如何正确使用Java中的“throws clause”？

我还是新手编程，我知道我下面的代码可能是一团糟，但是，如何正确使用“throws子句”？我应该使用它作为一个任务（添加一个throws子句的主要方法头），但当我尝试运行它，如何正确使用Java中的“throws clause”？

我得到的错误：线程“主”java.lang.Error异常：未解决的编译问题：此表达式的目标类型必须是功能性接口对标记“抛出”的语法错误，请删除此标记。

我在做什么错？我也应该使用三位小数格式打印输出文件的平均值和标准偏差，但是我不明白怎么去做。

import java.util.Random; 
import java.util.Scanner; 
import java.io.*; 

public class DiceSimulation { 
    public static void main(String[] args) { 
     final int NUMBER = 10000; // the number of times to roll the dice 

     Random generator = new Random(); 
     File myFile = new File("Results"); 
     Scanner inputFile = new Scanner(myFile); 
     PrintWriter outputFile = new PrintWriter("Results")throws::IOException; 
     outputFile.println("FileChooser.txt"); 
     outputFile.println("Filereader.txt"); 
     outputFile.println("FileWriter.txt"); 
     outputFile.close(); 
     Scanner keyboard = new Scanner(System.in); 

     int die1Value; // number of spots on the first die 
     int die2Value; // number of spots on the second die 
     int count = 0; // number of times the dice were rolled 
     int snakeEyes = 0; // number of times snake eyes is rolled 
     int twos = 0; // number of times double two is rolled 
     int threes = 0; // number of times double three is rolled 
     int fours = 0; // number of times double four is rolled 
     int fives = 0; // number of times double five is rolled 
     int sixes = 0; // number of times double six is rolled 

     do { 
      new Random(); 
      System.out.println("You rolled: "); 
      die1Value = keyboard.nextInt(); 

      new Random(); 
      System.out.println("You rolled: "); 
      die2Value = keyboard.nextInt(); 

     } while (count <= 0); 

     if (die1Value == 1) 
      ; 
     { 
      ++snakeEyes; 
     } 
     if (die1Value == 2) 
      ; 
     { 
      ++twos; 
     } 
     if (die1Value == 3) 
      ; 
     { 
      ++threes; 
     } 
     if (die1Value == 4) 
      ; 
     { 
      ++fours; 
     } 
     if (die1Value == 5) 
      ; 
     { 
      ++fives; 
     } 
     if (die1Value == 6) 
      ; 
     { 
      ++sixes; 
     } 
     ++count; 
     { 

      System.out.println("You rolled snake eyes " + snakeEyes 
        + " out of " + count + " rolls."); 
      System.out.println("You rolled double twos " + twos + " out of " 
        + count + " rolls."); 
      System.out.println("You rolled double threes " + threes 
        + " out of " + count + " rolls."); 
      System.out.println("You rolled double fours " + fours + " out of " 
        + count + " rolls."); 
      System.out.println("You rolled double fives " + fives + " out of " 
        + count + " rolls."); 
      System.out.println("You rolled double sixes " + sixes + " out of " 
        + count + " rolls."); 
     } 
    } 
}

我真的很感谢帮助，提前谢谢！

来源

2014-10-12 Joseph Shire

你觉得_add一个抛出子句的主要方法header_意味着什么？你有没有看过“抛出”条款是什么？ – 2014-10-12 02:55:02

请在问题结尾处删除道歉。它们不相关。 – 2014-10-12 02:55:37

看完你的评论后，我才明白...我感到如此密集的大声笑。谢谢你！ – 2014-10-12 02:56:50

试试这个：

PrintWriter outputFile = new PrintWriter("Results");

您不必声明构造函数（或与此有关的任何其他方法）调用构造函数（或方法）时抛出异常。我们在方法声明中使用throws关键字，而不是在实际调用它时使用。固定在此之后，Java将抱怨抛出一个异常，您可以：

声明，main()方法throws IOException

或环绕违规行以try/catch声明

来源

2014-10-12 02:57:37

更改您的第一个行到：

public static void main(String[] args) throws IOException {

来源

2014-10-12 02:59:09

如何正确使用Java中的“throws clause”？

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