问题

我想在文件中写入行，在我的本地机器上，文件位于`/home/localuser/Desktop/myProgram/files`，当我将它们放在服务器机器上时，它们位于`/userhome/my_name`。

当我在本地机器上运行程序时，它会在`/home/localuser/Desktop/myProgram/files/output.txt`下创建输出文件，并且会检测此文件是否已经存在，但它不会向其中写入任何内容，也不会引发任何异常。在服务器上，它会在`/userhome/my_name/output.txt`下创建并检测文件，并且会向其中写入内容。

以下是创建文件并在文件已存在时将其清空的代码部分：
```java
private static void createFile(String fileName){
    try{
        File printerFile = new File(fileName);
        if(printerFile.createNewFile()){
            System.out.println("文件已创建：" + printerFile.getName());
        }else{
            System.out.println("文件已存在。清空：" + fileName);
            emptyFile(fileName);
        }
    } catch (IOException e){
        System.out.println("创建新文件时出现问题");
        e.printStackTrace();
    }
}

private static void emptyFile(String filename){
    try{
        new PrintWriter(filename).close(); // 清空文件内容
    }catch (IOException e){
        System.out.println("清空文件时出现问题");
        e.printStackTrace();
    }
}

然后是写入内容的代码部分：

process Printer_P{
    String messageToPrint; // 用于存储打印机从客户端接收到的消息
    PrinterCommand command; // 用于存储客户端请求的操作

    try{ // 尝试打开文件写入器
        out = new FileWriter(filename,true);
    }catch(IOException e){
        System.out.println("在Printer.jr中打开新的FileWriter时出现问题");
        e.printStackTrace();
    }

    System.out.println(printerName + " " + "开机");

    while(true){
        receive action(command, messageToPrint); // 等待接收操作
        if(command == PrinterCommand.PRINT){
            System.out.println(printerName + " " + messageToPrint);
            try{ // 尝试写入操作
                out.write(messageToPrint+"\n");
            }catch(IOException e){
                System.out.println("在Printer.jr中写入输出文件时出现问题");
                e.printStackTrace();
            }
        }else if (command == PrinterCommand.CLOSE){
            try{
                out.close();
            }catch (Exception e){
                System.out.println("关闭Printer.jr中的文件写入器时出现问题");
                e.printStackTrace();
            }
            break;
        }
    }
    System.out.println(printerName + " " + "关机");
}
}

为什么在本地机器上使用时不会向文件中写入内容，而在服务器机器上使用时会写入呢？

<details>
<summary>英文:</summary>

I want to write lines in a file, on my local machine the file are under `/home/localuser/Desktop/myProgram/files` and when I put them on the server machine they are under `/userhome/my_name`. 

When I run the program on my local machine, it creates the output file under `/home/localuser/Desktop/myProgram/files/output.txt` and it detects if this file already exists but it doesn&#39;t write in it, neither throws any excpetions. On the server it creates and detects the file under `/userhome/my_name/output.txt` and it WRITES in it.

The code is the following one to create and make the file empty if it already exists:  
```java
    private static void createFile(String fileName){
        try{
            File printerFile = new File(fileName);
            if(printerFile.createNewFile()){
                System.out.println(&quot;File created: &quot; + printerFile.getName());
            }else{
                System.out.println(&quot;File already exists. Emptying &quot; + fileName);
                emptyFile(fileName);
            }
        } catch (IOException e){
            System.out.println(&quot;Problem while creating new file&quot;);
            e.printStackTrace();
        }
    }

private static void emptyFile(String filename){
        try{
            new PrintWriter(filename).close(); // make the file empty
        }catch (IOException e){
            System.out.println(&quot;Problem while emptying the file&quot;);
            e.printStackTrace();
        }
    }

and then to write the content :

    process Printer_P{
        String messageToPrint; // used to store the message that the printer get from the client
        PrinterCommand command; // used to store the action that the client asked for
 
        try{ // try and catch the openning of a file writer
            out = new FileWriter(filename,true);
        }catch(IOException e){
            System.out.println("Problem while openning a new FileWriter in Printer.jr");
            e.printStackTrace();
        }
 
        System.out.println(printerName +" " + "POWER ON");
 
        while(true){
            receive action(command, messageToPrint); // wait until it receive an action
            if(command == PrinterCommand.PRINT){
                System.out.println(printerName + " " + messageToPrint);
                try{ // try and catch the writting action
                    out.write(messageToPrint+"\n");
                }catch(IOException e){
                    System.out.println("Problem while writting in the output file in Printer.jr");
                    e.printStackTrace();
                }
            }else if (command == PrinterCommand.CLOSE){
                try{
                    out.close();
                }catch (Exception e){
                    System.out.println("Problem while close the filewriter in Printer.jr");
                    e.printStackTrace();
                }
                break;
            }
        }
        System.out.println(printerName +" " + "SHUTDOWN");
    }
}

Why doesn't it write in the file when I'm using it on local machine but it do when it's on the server machine ?