实现Comparable接口,进行排序

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class Book implements Comparable{
/*编写一个类Book，具有name,price,press,author属性.然后创建5个对象放入ArrayList中，并实现按照price大小排序（使用Comparable接口排序），
   然后遍历ArrayList输出每个Book对象。*/
private String name;
private float price;
private String press;
private String author;

//构造方法
public Book(String name,float price,String press,String author){
   this.name = name;
   this.price = price;
   this.press = press;
   this.author = author;
   System.out.println(name.toString());
}
@SuppressWarnings("unchecked")
public static void main(String[] args){
   List list = new ArrayList();
   Book b1=new Book("java1",25f,"不错的书","LY1");
   Book b2=new Book("java2",26f,"不错的书","LY2");
   Book b3=new Book("java3",50f,"不错的书","LY3");
   Book b4=new Book("java4",20f,"不错的书","LY4");
   Book b5=new Book("java5",15f,"不错的书","LY5");
   list.add(b1);
   list.add(b2);
   list.add(b3);
   list.add(b4);
   list.add(b5);
   Collections.sort(list);
   for(int i=0;i    Book book = (Book)list.get(i);
    System.out.println(book);
   }
}
   //重写
public int compareTo(Object obj) {
      Book p = (Book)obj;
      if(p.price>this.price){
     return 1;
      }
      else if(p.price     return -1;
      }
      else{
          return 0;
      }
}
//重写toString方法
public String toString(){//这上是重写了本类的toString方法,对系统自带的其它字段的toString方法无效
     return "书名："+this.name+", 价格："+this.price+", 说明："+this.press+", 作者: "+this.author;
     }
}
//.sort(List)方法,当然还可能使用java.util.Arrays.sort(数组),那样就必须把//list转化为数组,由于本例使用Collections.sort(List)已经足够,另一方法,大家可//以尝试自已使用.