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Java 是否可以使用同一FileWriter文件并通过多种方法写入?_Java_Methods_Fileoutputstream_Printwriter - Fatal编程技术网

Java 是否可以使用同一FileWriter文件并通过多种方法写入?

Java 是否可以使用同一FileWriter文件并通过多种方法写入?,java,methods,fileoutputstream,printwriter,Java,Methods,Fileoutputstream,Printwriter,我从用户那里接收一个输入文件和一个输出文件,并试图从main方法和towerOfHanoiMoves方法写入输出文件。我试图将输出变量作为参数传递给towerOfHanoiMoves方法,但始终出现错误 我收到的错误是: Exception in thread "main" java.lang.Error: Unresolved compilation problem: Unhandled exception type IOException at TowerofHanoiRecurs

我从用户那里接收一个输入文件和一个输出文件,并试图从main方法和towerOfHanoiMoves方法写入输出文件。我试图将输出变量作为参数传递给towerOfHanoiMoves方法,但始终出现错误

我收到的错误是:

 Exception in thread "main" java.lang.Error: Unresolved compilation problem: Unhandled exception type IOException 
   at TowerofHanoiRecursive.towerOfHanoiMoves(TowerofHanoiRecursive.java:72)
   at TowerofHanoiRecursive.main(TowerofHanoiRecursive.java:41)
有没有一种方法可以让我从两个不同的方法写入同一个输出文件

我尝试过使用PrintWriter,但这给了我同样的东西。 我也尝试过用towerOfHanoiMoves方法冲洗和关闭外流,但也不起作用。我还导入了所有必要的java.io文件,但由于某些原因,它们没有显示在这里

public class TowerofHanoiRecursive{


  public static void main(String[] args) throws IOException, EmptyFile,                                      
          FileNotFoundException{
    int n; //number of disks

    String rodLeft = "A", rodRight = "C", rodMiddle = "B";
            FileReader inputStream = null;
            FileWriter outputStream = null;
            BufferedReader str = null;  

   try {
        outputStream = new FileWriter(args[1]); // output file
        inputStream = new FileReader(args[0]);  // input file
            str = new BufferedReader(inputStream);  
            String nextLine; 
            File newFile = new File(args[0]);

     if (newFile.length()==0) { //Tests if input file is empty
       //if file is empty, the EmptyFile exception will be thrown
       throw new EmptyFile("Input file is empty");

       }

     while ((nextLine = str.readLine()) != null) {
        outputStream.write("----------------------------------------"
                + "------------------------\n");
        outputStream.write("Number of Disks in Starting Tower = " 
                + nextLine);
         n = Integer.parseInt(nextLine);

         towerOfHanoiMoves(n, rodLeft, rodRight, rodMiddle, 
              outputStream);

     }

   }catch (FileNotFoundException e) {
        outputStream.write("Input file not found.);
        outputStream.flush(); 
        if (outputStream != null) outputStream.close();

   }catch (EmptyFile e) {                               
        outputStream.write(e.getMessage());
        outputStream.flush();   
        if (inputStream != null) inputStream.close();
        if (outputStream != null) outputStream.close();
        str.close();
   } finally { 
        outputStream.write("");
        outputStream.write("\n\nSuccess!);
        outputStream.flush();

        if (inputStream != null) inputStream.close();
        if (outputStream != null) outputStream.close();
        str.close();
    }

}


  public static void towerOfHanoiMoves(int n, String leftRod, String 
            rightRod, String MidRod, FileWriter outStream) {

    if (n == 1) {
       outStream.write("Move disk 1 from ....");
    }
  }
}

具体的错误是
write()
方法可能引发
IOException
。因此,必须捕获或声明该异常。因此,可以修改
towerOfHannoiMoves
来抛出
IOException

    public static void towerOfHanoiMoves(int n,
        String leftRod,
        String rightRod,
        String MidRod,
        FileWriter outStream)
     throws IOException
另一个注意事项:发布的代码缺少一些右引号。例如:

outputStream.write("Input file not found.);

你愿意分享一下错误吗?因为您完全可以将Streams/FileWriter/etc传递到一旁:在发生一个异常的情况下,您关闭
outputStream
,然后尝试写入
finally
块中现在关闭的流。这种方法可能有问题。嗨,Kevin,这是我一直得到的错误:线程“main”java.lang中的异常。错误:未解决的编译问题:TowerofHanoiRecursive.towerOfHanoiMoves(TowerofHanoiRecursive.java:72)处TowerofHanoiRecursive.main(TowerofHanoiRecursive.java:41)的未处理异常类型IOException@kevino错误也发生在towerOfHanoiMoves方法中,这就是问题所在!非常感谢你!很高兴这有帮助。如果你能考虑接受这个答复,我将不胜感激。