异常在线程 “主” java.lang.IllegalArgumentException异常

Question

这是我的错误信息

Exception in thread "main" java.lang.IllegalArgumentException 
    at TestGrades.setRaceTime(TestGrade.java:49) 
    at GradeDriver.getGradeData(GradeDriver.java:40) 
    at Grade Driver.main(GradeDriver.java:26) 

Java的类：

import java.util.*; 
import java.io.*; 

public class GradeDriver{ 
public static void main(String[] args){ 
    double[] averageInfo = new double[3]; 

    Scanner console = new Scanner(System.in); 

    String[] fileName = new String[2]; 

    for(int i = 0; i < args.length; i++){ 
     fileName[i] = args[i]; 
    } 

    Scanner input = getInputFile(console, fileName); 
    PrintStream output = getOutputFile(console, fileName); 

    TestGrades[] grades = getGradeData(input); 
    showGradeInfo(output, grades); 
    getAverageInfo(averageInfo, grades); 
    showAverageInfo(output, averageInfo, grades[0]); 

} 

public static TestGrades[] getGradeData(Scanner input) { 
    int numberOfGrades = input.nextInt(); 
    TestGrades[] grades = new TestGrades[numberOfGrades]; 

    for(int driver = 0; driver < numberOfGrades && input.hasNext(); driver++) { 
     grades[driver] = new TestGrades(input.next(), input.next()); 
     for (int grade = 1; grade <= 4; grade++) { 
      grades[driver].setRaceTime(grade , input.nextDouble()); 
     } 
    } 
    return grades; 
} 

public static void showGradeInfo (PrintStream output, TestGrades[] grades) { 
    for (int i = 0; i < grades.length; i++) { 
     output.print((i + 1) + ". " + grades[i] + "\n"); 
    } 
} 

public static void getAverageInfo (double[] info, TestGrades[] grades) { 
    double low = 20.0; 
    double high = 0.0; 
    double average = 0.0; 
    double totalAverage = 0.0; 
    for (int i = 0; i < grades.length; i++) { 
     average = grades[i].getGradeAverage(); 
     if (average > high) { 
      high = average; 
     } 
     if (average < low) { 
      low = average; 
     } 
     totalAverage = totalAverage + average; 
    } 
    info[0] = low; 
    info[1] = high; 
    info[2] = totalAverage/grades[0].getCounter(); 
} 

public static void showAverageInfo(PrintStream o, double[] info, TestGrades d) { 
    String[] s = {"Total number of students: "}; 

    o.printf("\n%d. %s %d\n", 1, s[0], d.getCounter()); 
    for (int i = 1; i <info.length; i++) { 
     o.printf("%d. %s %.2f/n", i + i, s[i], info[i - 1]); 
    } 
} 
public static Scanner getInputFile(Scanner console, String[] inFileName) { 
    boolean fileFound = false; 
    Scanner s = null; 
    if (inFileName[0] == null) { 
     System.out.print("Please enter the input file name: "); 
     inFileName[0] = console.nextLine(); 
    } 

    do { 
     try { 
      s = new Scanner(new File(inFileName[0])); 
      fileFound = true; 
     } 

     catch (FileNotFoundException e) { 
      System.out.println("Cannot read file: " + e) ; 
      System.out.println("Enter the correct input file name: "); 
      inFileName[0] = console.nextLine(); 
     } 
    } 
    while (!fileFound); 
     return s; 
    } 

public static PrintStream getOutputFile (Scanner console, String[] outFileName) { 
    boolean fileFound = false; 
    PrintStream pS = null; 
    if (outFileName[1] == null) { 
     System.out.print("Please enter output file name: "); 
     outFileName[1] = console.nextLine(); 
    } 
    do { 
     try { 
      pS = new PrintStream (new File (outFileName[1])); 
      fileFound = true; 
     } 
     catch (FileNotFoundException e2) { 

      System.out.println("Cannot read file: " + e2); 
      System.out.println("Enter a correct output file name: "); 
      outFileName[1] = console.nextLine(); 
     } 
    } 
    while(!fileFound); 
     return pS; 
    } 
} 





import java.io.*; 
import java.util.*; 

public class TestGrades { 
private static int gradeCount = 0; 
private String firstName; 
private String lastName; 
private double[] raceTime = new double[4]; 

public TestGrades(String fName, String lName) { 
    firstName = fName; 
    lastName = lName; 
    gradeCount++; 
} 

private String getFirstName() { 
    return firstName; 

} 

private String getLastName() { 
    return lastName; 

} 

public double getGradeAverage() { 
    double highest = 0.0; 
    double sum = 0.0; 
    for (int i = 0; i < raceTime.length; i++) { 
     sum += raceTime[i]; 
     if (raceTime[i] > highest) { 
      highest = raceTime[i]; 
     } 
    } 
    sum = sum - highest; 
    sum = sum/3; 
    return sum; 
} 

public void setRaceTime(int grade, double time) { 
    if (grade < 1 || grade > 4 || time < 0.0 || time > 15.0) { 
     throw new IllegalArgumentException(); 
    } 
    raceTime[grade - 1 ] = time; 
} 

public int getCounter() { 
    return gradeCount; 
} 

public String toString() { 
    return (firstName + " " + lastName); 
} 
} 

任何帮助将真正理解！

Answer 1

你是你自己抛出异常......

if (grade < 1 || grade > 4 || time < 0.0 || time > 15.0) { 
    throw new IllegalArgumentException(); 
} 

Answer 2

看起来你自己扔IllegalArgumentException。

if (grade < 1 || grade > 4 || time < 0.0 || time > 15.0) { 
    throw new IllegalArgumentException(); 
} 

但是您没有提供消息作为构造函数的参数。你应该提供的消息显示时会更有意义，例如：

throw new IllegalArgumentException("grade (" + grade + ") or time (" + time + 
    ") outside of legal range."); 

您可能正在你的射程之外进入time值。