このjava.lang.NumberFormatExceptionはどのように解決されますか？

Question

下記のコードを参照してください

私はeclipseから受信しているエラーをどのように解決しますか？

package finalExam; 

//this is required for JOptionPane to work 
import javax.swing.JOptionPane; 

//this allows for exception throwing 
import java.io.*; 

public class Geometry { 

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

boolean valid = false; 

int menuChoice; 

do { 
     // create a menu and display it to the user 
     // then ask the user to choose an option 
     String menu = "1) Calculate the area of a circle\n" 
        + "2) Calculate the area of a rectangle\n" 
        + "3) Calculate the area of a triangle\n" 
        + "4) Quit\n" 
        + "Please enter your choice: (1, 2, 3, or 4)"; 

     JOptionPane.showInputDialog(menu); 
     menuChoice = Integer.parseInt(menu); 

     if(menuChoice == 1) 
     { 
      String unknownRadius = JOptionPane.showInputDialog("What is the radius of the circle?"); 
      double knownRadius = Double.parseDouble(unknownRadius); 
      double circleArea = Math.pow(knownRadius, 2) * 3.14159; 
      JOptionPane.showMessageDialog(null, "The area of the circle is " + circleArea); 
      valid = true; 

     } else if(menuChoice == 2){ 
      String unknownLength = JOptionPane.showInputDialog("What is the length of the rectangle?"); 
      double knownLength = Double.parseDouble(unknownLength); 
      String unknownWidth = JOptionPane.showInputDialog("What is the width of the rectangle?"); 
      double knownWidth = Double.parseDouble(unknownWidth); 
      double rectangleArea = knownLength * knownWidth; 
      JOptionPane.showMessageDialog(null, "The area of the rectangle is " + rectangleArea); 
      valid = true; 

     } else if(menuChoice == 3){ 
      String unknownBase = JOptionPane.showInputDialog("What is the base length of the triangle?"); 
      double knownBase = Double.parseDouble(unknownBase); 
      String unknownHeight = JOptionPane.showInputDialog("What is the height of the triangle?"); 
      double knownHeight = Double.parseDouble(unknownHeight); 
      double triangleArea = (knownBase/2) * knownHeight; 
      JOptionPane.showMessageDialog(null, "The area of the triangle is " + triangleArea); 
      valid = true; 

     }else if(menuChoice == 4){ 
      System.exit(0); 

     }else if(menuChoice > 0) 
      JOptionPane.showMessageDialog(null, "Please enter positive numbers only!"); 
} 

while(!valid || menuChoice != 4); 

} 
} 

これは誤りである：私はあなたがやろうとしているものと信じて

Exception in thread "main" java.lang.NumberFormatException: For input string: "1) Calculate the area of a circle 
2) Calculate the area of a rectangle 
3) Calculate the area of a triangle 
4) Quit 
Please enter your choice: (1, 2, 3, or 4)" 
    at java.lang.NumberFormatException.forInputString(Unknown Source) 
    at java.lang.Integer.parseInt(Unknown Source) 
    at java.lang.Integer.parseInt(Unknown Source) 
    at finalExam.Geometry.main(Geometry.java:25) 

Answer 1

はこれです：あなたはもともとあなたから整数を解析しようとしているやっていた

// create a menu and display it to the user 
// then ask the user to choose an option 
String menu = "1) Calculate the area of a circle\n" 
    + "2) Calculate the area of a rectangle\n" 
    + "3) Calculate the area of a triangle\n" 
    + "4) Quit\n" 
    + "Please enter your choice: (1, 2, 3, or 4)"; 
/*JOptionPane#showInputDialog returns a string of the input, so that is what you want to parse*/ 
/*also you may want to add a try catch to prevent crashes, should the user not input a valid integer*/ 
menuChoice = Integer.parseInt(JOptionPane.showInputDialog(menu)); 

if(menuChoice == 1) 
{ 

何メニューテキスト[1]領域を計算してください]

Answer 2

文字列でオプションの応答をキャプチャしていない場合：

String choice = JOptionPane.showInputDialog(menu); 
    menuChoice = Integer.parseInt(choice); 

か、直接それを解析：あなたは整数として `menu`を解析しようとしている

menuChoice = Integer.parseInt(JOptionPane.showInputDialog(menu));