java - 如何在 Java 中的 try catch 中获取异常？

Question

所以我正在编写一个程序，我想要一个异常(exception)，这样程序就不会崩溃。
如果用户输入的字符串不在 else if 语句 中，则不会崩溃。

此外，我尝试对整数执行此操作，因此如果有人尝试编写非整数的内容，它不会崩溃。程序会捕获它并指出它不是整数。

如何在 java 中的 try catch 中获取异常。

感谢您的帮助

代码如下:

import java.util.InputMismatchException;
import java.util.Scanner; 


public class WeightOnADifferentPlanet { 
public static void main ( String[] args ){   
 Scanner scan = new Scanner ( System.in ); 


System.out.println("Where do you want to travel:?");
try{
     String planetName = scan.nextLine(); 
 }
 catch(/*need help here*/){
     System.out.println("Please check your spelling");
 }



 System.out.println("Please enter your weight:"); 
 try{
     int weight = scan.nextInt(); 
 }
 catch(InputMismatchException e)
 {
    System.out.println("That is not an integer"); 
 }
 double earthCalculation = weight * 1.0; 
 double jupiterCalculation = weight * (21.0 / 8.0); //check
 double marsCalculation = weight * (3.0 / 8.0); 
 double mercuryCalculation = weight * (3.0 / 10.0); 
 double neptuneCalculation = weight * (11.0 / 10.0); //check 
 double plutoCalculation = weight * (7.0 / 10.0); 
 double saturnCalculation = weight * (6.0 / 5.0); //check
 double uranusCalculation = weight * (9.0 / 10.0); 
 double venusCalculation = weight * (7.0 / 8.0);


 if (planetName.equalsIgnoreCase("Earth")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+earthCalculation+" pounds."); 
 }
 else if (planetName.equalsIgnoreCase("Jupiter"))
 {
   System.out.println("Your weight on "+planetName+" is: "+jupiterCalculation+" pounds."); 
 }
 else if (planetName.equalsIgnoreCase("Mars")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+marsCalculation+" pounds."); 
 }
 else if (planetName.equalsIgnoreCase("Mercury")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+mercuryCalculation+" pounds."); 
 } 
 else if (planetName.equalsIgnoreCase("Neptune")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+neptuneCalculation+" pounds."); 
 }
 else if (planetName.equalsIgnoreCase("Pluto")) 
 {
    System.out.println("Your weight on "+planetName+" is: "+plutoCalculation+" pounds."); 
 }
 else if (planetName.equalsIgnoreCase("Saturn")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+saturnCalculation+" pounds."); 
 }
  else if (planetName.equalsIgnoreCase("Uranus")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+uranusCalculation+" pounds."); 
 } 
   else if (planetName.equalsIgnoreCase("Venus")) 
 {
   System.out.println("Your weight on "+planetName+" is: "+venusCalculation+" pounds."); 

 }


     }
   }    
}

Answer 1

我相信 scan.nextInt(); 无论如何都只会扫描整数，因此不需要捕获非整数