如何创建多个java txt文件而不覆盖以前的数据?

如何创建多个java txt文件而不覆盖以前的数据?,java,Java,可能重复: 嗨,我正在创建一个程序,它执行数据并打印到txt文件中。我遇到的问题是,每次运行该程序都会覆盖我以前的txt文件。我不希望它覆盖,也不希望附加数据。我想创建一个新的txt文件,每次有它产生的日期或时间创建。有人能帮我吗 这是我的密码: private static PrintWriter outFile; /** * @param args */ //Main Method public static void main(String[

可能重复:

嗨,我正在创建一个程序,它执行数据并打印到txt文件中。我遇到的问题是,每次运行该程序都会覆盖我以前的txt文件。我不希望它覆盖,也不希望附加数据。我想创建一个新的txt文件,每次有它产生的日期或时间创建。有人能帮我吗

这是我的密码:

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();
        }

}
私有静态PrintWriter输出文件;
/**
*@param args
*/
//主要方法
公共静态void main(字符串[]args)引发IOException
{
//创建要保存的新文件
outFile=newprintWriter(newfilewriter(“trilogy.txt”);
//创建生成器对象以创建随机数
Random gen=新的Random();
//创建扫描仪对象以扫描用户输入。
扫描仪扫描=新扫描仪(System.in);
DateFormat DateFormat=新的简化格式(“yyyy/MM/dd”);
//使用日期()获取当前日期时间
日期=新日期();
outFile.println(dateFormat.format(date));
outFile.println();
//提示用户输入他/她希望生成的锁组合数。
System.out.print(“输入数量:”);
int数量=scan.nextInt();
整数计数=1;
//循环-仅使用数字1-5
//每个锁组合只生成五个数字
对于(int i=0;i
您需要更改以下行:

 outFile = new PrintWriter(new FileWriter("trilogy.txt"));
指向上面有时间/日期的对象:

 outFile = new PrintWriter(new FileWriter("trilogy" + DATE_TIME + ".txt"));
尝试更改此选项:

        outFile = new PrintWriter(new FileWriter("trilogy.txt"));
要使其附加文本,请执行以下操作:

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

:)。如果第二个参数为真,那么字节将被写入文件的末尾而不是开头。故事的寓意:总是,总是读取方法的specsHI Angel Olle Blazquez感谢您的反馈。我试图避免它在文件末尾追加和输出。我希望它在用户每次运行程序时创建一个新的txt文件,而不是重写。请尝试以下操作:
outFile=new PrintWriter(new FileWriter(“trilogy”+new Date()+“.txt”)和注释