badidea.java

来自「基于netbeans的java桌面应用程序合集」· Java 代码 · 共 42 行

package com.sun.tiger.generic;

import java.util.ArrayList;
import java.util.List;

public class BadIdea {
    
    private static List<Integer> ints = new ArrayList<Integer>();
    
    public static void fillList(List<Integer> list) {
        for (Integer i : list) {
            ints.add(i);
        }
    }
    
    public static void printList() {
        for (Integer i : ints) {
            System.out.println(i);
        }
    }
    
    public static void main(String[] args) {
        List<Integer> myInts = new ArrayList<Integer>();
        myInts.add(1);
        myInts.add(2);
        myInts.add(3);
        
        System.out.println("Filling list and printing in normal way...");
        fillList(myInts);
        printList();
        
        try {
            List list = (List)BadIdea.class.getDeclaredField("ints").get(null);
            list.add("Illegal Value!");
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        System.out.println("Printing with illegal values in list...");
        printList();
    }
}