How to wait until processes finish Java AWS Lambda - java

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;

Related

Akka references increasing constantly with Play Framework

I have changed all my multi-thread actions in my application to Akka a few weeks ago.
However, since it seems that I am starting to run out of Heap space (after a week or so).
By basically looking at all actors with
ActorSelection selection = getContext().actorSelection("/*");
the number of actors seems to increase all the time. After an hour of running I have more then 2200. They are called like:
akka://application/user/$Aic
akka://application/user/$Alb
akka://application/user/$Alc
akka://application/user/$Am
akka://application/user/$Amb
I also noticed that when opening websockets (and closing them) there are these:
akka://application/system/Materializers/StreamSupervisor-2/flow-21-0-unnamed
akka://application/system/Materializers/StreamSupervisor-2/flow-2-0-unnamed
akka://application/system/Materializers/StreamSupervisor-2/flow-27-0-unnamed
akka://application/system/Materializers/StreamSupervisor-2/flow-23-0-unnamed
Is there something specific that I need to do to close them and let them be cleaned?
I am not sure the memory issue is related, but the fact that there seem so many after an hour on the production server it could be.
[EDIT: added the code to analyse/count the actors]
public class RetrieveActors extends AbstractActor {
private String identifyId;
private List<String> list;
public RetrieveActors(String identifyId) {
Logger.debug("Actor retriever identity: " + identifyId);
this.identifyId = identifyId;
}
#Override
public Receive createReceive() {
Logger.info("RetrieveActors");
return receiveBuilder()
.match(String.class, request -> {
//Logger.info("Message: " + request + " " + new Date());
if(request.equalsIgnoreCase("run")) {
list = new ArrayList<>();
ActorSelection selection = getContext().actorSelection("/*");
selection.tell(new Identify(identifyId), getSelf());
//ask(selection, new Identify(identifyId), 1000).thenApply(response -> (Object) response).toCompletableFuture().get();
} else if(request.equalsIgnoreCase("result")) {
//Logger.debug("Run list: " + list + " " + new Date());
sender().tell(list, self());
} else {
sender().tell("Wrong command: " + request, self());
}
}).match(ActorIdentity.class, identity -> {
if (identity.correlationId().equals(identifyId)) {
ActorRef ref = identity.getActorRef().orElse(null);
if (ref != null) { // to avoid NullPointerExceptions
// Log or store the identity of the actor who replied
//Logger.info("The actor " + ref.path().toString() + " exists and has replied!");
list.add(ref.path().toString());
// We want to discover all children of the received actor (recursive traversal)
ActorSelection selection = getContext().actorSelection(ref.path().toString() + "/*");
selection.tell(new Identify(identifyId), getSelf());
}
}
sender().tell(list.toString(), self());
}).build();
}
}

I cant able to query the queue element using queuequery in PE filenet

I am facing an issue when i try to query the queue using createquery api to fetch the queue element.
I am getting an error at the while statement stating the error below as
errorjava.lang.illegalstateexception :unread block data
i dont know why i am getting this error. I can able to use the fetchcount() api to get the count of workitem in the queue but the hasnext() api is not working nor next().
Is there any reason why this statement is not getting executed. is this related to any java issue. Can any one help
The code is
VWSession session = new VWSession();
session.setBootstrapCEURI(Ceuri);
session.logon(cename, fnPassword, connectionPoint);
VWQueue queue = session.getQueue(queue));
int queryFlag = VWQueue.QUERY_NO_OPTIONS;
int fetchType = VWFetchType.FETCH_TYPE_STEP_ELEMENT;
VWQueueQuery queueQuery = queue.createQuery(null,null, null,queryFlag, null, null, fetchType);
while (queueQuery.hasNext()) {
queueElement = (VWStepElement) queueQuery.next();
}
In you main (calling) method, do this :
VWSession vwsession = new VWSession();
vwsession.setBootstrapCEURI("http://servername:9080/wsi/FNCEWS40MTOM/");
vwsession.logon("userid", "password", "ConnPTName");
IteratePEWorkItems queueTest = new IteratePEWorkItems();
queueTest.testQueueElements(vwsession);
Later on create below metioned helper method:
public void testQueueElements(VWSession vwsession) {
System.out.println("Inside getListOfWorkitems: : ");
VWRoster roster = vwsession.getRoster("DefaultRoster");
int fetchType = VWFetchType.FETCH_TYPE_STEP_ELEMENT;
int queryFlags = VWQueue.QUERY_READ_UNWRITABLE;
try {
dispatchWorkItems(roster, fetchType, queryFlags, vwsession);
} catch (Exception exception) {
log.error(exception.getMessage());
}
}
public void dispatchWorkItems(VWRoster roster, int fetchType, int queryFlags, VWSession vwsession) {
String filter = "SLA_Date>=:A";
// get value and replace with 1234567890 as shown in process administrator
Object[] subVars = { 1234567890 };
VWRosterQuery rosterQuery = roster.createQuery(null, null, null,
VWRoster.QUERY_MIN_VALUES_INCLUSIVE | VWRoster.QUERY_MAX_VALUES_INCLUSIVE, filter, subVars,
VWFetchType.FETCH_TYPE_WORKOBJECT);
int i = 0;
// Iterate work items here...
while (rosterQuery.hasNext() == true) {
VWWorkObject workObject = (VWWorkObject) rosterQuery.next();
try {
i++;
System.out.println(" Subject: " + workObject.getFieldValue("F_Subject") + " Count: " + i);
} catch (Exception exception) {
exception.printStackTrace();
log.error(exception);
}
}
}
Try it and share the output.

How to get all the queues and topics from solace

I want to discover all the destinations from solace (queues and topics)
I tried using MBeanServerConnection and query after names (but I didn't find a proper way to use this) or JNDI lookups Destination dest = (Destination) context.lookup(Dest_name), but I don't have the names of the queues/topics.
I am using solace - jms library.
I am searching for smth like this: (but for solace, not activeMq)
get all Queue from activeMQ
You will need to make use of SEMP over the management interface for this.
Sample commands:
curl -d '<rpc><show><queue><name>*</name></queue></show></rpc>' -u semp_username:semp_password http://your_management_ip:your_management_port/SEMP
curl -d '<rpc><show><topic-endpoint><name>*</name></topic-endpoint></show></rpc>' -u semp_username:semp_password http://your_management_ip:your_management_port/SEMP
Note that I'm using curl for simplicity, but any application can perform HTTP POSTs to execute these commands.
If you are using Java, you can refer to the SempHttpSetRequest sample found within the Solace API samples.
Documentation on SEMP can be found here.
However, the larger question here is why do you need to discover all destinations?
One of the features of the message broker is to decouple the publishers and consumers.
If you need to know if your persistent message is being published to a topic with no consumers, you can make use of the reject-msg-to-sender-on-no-subscription-match setting in the publishing application's client-profile.
This means that the publisher will obtain a negative acknowledgement in the event that it tries to publish a message on a topic that has no matching subscribers.
You can refer to "Handling Guaranteed Messages with No Matches" at https://docs.solace.com/Configuring-and-Managing/Configuring-Client-Profiles.htm for further details.
Here is some source code that might help. With the appliance configured correctly, SEMP is also available over JMS on topic "#SEMP/(router)/SHOW".
/**
* Return the SolTopicInfo for this topic (or all topics if 'topic' is null).
*
* #param session
* #param endpointName
* #return
*/
public static SolTopicInfo[] getTopicInfo(JCSMPSession session, String endpointName, String vpn,
String sempVersion) {
XMLMessageConsumer cons = null;
XMLMessageProducer prod = null;
Map<String, SolTopicInfo> tiMap = new HashMap<String, SolTopicInfo>();
try {
// Create a producer and a consumer, and connect to appliance.
prod = session.getMessageProducer(new PubCallback());
cons = session.getMessageConsumer(new SubCallback());
cons.start();
if (vpn == null) vpn = (String) session.getProperty(JCSMPProperties.VPN_NAME);
if (sempVersion == null) sempVersion = getSempVersion(session);
// Extract the router name.
final String SEMP_SHOW_TE_TOPICS = "<rpc semp-version=\""
+ sempVersion
+ "\"><show><topic-endpoint><name>"
+ endpointName
+ "</name><vpn-name>"+ vpn + "</vpn-name></topic-endpoint></show></rpc>";
RpcReply teTopics = sendRequest(session, SEMP_SHOW_TE_TOPICS);
for (TopicEndpoint2 te : teTopics.getRpc().getShow().getTopicEndpoint().getTopicEndpoints()
.getTopicEndpointArray()) {
SolTopicInfo ti = new SolTopicInfo();
ti.setBindCount(te.getInfo().getBindCount());
//qi.setDescription(qt.getInfo().getNetworkTopic());
ti.setEndpoint(te.getName());
ti.setMessageVPN(te.getInfo().getMessageVpn());
ti.setTopic(te.getInfo().getDestination());
ti.setDurable(te.getInfo().getDurable());
ti.setInSelPres(te.getInfo().getIngressSelectorPresent());
ti.setHwmMB(formatter.format(te.getInfo().getHighWaterMarkInMb()));
ti.setSpoolUsageMB(formatter.format(te.getInfo().getCurrentSpoolUsageInMb()));
ti.setMessagesSpooled(te.getInfo().getNumMessagesSpooled().longValue());
String status = te.getInfo().getIngressConfigStatus().substring(0, 1).toUpperCase();
status += " " + te.getInfo().getEgressConfigStatus().substring(0, 1).toUpperCase();
status += " " + te.getInfo().getIngressSelectorPresent().substring(0, 1).toUpperCase();
status += " " + te.getInfo().getType().substring(0, 1).toUpperCase();
ti.setStatus(status);
tiMap.put(ti.getEndpoint(), ti);
}
} catch (JCSMPException e) {
throw new RuntimeException(e.getMessage(), e);
} finally {
if (cons != null)
cons.close();
if (prod != null)
prod.close();
}
return tiMap.values().toArray(new SolTopicInfo[0]);
}
/**
* Return the SolQueueInfo for this queue (or all queues if 'queue' is null).
*
* #param session
* #param queue
* #param vpn (if null, use the session's vpn name)
* #param sempVersion, if null use 'soltr/7_1_1'
* #return
*/
public static SolQueueInfo[] getQueueInfo(JCSMPSession session, String queue, String vpn,
String sempVersion) {
XMLMessageConsumer cons = null;
XMLMessageProducer prod = null;
Map<String, SolQueueInfo> qiMap = new HashMap<String, SolQueueInfo>();
try {
// Create a producer and a consumer, and connect to appliance.
prod = session.getMessageProducer(new PubCallback());
cons = session.getMessageConsumer(new SubCallback());
cons.start();
if (vpn == null) vpn = (String) session.getProperty(JCSMPProperties.VPN_NAME);
if (sempVersion == null) sempVersion = getSempVersion(session);
// Extract the router name.
final String SEMP_SHOW_QUEUE_SUBS = "<rpc semp-version=\""
+ sempVersion
+ "\"><show><queue><name>"
+ queue
+ "</name><vpn-name>"+ vpn + "</vpn-name><subscriptions/><count/><num-elements>200</num-elements></queue></show></rpc>";
RpcReply queueSubs = sendRequest(session, SEMP_SHOW_QUEUE_SUBS);
for (QueueType qt : queueSubs.getRpc().getShow().getQueue().getQueues().getQueueArray()) {
SolQueueInfo qi = new SolQueueInfo();
qi.setBindCount(qt.getInfo().getBindCount());
//qi.setDescription(qt.getInfo().getNetworkTopic());
qi.setName(qt.getName());
qi.setMessageVPN(qt.getInfo().getMessageVpn());
qi.setDurable(qt.getInfo().getDurable());
qi.setEgSelPres(qt.getInfo().getEgressSelectorPresent());
qi.setHwmMB(formatter.format(qt.getInfo().getHighWaterMarkInMb()));
qi.setMessagesSpooled(qt.getInfo().getNumMessagesSpooled().longValue());
qi.setSpoolUsageMB(formatter.format(qt.getInfo().getCurrentSpoolUsageInMb()));
String status = qt.getInfo().getIngressConfigStatus().substring(0, 1).toUpperCase();
status += " " + qt.getInfo().getEgressConfigStatus().substring(0, 1).toUpperCase();
status += " " + qt.getInfo().getAccessType().substring(0, 1).toUpperCase();
status += " " + qt.getInfo().getEgressSelectorPresent().substring(0, 1).toUpperCase();
status += " " + qt.getInfo().getType().substring(0, 1).toUpperCase();
status += qt.getInfo().getDurable() ? " D" : " N";
qi.setStatus(status);
for (Subscription sub : qt.getSubscriptions().getSubscriptionArray()) {
qi.addSubscription(sub.getTopic());
}
qiMap.put(qi.getName(), qi);
}
} catch (JCSMPException e) {
throw new RuntimeException(e.getMessage(), e);
} finally {
if (cons != null)
cons.close();
if (prod != null)
prod.close();
}
return qiMap.values().toArray(new SolQueueInfo[0]);
}
private static String getSempVersion(JCSMPSession session)
{
String retval = "soltr/7_1_1";
try {
String peerVersion = (String)session.getCapability(CapabilityType.PEER_SOFTWARE_VERSION);
if (peerVersion != null)
{
retval = "soltr/";
String[] version = peerVersion.split("\\.");
retval += version[0];
retval += "_" + version[1];
if (!version[2].equals("0")) retval += "_" + version[2];
}
} catch (Throwable e) {
System.err.println(e);
}
return retval;
}
private static RpcReply sendRequest(JCSMPSession session,
final String requestStr) {
try {
// Set up the requestor and request message.
String routerName = (String) session
.getCapability(CapabilityType.PEER_ROUTER_NAME);
final String SEMP_TOPIC_STRING = String.format("#SEMP/%s/SHOW",
routerName);
final Topic SEMP_TOPIC = JCSMPFactory.onlyInstance().createTopic(
SEMP_TOPIC_STRING);
Requestor requestor = session.createRequestor();
BytesXMLMessage requestMsg = JCSMPFactory.onlyInstance().createMessage(
BytesXMLMessage.class);
requestMsg.writeAttachment(requestStr.getBytes());
BytesXMLMessage replyMsg = requestor
.request(requestMsg, 5000, SEMP_TOPIC);
String replyStr = new String();
if (replyMsg.getAttachmentContentLength() > 0) {
byte[] bytes = new byte[replyMsg.getAttachmentContentLength()];
replyMsg.readAttachmentBytes(bytes);
replyStr = new String(bytes, "US-ASCII");
}
RpcReplyDocument doc = RpcReplyDocument.Factory.parse(replyStr);
RpcReply reply = doc.getRpcReply();
if (reply.isSetPermissionError()) {
throw new RuntimeException(
"Permission Error: Make sure SEMP over message bus SHOW commands are enabled for this VPN");
}
if( reply.isSetParseError() ) {
throw new RuntimeException( "SEMP Parse Error: " + reply.getParseError() );
}
if( reply.isSetLimitError() ) {
throw new RuntimeException( "SEMP Limit Error: " + reply.getLimitError() );
}
if( reply.isSetExecuteResult() && reply.getExecuteResult().isSetReason() ) { // axelp: encountered this error on invalid 'queue' name
throw new RuntimeException( "SEMP Execution Error: " + reply.getExecuteResult().getReason() );
}
return reply;
} catch (JCSMPException e) {
throw new RuntimeException(e.getMessage(), e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e.getMessage(), e);
} catch (XmlException e) {
throw new RuntimeException(e.getMessage(), e);
}
}
You can get message VPN specific queues and topics using following SEMPv2 command.
curl -s -X GET -u semp_user:semp_pass management_host:management_port/SEMP/v2/monitor/msgVpns/{vpn-name}/queues?select="queueName"
curl -s -X GET -u semp_user:semp_pass management_host:management_port/SEMP/v2/monitor/msgVpns/{vpn-name}/topicEndpoints?select="topicEndpointName"

Multithreading issues for database insertion

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?

reducing number of return statements in a method

I have a java code in which there are multiple return statements in a single method. But for code cleaning purpose, I can have only one return statement per method. What can be done to overcome this.
Here is a method from my code:-
public ActionForward login(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
// Kill any old sessions
//request.getSession().invalidate();
DynaValidatorForm dynaform = (DynaValidatorForm)form;
// validate the form
ActionErrors errors = form.validate(mapping, request);
if(!errors.isEmpty()) {
this.saveErrors(request, errors);
return mapping.getInputForward();
}
// first check if token is set
if(!isTokenValid(request, true)) {
String errmsg="There was a problem with your login. Please close your browser then reopen it and try again. Make sure to click the Login button only ONCE.";
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// check the form for input errors
String errmsg = checkInput(form);
if (errmsg != null) {
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// no input errors detected
String resumekey = null;
// check for valid login
ObjectFactory objFactory = ObjectFactory.getInstance();
DataAccessor dataAccessor = objFactory.getDataAccessor();
request.setCharacterEncoding("UTF-8");
String testcode = dynaform.getString("testcode").trim();
String studentname = dynaform.getString("yourname").trim();
String password = dynaform.getString("password").trim();
// 4/3/07 - passwords going forward are ALL lower case
if (!CaslsUtils.isEmpty(password)) {
password = password.toLowerCase();
}
try{
resumekey = new String(studentname.getBytes("ISO-8859-1"),"UTF-8");
} catch (Exception e) {
log_.error("Error converting item content data to UTF-8 encoding. ",e);
}
String hashWord = CaslsUtils.encryptString(password);
// Make sure this is short enough to fit in the db
if (hashWord.length() > ConstantLibrary.MAX_PASSWORD_LENGTH) {
hashWord = hashWord.substring(0, ConstantLibrary.MAX_PASSWORD_LENGTH);
}
Login login = dataAccessor.getLogin(testcode, hashWord, false);
if (login == null || !login.getUsertype().equals(Login.USERTYPE_SUBJECT)) {
request.setAttribute("errormessage", "Incorrect test code or password.");
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// Check if the login has expired
if (login.getLoginexpires() != null && login.getLoginexpires().before(new Date())) {
request.setAttribute("errormessage", "Your login has expired.");
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// Check if the password has expired
if (login.getPasswordexpires() != null && login.getPasswordexpires().before(new Date())) {
request.setAttribute("errormessage", "Your login password has expired.");
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
HttpSession session = request.getSession();
session.setAttribute(ConstantLibrary.SESSION_LOGIN, login);
session.setAttribute(ConstantLibrary.SESSION_STUDENTNAME, studentname);
List<Testtaker> testtakers = null;
try {
//invalidate the old session if the incoming user is already logged in.
synchronized(this){
invalidateExistingSessionOfCurrentUser(request, studentname, testcode);
testtakers = dataAccessor.getTesttakersByResumeKey(studentname, login);// Adding this code to call getTesttakersByResumeKey instead of getTesttakers to improve the performance of the application during student login
}
} catch (Exception e) {
log.error("Exception when calling getTesttakers");
CaslsUtils.outputLoggingData(log_, request);
throw e;
}
session = request.getSession();
if(testtakers!=null)
{
if(testtakers.size() == 0) {
// new student -> start fresh
log_.debug("starting a fresh test");
// if this is a demo test, skip the consent pages and dump them directly to the select test page
if (login.getTestengine().equals(Itemmaster.TESTENGINE_DEMO)) {
return mapping.findForward("continue-panel");
}
}
// send them to fill out the profile
// check for custom profiles
String[] surveynames = new String[4];
List<Logingroup> logingroups = dataAccessor.getLoginGroupsByLogin(login.getLoginid());
for(Logingroup logingroup : logingroups) {
Groupmaster group = logingroup.getGroupmaster();
log_.debug(String.format("group: {groupid: %d, grouptype: %s, groupname: %s}", new Object[] {group.getGroupid(), group.getGrouptype(), group.getName()}));
Set<Groupsurvey> surveys = group.getGroupsurveys();
if(surveys.size() > 0) {
// grab the first (and only) one
Groupsurvey survey = surveys.toArray(new Groupsurvey[0])[0];
if(group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_CLASS)) {
surveynames[0] = survey.getSurveyname();
} else if (group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_SCHOOL)){
surveynames[1] = survey.getSurveyname();
} else if (group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_DISTRICT)){
surveynames[2] = survey.getSurveyname();
} else if (group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_STATE)){
surveynames[3] = survey.getSurveyname();
}
}
}
// match the most grandular survey
for(int i=0; i < surveynames.length; ++i) {
if(surveynames[i] != null) {
saveToken(request);
return mapping.findForward("student-profile-"+surveynames[i]);
}
}
// no custom profile, send them to the default
saveToken(request);
return mapping.findForward("student-profile");
}
// get the set of availible panels
Set<Panel> availiblePanels = dataAccessor.getAvailiblePanels(login, studentname);
if(availiblePanels.size() == 0) {
// no panels availible. send to all done!
log_.debug(String.format("No panels availible for Login:%s with resumekey:%s", login.toString(), studentname));
session.setAttribute("logoutpage", true);
resetToken(request);
return mapping.findForward("continue-alldone");
}
//Eventum #427 - Prevent test takers from retaking a finished test.
TestSubjectResult testSubjecResult=dataAccessor.getTestSubjectResult(login, resumekey);
if(testSubjecResult != null){
if(testSubjecResult.getRdscore() != null && testSubjecResult.getWrscore() != null && testSubjecResult.getLsscore() != null && testSubjecResult.getOlscore() != null){
if(testSubjecResult.getRdscore().getFinishtime() != null && testSubjecResult.getWrscore().getFinishtime() != null && testSubjecResult.getLsscore().getFinishtime() != null && testSubjecResult.getOlscore().getFinishtime() != null){
log_.debug(String.format("Already completed all the Skill Tests.", login.toString(), studentname));
session.setAttribute("logoutpage", true);
resetToken(request);
return mapping.findForward("continue-alldone");
}
}
}
// get a list of resumeable testtakers
List<Testtaker> resumeableTesttakers = new ArrayList<Testtaker>();
for(Testtaker testtaker : testtakers) {
if(testtaker.getPhase().equals(ConstantLibrary.PHASE_GOODBYE)) {
// testtaker is done with test. skip.
continue;
}
if(testtaker.getCurrentpanelid() == null) {
// testtaker is the profile testtaker
continue;
}
resumeableTesttakers.add(testtaker);
}
// sort them from least recent to latest
Collections.sort(resumeableTesttakers, new Comparator<Testtaker>() {
#Override
public int compare(Testtaker o1, Testtaker o2) {
// TODO Auto-generated method stub
//return 0;
return new CompareToBuilder()
.append(o1.getLasttouched(), o2.getLasttouched())
.toComparison();
}
});
if(resumeableTesttakers.size() == 0 && availiblePanels.size() > 0) {
// nobody is resumeable but there are panels left to take
// send them to the panel choice
// TODO: This is probably a misuse of Struts.
log_.info("No resumeable testtakers. Sending to panel select");
saveToken(request);
ActionForward myForward = (new ActionForward("/do/capstartpanel?capStartPanelAction=retest&lasttesttakerid="
+ testtakers.get(0).getTesttakerid(), true));
return myForward;// mapping.findForward(ConstantLibrary.FWD_CONTINUE + "-panel");
} else {
// grab the one most recently created and take their test
log_.info(String.format("Resuming with choice of %d testtakers", resumeableTesttakers.size()));
// we're forwarding to resume at this point, so we should do the some of the initialization
// that would have happened if we were still using getTesttaker() instead of getTesttakers() above.
session.setAttribute(ConstantLibrary.SESSION_LOGIN, login);
session.setAttribute(ConstantLibrary.SESSION_TESTTAKER, resumeableTesttakers.get(resumeableTesttakers.size()-1));
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_RESUME);
}
}
It's not a worth changing multiple returns to a single return statement per method. Actually, that will unnecessarily increase the burden of storing the result in a local variable and then making the return finally,
ActionForward result = null;
//scenario 1
result = ...
//scenario 2
result = ...
//scenario 3
result = ...
//finally
return result;
Hope this helps, but, it doesn't make much sense to me
As pointed out by others, having a single return statement does not necessarily make your code cleaner. However, in this case splitting up the method in smaller pieces probably makes the code more readable.
For example, this part:
// first check if token is set
if(!isTokenValid(request, true)) {
String errmsg="There was a problem with your login. Please close your browser then reopen it and try again. Make sure to click the Login button only ONCE.";
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// check the form for input errors
String errmsg = checkInput(form);
if (errmsg != null) {
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
could be replaced by introducing two methods and using those to write:
If(tokenNotSet() || formHasErrors()){
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
By doing this on multiple places the structure of the algorithm becomes more clear, possibly giving you more insight in how this code could be refactored to adhere to your coding guidelines.
I would set a an action forward variable at the start of the method.
ActionForward actionForwardToReturn = null;
Then replace each of these two lines
return mapping.getInputForward();
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
with these two lines :
actionForwardToReturn = mapping.getInputForward()
actionForwardToReturn = mapping.findForward(ConstantLibrary.FWD_CONTINUE);
finally return the variable.
return actionForwardToReturn;
This shouldn't be too difficult :)
On a side note... (actually the orginal answer to the question) :
Multiple return statements can make it hard to debug code.
I personally would have just one action object that you return at the end of the method. The benefit of this, is that i can put a break point right on the return statement and look at exactly what that object is.
Any logging or other cross cutting concern I would want to add later, would only have to be done at one point. Otherwise I would have to add a log statement to every line where you are returning.
The complexity added to a method in an attempt to remove multiple return statements is many a times not worth it, especially in a method such as yours.There's nothing wrong with using them in this case.
Like user3580294 there's nothing wrong with multiple return statements. However you could combine the last two if statements since they are essentially returning the same thing.
Use #Octopus 's method if you absolutely have to have one return statement

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