import *;
import java.util.*;

//商品类
class Goods{
private String name;
private int identifier;
private double price;
private int number;

public void setName(String n){
      name=n;
  }
  
  public void setIdentifier(int i){
      identifier=i;
  }
  
  public void setPrice(double p){
      price=p;
  }
         
 public void setNumber(int n){
     number=n;
 }
 
 public String getName(){
     return name;
 }
 
 public double getPrice(){
     return price;
 }
 
 public int getIdentifier(){
     return identifier;
 }
 
 public int getNumber(){
     return number;
 }
 
}
public class Lianxi2 {

    public static void main(String[] args) throws IOException{
       Goods[] g=new Goods[2];
       Goods[] goods=new Goods[2];
      
       BufferedWriter f1 = new BufferedWriter(new FileWriter("goods.txt"));
    File file= new File("goods.txt");  
    Scanner in=new Scanner(file);
      Scanner input= new Scanner(System.in);
       int i,j,t;
       String name;
       double price;
       int number;
       int identifier;
       long sum;
          String s;
  //从键盘读取并写入文件中      
  for (i=0;i<2;i++){
           g[i]=new Goods();
           System.out.print("请输入商品编号：");
           identifier=input.nextInt();
          g[i].setIdentifier(identifier);
   
           System.out.print("请输入商品名称：");
           name=input.next();
           g[i].setName(name);
   
           System.out.print("请输入商品单价：");
           price=input.nextDouble();
           g[i].setPrice(price);
 
           System.out.print("请输入商品数量：");
           number=input.nextInt();
           g[i].setNumber(number);
   
       }
       for(i=0;i<2;i++){
       f1.write(g[i].getIdentifier()+"  "+g[i].getName()+"  "+ g[i].getPrice()+"  "+  g[i].getNumber()+"\r\n");
       }
       f1.close();
      /*
       for(i=0;i<4;i++){
       g[i].setIdentifier(0);
       g[i].setName("");
       g[i].setPrice(0);
       g[i].setNumber(0);  
       }
   */
      
       //从文件中读取
       i=0;
    while(in.hasNext()){
        int a = in.nextInt();
        String b = in.next();
        double c= in.nextDouble();
        int d = in.nextInt();
        g[i].setIdentifier(a);
        g[i].setName(b);
        g[i].setPrice(c);
        g[i].setNumber(d);
        i++;
    }
   in.close();

//想实现根据价格对商品进行排序
    for(i=0;i<3;i++){
         goods[i]=new Goods();
        for(j=i+1;j<4;j++){
            if((g[i].getPrice())<(g[j].getPrice())){
                t=j; j=i;i=t;           
            }      
        }     
        }
   
    //打印
     for(i=0;i<4;i++){
         System.out.println(goods[i].getIdentifier()+"  "+goods[i].getName()+"   "+goods[i].getPrice()+"  "+goods[i].getNumber() );
     }
    }  
}

怎么就没一个回复滴呢

你是想大家挑问题，还是夸奖？不知道你要回复什么啊

可以呀，写的这代码

可是这无法实现排序啊

实现不了排序