JAVA中两个列表的交集

Question

我正在尝试获取JAVA中两个列表之间的交集，请在下面找到列表

清单1：列表list1 = new ArrayList <>（）;

list1 = [EligViewEventSubject [event = EOD，subjectTypeCd = HOLDINGS，区域= IA]，EligViewEventSubject [event = EOD，subjectTypeCd = ASSETS，区域= IA]]

清单2：列表list2 = new ArrayList <>（）;

list2 = [EligViewEventSubject [事件= EOD，subjectTypeCd =资产，区域= IA]]

以上结果应与下面类似

List resultList = new ArrayList <>（）;

resultList = [EligViewEventSubject [event = EOD，subjectTypeCd = ASSETS，region = IA]]

总之我只想匹配的对象（交叉点）

我在下面尝试过，

List unionList = new ArrayList <>（list1）;unionList.addAll（list2）;

列表交集列表=新的ArrayList <>（list1）;junctionList.retainAll（list2）;

[我得到的联合列表为[EligViewEventSubject [event = EOD，subjectTypeCd = HOLDINGS，region = IA]，EligViewEventSubject [event = EOD，subjectTypeCd = ASSETS，region = IA]，EligViewEventSubject [event = EOD，subjectTypeCd = ASSETS，region = IA]]

交叉点是[]

请分享您对此的想法。

Answer 1

请参考这个问题，因为已经回答了。 Intersection and union of ArrayLists in Java

总而言之，您可以像这样在Java中获得两个arraylist的交集：

public <T> List<T> intersection(List<T> list1, List<T> list2) {
    List<T> list = new ArrayList<T>(); 

    for (T t : list1){
       if(list2.contains(t)){
           list.add(t); 
       } 
    } 

   return list; 
}