輸入文本到file.txt的，無需更換時，在環

Question

我使用的緩衝筆者嘗試輸入文本到記事本，這是我來什麼碼了文本，

import java.util.Scanner; 
import java.io.*; 
public class FileSample { 
    public static void main (String[] args) { 
    Scanner sc = new Scanner(System.in); 
    String yourtext = " "; 
    String fn = "file.txt"; 
    String choice = " "; 
    do{ 
    try{ 
     FileWriter fw = new FileWriter(fn); 
     BufferedWriter bw = new BufferedWriter(fw); 
     System.out.print("Enter text: "); 
     yourtext = sc.nextLine(); 
     bw.write(yourtext); 
     bw.newLine(); 

     bw.close(); 
     System.out.println("==================================="); 
     System.out.print("Do you still want to continue?:\n [Y]Yes \n [N]No 
     \n::"); 
     choice = sc.nextLine(); 
    }catch(IOException ex){ 
     System.out.println("Error writing to file '" + fn + "'"); 
    } 
    }while(choice.equalsIgnoreCase("Y")); 


} 
} 

所以問題是當用戶想要繼續並再次輸入文本並完成該過程時，應該在file.txt中的文本被新輸入的文本替換。

Answer 1

只需添加FileWriter(fn,true)這將保留現有內容並將新內容附加到文件末尾。

Answer 2

你的問題是，你只是在覆蓋模式下打開fileWriter，以使其只需將新文本附加到現有文件，只需將new FileWriter(fn)替換爲FileWriter(fn,true)即可解決該問題。

但是，我也注意到，你的排序處理不當的資源（在我看來），所以我建議你一旦打開流/讀/寫，並在年底關閉它們：

public static void main(String[] args) { 
    String yourtext = " "; 
    String fn = "file.txt"; 
    String choice = " "; 
    try (Scanner sc = new Scanner(System.in); 
      FileWriter fw = new FileWriter(fn);   // making sure to free resources after using them 
      BufferedWriter bw = new BufferedWriter(fw);) { 
     do { 
      System.out.print("Enter text: "); 
      yourtext = sc.nextLine(); 
      bw.write(yourtext); 
      bw.newLine(); 
      System.out.println("==================================="); 
      System.out.print("Do you still want to continue?:\n [Y]Yes \n [N]No \n::"); 
      choice = sc.nextLine(); 
     } while (choice.equalsIgnoreCase("Y")); 
    } catch (IOException ex) { 
     System.out.println("Error writing to file '" + fn + "'"); 
    } 
}