FileWriter只在循環中寫入最後一行。需要它寫一個所有輸入的日誌

Question

我有一個JOptionPane，提示用戶提問並接收一個隨機生成的答案。我「米想寫記錄了所有的問題和答案一個文件，但FileWriter的只記錄了最後一個問題&答案這裏是我的代碼：

import javax.swing.JOptionPane; 
import java.util.Random; 
import java.io.*; 

public class Magic8Ball { 

    public static void main(String [] args)throws Exception { 

     final String QUIT = "quit"; 
     Random rand = new Random(); 
     int max = 7; 
     int min = 0; 
     int randomNum; 

     FileWriter fw = new FileWriter("fortune.txt"); 
     PrintWriter pw = new PrintWriter(fw); 
     BufferedWriter out = new BufferedWriter(fw); 

     String[] answers = new String[8]; 

     String question = JOptionPane.showInputDialog(" Enter a question or " + QUIT + " to exit "); 

     Create8Ball(answers);  

     while (!question.equals(QUIT)) { 

      randomNum = rand.nextInt((max - min) + 1) + min; 

      System.out.println(answers[randomNum]); 

      pw.println("Question: " + question); 
      pw.println("Fortune Response: " + answers[randomNum]); 


      question = JOptionPane.showInputDialog(" Enter a question or " + QUIT + " to exit "); 
      } 

     pw.close(); 
     System.exit(0); 

     } 

     public static void Create8Ball(String answers[]) throws Exception 
     { 
     FileReader fr = new FileReader ("answers.txt"); 
     BufferedReader br = new BufferedReader (fr); 

     String dog = null; 
     int cat = 0; 
     while ((dog = br.readLine()) != null) 
      { 
      answers[cat] = dog; 
      cat++; 
      } 
     //close the input file 
     br.close(); 

     } 

    } 

Answer 1

追加到文件：

FileWriter fw = new FileWriter("fortune.txt", true); 

Answer 2

可能你想這個構造FileWriter(String fileName, boolean append)，它會構造一個FileWriter對象給出指示是否要寫入的數據附加一個文件名用布爾。

這大概一會工夫FileWriter fw = new FileWriter("fortune.txt",true);