定义
原型模式主要解决的问题就是创建复对象，⽽这部分 对象 内容本身⽐较复杂，⽣成过程可能从库或者RPC接⼝中获取数据的耗时较⻓，因此采⽤克隆的⽅式节省时间。
上机考试抽题
从⼀部分可以上机考试的内容开始，在保证⼤家的公平性⼀样的题⽬下，开始出现试题混排更有做的好的答案选项也混排。这样⼤⼤的增加了抄的成本，也更好的做到了考试的公平性。因为需要实现⼀个上机考试抽题的服务，因此在这⾥建造⼀个题库题⽬的场景类信息，⽤于创建； 选择题 、 问答题 。
选择题
public class ChoiceQuestion {
private String name; // 题⽬
private Map<String, String> option; // 选项；A、B、C、D
private String key; // 答案；B
public ChoiceQuestion() {}
public ChoiceQuestion(String name, Map<String, String> option, String key) {
this.name = name;
this.option = option;
this.key = key;
}
// ...get/set
}问答题
public class AnswerQuestion {
private String name; // 问题
private String key; // 答案
public AnswerQuestion() {}
public AnswerQuestion(String name, String key) {
this.name = name;
this.key = key;
}
// ...get/set
}代码实现
题⽬选项乱序操作⼯具包
/**
* 乱序Map元素，记录对应答案key
* @param option 题⽬
* @param key 答案
* @return Topic 乱序后 {A=c., B=d., C=a., D=b.}
*/
static public Topic random(Map<String, String> option, String key) {
Set<String> keySet = option.keySet();
ArrayList<String> keyList = new ArrayList<String>(keySet);
Collections.shuffle(keyList);
HashMap<String, String> optionNew = new HashMap<String, String>();
int idx = 0;
String keyNew = "";
for (String next : keySet) {
String randomKey = keyList.get(idx++);
if (key.equals(next)) {
keyNew = randomKey;
}
optionNew.put(randomKey, option.get(next));
}
return new Topic(optionNew, keyNew);
}克隆对象处理类
public class QuestionBank implements Cloneable {
private String candidate; // 考⽣
private String number; // 考号
private ArrayList<ChoiceQuestion> choiceQuestionList = new ArrayList<ChoiceQuestion>();
private ArrayList<AnswerQuestion> answerQuestionList = new ArrayList<AnswerQuestion>();
public QuestionBank append(ChoiceQuestion choiceQuestion) {
choiceQuestionList.add(choiceQuestion);
return this;
}
public QuestionBank append(AnswerQuestion answerQuestion) {
answerQuestionList.add(answerQuestion);
return this;
}
@Override
public Object clone() throws CloneNotSupportedException {
QuestionBank questionBank = (QuestionBank) super.clone();
questionBank.choiceQuestionList = (ArrayList<ChoiceQuestion>) choiceQuestionList.clone();
questionBank.answerQuestionList = (ArrayList<AnswerQuestion>) answerQuestionList.clone();
// 题⽬乱序
Collections.shuffle(questionBank.choiceQuestionList);
Collections.shuffle(questionBank.answerQuestionList);
// 答案乱序
ArrayList<ChoiceQuestion> choiceQuestionList = questionBank.choiceQuestionList;
for (ChoiceQuestion question : choiceQuestionList) {
Topic random = TopicRandomUtil.random(question.getOption(), question.getKey());
question.setOption(random.getOption());
question.setKey(random.getKey());
}
return questionBank;
}
public void setCandidate(String candidate) {
this.candidate = candidate;
}
public void setNumber(String number) {
this.number = number;
}
@Override
public String toString() {
StringBuilder detail = new StringBuilder("考⽣：" + candidate + "\r\n" +
"考号：" + number + "\r\n" +
"--------------------------------------------\r\n" +
"⼀、选择题" + "\r\n\n");
for (int idx = 0; idx < choiceQuestionList.size(); idx++) {
detail.append("第").append(idx + 1).append("题：").append(choiceQuestionList.get(idx).getName()).append("\r\n");
Map<String, String> option = choiceQuestionList.get(idx).getOption();
for (String key : option.keySet()) {
detail.append(key).append("：").append(option.get(key)).append("\r\n");
}
detail.append("答案：").append(choiceQuestionList.get(idx).getKey()).append("\r\n\n");
}
detail.append("⼆、问答题" + "\r\n\n");
for (int idx = 0; idx < answerQuestionList.size(); idx++) {
detail.append("第").append(idx + 1).append("题：").append(answerQuestionList.get(idx).getName()).append("\r\n");
detail.append("答案：").append(answerQuestionList.get(idx).getKey()).append("\r\n\n");
}
return detail.toString();
}
}初始化试卷数据
public class QuestionBankController {
private QuestionBank questionBank = new QuestionBank();
public QuestionBankController() {
Map<String, String> map01 = new HashMap<String, String>();
map01.put("A", "JAVA2 EE");
map01.put("B", "JAVA2 Card");
map01.put("C", "JAVA2 ME");
map01.put("D", "JAVA2 HE");
map01.put("E", "JAVA2 SE");
Map<String, String> map02 = new HashMap<String, String>();
map02.put("A", "JAVA程序的main⽅法必须写在类⾥⾯");
map02.put("B", "JAVA程序中可以有多个main⽅法");
map02.put("C", "JAVA程序中类名必须与⽂件名⼀样");
map02.put("D", "JAVA程序的main⽅法中如果只有⼀条语句，可以不⽤{}(⼤括号)括起来");
Map<String, String> map03 = new HashMap<String, String>();
map03.put("A", "变量由字⺟、下划线、数字、$符号随意组成；");
map03.put("B", "变量不能以数字作为开头；");
map03.put("C", "A和a在java中是同⼀个变量；");
map03.put("D", "不同类型的变量，可以起相同的名字；");
Map<String, String> map04 = new HashMap<String, String>();
map04.put("A", "STRING");
map04.put("B", "x3x;");
map04.put("C", "void");
map04.put("D", "de$f");
Map<String, String> map05 = new HashMap<String, String>();
map05.put("A", "31");
map05.put("B", "0");
map05.put("C", "1");
map05.put("D", "2");
questionBank.append(new ChoiceQuestion("JAVA所定义的版本中不包括", map01, "D"))
.append(new ChoiceQuestion("下列说法正确的是", map02, "A"))
.append(new ChoiceQuestion("变量命名规范说法正确的是", map03, "B"))
.append(new ChoiceQuestion("以下()不是合法的标识符",map04, "C"))
.append(new ChoiceQuestion("表达式(11+3*8)/4%3的值是", map05, "D"))
.append(new AnswerQuestion("⼩红⻢和⼩⿊⻢⽣的⼩⻢⼏条腿", "4条腿"))
.append(new AnswerQuestion("铁棒打头疼还是⽊棒打头疼", "头最疼"))
.append(new AnswerQuestion("什么床不能睡觉", "⽛床"))
.append(new AnswerQuestion("为什么好⻢不吃回头草", "后⾯的草没了"));
}
public String createPaper(String candidate, String number) throws CloneNotSupportedException {
QuestionBank questionBankClone = (QuestionBank) questionBank.clone();
questionBankClone.setCandidate(candidate);
questionBankClone.setNumber(number);
return questionBankClone.toString();
}
}测试验证
@Test
public void test_QuestionBank() throws CloneNotSupportedException {
QuestionBankController questionBankController = new QuestionBankController();
System.out.println(questionBankController.createPaper("花花", "1000001921032"));
System.out.println(questionBankController.createPaper("⾖⾖", "1000001921051"));
System.out.println(questionBankController.createPaper("⼤宝", "1000001921987"));
}