//需求：删除集合中的重复数据
class Book{
    
    int id;
    String name;
    
    public Book(int id , String name) {
        this.id = id;
        this.name = name;
    }
    @Override
    public boolean equals(Object obj) {
        Book book = (Book)obj;
        if(this.id == book.id) {
            return true;
        }else {
            return false;
        }
    }
    @Override
    public String toString() {
        
        return "{ 书号："+this.id+" 书名："+this.name+" }";
    }
}
public class Demo2 {
    public static void main(String[] args) {
        ArrayList list = new ArrayList();
        list.add(new Book(1001, "java编程思想"));
        list.add(new Book(1002, "java核心技术"));
        list.add(new Book(1003, "javaweb"));
        list.add(new Book(1004, "java编程思想"));
        clearRepeat(list);
        System.out.println(list);
    }
    
    public static void clearRepeat(ArrayList list) {
        Iterator it = list.iterator();
        while(it.hasNext()) {
            Book book = (Book)it.next();
            if(list.contains(book)) {
                list.remove(book);
            }
        }
    }
}