Question

我现在已经看了一段时间了，我确信这个解决方案正好在我面前，但我只是对它视而不见。有人想指出为什么我的int给我一个错误？

CacheDownloader类：

  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

您必须在i块之前声明您的int try-catch。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; 
  }

Answer 2

我在main，private final int中声明了VERSION在main之外。将其移到main中或将i声明为全局。

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;

错误：找不到符号--Java编译错误

2 个答案: