文本文件中有几个数字，对他进行排序再重新输入到文本中 但是有问题

                      Integer.parseInt(a1[j])=Integer.parseInt(a1[i]);
                  Integer.parseInt(a1[i])=temp;
        这两行编译器说意外的类型 文本里是数字这没问题。请大家帮看看

import *;

public class Test1{

 public static void main(String args[]){
     int temp=0;
     try{
     
          FileReader rf=new FileReader("b.txt");
          BufferedReader ax=new BufferedReader(rf);
     
          String a=ax.readLine();
          String a1[]=a.split(" ");
     
     
           int j;
           int i;
            for(i=0;i<a1.length;i++)
          for(j=i;j<a1.length;j++)
                 if(Integer.parseInt(a1[i])<Integer.parseInt(a1[j]))
                {
                  temp=Integer.parseInt(a1[j]);
                  Integer.parseInt(a1[j])=Integer.parseInt(a1[i]);
                  Integer.parseInt(a1[i])=temp;                   
                }
          i=0;
          String c="";
          while(i<a1.length)
              {   c=c+a1[i]+" ";
              i++;
          }
        
          FileWriter r=new FileWriter("b.txt");
          r.write(c);
     
          ax.close();
          r.close();
     
           }catch(IOException e){
           System.out.println(e);}
            catch(Exception e){
            System.out.println(e);
        }

    
    
    }    
    
    
    
  }

给你改了，
1。 temp 换成 String
2.  你有问题的两句。  

但你的程序可以更好的设计一下。



import *;

public class Test1{

public static void main(String args[]){
    String temp;
    try{
   
         FileReader rf=new FileReader("b.txt");
         BufferedReader ax=new BufferedReader(rf);
   
         String a=ax.readLine();
         String a1[]=a.split(" ");
   
   
         int j;
         int i;
         for(i=0;i<a1.length;i++)
         for(j=i;j<a1.length;j++)
                if(Integer.parseInt(a1[i])<Integer.parseInt(a1[j]))
               {
                 temp=a1[j];
                 a1[j]=a1[i];
                 a1[i]=temp;                  
               }
         i=0;
         String c="";
         while(i<a1.length)
              {   c=c+a1[i]+" ";
             i++;
         }
        
         FileWriter r=new FileWriter("b.txt");
         r.write(c);
   
         ax.close();
         r.close();
   
           }catch(IOException e){
          System.out.println(e);}
            catch(Exception e){
            System.out.println(e);
        }

   
   
    }   
   
   
   
  }

Integer.parseInt(a1[j])=Integer.parseInt(a1[i]);
Integer.parseInt(a1[i])=temp;
这两个赋值表达式左边要是变量,而不是表达式.
比如:Integer.parseInt(a1[j]) == 3; Integer.parseInt(a1[i]) == 4
Integer.parseInt(a1[j])=Integer.parseInt(a1[i]);就变成 3 = 4;
当然有问题了.

谢谢楼上的两位朋友