List<Student>?set?=?new?ArrayList<>();
set.add(new?Student(3,?"Java"));
isListContains(set);????//?判斷是否存在Map值
private?void?isListContains(List<Student>?set)?{
???Student?course?=?new?Student(3,"Java");
???if?(set.contains(course))?{
???????L.i("1找到了");
???}?else
???????L.i("1沒找到");
}
public?class?Student?{
???public?int?getId()?{
???????return?id;
???}

???public?void?setId(int?id)?{
???????this.id?=?id;
???}

???public?String?getName()?{
???????return?name;
???}

???public?void?setName(String?name)?{
???????this.name?=?name;
???}

???private?int?id;
???private?String?name;

???public?Student(int?id,?String?name)?{
???????this.id?=?id;
???????this.name?=?name;
???}

???@Override
???public?boolean?equals(Object?o)?{
???????if?(this?==?o)?return?true;
???????if?(o?==?null)?return?false;
???????if?(!(o?instanceof?Student))?return?false;
???????if?(this.getName()?==?null)?{
???????????Student?stu?=?(Student)?o;
???????????if?(stu.getName()?==?null)?return?true;
???????????else?return?false;
???????}?else?{
???????????Student?stu?=?(Student)?o;
???????????if?(this.getName().equals(stu.getName()))?return?true;
???????????else?return?false;
???????}
???}
}

這樣寫contains判斷是可以的。但是把

List<Student>?set?=?new?ArrayList<>();
set.add(new?Student(3,?"Java"));
isListContains(set);????//?判斷是否存在Map值

改成Set就不行了？？？

Set<Student>?set?=?new?HashSet<>();
set.add(new?Student(3,?"Java"));
isListContains(set);????//?判斷是否存在Map值