如何在不覆蓋以前的數據的情況下創建多個java txt文件？

可能重複：
Writing to a file without overwriting or appending 如何在不覆蓋以前的數據的情況下創建多個java txt文件？

嗨，我創建一個執行數據並打印成txt文件的程序。我遇到的問題是每次運行該程序都會覆蓋我以前的txt文件。我不希望它覆蓋，也不想追加數據。我想創建一個新的txt文件，每次它產生它創建的日期或時間。請有人幫助我嗎？

這裏是我的代碼：

private static PrintWriter outFile; 
    /** 
    * @param args 
    */ 
    //Main Method 
    public static void main(String[] args) throws IOException 
     { 



     //creates the new file to be saved 
     outFile = new PrintWriter(new FileWriter("trilogy.txt")); 
     //Create a generator object to create random numbers 
     Random gen = new Random(); 

     //Create a scanner object to scan user input. 
     Scanner scan = new Scanner(System.in); 

     DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd"); 
     //get current date time with Date() 
     Date date = new Date(); 
     outFile.println(dateFormat.format(date)); 
     outFile.println(); 

     //Prompts the user to input how many lock combinations he/she wants generated. 
     System.out.print ("Enter quantity: "); 
     int quantity = scan.nextInt(); 


     int count = 1; 
     //Loop - Only numbers 1 - 5 are used 
     //  Only five numbers are generated per one lock combination 
     for (int i = 0; i < quantity; i++) 
     { 

       int n1 = gen.nextInt(5)+1; 
       int n2 = gen.nextInt(5)+1; 
       int n3 = gen.nextInt(5)+1; 
       int n4 = gen.nextInt(5)+1; 
       int n5 = gen.nextInt(5)+1; 


    //While loop making sure that NO numbers are repeated 
     while (n2==n1) 
     { 
      n2 = gen.nextInt(5)+1; 
     } 

       while (n3==n2 || n3 == n1 || n3==n4||n3==n5) 
       { 
        n3 = gen.nextInt(5)+1; 
       } 

        while (n4 == n3 || n4 == n2 || n4 == n1||n4==n5) 
        { 
         n4 = gen.nextInt(5)+1; 
        } 

         while (n5== n1 || n5==n2 || n5==n3 || n5==n4) 
         { 
          n5 = gen.nextInt(5)+1; 
         } 

      //If statements that output the random lock combinations in different formats. 
         if (n1==1){ 
          outFile.println ("(" + count +") " + (n1*10 +n2) +"-"+ (n3*10+n4)+"-"+n5);} 
         else if (n2==2){ 
          outFile.println ("(" + count +") " + n2 + "-" + (n1*10 + n3)+ "-" + (n4*10+ n5));} 
         else if (n3==3){ 
          outFile.println ("(" + count +") " + (n3*10 +n2) +"-"+ n1+ "-" +(n4*10+n5));} 
         else if (n4 == 4){ 
          outFile.println ("(" + count +") " + (n4 +"-"+ (n2*100 +n3*10+n1)+"-"+n5));} 
         else 
          outFile.println ("(" + count +") " + (n5) +"-"+ (n2) +"-"+ (n3) + "-"+ (n4) +"-" +(n1)); 

         count++; 

      //Spaces one line in between each lock combination 
      outFile.println(); 

     } 
     outFile.close(); 
     } 

}

來源

2012-06-15 Kamel Powers

奇怪的是，這個問題被問不到一個小時前：http://stackoverflow.com/questions/11055695/writing-to-一個文件，而無需-覆蓋有或附加 –

這是一個重複的，但我更喜歡這個版本，原來的 – finnw

您需要更改以下行：

outFile = new PrintWriter(new FileWriter("trilogy.txt"));

的東西，有時間/日期就可以了：

outFile = new PrintWriter(new FileWriter("trilogy" + DATE_TIME + ".txt"));

來源

2012-06-15 18:40:19

嘗試改變這個：

 outFile = new PrintWriter(new FileWriter("trilogy.txt"));

此追加文本：

 outFile = new PrintWriter(new FileWriter("trilogy.txt",true));

來源

2012-06-15 19:06:26 Angel

從API：http://docs.oracle.com/javase/1.4.2/docs/api/java /io/FileWriter.html FileWriter的（文件文件，布爾附加）構建一個給定文件對象一個FileWriter對象。如果第二個參數爲true，則字節將寫入文件的末尾而不是開頭。 – Angel

故事的道德：總是，總是閱讀方法的規格 – Alfabravo

是的！當然！ – Angel

如何在不覆蓋以前的數據的情況下創建多個java txt文件？

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