java 经典例题-j2se阶段各个知识点例题

import java.io.*; class AgeException extends Exception { int age; AgeException(String message) { super(message); } AgeException() { super(); } } class OutOfAgeLimitException extends AgeException { int ageLimit; OutOfAgeLimitException( int ageLimit,String message) { super(message); this.ageLimit = ageLimit; } OutOfAgeLimitException(String message) { super(message); } } class TooYoungException extends OutOfAgeLimitException { TooYoungException(int age, int ageLimit, String message) { super(ageLimit, "Your are too Young to " + message + "."); this.age = age; } TooYoungException() { super("Too young"); } } class TooOldException extends OutOfAgeLimitException { TooOldException(int age, int ageLimit, String message) { super(ageLimit, "You are too old to " +message + "."); this.age = age; } TooOldException () { super("too Old"); } } class IllegalAgeFormatException extends AgeException { IllegalAgeFormatException(String message) { super(message); } IllegalAgeFormatException() { super("Illegal age format"); } } class NegativeAgeException extends IllegalAgeFormatException { NegativeAgeException(String message) { super(message); } NegativeAgeException(int age) { super("Age must be nonnegative."); this.age = age; } } public class AgeExceptionTest { static PrintWriter out = new PrintWriter(System.out, true); static void rideRollerCoasterAtAge(int age) throws NegativeAgeException,OutOfAgeLimitException { out.println("Try to ride a roller coaster at age" + age + " ..."); if(age < 0) { throw new NegativeAgeException(age); }else if(age < 5) { throw new TooYoungException(age,5,"ride a roller coaster"); }else if(age > 45) { throw new TooOldException(age, 45, "ride a rooler coaster"); } out.println("Riding the roller coaster......"); } public static void main(String[] args) { int[] ages = {-3, 2, 10,35,65}; for( int i = 0; i < ages.length; i++) { try { rideRollerCoasterAtAge(ages[i]); out.println("Wow! what.an experience!"); }catch(OutOfAgeLimitException e) { if(ages[i] < e.ageLimit) { out.println((e.ageLimit - ages[i]) + "more years and you'll be able to try it."); } else { out.println((ages[i] - e.ageLimit) + "years ago riding it was like a piece of cake."); } }catch(NegativeAgeException e) { out.println(e.getMessage()); }finally { out.println(); } } } }