Linux和java：正在创建文件，但未写入文本

我正在编写一个简单的终端程序，它记录一些信息，并将其放入一个文本文件中，以后有人可以回忆起来。主要是为了记录一个人所做的事情。我在windows上一直很好，并没有遇到过这个问题，但我担心我在看一些简单的东西

如前所述，如果导航到项目目录，我会看到文件已创建，但当我使用文本编辑器打开文件时，创建的字符串中的任何数据都不会打印

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);
     }
}

---

从

BufferedWriter

类调用

write（）

函数后，需要调用

close（）

函数。您还应该在

FileOutputStream

对象上调用

close（）

函数

因此，您的新代码应该如下所示：

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");
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");

     // Close your Writer
     write.close();

     // Close your OutputStream
     fos.close();

     i++;
     System.out.println("File has been updated!");
 } catch (FileNotFoundException ex) {
     Logger.getLogger(QtLogger.class.getName()).log(Level.SEVERE, null, ex);
 }

}

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);
     }
}

---

您需要关闭输出，或者更准确地说，您需要编写代码以使其关闭（不一定要显式关闭）。Java7引入了能够精确处理这种情况的语法

任何可自动关闭的对象都可以使用以下语法自动安全地关闭：

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");

     // Close your Writer
     write.close();

     // Close your OutputStream
     fos.close();

     i++;
     System.out.println("File has been updated!");
 } catch (FileNotFoundException ex) {
     Logger.getLogger(QtLogger.class.getName()).log(Level.SEVERE, null, ex);
 }

}

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到

try

资源块中，即可确保它们已关闭，这将

flush（）

它们作为关闭的结果。

与问题无关，但变量

fileName

的名称有点不正确。这是实际的

文件

对象，不是文件名。哈哈，很好，谢谢！这可能是因为您需要关闭BufferedWriter和FileOutputStream以确保所有内容都写入文件？是的，缺少

。close

调用是问题所在，为什么它在Windows中工作？可能是因为Windows在应用程序关闭时刷新缓冲区，而不是Linux，这只是一个猜测，即使它是真的，您也不能依赖它在关闭之前调用

flush

，根本没有必要，

flush

仅当我们想写一些东西时才应该使用，但我们仍然希望有文件句柄以便稍后写入（例如套接字编程）至于关闭包装流，然后关闭底层流，同样没有必要（因此

write.close

就足够了，不需要

fos.close（）

）