使用fileWriter命令ReWriting一行

Question

我是java新手，我有一个在txt文件上写信息的程序，唯一的问题似乎是，如果fileWriter附加了我不能编辑的文件，或者重写了文件上的特定行，有没有办法将写入器设置为从文件的开头开始，而不是在不擦除数据的情况下从结尾开始？因为这样我就不能编辑文件中的信息了。提前感谢您的回复！

Answer 1

FileWriter类有几个构造函数。其中一些带有类型为boolean的"append“参数。您是否在true中使用了这些构造函数之一？

您应该对该参数使用false。

    /**
 * Constructs a FileWriter object given a File object. If the second
 * argument is <code>true</code>, then bytes will be written to the end
 * of the file rather than the beginning.
 *
 * @param file  a File object to write to
 * @param     append    if <code>true</code>, then bytes will be written
 *                      to the end of the file rather than the beginning
 * @throws IOException  if the file exists but is a directory rather than
 *                  a regular file, does not exist but cannot be created,
 *                  or cannot be opened for any other reason
 * @since 1.4
 */
public FileWriter(File file, boolean append) throws IOException {
    super(new FileOutputStream(file, append));
}