爲什麼給我看最後一個對象，我把它放在TXT

Question

我有一個很大的問題，我在一個txt文件中寫入相同的對象帳戶當我點擊查看所有對象我已經寫在TXT是隻顯示我最後一個，在JOptionPane中顯示帳戶，第二個是我如何使帳戶採取一，二，三......每個帳戶，我寫了一個數字加一先前帳戶。 我believ解釋清楚

if(str.equals("Receipt")) 
{ 
     ObjectInputStream in = null; 
     Account acc = null; 
     try 
     { 
      in = new ObjectInputStream(new FileInputStream("Accounts.txt")); 
      while((acc = (Account) in.readObject()) !=null) 
      { 
       if (acc instanceof Account) 
        ((Account)acc).print(); 
       //acc.print(); 
      } 
     } 
     catch(EOFException ex) 
     { 
      System.out.println("End of file reached."); 
     } 
     catch(ClassNotFoundException ex) 
     { 
      System.out.println("Error casting"); 
      ex.printStackTrace(); 
     } 
     catch(FileNotFoundException ex) 
     { 
      System.out.println("Error specified file does not exist"); 
      ex.printStackTrace(); 
     } 
     catch(IOException ex) 
     { 
      System.out.println("Error with I/O processes"); 
      ex.printStackTrace(); 
     } 
     finally 
     { 
      try 
      { 
       in.close(); 
      } 
      catch(IOException ex) 
      { 
       System.out.println("Another IOException during the closing"); 
       ex.printStackTrace(); 
      } 
     } 
} 

代碼寫入對象文件

Account ac=new Account(posoOfil,poso,ariLoga,aitiol,diafor); 
     ac.print(); 

     try{ 

     OutputStream file = new FileOutputStream("Accounts.txt"); 
     OutputStream buffer = new BufferedOutputStream(file); 
     ObjectOutput output = new ObjectOutputStream(buffer); 
     try{ 
     output.writeObject(ac); 
     output.flush(); 

System.out.println("Object written to file"); 
     } 
     finally{ 
     output.close(); 
     } 
    } 
     catch 
(FileNotFoundException ex) {System.out.println("Error with specified file") ; 
ex.printStackTrace();} 

    catch(IOException ex){ 
     System.out.println("Cannot perform output."); 
    } 

     } 

和類賬戶

public class Account implements Serializable { 

    private int arithmKat; 
// private Date date ; 
    private int posoOfil; 
    private int posoKat; 
    private String ariLoga ; 
    private String aitiol; 
    private boolean diafor=false; 

    public Account(int posoOfil, int posoKat,String ariLoga,String aitiol,boolean diafor){ 
    arithmKat++; 
    this.posoOfil=posoOfil; 
    this.posoKat=posoKat; 
    this.ariLoga=ariLoga; 
    this.aitiol=aitiol; 
    this.diafor=diafor; 

    } 
    void print(){ 
    System.out.println(arithmKat+" "+posoOfil+" "+posoKat+" "+diafor);} 

} 

Answer 1

你只寫一個帳戶文件。在編寫帳戶的代碼中根本沒有循環。編寫幾個帳戶的代碼如下所示：

private void writeAccounts(List<Account> accounts) throws IOException { 
    OutputStream file = new FileOutputStream("Accounts.txt"); 
    OutputStream buffer = new BufferedOutputStream(file); 
    ObjectOutput output = new ObjectOutputStream(buffer); 

    try { 
     for (Account account : accounts) {   
      output.writeObject(account); 
     } 
     output.close(); 
    } 
    finally { 
     output.close(); 
    } 
}