Error: cannot find symbol - Java compile error

Question

我已经研究了一段时间了，我确信修复就在我面前，但我只是视而不见。有人关心指出为什么我的 int i 给我一个错误？

缓存下载器class:

  public static void main(String[] args) {
    String strFilePath = "./version.txt";
    try
    {
      FileInputStream fin = new FileInputStream(strFilePath);
     DataInputStream din = new DataInputStream(fin);
     int i = din.readInt();
       System.out.println("int : " + i);
       din.close();
    }
    catch(FileNotFoundException fe)
    {
      System.out.println("FileNotFoundException : " + fe);
    }
    catch(IOException ioe)
    {
      System.out.println("IOException : " + ioe);
    }
  }

    private final int VERSION = i;

错误：

CacheDownloader.java:54: error: cannot find symbol
        private final int VERSION = i;
                                    ^
  symbol:   variable i
  location: class CacheDownloader

Answer 1

i 在main 中声明，private final int VERSION 在main 之外。将其移入 main 或将 i 声明为全局变量。

static int i=0;
public static void main(String[] args) {
    String strFilePath = "./version.txt";
    try
    {
      FileInputStream fin = new FileInputStream(strFilePath);
      DataInputStream din = new DataInputStream(fin);
      i = din.readInt();
      System.out.println("int : " + i);
      din.close();
    }
    catch(FileNotFoundException fe)
    {
       System.out.println("FileNotFoundException : " + fe);
    }
    catch(IOException ioe)
    {
       System.out.println("IOException : " + ioe);
    }
}
private final int VERSION = i;

Answer 2

您必须在 try-catch 块之前声明您的 int i。此外，您必须在 main 方法中声明常量：

  public static void main(String[] args) {
    String strFilePath = "./version.txt";
    int i;
    try
    {
      FileInputStream fin = new FileInputStream(strFilePath);
      DataInputStream din = new DataInputStream(fin);
      i = din.readInt();
      System.out.println("int : " + i);
      din.close();
    }
    catch(FileNotFoundException fe)
    {
      System.out.println("FileNotFoundException : " + fe);
    }
    catch(IOException ioe)
    {
      System.out.println("IOException : " + ioe);
    }
    final int VERSION = i; 
  }

Error: cannot find symbol - Java compile error

Error: cannot find symbol - Java compile error

java

int

symbols