如何調試try和catch塊？

-4

我想知道是否有人能夠幫助我在Java中使用這兩個調試任務，涉及try/catch/throw語句。我似乎無法弄清楚如何調試在NetBeans Zip文件中工作的任務。如何調試try和catch塊？

所有或任何幫助表示讚賞。謝謝。

作業1：

package debugmeone; 

import java.io.File; 
import java.io.FileNotFoundException; 
import java.util.Scanner; 
/* 
* This file requires debugging. This is a partial file to read a text file 
* with simple error checking. If the file is not found (you are testing this) 
* a FileNotFoundException should be thrown. The second catch statement is 
* producing an error (red stop sign). Why? Your job is to have both 
* Exception and FileNotFoundException in this file. Do not remove either one 
* of them. Don't create the file accountrecords.txt; you are testing for 
* a file not found condition so there is no need to create the file. 
* 
* The output should be: 
* 
* run: 
* Error - File Not Found: accountrecords.txt 
* Java Result: 100 
* BUILD SUCCESSFUL (total time: 0 seconds) 
*/ 

public class ReadTextFile { 

    private Scanner input; // Ignore the hint given by NetBeans 

    public void openFile() { 
     try 
     { 
      input = new Scanner(new File("accountrecords.txt")); 
     } 
     catch(Exception e) 
     { 
      System.out.println("Something bad just happened here."); 
      System.exit(707); 
     } 
     // Debug this line; what should you do to solve this error message? 
     // Carefully read the error message provided by the IDE 
     catch(FileNotFoundException fnfe) 
     { 
      System.out.println("Error - File Not Found: accountrecords.txt"); 
      System.exit(100); 
     } 
    } 
}

作業2：

package debugmetwo; 

/* 
* You will need to debug this file. 
* 
* The output should be: 
* 
* run: 
* There is a problem with the Eagle! 
* Java Result: 9999 
* BUILD SUCCESSFUL (total time: 0 seconds) 
*/ 
public class ThrowEagleExceptionTest { 

    public static void main(String[] args) { 
     try { 
     EagleLanding(); 
     } catch (EagleLandingException badEagle) { 
      System.out.printf("%s\n", badEagle.getMessage()); 
      System.exit(9999); 
     } 
    } 

    private static void EagleLanding { 
     EagleLandingException("There is a problem with the Eagle!"); 
    } 
}

來源

2016-11-05 Hayden Weinger

恩，你有什麼具體問題嗎？你有什麼嘗試？您遇到什麼問題？建議：1）找到一個Netbeans調試器教程（如[this]（http://www.cs.columbia.edu/~cmurphy/summer2008/1007/netbeans/7_debugging.html）），2）在調試器中打開你的代碼，3）在'main（）'中設置一個斷點，4）在調試器中跟蹤你的代碼。 5）跟蹤「成功」和「錯誤」代碼路徑。 – paulsm4

您的文章沒有描述您有什麼問題... –

在您的ReadTextFile類中，openFile方法永遠不會進入FileNotFoundException catch塊。 –

你有一個編譯時錯誤信息，而不是一個運行一個這是一個調試器是什麼。要閱讀的消息是

// Debug this line; what should you do to solve this error message? 
    // Carefully read the error message provided by the IDE 
    catch(FileNotFoundException fnfe)

您需要閱讀IDE中提供的錯誤消息並對其進行修復。提示：最具體的例外必須先來。

你的第二個例子也不會編譯。你需要通過拋出異常來編譯它。如果你不知道如何做，請看一個例子。

來源

2016-11-05 19:39:20

如何調試try和catch塊？

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