java - Linux 和 java : File is being created but text is not written

Question

我正在编写一个简单的终端程序，用于记录一些信息，并将其放入一个文本文件中，供以后调用。主要是为了记录他的人所做的事情。我在 Windows 中一直很好，并没有真正遇到这个问题，但我担心我正在寻找一些简单的东西。

就像我之前说的，如果我导航到项目目录，我会看到文件已经创建，但是当我用文本编辑器打开文件时，创建的字符串中的任何数据都没有被打印出来。

private static void writeFile( String call,float freq,String mode,int rstSnt,int rstRx,String city, String state) throws IOException{
    File fileName = new File("log.txt");
    FileOutputStream fos;
     try {
         fos = new FileOutputStream(fileName);
         BufferedWriter write = new BufferedWriter(new OutputStreamWriter(fos));
         int i =0;
         write.write(i +"; " + call + "; " + freq + "; " + mode + "; " + rstSnt + "; " + rstRx + "; " + city + "," + state + "\n");
         i++;
         System.out.println("File has been updated!");
     } catch (FileNotFoundException ex) {
         Logger.getLogger(QtLogger.class.getName()).log(Level.SEVERE, null, ex);
     }
}

Answer 1

您需要关闭输出，或者更准确地说，您需要编写代码以便将其关闭(不一定明确关闭)。 Java 7 引入了 try with resources巧妙地处理这种情况的语法。

任何 AutoCloseable 的对象都可以使用此语法自动安全地关闭，如下所示:

private static void writeFile( String call,float freq,String mode,int rstSnt,int rstRx,String city, String state) throws IOException{
    File fileName = new File("log.txt");
    try (FileOutputStream fos = = new FileOutputStream(fileName);
         BufferedWriter write = new BufferedWriter(new OutputStreamWriter(fos));) {
         int i =0;
         write.write(i +"; " + call + "; " + freq + "; " + mode + "; " + rstSnt + "; " + rstRx + "; " + city + "," + state + "\n");
         i++;
         System.out.println("File has been updated!");
     } catch (FileNotFoundException ex) {
         Logger.getLogger(QtLogger.class.getName()).log(Level.SEVERE, null, ex);
     }
}

只需将可关闭对象的初始化移动到 try 资源 block 中即可确保它们已关闭，这将在关闭后 flush() 它们。