<spanDejaVu Sans Mono', 'Bitstream Vera Sans Mono', Consolas, 'Courier New', monospace;">boolean</span><spanDejaVu Sans Mono', 'Bitstream Vera Sans Mono', Consolas, 'Courier New', monospace;">retainAll(Collection<?>c);</span>
在网上查到了 retainAll方法
然后就在代码中添加
<pre name="code">List<Employee> <span>employeeOfIntermediarys </span><span>= new ArrayList<Employee>(); </span><pre name="code">List<Employee> <span>tempList </span><span>= new ArrayList<Employee>();</span>
if(tempList != null){ <span> </span>//去掉<span>tempList 中与</span><span>employeeOfIntermediarys 中</span>相同的元素,在合并 List<Employee> eoiList = new ArrayList<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
public class Book { private int id; private String nameString; private String writer; public Book(){ id= -1; nameString = ""; writer = ""; }
List<Book> books = new ArrayList<Book>(); List<Book> tempList = new ArrayList<Book>(); Book book1 = new Book(); book1.setId(1); book1.setNameString("dkjdf"); Book book2 = new Book(); book2.setId(2); book2.setNameString("到加福禄寿"); Book book3 = new Book(); book3.setId(3); book3.setNameString("dj地方"); Book book4 = new Book(); book4.setId(4); book4.setNameString("dkjdf"); Book book5 = new Book(); book5.setId(5); book5.setNameString("到加福禄寿"); Book book6 = new Book(); 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 public boolean equals(Object c){ if (!(c instanceof Employee)) { return false; } Employee eoi = (Employee) c; if (eoi.getUserGuid().equals(userGuid)) { return true; } return false; }
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,多多支持查字典教程网~