Hi all,
I am relatively new to the spring world, and have been thrust into maintaining
a java application which appears to use Spring 2.0.6 with iBATIS 2.3. My
problem is that while debugging what turned out to be a SQL syntax error, I
found what appears to be a transaction failure. I fixed the SQL issue, but the
transaction failure worries me, and any insight on what I'm doing wrong would
be much appreciated.
Here is the relevant code:
[CODE] transactionTemplate.execute(new TransactionCallback()
{
// the code in this method executes in a transactional context
public Object doInTransaction(TransactionStatus status) {
int rowsChangedTotal = 0;
int rowsChanged = 0;
Iterator<Question> qIterator = qn.iterator();
String userID = null;
// For each question, get the user instance
either from answer, tag, or comment
// and delete answer,comments, and tags for
that user
if(qn != null && !qn.isEmpty()) {
for (Question q:qn) {
Map<String, String> defaultMap
= new HashMap<String, String>();
defaultMap.put(ENG_ID_CONSTANT,
engagementID);
Question qntemp = q;
userID =
doStoreLogicForUserID(qntemp);
defaultMap.put(USER_ID_CONSTANT, userID);
rowsChanged =
getSqlMapClientTemplate().delete("deleteTagResponsesFromEngagement",
defaultMap);
rowsChanged =
getSqlMapClientTemplate().delete("deleteComments", defaultMap);
rowsChanged =
getSqlMapClientTemplate().delete("deleteCommentResponsesFromEngagement",
defaultMap);
rowsChanged =
getSqlMapClientTemplate().delete("deleteAnswerResponsesFromEngagement",
defaultMap);
rowsChanged = rowsChangedTotal;
}
}
//now store the new data
while (qIterator.hasNext()) {
Question question = qIterator.next();
// Setting the collections of answers,
comments, and tags for this question
List<Tag> tagList = question.getTags();
Comment comment = question.getComment();
List<Answer> answerList =
question.getAnswers();
processTagsForStoreQuestions(tagList,
engagementID, question);
processCommentsAndAnswersForStoreQuestion(comment, engagementID, answerList,
question);
}
// update engagement state
setState(engagementID, STORED);
return null;
}
});[/CODE]
A simple explanation of the code's function is that data is first deleted from
the DB (MySQL 5.0), and then re-written with the most current data. The
problem I observed is that the 3rd delete statement failed (did not delete any
lines when it should have, due to the SQL error), however did not result in a
data access exception because the SQL simply returned 0 lines modified.
However, one of the data updates called later on by the
processCommentsAndAnswersForStoreQuestion() method Did fail, throwing the
following error:
[CODE]
--- The error occurred in
edu/cmu/sei/smart/zen/common/core/dao/internal/Server.xml.
--- The error occurred while applying a parameter map.
--- Check the insertCommentInServerDB-InlineParameterMap.
--- Check the statement (update failed).
--- Cause:
com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Duplicate
entry 'e030f0b2-2a4b-4bf0-bc3b-9b6a89a20d50' for key 1).
[/CODE]
The problem I have is that the transaction is not rolled back. All data access
calls up until the point of the exception are committed to the DB, and that is
clearly not what I want.
Now again, I am no expert at this, but the research I've done indicates that
when you put business logic within the doInTransaction() method of a
TransactionCallback object, it's supposed to provide transaction support (i.e.
either all data access calls are made or none are). It's my understanding that
if a RuntimeException is called within the doInTransaction() method, the
transaction state is set to rollback only, resulting in the rollback that I
want.
So, I did a bit more research and confirmed that the exception I'm getting is
in fact Not a RuntimeException, which would explain why the TransactionCallback
object is not rolling back the results up to the point of the exception. So
what I did was to encapsulate the entirety of the code within the
doInTransaction() method in a try/catch block that caught Any exception, and if
that occurs, set the status to rollback only. I even created a savepoint at
the start of the transaction and, if an exception is caught, rolled back to the
savepoint. However, it still doesn't work! The resulting code is here:
[CODE]
transactionTemplate.execute(new TransactionCallback()
{
// the code in this method executes in a transactional context
public Object doInTransaction(TransactionStatus status) {
Object savepoint = status.createSavepoint();
try{
int rowsChangedTotal = 0;
int rowsChanged = 0;
Iterator<Question> qIterator =
qn.iterator();
String userID = null;
if(qn != null && !qn.isEmpty()) {
for (Question q:qn) {
Map<String, String>
defaultMap = new HashMap<String, String>();
defaultMap.put(ENG_ID_CONSTANT, engagementID);
Question qntemp = q;
userID =
doStoreLogicForUserID(qntemp);
defaultMap.put(USER_ID_CONSTANT, userID);
rowsChanged =
getSqlMapClientTemplate().delete("deleteTagResponsesFromEngagement",
defaultMap);
rowsChanged =
getSqlMapClientTemplate().delete("deleteComments", defaultMap);
rowsChanged =
getSqlMapClientTemplate().delete("deleteCommentResponsesFromEngagement",
defaultMap);
rowsChanged =
getSqlMapClientTemplate().delete("deleteAnswerResponsesFromEngagement",
defaultMap);
}
}
//now store the new data
while (qIterator.hasNext())
{
Question question =
qIterator.next();
// Setting the collections of
answers, comments, and tags for this question
List<Tag> tagList =
question.getTags();
Comment comment =
question.getComment();
List<Answer> answerList =
question.getAnswers();
processTagsForStoreQuestions(tagList, engagementID, question);
processCommentsAndAnswersForStoreQuestion(comment, engagementID, answerList,
question);
}
// update engagement state
setState(engagementID, STORED);
}
catch(Exception e){
System.out.println("Caught exception
within storeQuestionsForEngagement(): " + e.getClass().toString());
e.printStackTrace();
// Set transaction status to rollback
status.rollbackToSavepoint(savepoint);
status.setRollbackOnly();
}
status.releaseSavepoint(savepoint);
return null;
}
});
[/CODE]
I have verified when running my test that the exception is in fact caught, thus
the savepoint rollback should happen and the status should be set to rollback
only; however, I still find that all data access calls up to the point of the
exception are committed, resulting in corrupted data. Any help in terms of why
the rollbacks are not happening would be greatly appreciated. Thanks!
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