I have a piece of JAVA code that is accessed by multiple threads.
synchronized (this.getClass())
{
System.out.println("stsrt");
certRequest.setRequestNbr(
generateRequestNumber(
certInsuranceRequestAddRq.getAccountInfo().getAccountNumberId()));
System.out.println("outside funcvtion"+certRequest.getRequestNbr());
reqId = Utils.getUniqueId();
certRequest.setRequestId(reqId);
System.out.println(reqId);
ItemIdInfo itemIdInfo = new ItemIdInfo();
itemIdInfo.setInsurerId(certRequest.getRequestId());
certRequest.setItemIdInfo(itemIdInfo);
dao.insert(certRequest);
addAccountRel();
System.out.println("end");
}
the function generateRequestNumber() generates a request number based on the data fetched from two database tables.
public String generateRequestNumber(String accNumber) throws Exception
{
String requestNumber = null;
if (accNumber != null)
{
String SQL_QUERY = "select CERTREQUEST.requestNbr from CertRequest as CERTREQUEST, "
+ "CertActObjRel as certActObjRel where certActObjRel.certificateObjkeyId=CERTREQUEST.requestId "
+ " and certActObjRel.certObjTypeCd=:certObjTypeCd "
+ " and certActObjRel.certAccountId=:accNumber ";
String[] parameterNames = { "certObjTypeCd", "accNumber" };
Object[] parameterVaues = new Object[]
{
Constants.REQUEST_RELATION_CODE, accNumber
};
List<?> resultSet = dao.executeNamedQuery(SQL_QUERY,
parameterNames, parameterVaues);
// List<?> resultSet = dao.retrieveTableData(SQL_QUERY);
if (resultSet != null && resultSet.size() > 0) {
requestNumber = (String) resultSet.get(0);
}
int maxRequestNumber = -1;
if (requestNumber != null && requestNumber.length() > 0) {
maxRequestNumber = maxValue(resultSet.toArray());
requestNumber = Integer.toString(maxRequestNumber + 1);
} else {
requestNumber = Integer.toString(1);
}
System.out.println("inside function request number"+requestNumber);
return requestNumber;
}
return null;
}
The tables CertRequest and CertActObjRel used in generateRequestNumber() are updated by the functions "dao.insert(certRequest);" and "addAccountRel();" used in my initial code respectively. Also the System.out.println() statements used in my initial code have following output.
stsrt
inside function request number73
outside funcvtion73
A1664886-5F84-45A9-AB5F-C69768B83EAD
end
stsrt
inside function request number73
outside funcvtion73
44DAD872-6A1D-4524-8A32-15741FAC0CA9
end
If you notice both the threads run in a synchronized manner, but when the request number is generated , it's the same. My assumption is the database updation for CertRequest and CertActObjRel is done when both the threads finish their execution.
Could anyone help me to fix this?
Related
I am working with JPA, my web application is taking 60 sec to execute this method, I want to execute it faster how to achive ?
public boolean evaluateStudentTestPaper (long testPostID, long studentID, long howManyTimeWroteExam) {
Gson uday = new Gson();
Logger custLogger = Logger.getLogger("StudentDao.java");
// custLogger.info("evaluateTestPaper test paper for testPostID: " +
// testPostID);
long subjectID = 0;
// checking in table
EntityManagerFactory EMF = EntityManagerFactoryProvider.get();
EntityManager em = EMF.createEntityManager();
List<StudentExamResponse> studentExamResponses = null;
try {
studentExamResponses = em
.createQuery(
"SELECT o FROM StudentExamResponse o where o.studentId=:studentId And o.testPostID=:testPostID and o.howManyTimeWroteExam=:howManyTimeWroteExam")
.setParameter("studentId", studentID).setParameter("testPostID", testPostID)
.setParameter("howManyTimeWroteExam", howManyTimeWroteExam).getResultList();
System.out.println("studentExamResponses--------------------------------------------------"
+ uday.toJson(studentExamResponses) + "---------------------------------------");
} catch (Exception e) {
custLogger.info("exception at getting student details:" + e.toString());
studentExamResponses = null;
}
int studentExamResponseSize = studentExamResponses.size();
if (AppConstants.SHOWLOGS.equalsIgnoreCase("true")) {
custLogger.info("student questions list:" + studentExamResponseSize);
}
// Get all questions based on student id and test post id
List<ExamPaperRequest> examPaperRequestList = new ArrayList<ExamPaperRequest>();
List<Questions> questionsList = new ArrayList<Questions>();
// StudentExamResponse [] studentExamResponsesArgs =
// (StudentExamResponse[]) studentExamResponses.toArray();
// custLogger.info("Total questions to be evaluated: " +
// examPaperRequestList.size());
List<StudentTestResults> studentTestResultsList = new ArrayList<StudentTestResults>();
StudentTestResults studentTestResults = null;
StudentResults studentResults = null;
String subjectnames = "", subjectMarks = "";
int count = 0;
boolean lastIndex = false;
if (studentExamResponses != null && studentExamResponseSize > 0) {
// studentExamResponses.forEach(studentExamResponses->{
for (StudentExamResponse o : studentExamResponses.stream().parallel()) {
// 900 lines of coade inside which includes getting data from database Queries
}
}
As #Nikos Paraskevopoulos mentioned, it should probably be the ~900 * N database iterations inside that for loop.
I'd say to avoid DB iterations as much as you can, specially inside a loop like that.
You can try to elaborate your current StudentExamResponse sql to englobe more clauses - those you're using inside your for mainly, which could even diminish the amount of items you iterate upon.
My guess would be your select query is taking time.
If possible, set query timeout to less than 60 seconds & confirm this.
Ways of setting query timeout can be found out there - How to set the timeout period on a JPA EntityManager query
If this is because of query, then you may need to work to make select query optimal.
I want to wait until my processes finish before I return my speechlet response, otherwise it seems to cut my process off and thus, not complete it, I actually believe it may freeze the process, but thats not my desire.
How do I go about waiting?
#Override
public SpeechletResponse onIntent(SpeechletRequestEnvelope<IntentRequest> requestEnvelope) {
IntentRequest request = requestEnvelope.getRequest();
Intent intent = request.getIntent();
String intentName = (intent != null) ? intent.getName() : null;
if (intentName == null) return null;
switch (intentName) {
case IntentTitle.NEW_TICKET:
switch (request.getDialogState()) {
case STARTED:
return Response.getDialogueResponse(intent, true);
case IN_PROGRESS:
return Response.getDialogueResponse(intent, false);
case COMPLETED:
String numberString = intent.getSlot(SlotTitle.ID).getValue();
if (!NumberUtils.isCreatable(numberString)) return Response.ERROR;
Member member = Info.GUILD.getMemberById(numberString);
User sender = UserDB.getUser(member);
CommissionTicket commissionTicket = new CommissionTicket(sender);
commissionTicket.create();
//wait until processes finish before continuing
return Response.NEW_TICKED_CREATED;
}
}
return null;
}
UPDATE:
Had a look at the CloudWatch logs, and well, pretty much what I expected was happening is happening... have a look at the times for these logs (I ran them 3 different times, so 3 different times are logged, but apart of the same lambda session)
public void create() {
System.out.println("log2");
GuildController guildController = Info.GUILD.getController();
guildController.createTextChannel(ticketType.name().toLowerCase() + "-" + creator.getName() + "-" + id.value()).queue(channel -> {
System.out.println("log3");
ChannelManager channelManager = channel.getManager();
GuildManager guildManager = channelManager.getGuild().getManager();
List<Member> members = guildManager.getGuild().getMembers();
List<Member> admins = new ArrayList<>();
for (Member member : members) {
for (Role role : member.getRoles()) {
if (!role.getName().equalsIgnoreCase(Info.ADMIN_STRING)) continue;
admins.add(member);
}
}
System.out.println("log4");
for (Member member : members) {
if (member.equals(creator.getMember())) continue;
channel.createPermissionOverride(member).setDeny(Permission.MESSAGE_READ).queue();
}
System.out.println("log5");
for (Member admin : admins) {
if (admin.equals(creator.getMember())) continue;
channel.createPermissionOverride(admin).setAllow(Permission.MESSAGE_READ).queue();
}
System.out.println("log6");
BotMessage botMessage = new BotMessage();
botMessage
.setTitle("New Ticket! User: " + creator.getName())
.setColour(Color.CYAN)
.setDescription("Please enter your full request here! \n" +
"Make sure to let us know whether you are looking for a quote/timeframe,\n" +
"or have a budget in mind, and we will work around you!\n\n" +
"A sales representative will be with you as soon as possible!")
.send((TextChannel) channel);
System.out.println("log7");
this.textChannel = (TextChannel) channel;
TicketDB.addTicket(this);
System.out.println("log8");
}
);
Logs:
https://gyazo.com/0ad2baa8d1438be8364dd1112159c4f4
https://gyazo.com/e197f33335046afe3c9f8f1ace267d30
UPDATE
Implemented the Future class, worked, but still a bit buggy.
It now completely creates the ticket, which is great, however, when I go to send the same call again, it for some reason sends a message in the same channel before preceding to create the next ticket.
So, to simulate...
Function call through AWS Lambda
Creates ticket completely
Function call through AWS Lambda again
Sends a message or two in the previous tickets channel
Creates new ticket completely
https://gyazo.com/dc6e4391f4964f41a73f1c3be92190f9
#Override
public SpeechletResponse onIntent(SpeechletRequestEnvelope<IntentRequest> requestEnvelope) {
IntentRequest request = requestEnvelope.getRequest();
Intent intent = request.getIntent();
String intentName = (intent != null) ? intent.getName() : null;
if (intentName == null) return null;
switch (intentName) {
case IntentTitle.NEW_TICKET:
switch (request.getDialogState()) {
case STARTED:
return Response.getDialogueResponse(intent, true);
case IN_PROGRESS:
return Response.getDialogueResponse(intent, false);
case COMPLETED:
String numberString = intent.getSlot(SlotTitle.ID).getValue();
if (!NumberUtils.isCreatable(numberString)) return Response.ERROR;
Member member = Info.GUILD.getMemberById(numberString);
User sender = UserDB.getUser(member);
System.out.println("log1");
Future<Ticket> commissionTicket = new CommissionTicket(sender).create();
try {
commissionTicket.get(10000, TimeUnit.MILLISECONDS);
} catch (Exception e) {
e.printStackTrace();
}
//wait until processes finish before continuing
return Response.NEW_TICKED_CREATED;
}
}
return null;
}
In the Ticket class:
public Future<Ticket> create() {
System.out.println("log2");
GuildController guildController = Info.GUILD.getController();
RequestFuture<Channel> channelRequestFuture = guildController.createTextChannel(ticketType.name().toLowerCase() + "-" + creator.getName() + "-" + id.value()).submit();
try {
Channel channel = channelRequestFuture.get(10000, TimeUnit.MILLISECONDS);
System.out.println("log3");
ChannelManager channelManager = channel.getManager();
GuildManager guildManager = channelManager.getGuild().getManager();
List<Member> members = guildManager.getGuild().getMembers();
List<Member> admins = new ArrayList<>();
for (Member member : members) {
for (Role role : member.getRoles()) {
if (!role.getName().equalsIgnoreCase(Info.ADMIN_STRING)) continue;
admins.add(member);
}
}
System.out.println("log4");
for (Member member : members) {
if (member.equals(creator.getMember())) continue;
channel.createPermissionOverride(member).setDeny(Permission.MESSAGE_READ).queue();
}
System.out.println("log5");
for (Member admin : admins) {
if (admin.equals(creator.getMember())) continue;
channel.createPermissionOverride(admin).setAllow(Permission.MESSAGE_READ).queue();
}
System.out.println("log6");
BotMessage botMessage = new BotMessage();
botMessage
.setTitle("New Ticket! User: " + creator.getName())
.setColour(Color.CYAN)
.setDescription("Please enter your full request here! \n" +
"Make sure to let us know whether you are looking for a quote/timeframe,\n" +
"or have a budget in mind, and we will work around you!\n\n" +
"A sales representative will be with you as soon as possible!")
.send((TextChannel) channel);
System.out.println("log7");
this.textChannel = (TextChannel) channel;
TicketDB.addTicket(this);
System.out.println("log8");
Future<Ticket> future = ConcurrentUtils.constantFuture(this);
return future;
} catch (Exception e) {
e.printStackTrace();
}
if (!userIsInTicket(creator)) users.add(creator);
return null;
}
I'm not sure what's going on inside commissionTicket.create(); (I assume it's your code, not part of some library, and that it's running asynchronously somehow), but one solution would be to have that method return a Future<> object and then wait on it to finish. Something along the lines of:
Future<CommissionTicket> commissionTicketFuture = CommissionTicket.create(sender);
commissionTicketFuture.get(SOME_TIMEOUT, TimeUnit.MILLIS);
return Response.NEW_TICKET_CREATED;
I am working on a school assignment that required us to use SQL statements in Java code as well as use the LIKE operator for a search. In order to properly search I have to get a string from the user, and split the string by any delimiter, and then run the query like so:
SELECT * FROM movies WHERE (movies.title LIKE '%userInput%');
I then return this query in the form of an ArrayList.
Now, when I was testing it out. I originally tested it with no user input, and my query became: SELECT * FROM movies WHERE (movies.title LIKE '%%');. This gave me the correct results.
However when I put a title in there, all of the sudden I get a NullPointerException on this line:
if(title.equals("")) { return "(movies.title LIKE '%%') "; from this section of my code:
public String getSearchString(String title) {
if(title.equals("")) { return "(movies.title LIKE '%%') "; }
String ret = "(";
ArrayList<String> titleArray = Util.splitSearch(title);
for(int i = 0; i < titleArray.size() - 1; ++i) {
String temp = titleArray.get(i);
String stmt = "movies.title LIKE '%" + temp + "%' OR ";
ret += stmt;
}
String temp = "movies.title LIKE '%" + titleArray.get(titleArray.size() - 1) + "%')";
ret += temp;
return ret;
}
This is then called like so:
public List<Movie> listMovies(String title) throws SQLException {
List<Movie> search = new ArrayList<Movie>();
if(null != title && title.isEmpty()) { title = ""; }
ResultSet res = queryMovies(getSearchString(title));
while(res.next()) {
Movie mov = new Movie();
mov.setTitle(res.getString("title"));
search.add(mov);
}
return search;
}
private static queryMovies(String st) throws SQLException {
ResultSet res = null;
try {
PreparedStatement ps = dbcon.prepareStatement(st);
res = ps.executeQuery();
} catch(SQLException e) {
e.printStackTrace();
}
return res;
}
I unfortunately have to do this since I won't know how much a user will enter. And I am also not allowed to use external libraries that make the formatting easier. For reference my Util.splitSearch(...) method looks like this. It should be retrieving anything that is a alphanumeric character and should be splitting on anything that is not alphanumeric:
public static ArrayList<String> splitSearch(String str) {
String[] strArray = str.split("[^a-zA-Z0-9']");
return new ArrayList(Arrays.asList(strArray));
}
What is interesting is when I pass in getSearchString(""); explicitly, I do not get a NullPointerException. It is only when I allows the variable title to be used do I get one. And I still get one when no string is entered.
Am I splitting the String wrong? Am I somehow giving SQL the wrong statement? Any help would be appreciated, as I am very new to this.
the "title" which is passed from input is null, hence you're getting nullpointerexception when you do title.equals("").
Best practices suggest you do a null check like (null != title && title.equals("")).
You can also do "".equals(title)
I am getting too many deadlocks on OrientDb while I am using Java API to query the vertices. After the deadlock happens, the entire database becomes unresponsive and I have to kill the daemon and start again. As example, the error that I get from deadlocks is :
com.orientechnologies.common.concur.OTimeoutException: Can not lock record for 2000 ms. seems record is deadlocked by other record
at com.orientechnologies.orient.core.storage.impl.local.OAbstractPaginatedStorage.acquireReadLock(OAbstractPaginatedStorage.java:1300)
at com.orientechnologies.orient.core.tx.OTransactionAbstract.lockRecord(OTransactionAbstract.java:120)
at com.orientechnologies.orient.core.id.ORecordId.lock(ORecordId.java:282)
at com.orientechnologies.orient.core.storage.impl.local.OAbstractPaginatedStorage.lockRecord(OAbstractPaginatedStorage.java:1776)
at com.orientechnologies.orient.core.storage.impl.local.OAbstractPaginatedStorage.readRecord(OAbstractPaginatedStorage.java:1416)
at com.orientechnologies.orient.core.storage.impl.local.OAbstractPaginatedStorage.readRecord(OAbstractPaginatedStorage.java:694)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.executeReadRecord(ODatabaseDocumentTx.java:1569)
at com.orientechnologies.orient.core.tx.OTransactionNoTx.loadRecord(OTransactionNoTx.java:80)
at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.load(ODatabaseDocumentTx.java:1434)
at com.orientechnologies.orient.server.network.protocol.binary.ONetworkProtocolBinary.readRecord(ONetworkProtocolBinary.java:1456)
at com.orientechnologies.orient.server.network.protocol.binary.ONetworkProtocolBinary.executeRequest(ONetworkProtocolBinary.java:346)
at com.orientechnologies.orient.server.network.protocol.binary.OBinaryNetworkProtocolAbstract.execute(OBinaryNetworkProtocolAbstract.java:216)
at com.orientechnologies.common.thread.OSoftThread.run(OSoftThread.java:65)
Following is the block that I use to query edges and create associations between vertices
public User generateFriend(String mobile, String userRID) {
StringBuilder errorMsg = new StringBuilder();
Iterable<OrientVertex> vertexes;
//Retrieve friends of the user
List<User> friendsList = new ArrayList<User>();
vertexes = db.queryVertices("select expand( unionAll(inE('E_Friend').out,outE('E_Friend').in) ) from " + userRID,errorMsg);
if (!errorMsg.toString().equals("")) {
throw new DbException("Db exception occured, " + errorMsg);
}
for (OrientVertex v : vertexes){
friendsList.add(vertexToUser(v));
}
//Create edges if between the user and other users with mobile number in the list and if the edge is not yet created
User u = findUserByMobileNo(friendsList,mobile);
if ( u == null){
u = findByMobileNo(mobile);
if (u != null) {
//create edge
db.executeQuery("select createEdge('E_Friend','" + userRID + "','" + u.getRid() + "') from " + userRID, new HashMap<String, Object>(), errorMsg);
if (!errorMsg.toString().equals("")) {
throw new DbException("Db exception occured, " + errorMsg);
}
}
}
return u;
}
public Iterable<OrientVertex> queryVertices(String query, StringBuilder errMsg){
logger.error("before getGraph, " + errMsg.toString());
graph = getGraph(errMsg);
if (!errMsg.toString().equals("")){
return null;
}
logger.error("after getGraph, " + errMsg.toString());
Iterable<OrientVertex> vertices = null;
try {
OSQLSynchQuery<OrientVertex> qr = new OSQLSynchQuery<OrientVertex>(query);
vertices = graph.command(qr).execute();
logger.error("after graph command execute, " + errMsg.toString());
}
catch (Exception ex){
errMsg.append(ex.getMessage());
logger.error("graph command exception, " + errMsg.toString());
}
logger.error("before return vertices, " + errMsg.toString());
return vertices;
}
public List<ODocument> executeQuery(String sql, HashMap<String,Object> params,StringBuilder errMsg) {
List<ODocument> result = new ArrayList<ODocument>();
try {
db = getDatabase(errMsg);
if (!errMsg.toString().equals("")){
return null;
}
OSQLSynchQuery<ODocument> query = new OSQLSynchQuery<ODocument>(sql);
if (params.isEmpty()) {
result = db.command(query).execute();
} else {
result = db.command(query).execute(params);
}
} catch (Exception e) {
errMsg.append(e.getMessage());
//TODO: Add threaded error log saving mechanism
}
return result;
}
Due to index missing on table deadlock come, so check your all table which are involved in this operation and find out that indexes are present or not on column.
Refer link in which I have a same problem of deadlock.
I'm trying to debug a method in Java using NetBeans.
That method is:
public Integer getNumberOfClamps(Locations paLocation) {
Integer ret = -1;
List list = new ArrayList();
String removeme = "ABC";
if (paLocation == null) {
return ret;
}
try {
IO io = new IO(this.getSchemaName());
Session session = io.getSession();
String sql = "select count(*) from assets a join assettypes at on (at.id = a.assettype_id) ";
sql += "where a.currentlocation_id = " + paLocation.getId() + " and at.clamp = 1 and at.active = 1;";
list = session.createQuery(sql).list();
// for some reason, list is empty yet MySQL reports 40 records
// and the following two lines are never reached!
ret = list.size();
removeme = "WHAT???";
} catch (Exception ex) {
ret = -1; // explicitly set return
} finally {
return ret;
}
}
Towards the middle of the method you will see list = session.createQuery(sql).list();
For some reason, this is returning an empty list even though when the SQL is run manually, I get 40 results.
But the odd part is that once the .list() is called, it jumps to the finally block and never reaches the rest! So for testing, 'removeme' should equal WHAT??? but the debugger reports it as still ABC.
What gives?
You are using the wrong method. 'createQuery' is expecting HQL syntax. Change your method to 'createSQLQuery'