將appendFile轉換為不會覆蓋的文本文件

Question

我在append方法上失去了。

我有一個輸入信息然后在文本文件中打印的程序。

問題是，我也想將新的信息輸入也添加到文本文件中而不進行覆蓋，這意味着如果我重新運行該程序，則我編碼的信息將與該程序的最后一次運行時的編碼一起存儲在文本文件中。

請幫我。 這是程序：

@SuppressWarnings("resource")
public static void main(String[] args) throws IOException
{
   System.out.println("STUDENT INFORMATION");
   System.out.println("-------------------");
   System.out.println("Full Name            :   ");
    Scanner sc = new Scanner(System.in);
    String name = sc.nextLine();
   System.out.println("\nCourse and Year      :   ");
    String yearcourse = sc.nextLine();
   System.out.println("\nStudent Number       :   ");
    String studentnumber = sc.nextLine();
   System.out.println("\nE-mail Address       :   ");
    String eadd = sc.nextLine();
   System.out.println("\nCellphone Number     :   ");
    String cpnumber = sc.nextLine();
   System.out.println("\nGender               :   ");
    String gender = sc.nextLine();
   System.out.println("\nAge                  :   ");
    String age = sc.nextLine();
   System.out.println("\nDate of Birth        :   ");
    String dob = sc.nextLine();
   System.out.println("\nCivil Status         :   ");
    String status = sc.nextLine();
   System.out.println("\nAddress              :   ");
    String address = sc.nextLine();
   System.out.println("\n\n________________________________________________");
   System.out.println("STUDENT INFORMATION");
   System.out.println("\nName             :   " + name + "");
   System.out.println("Year and Course  :   " + yearcourse + "");
   System.out.println("Student Number   :   " + studentnumber + "");
   System.out.println("E-mail Address   :   " + eadd + "");
   System.out.println("Cellphone Number :   " + cpnumber + "");
   System.out.println("Gender           :   " + gender + "");
   System.out.println("Age              :   " + age + "");
   System.out.println("Date of Birth    :   " + dob + "");
   System.out.println("Civil Status     :   " + status + "");
   System.out.println("Address          :   " + address + "");
   System.out.println("");


    File file = new File("Student Information.txt");
    if(!file.exists())
    {
        file.createNewFile();
    }
    try (PrintWriter writer = new PrintWriter(file)){
        BufferedWriter bufferWritter = new BufferedWriter(writer);
        writer.println("\nSTUDENT INFORMATION:");
        writer.println("--------------------");
        writer.println("Name             :   " + name + "");
        writer.println("Year and Course  :   " + yearcourse + "");
        writer.println("Student Number   :   " + studentnumber + "");
        writer.println("E-mail Address   :   " + eadd + "");
        writer.println("Cellphone Number :   " + cpnumber + "");
        writer.println("Gender           :   " + gender + "");
        writer.println("Age              :   " + age + "");
        writer.println("Date of Birth    :   " + dob + "");
        writer.println("Civil Status     :   " + status + "");
        writer.println("Address          :   " + address + "");
        writer.flush();
    }
}

}

在此。 如果我重新運行該程序，則文本文件將被新的編碼信息覆蓋。 他們說要使用append bufferwriter 。 但我真的迷路了

Answer 1

嘗試將您的代碼更改為如下所示：

File file = new File("Student Information.txt");
    if(!file.exists())
    {
        file.createNewFile();
    }
    try(PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(file, true)))) {
        out.println("\nSTUDENT INFORMATION:");
        out.println("--------------------");
        out.println("Name             :   " + name + "");
        out.println("Year and Course  :   " + yearcourse + "");
        out.println("Student Number   :   " + studentnumber + "");
        out.println("E-mail Address   :   " + eadd + "");
        out.println("Cellphone Number :   " + cpnumber + "");
        out.println("Gender           :   " + gender + "");
        out.println("Age              :   " + age + "");
        out.println("Date of Birth    :   " + dob + "");
        out.println("Civil Status     :   " + status + "");
        out.println("Address          :   " + address + "");
}catch (IOException e) {
    // Handle IO exception.
}

這部分代碼：

new FileWriter(file,true)

告訴它在設置為true時追加，如您在docs上看到的 。

---

或者您可以更改行：

PrintWriter writer = new PrintWriter(file);

對此：

PrintWriter writer = new PrintWriter(new FileWriter(file,true));

Answer 2

代替這個

PrintWriter writer = new PrintWriter(file);

嘗試這個

PrintWriter writer= new PrintWriter(new BufferedWriter(new FileWriter(file, true));

也可以看看

• 如何在Java中將內容附加到文件
• 如何在Java中將文本追加到現有文件