Search Results

Search found 33297 results on 1332 pages for 'java java ee'.

Page 717/1332 | < Previous Page | 713 714 715 716 717 718 719 720 721 722 723 724  | Next Page >

  • Force full garbage collection when memory occupation goes beyond a certain threshold

    - by Silvio Donnini
    I have a server application that, in rare occasions, can allocate large chunks of memory. It's not a memory leak, as these chunks can be claimed back by the garbage collector by executing a full garbage collection. Normal garbage collection frees amounts of memory that are too small: it is not adequate in this context. The garbage collector executes these full GCs when it deems appropriate, namely when the memory footprint of the application nears the allotted maximum specified with -Xmx. That would be ok, if it wasn't for the fact that these problematic memory allocations come in bursts, and can cause OutOfMemoryErrors due to the fact that the jvm is not able to perform a GC quickly enough to free the required memory. If I manually call System.gc() beforehand, I can prevent this situation. Anyway, I'd prefer not having to monitor my jvm's memory allocation myself (or insert memory management into my application's logic); it would be nice if there was a way to run the virtual machine with a memory threshold, over which full GCs would be executed automatically, in order to release very early the memory I'm going to need. Long story short: I need a way (a command line option?) to configure the jvm in order to release early a good amount of memory (i.e. perform a full GC) when memory occupation reaches a certain threshold, I don't care if this slows my application down every once in a while. All I've found till now are ways to modify the size of the generations, but that's not what I need (at least not directly). I'd appreciate your suggestions, Silvio P.S. I'm working on a way to avoid large allocations, but it could require a long time and meanwhile my app needs a little stability

    Read the article

  • Best fit curve for trend line

    - by Dave Jarvis
    Problem Constraints Size of the data set, but not the data itself, is known. Data set grows by one data point at a time. Trend line is graphed one data point at a time (using a spline/Bezier curve). Graphs The collage below shows data sets with reasonably accurate trend lines: The graphs are: Upper-left. By hour, with ~24 data points. Upper-right. By day for one year, with ~365 data points. Lower-left. By week for one year, with ~52 data points. Lower-right. By month for one year, with ~12 data points. User Inputs The user can select: the type of time series (hourly, daily, monthly, quarterly, annual); and the start and end dates for the time series. For example, the user could select a daily report for 30 days in June. Trend Weight To calculate the window size (i.e., the number of data points to average when calculating the trend line), the following expression is used: data points / trend weight Where data points is derived from user inputs and trend weight is 6.4. Even though a trend weight of 6.4 produces good fits, it is rather arbitrary, and might not be appropriate for different user inputs. Question How should trend weight be calculated given the constraints of this problem?

    Read the article

  • Play framework 1.x on Tomcat - httpOnly cookies

    - by aishwarya
    I'm setting application.session.httpOnly=true in the application.conf and generating a war file and deploying on tomcat. I still see the cookie generated as HttpOnly=No and it is editable. This is an issue with play 1.x running on tomcat 6 (i.e. servlet api 2.x). Apparently, http only flag for cookies was only introduced in servlet 3.0 and so is only available in tomcat 7+ has anybody identified a workaround for this so far (so I could have http only cookies for play 1.x on tomcat 6.x ) ? the httpOnly flag on context in tomcat only works for tomcat's jsessionid cookie... also, can I run a play 1.x app on servlet 3.0 ? PS: This was also posted on the play framework's google groups but we did not receive a response and so posting on SO.

    Read the article

  • Basic jUnit Questions

    - by Epitaph
    I was testing a String multiplier class with a multiply() method that takes 2 numbers as inputs (as String) and returns the result number (as String) `public String multiply(String num1, String num2); I have done the implementation and created a test class with the following test cases involving the input String parameter as 1) valid numbers 2) characters 3) special symbol 4) empty string 5) Null value 6) 0 7) Negative number 8) float 9) Boundary values 10) Numbers that are valid but their product is out of range 11) numbers will + sign (+23) 1) I'd like to know if "each and every" assertEquals() should be in it's own test method? Or, can I group similar test cases like testInvalidArguments() to contains all asserts involving invalid characters since ALL of them throw the same NumberFormatException ? 2) If testing an input value like character ("a"), do I need to include test cases for ALL scenarios? "a" as the first argument "a" as the second argument "a" and "b" as the 2 arguments 3) As per my understanding, the benefit of these unit tests is to find out the cases where the input from a user might fail and result in an exception. And, then we can give the user with a meaningful message (asking them to provide valid input) instead of an exception. Is that the correct? And, is it the only benefit? 4) Are the 11 test cases mentioned above sufficient? Did I miss something? Did I overdo? When is enough? 5) Following from the above point, have I successfully tested the multiply() method?

    Read the article

  • How do I add a namespace attribute to an element in JAXB when marshalling?

    - by Ryan Elkins
    I'm working with eBay's LMS (Large Merchant Services) and kept running into the error: org.xml.sax.SAXException: SimpleDeserializer encountered a child element, which is NOT expected, in something it was trying to deserialize. After alot of trial and error I traced the problem down. It turns out this works: <?xml version="1.0" encoding="UTF-8"?> <BulkDataExchangeRequests xmlns="urn:ebay:apis:eBLBaseComponents"> <Header> <Version>583</Version> <SiteID>0</SiteID> </Header> <AddFixedPriceItemRequest xmlns="urn:ebay:apis:eBLBaseComponents"> while this (what I've been sending) doesn't: <?xml version="1.0" encoding="UTF-8"?> <BulkDataExchangeRequests xmlns="urn:ebay:apis:eBLBaseComponents"> <Header> <Version>583</Version> <SiteID>0</SiteID> </Header> <AddFixedPriceItemRequest> The difference is the xml namespace attribute on the AddFixedPriceItemRequest . All of my XML is currently being marshalled via JAXB and I'm not sure what is the best way to go about adding a second xmlns attribute to a different element in my file. So that's the question. How do I add an xmlns attribute to another element in JAXB? UPDATE: package ebay.apis.eblbasecomponents; import javax.xml.bind.annotation.XmlAccessType; import javax.xml.bind.annotation.XmlAccessorType; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlType; @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "AddFixedPriceItemRequestType", propOrder = { "item" }) public class AddFixedPriceItemRequestType extends AbstractRequestType { @XmlElement(name = "Item") protected ItemType item; public ItemType getItem() { return item; } public void setItem(ItemType value) { this.item = value; } } Added class definition by request. UPDATE 2: Edited the above class like so to no effect: @XmlAccessorType(XmlAccessType.FIELD) @XmlType(namespace = "urn:ebay:apis:eBLBaseComponents", name = "AddFixedPriceItemRequestType", propOrder = { "item" }) public class AddFixedPriceItemRequestType UPDATE 3: Here is a snippet of the BulkDataExchangeRequestsType class. I tried throwing a namespace="urn:ebay:apis:eBLBaseComponents" into the @XmlElement for AddFixedPriceItemRequest but it didn't do anything. @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "BulkDataExchangeRequestsType", propOrder = { "header", "addFixedPriceItemRequest" }) public class BulkDataExchangeRequestsType { @XmlElement(name = "Header") protected MerchantDataRequestHeaderType header; @XmlElement(name = "AddFixedPriceItemRequest") protected List<AddFixedPriceItemRequestType> addFixedPriceItemRequest; UPDATE 4: Here's the hideous chunk of code that is updating the xml after marshalling for me. This is currently working although I'm not particulary proud of it. DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); dbf.setNamespaceAware(true); DocumentBuilder db = dbf.newDocumentBuilder(); Document doc = db.newDocument(); marshaller.marshal(request, doc); NodeList nodes = doc.getChildNodes(); nodes = nodes.item(0).getChildNodes(); for(int i = 0; i < nodes.getLength(); i++){ Node node = nodes.item(i); if (!node.getNodeName().equals("Header")){ ((Element)node).setAttribute("xmlns", "urn:ebay:apis:eBLBaseComponents"); } } Update 5: For anyone else that runs into this problem with eBay and wonders why - The reasoning behind this most likely has to do with how eBay is handling these requests. The BulkDataExchange probably takes the XML payload, breaks it up, and send the pieces out to the Merchant or Trading API. The inner pieces of the payload then do not have the namespace and the get the error. This is a guess on my part but I wouldn't be surprised if this is what was going on behind the scenes. Thanks for all the help everyone.

    Read the article

  • How to implement a custom cell renderer for ScrollTable in GWT

    - by tronda
    I've used the ScrollTable widget for GWT and I have a need for a custom cell renderer so I can isolate this code from the rest of the app. I would like to use generics if possible to get it type safe. This cell renderer will take a long as a value and do some calculation before displaying the result. Anyone having a good example on how to implement such a custom renderer?

    Read the article

  • How to user Hibernate @Valid constraint with Spring 3.x?

    - by Burak Dede
    I am working on simple form to validate fields like this one. public class Contact { @NotNull @Max(64) @Size(max=64) private String name; @NotNull @Email @Size(min=4) private String mail; @NotNull @Size(max=300) private String text; } I provide getter and setters hibernate dependencies on my classpath also.But i still do not get the how to validate simple form there is actually not so much documentation for spring hibernate combination. @RequestMapping(value = "/contact", method = RequestMethod.POST) public String add(@Valid Contact contact, BindingResult result) { .... } Could you explain it or give some tutorial , except original spring 3.x documentation

    Read the article

  • Piano Keys using GridLayout (or Something Else)

    - by yar
    I am creating a container of JComponents which will look like a piano keyboard. The black keys look like this (Groovy) def setBlackNotes(buttons) { def octaves = (int)(buttons.size() / 5) def gridLayout = new GridLayout(1, octaves*7); def blackNotePanel = new JPanel(gridLayout) this.add blackNotePanel def i = 0 octaves.times { 2.times { blackNotePanel.add buttons[i++] } blackNotePanel.add Box.createHorizontalBox() 3.times { blackNotePanel.add buttons[i++] } blackNotePanel.add Box.createHorizontalBox() } } Which is just what I need, and looks like this: but then I'd like to move this over to the right by half-a-key width. All of my attempts to move the blackNotePanel over by an arbitrary width -- wrapping it a BorderLayout, a MigLayout, etc. -- have failed or changed the spacing of the GridLayout radically. Any suggestions on how to move this over to the right by an arbitrary amount in pixels?

    Read the article

  • Servlet, JSP, JavaBeans and HTML form

    - by dedalo
    Hi, I'm working on a servlet that makes a connection to a database gets the information of one of the tables ans sends this information to a jsp file. This file will print on the brower the information table, adding radio buttons that allows us to choose one of the rows. The servlet looks like this: List<InfoBean> items = new ArrayList<InfoBean>(); if (!conexion.isClosed()){ Statement st = (Statement) conexion.createStatement(); ResultSet rs = st.executeQuery("select * from lista_audio" ); while (rs.next()) {items.add(getRow(rs));} conexion.close();} req.getSession().setAttribute("items", items); In the JSP file I can print a table with the information, adding radio buttons that the user will use to choose 1 row and send the selected info to a servlet using a form I can add: < form action="administ" method=get enctype=multipart/form-data> < table> < table border=\"1\">< tr>< th>Title< /th>< th>Author< /th>< th>Album< /th>< /tr> < c:forEach items="${items}" var="item"> < tr>< td><input type="radio" name="SongInfo" value=${item.title}> < td>${item.title}< /td> < td>${item.author}< /td> < td>${item.album}< /td>< /tr> < /c:forEach> < /table> In the field 'value' I should be able to send to the servlet the information stored in ${item.title}. When I set value = ${item.title} and title is, for example "The bodyguard", in the servlet the information I can retrieve is just "The". It looks like it sends the characters located before the first white space of the string. How could I get the whole string? Thanks

    Read the article

  • Spring 2.5 Hibernate 3.5 NamedQuery

    - by EugeneP
    I do not use HibernateTemplate, but work with getCurrentSession() in my DAO. I would like to know how to declare Hibernate named queries in a beans.xml file (I do not use hbm.xml). And maybe Spring has alternative means to declare Hibernate named queries?

    Read the article

  • How to use RTPSocket to send RTP packets

    - by Afro Genius
    Hi there, am relatively new to JMF but have gone through the documents and have a sufficient understanding of how it works. That been said am having some trouble implementing a the server side for RTPSockets. After looking at their illustrations and example. I am still abit confused. Am I to develop a datasource and also datasink classes to handle the transfer? What am trying to do is stream data from my application to the underlying network and receive it back through another application. I have and understand receiving but just can't get my head around the steps involved for sending. Any help would be most appreciated.

    Read the article

  • Hibernate: order multiple one-to-many relations

    - by Markos Fragkakis
    I have a search screen, using JSF, JBoss Seam and Hibernate underneath. There are columns for A, B and C, where the relations are as follows: A (1< -- ) B (1< -- ) C A has a List< B and B has a List< C (both relations are one-to-many). The UI table supports ordering by any column (ASC or DESC), so I want the results of the query to be ordered. This is the reason I used Lists in the model. However, I got an exception that Hibernate cannot eagerly fetch multiple bags (it considers both lists to be bags). There is an interesting blog post here, and they identify the following solutions: Use @IndexColumn annotation (there is none in my DB, and what's more, I want the position of results to be determined by the ordering, not by an index column) Fetch lazily (for performance reasons, I need eager fetching) Change List to Set So, I changed the List to Set, which by the way is more correct, model-wise. First, if don't use @OrderBy, the PersistentSet returned by Hibernate wraps a HashSet, which has no ordering. Second, If I do use @OrderBy, the PersistentSet wraps a LinkedHashSet, which is what I would like, but the OrderBy property is hardcoded, so all other ordering I perform through the UI comes after it. I tried again with Sets, and used SortedSet (and its implementation, TreeSet), but I have some issues: I want ordering to take place in the DB, and not in-memory, which is what TreeSet does (either through a Comparator, or through the Comparable interface of the elements). Second, I found that there is the Hibernate annotation @Sort, which has a SortOrder.UNSORTED and you can also set a Comparator. I still haven't managed to make it compile, but I am still not convinced it is what I need. Any advice?

    Read the article

  • how do I know when/where to invoke the overridden method of the super class

    - by Henry
    Hi, This question occured to me while programming a Android application, but it seems to be a general programming question more. The situation is, I am extending (subclass-ing) an class from a library, and overriding a method. how do I know if I should invoke the method of super-class? and when? (in the beginning of the overridden method or in the end?) For example, I am overriding the method "public boolean onCreateOptionsMenu(Menu menu)" from class "Activity" in Android platform. And I saw someone write "return super.onCreateOptionsMenu(menu)" in the end of the method, in an example. But how do I know it should be done this way? and it is correct or not? what's the difference if I begin my method with "super.onCreateOptionsMenu(menu)"? BR, Henry

    Read the article

  • using Swing components in javafx if they're not in the NetBeans javafx palette

    - by Jason S
    I'm just getting started with javafx in NetBeans, and I have it doing simple stuff (windows with buttons + the like) but would like to try something slightly more realistic. The "Swing/AWT Components" palette has a whole bunch of stuff that the "JavaFX Script Code Clips" palette does not (it has Button, CheckBox, ComboBox, ComboBoxItem, Label, RadioButton, Slider, TextField, and ToggleButton). How do I add stuff to this palette? I would like to try using some of the components in org-netbeans-swing-outline.jar edit: Aha. I was missing the point somewhat: there are only some javafx-wrapped Swing components available in javafx.ext.Swing.*, so if you want one of the other Swing components you have to wrap them yourself.

    Read the article

  • Compute the Length of Largest substring that starts and ends with the same substring

    - by Deepak
    Hi People, Below is the Problem Statement: PS: Given a string and a non-empty substring sub, compute recursively the largest substring which starts and ends with sub and return its length. Examples: strDist("catcowcat", "cat") ? 9 strDist("catcowcat", "cow") ? 3 strDist("cccatcowcatxx", "cat") ? 9 Below is my Code: (Without recursion)//since i found it hard to implement with recursion. public int strDist(String str, String sub){ int idx = 0; int max; if (str.isEmpty()) max = 0; else max=1; while ((idx = str.indexOf(sub, idx)) != -1){ int previous=str.indexOf(sub, idx); max = Math.max(max,previous); idx++; } return max; } Its working for few as shown below but returns FAIL for others. Expected This Run strDist("catcowcat", "cat") ? 9 6 FAIL strDist("catcowcat", "cow") ? 3 3 OK strDist("cccatcowcatxx", "cat") ? 9 8 FAIL strDist("abccatcowcatcatxyz", "cat") ? 12 12 OK strDist("xyx", "x") ? 3 2 FAIL strDist("xyx", "y") ? 1 1 OK strDist("xyx", "z") ? 0 1 FAIL strDist("z", "z") ? 1 1 OK strDist("x", "z") ? 0 1 FAIL strDist("", "z") ? 0 0 OK strDist("hiHellohihihi", "hi") ? 13 11 FAIL strDist("hiHellohihihi", "hih") ? 5 9 FAIL strDist("hiHellohihihi", "o") ? 1 6 FAIL strDist("hiHellohihihi", "ll") ? 2 4 FAIL Could you let me whats wrong with the code and how to return the largest substring that begins and ends with sub with its respective length.

    Read the article

  • Eclispe RCP SWT menus for Windows and Mac OS

    - by Raven
    Hi, how do I configure an Eclipse RCP command style menu to match the different menu structures on Windows and on Mac OS? Mac OS X menu example http://images.apple.com/macosx/refinements/images/services_menu_20090902.jpg Windows menu example http://www.flamingpear.com/images/psp8menu.gif In the example you see, the differences in the menu structures. For example has the Mac in its application menu the preference command, the about command and the exit command. These are under Windows usally in the file menu and the about command is found in the help menu. Is there a "standard" way of doing it with RCP programs? It should somehow be possible because Eclipse itself does it. But I can not figure out how.

    Read the article

  • Maven GAE Plugin - Unable to run gae:debug

    - by Taylor L
    I'm having trouble running the gae:debug goal of the Maven GAE Plugin. The error I'm receiving is below. Any ideas? I'm running it with "mvn gae:debug". [INFO] Packaging webapp [INFO] Assembling webapp[test-gae] in [C:\development\test-gae\target\test-gae-0.0.1-SNAPSHOT] [INFO] Processing war project [INFO] Webapp assembled in[56 msecs] [INFO] Building war: C:\development\test-gae\target\test-gae-0.0.1-SNAPSHOT.war [INFO] [statemgmt:end-fork] [INFO] Ending forked execution [fork id: -2101914270] [INFO] [gae:debug] Usage: <dev-appserver> [options] <war directory> Options: --help, -h Show this help message and exit. --server=SERVER The server to use to determine the latest -s SERVER SDK version. --address=ADDRESS The address of the interface on the local machine -a ADDRESS to bind to (or 0.0.0.0 for all interfaces). --port=PORT The port number to bind to on the local machine. -p PORT --sdk_root=root Overrides where the SDK is located. --disable_update_check Disable the check for newer SDK versions. EDIT: gae:run with the jvmFlags option is also giving me the same result with the below configuration. <plugin> <groupId>net.kindleit</groupId> <artifactId>maven-gae-plugin</artifactId> <version>0.5.0</version> <configuration> <jvmFlags> <jvmFlag>-Xdebug</jvmFlag> <jvmFlag>-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8000</jvmFlag> </jvmFlags> </configuration> </plugin>

    Read the article

  • Ensure a new session every time the user connects to a Servlet

    - by Daziplqa
    Hi, I've a JSP/Servlet Web App that consist of more than one servlet (and some JSPs) I need to create an new HttpSession whenever the users access servlet A, knowing that, servlet A is the home page (i.e. he access it as the first servlet/page in the application) so far so good, I can write the following code at the start of the servlet A: HttpSession session = request.getSession(false); if (session == null) { logger.debug("starting new session..."); session = request.getSession(); // other staff here } But the problem is, if the user didn't close his browser (even if he closes the tab - in firefox for instance - the session will still be open), so when he try to open my site again, the last session will be re-used (in the rage of session timeout ofcourse), and this I don't need. I need whenever he access Servlet A, he got created a brand new HttpSession. but unfortunately, he may access this servlet twice per session based on some scenario!! Please help.

    Read the article

  • in which namespace / package to put exceptions

    - by Fabiano
    Hi What is the common or best practice to structure the location of your exception classes? Let's say you have the packages/namespaces myproject.person (models and DAOs for persons) and myproject.order (models and DAOs for orders) and the exceptions PersonException and OrderException. Should I put the exceptions in their corresponding packages or in a separate package for exceptions (e.g. myproject.exceptions)? The first approach seems more reasonable (because it's sorted by functionality). But there the question arises where you should put exceptions that are related to both? e.g. a ConstraintViolationException Thanks

    Read the article

  • remove notification bar shadow in android app

    - by defrex
    In android, the notification bar at the top has a shadow most of the time. However, sometimes, such as when an app has it's title-bar showing, or in some other cases (such as in the twitter app or the market) that shadow effect is gone. My guess is that the shadow is supposed to be there when the content underneath can scroll. In my app, however, the content underneath can't scroll, and I think the shadow looks bad on the top part of my logo. Does anyone know how to disable it?

    Read the article

< Previous Page | 713 714 715 716 717 718 719 720 721 722 723 724  | Next Page >