badidea.java

来自「非常实用的Java Tiger源代码程序例程」· Java 代码 · 共 42 行

package com.oreilly.tiger.ch02;

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();
  }
}