如何在Java中的自定义异常中添加条件？
在构造函数或任何方法中从用户读取值时，可以使用if条件验证这些值。
示例
在下面的Java示例中，我们定义了两个自定义异常类，用于验证名称和年龄。
import java.util.Scanner;
class NotProperAgeException extends Throwable{
NotProperAgeException(String msg){
super(msg);
}
}
class NotProperNameException extends Throwable{
NotProperNameException(String msg){
super(msg);
}
}
public class CustomException{
private String name;
private int age;
public static boolean containsAlphabet(String name) {
for (int i = 0; i < name.length(); i++) {
char ch = name.charAt(i);
if (!(ch >= 'a' && ch <= 'z')) {
return false;
}
}
return true;
}
public CustomException(String name, int age){
try {
if (age<0||age>125) {
String msg = "Improper age (not between 0 to 125)";
NotProperAgeException exAge = new NotProperAgeException(msg);
throw exAge;
}else if(!containsAlphabet(name)&&name!=null) {
String msg = "Improper name (Should contain only characters between a to z (all small))";
NotProperNameException exName = new NotProperNameException(msg);
throw exName;
}
}catch(NotProperAgeException e) {
e.printStackTrace();
}catch(NotProperNameException e) {
e.printStackTrace();
}
this.name = name;
this.age = age;
}
public void display(){
System.out.println("Name of the Student: "+this.name );
System.out.println("Age of the Student: "+this.age );
}
public static void main(String args[]) {
Scanner sc= new Scanner(System.in);
System.out.println("Enter the name of the person: ");
String name = sc.next();
System.out.println("Enter the age of the person: ");
int age = sc.nextInt();
CustomException obj = new CustomException(name, age);
obj.display();
}
}输出结果
Enter the name of the person: Krishna Enter the age of the person: 136 Name of the Student: Krishna Age of the Student: 136 july_set3.NotProperAgeException: Improper age (not between 0 to 125) at july_set3.CustomException.<init>(CustomException.java:31) at july_set3.CustomException.main(CustomException.java:56) Output2: Enter the name of the person: !23Krishna Enter the age of the person: 24 Name of the Student: !23Krishna july_set3.NotProperNameException: Improper name (Should contain only characters between a to z (all small)) Age of the Student: 24 at july_set3.CustomException<init>(CustomException.java:35) at july_set3.CustomException.main(CustomException.java:56)