去除arraylist容器中的相同的对象元素的方法
<spanclass="keyword"style="background-color:rgb(250,250,250);font-size:1em;font-family:Monaco,'DejaVuSansMono','BitstreamVeraSansMono',Consolas,'CourierNew',monospace;">boolean</span><spanstyle="color:black;background-color:rgb(250,250,250);font-size:1em;font-family:Monaco,'DejaVuSansMono','BitstreamVeraSansMono',Consolas,'CourierNew',monospace;"> retainAll(Collection<?> c); </span>
在网上查到了retainAll方法
然后就在代码中添加
<prename="code"class="html">List<Employee><spanstyle="font-family:Arial,Helvetica,sans-serif;">employeeOfIntermediarys</span><spanstyle="font-family:Arial,Helvetica,sans-serif;">=newArrayList<Employee>(); </span><prename="code"class="html">List<Employee><spanstyle="font-family:Arial,Helvetica,sans-serif;">tempList</span><spanstyle="font-family:Arial,Helvetica,sans-serif;">=newArrayList<Employee>();</span>
if(tempList!=null){
<spanstyle="white-space:pre"> </span>//去掉<spanstyle="font-family:Arial,Helvetica,sans-serif;">tempList中与</span><spanstyle="font-family:Arial,Helvetica,sans-serif;">employeeOfIntermediarys中</span>相同的元素,在合并
List<Employee>eoiList=newArrayList<Employee>(employeeOfIntermediarys);
if(eoiList.retainAll(tempList)){
tempList.removeAll(eoiList);
}
employeeOfIntermediarys.addAll(tempList); }
然后发现不可以,查了好多东西,发现代码是对的,只是需要重写equals方法。
不知道为什么,因为之前写的小demo中用自定义的类book,如下,是可以正常使用的
publicclassBook{
privateintid;
privateStringnameString;
privateStringwriter;
publicBook(){
id=-1;
nameString="";
writer="";
}
List<Book>books=newArrayList<Book>();
List<Book>tempList=newArrayList<Book>();
Bookbook1=newBook();
book1.setId(1);
book1.setNameString("dkjdf");
Bookbook2=newBook();
book2.setId(2);
book2.setNameString("到加福禄寿");
Bookbook3=newBook();
book3.setId(3);
book3.setNameString("dj地方");
Bookbook4=newBook();
book4.setId(4);
book4.setNameString("dkjdf");
Bookbook5=newBook();
book5.setId(5);
book5.setNameString("到加福禄寿");
Bookbook6=newBook();
book6.setId(6);
book6.setNameString("dj地方");
books.add(book1);
books.add(book2);
books.add(book5);
books.add(null);
tempList.add(book1);
tempList.add(book4);
tempList.add(null);
tempList.retainAll(books);
System.out.println(tempList.get(0).booktoString());
whatever,准备找一找collection的源代码看看,
重写了Employee中的equals方法后。
如下:
@Override
publicbooleanequals(Objectc){
if(!(cinstanceofEmployee)){
returnfalse;
}
Employeeeoi=(Employee)c;
if(eoi.getUserGuid().equals(userGuid)){
returntrue;
}
returnfalse;
}
上面的代码就可以正常运行了。
以上就是小编为大家带来的去除arraylist容器中的相同的对象元素的方法的全部内容了,希望对大家有所帮助,多多支持毛票票~