String[] args) {
    
            List<String> aList = new ArrayList<String>();
            aList.add("aaa");
            aList.add("bbb");
            aList.add("ccc");
            List<String> bList = new ArrayList<String>();
            bList.add("aaa");
            bList.add("ddd");
            bList.add("eee");
            // 并集
            Collection<String> unionList = CollectionUtils.union(aList, bList);
            // 交集
            Collection<String> intersectionList = CollectionUtils.intersection(aList, bList);
            // 是否存在交集
            boolean isContained = CollectionUtils.containsAny(aList, bList);
            // 交集的补集
            Collection<String> disjunctionList = CollectionUtils.disjunction(aList, bList);
            // 集合相减
            Collection<String> subtractList = CollectionUtils.subtract(aList, bList);
            
            // 排序
            Collections.sort((List<String>) unionList);
            Collections.sort((List<String>) intersectionList);
            Collections.sort((List<String>) disjunctionList);
            Collections.sort((List<String>) subtractList);
    
            // 测试
            System.out.println("A: " + ArrayUtils.toString(aList.toArray()));
            System.out.println("B: " + ArrayUtils.toString(bList.toArray()));
            System.out.println("A has one of B? : " + isContained);
            System.out.println("Union(A, B): "
                    + ArrayUtils.toString(unionList.toArray()));
            System.out.println("Intersection(A, B): "
                    + ArrayUtils.toString(intersectionList.toArray()));
            System.out.println("Disjunction(A, B): "
                    + ArrayUtils.toString(disjunctionList.toArray()));
            System.out.println("Subtract(A, B): "
                    + ArrayUtils.toString(subtractList.toArray()));
    
        }
    }

[http_www.blogjava.net_jakin_archive_2009_05_14_270634.html]: http://www.blogjava.net/jakin/archive/2009/05/14/270634.html