我已经HashTable<String,Object>
使用ObjectOutputStream
. 序列化对象时,我没有得到任何异常,但是在反序列化时,会发生以下异常:
Exception in thread "main" java.io.InvalidClassException: java.lang.Long; local class
incompatible: stream classdesc serialVersionUID = 4290774032661291999, local class
serialVersionUID = 4290774380558885855
HashTable
当我删除 中的所有键值不是 a时,我不再收到错误消息(我删除的所有String
键/值对都有一个原始类型作为它们的值)。
什么可能导致此错误?
更新 - 这是代码
public static String serialize(Quiz quiz) throws IOException{
HashMap<String,Object> quizData = new HashMap<String,Object>();
quizData.put("version", 0); //int
quizData.put("name", quiz.getName()); //String
quizData.put("desc", quiz.getDesc()); //String
quizData.put("timelimitType", quiz.getTimelimitType()); //String
quizData.put("timelimit", quiz.getTimelimit()); //long
ArrayList<String> serializedQuestionsData = new ArrayList<String>();
for (Question question : quiz.getQuestions())
serializedQuestionsData.add(Question.serialize(question));
quizData.put("questions", serializedQuestionsData.toArray(new String[0])); //String[]
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos;
try { oos = new ObjectOutputStream(baos); } catch (IOException error){ throw error; }
try { oos.writeObject(quizData); } catch (IOException error){ throw error; }
return baos.toString();
}
@SuppressWarnings("unchecked")
public static Quiz deserialize(String serializedQuizData) throws IOException, ClassNotFoundException{
ByteArrayInputStream bais = new ByteArrayInputStream(serializedQuizData.getBytes());
ObjectInputStream ois;
try { ois = new ObjectInputStream(bais); } catch (IOException error){ throw error; }
HashMap<String,Object> quizData;
// Exception occurs on the following line!!
try { quizData = (HashMap<String,Object>) ois.readObject(); } catch (ClassNotFoundException error){ throw error; }
Quiz quiz;
if ((int) quizData.get("version") == 0){
quiz = new Quiz((String) quizData.get("name"),
(String) quizData.get("desc"),
(String) quizData.get("timelimitType"),
(long) quizData.get("timelimit"));
for (String serializedQuestionData : (String[]) quizData.get("questions"))
quiz.addQuestion(Question.deserialize(serializedQuestionData));
} else {
throw new UnsupportedOperationException("Unsupported version: \"" + quizData.get("version") + "\"");
}
return quiz;
}