嘗試捕捉本地化變量

Question

運行下面的代碼時出現編譯錯誤。在try-catch塊之後的if語句中，編譯器無法「解析爲變量」。不過，我已經初始化了這些變量。任何幫助將非常感激。

public void Load(UniversityListing uListing, StudentBody sBody) { 

    try { 
     FileInputStream fIn1= new FileInputStream(filename1); 
     BufferedReader bufferedReader1 = new BufferedReader(new InputStreamReader(fIn1)); 
     existence1 = true; 

    }catch(FileNotFoundException ex){ 
     System.out.println("Unable to open file '" + filename1 +"'"); 
     existence1 = false; 
    }catch(IOException ex){ 
     System.out.println("Error reading file '" + filename1+ "'"); 
     existence1 = false; 
    } 


    if (existence1 == true){ 
     LoadUListing(uListing, bufferedReader1,fIn1); 
    } 
} 

Answer 1

當你在聲明和初始化FIN1和bufferedReader1 try塊內，他們將無法訪問外嘗試。

嘗試改變如下：

public void Load(UniversityListing uListing, StudentBody sBody) { 
    BufferedReader bufferedReader1 = null; 
    FileInputStream fIn1 = null; 
    try { 
     fIn1 = new FileInputStream(filename1); 
     bufferedReader1 = new BufferedReader(new InputStreamReader(fIn1)); 
     existence1 = true; 

    } catch (FileNotFoundException ex) { 
     System.out.println("Unable to open file '" + filename1 + "'"); 
     existence1 = false; 
    } catch (IOException ex) { 
     System.out.println("Error reading file '" + filename1 + "'"); 
     existence1 = false; 
    } 


    if (existence1 == true) { 
     LoadUListing(uListing, bufferedReader1, fIn1); 
    } 
}