Search Results

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

Page 649/1332 | < Previous Page | 645 646 647 648 649 650 651 652 653 654 655 656  | Next Page >

  • resource-ref at application scope in EJB 2.1 Project

    - by Mike Deck
    Is it possible to define resource references that are applicable to all EJBs in an application? Currently I have an ejb-jar.xml that looks something like this: <ejb-jar> <enterprise-beans> <session id="foo"> <!-- snip --> <resource-ref> <res-ref-name>jdbc/myDatasource</res-ref-name> <res-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> </resource-ref> </session> <session id="bar"> <!-- snip --> <resource-ref> <res-ref-name>jdbc/myDatasource</res-ref-name> <res-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> </resource-ref> </session> </enterprise-beans> </ejb-jar> You'll notice that both EJBs have the same resource-ref defined for both of them. Is there a way to factor this duplication out within a J2EE 1.4 application? Ideally I should be able to define the jdbc/myDatasource resource once within the application and have anything running inside that container be able to access it by doing a JNDI lookup for "java:comp/env/jdbc/myDatasource". Is there any way to accomplish this?

    Read the article

  • GC output clarification

    - by elec
    I'm running a java application with the following settings: -XX:+CMSParallelRemarkEnabled -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCApplicationConcurrentTime -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution I'm not sure how to interpret the related gc logs(below). In particular: Heap after GC invocations=31 (full 3): does this mean there were 31 minor GCs, and 3 full GCs ? What triggers the several consecutive lines of Total time for which the application threads were stopped and Application Time ? Is it possible to get the time stamps associated with each of these lines ? GC logs: Total time for which application threads were stopped: 0.0046910 seconds Application time: 0.7946670 seconds Total time for which application threads were stopped: 0.0002900 seconds Application time: 1.0153640 seconds Total time for which application threads were stopped: 0.0002780 seconds Application time: 1.0161890 seconds Total time for which application threads were stopped: 0.0002760 seconds Application time: 1.0145990 seconds Total time for which application threads were stopped: 0.0002950 seconds Application time: 0.9999800 seconds Total time for which application threads were stopped: 0.0002770 seconds Application time: 1.0151640 seconds Total time for which application threads were stopped: 0.0002730 seconds Application time: 0.9996590 seconds Total time for which application threads were stopped: 0.0002880 seconds Application time: 0.9624290 seconds {Heap before GC invocations=30 (full 3): par new generation total 131008K, used 130944K [0x00000000eac00000, 0x00000000f2c00000, 0x00000000f2c00000) eden space 130944K, 100% used [0x00000000eac00000, 0x00000000f2be0000, 0x00000000f2be0000) from space 64K, 0% used [0x00000000f2bf0000, 0x00000000f2bf0000, 0x00000000f2c00000) to space 64K, 0% used [0x00000000f2be0000, 0x00000000f2be0000, 0x00000000f2bf0000) concurrent mark-sweep generation total 131072K, used 48348K [0x00000000f2c00000, 0x00000000fac00000, 0x00000000fac00000) concurrent-mark-sweep perm gen total 30000K, used 19518K [0x00000000fac00000, 0x00000000fc94c000, 0x0000000100000000) 2010-05-11T09:30:13.888+0100: 384.955: [GC 384.955: [ParNew Desired survivor size 32768 bytes, new threshold 0 (max 0) : 130944K-0K(131008K), 0.0052470 secs] 179292K-48549K(262080K), 0.0053030 secs] [Times: user=0.00 sys=0.00, real=0.01 secs] Heap after GC invocations=31 (full 3): par new generation total 131008K, used 0K [0x00000000eac00000, 0x00000000f2c00000, 0x00000000f2c00000) eden space 130944K, 0% used [0x00000000eac00000, 0x00000000eac00000, 0x00000000f2be0000) from space 64K, 0% used [0x00000000f2be0000, 0x00000000f2be0000, 0x00000000f2bf0000) to space 64K, 0% used [0x00000000f2bf0000, 0x00000000f2bf0000, 0x00000000f2c00000) concurrent mark-sweep generation total 131072K, used 48549K [0x00000000f2c00000, 0x00000000fac00000, 0x00000000fac00000) concurrent-mark-sweep perm gen total 30000K, used 19518K [0x00000000fac00000, 0x00000000fc94c000, 0x0000000100000000) } Total time for which application threads were stopped: 0.0056410 seconds Application time: 0.0475220 seconds Total time for which application threads were stopped: 0.0001800 seconds Application time: 1.0174830 seconds Total time for which application threads were stopped: 0.0003820 seconds Application time: 1.0126350 seconds Total time for which application threads were stopped: 0.0002750 seconds Application time: 1.0155910 seconds Total time for which application threads were stopped: 0.0002680 seconds Application time: 1.0155580 seconds Total time for which application threads were stopped: 0.0002880 seconds Application time: 1.0155480 seconds Total time for which application threads were stopped: 0.0002970 seconds Application time: 0.9896810 seconds

    Read the article

  • Updating Multiple Drop-Down Lists in AjaxTags

    - by Berin
    I'm using AjaxTags as a defined set of JSP tags to facilitate AJAX programming, saving me from some heavy lifting. The project is in trial mode, so I may not adopt the technology and write my own solution. Here's what I'm running into (code abbreviated) I have a drop-down list that defines an item that populates numerous other drop-down lists. <form> ... <select id="item1" name="item1"> <c:forEach items="${list1}" var="item"> <option value="${item}">${item}</option> </c:forEach> </select> <select id="item2" name="items2"></select> <select id="item3" name="items3"></select> ... </form> <ajax:select source="item1" target="item2" baseUrl="${pageContext.request.contextPath}/doAction.view" parameters="action1 = {item}" /> <ajax:select source="item1" target="item3" baseUrl="${pageContext.request.contextPath}/doAction.view" parameters="action2 = {item}" /> The code above works with my back-end, initiating a call to a servlet class that is listening for calls, parses the parameter and takes action based upon the name of the parameter passed. The problem comes from adding the second ajax:select tag above. An action in drop-down "item 1" only causes "item 3" to be populated with new values. What I want is for an action in "item 1" to populate "item 2" and "item 3" (and 4, 5, 6...). Has anyone else used AjaxTags (ajaxtags.sourceforge.net) and solved a similar solution? Environment Details: Tomcat 5.5.27, Spring 2.0.8, Struts 1.2.9, Java 6

    Read the article

  • Why this method does not use any properties of the object?

    - by Roman
    Here I found this code: import java.awt.*; import javax.swing.*; public class FunWithPanels extends JFrame { public static void main(String[] args) { FunWithPanels frame = new FunWithPanels(); frame.doSomething(); } void doSomething() { Container c = getContentPane(); JPanel p1 = new JPanel(); p1.setLayout(new BorderLayout()); p1.add(new JButton("A"), BorderLayout.NORTH); p1.add(new JButton("B"), BorderLayout.WEST); JPanel p2 = new JPanel(); p2.setLayout(new GridLayout(3, 2)); p2.add(new JButton("F")); p2.add(new JButton("G")); p2.add(new JButton("H")); p2.add(new JButton("I")); p2.add(new JButton("J")); p2.add(new JButton("K")); JPanel p3 = new JPanel(); p3.setLayout(new BoxLayout(p3, BoxLayout.Y_AXIS)); p3.add(new JButton("L")); p3.add(new JButton("M")); p3.add(new JButton("N")); p3.add(new JButton("O")); p3.add(new JButton("P")); c.setLayout(new BorderLayout()); c.add(p1, BorderLayout.CENTER); c.add(p2, BorderLayout.SOUTH); c.add(p3, BorderLayout.EAST); pack(); setVisible(true); } } I do not understand how "doSomething" use the fact that "frame" is an instance of the class JFrame. It is not clear to me because there is no reference to "this" in the code for the method "doSomething".

    Read the article

  • casting Collection<SomeClass> to Collection<SomeSuperClass>

    - by skrebbel
    Hi all, I'm sure this has been answered before, but I really cannot find it. I have a java class SomeClass and an abstract class SomeSuperClass. SomeClass extends SomeSuperClass. Another abstract method has a method that returns a Collection<SomeSuperClass>. In an implementation class, I have a Collection<SomeClass> myCollection I understand that I cannot just return myCollection, because Collection<SomeClass> does not inherit from Collection<SomeSuperClass>. Nevertheless, I know that everything in myCollection is a SomeSuperClass because after all, they're SomeClass objects which extend SomeSuperClass. How can I make this work? I.e. I want public class A { private Collection<SomeClass> myCollection; public Collection<SomeSuperClass> getCollection() { return myCollection; //compile error! } } The only way I've found is casting via a non-generic type and getting unchecked warnings and whatnot. There must be a more elegant way, though? I feel that also using Collections.checkedSet() and friends are not needed, since it is statically certain that the returned collection only contains SomeClass objects (this would not be the case when downcasting instead of upcasting, but that's not what I'm doing). What am I missing? Thanks!

    Read the article

  • GUI for generating XML

    - by Kenston
    Hello. Does anybody know of GUIs for generating XMLs? This means the user will not be presented with an IDE with support for XML for him to type XML codes. This would be helpful for non-technical people using the system. I know this sounds easy, given many libraries that can help in generating XMLs. The issue here is that the schema is really that flexible rather than being straightforward like representing books in a library with their properties. Imagine HTML, where we can create font tags inside a body, a table, a div, or nested even within itself. The solution is a WYSIWYG application that allows user to generate html codes (XML). However, that is good for XML applied in webpages since they involve visual aspect and design. My application of XML would focus on representing some conceptual and computational definitions, much like sql-like syntax, but more than that. I'm actually after the approach or previous works done or tried, although having a library/working framework for that would be better. Btw, I'm using Java for this project. Currently, I'm just thinking of presenting element tags where user will be able to drag and drop them and nest them with each other. And perhaps, assist them through a forms in inputing values for XML attributes. I'm still hoping if there are better ideas from the community. Thank you.

    Read the article

  • Validate XSD with XML .

    - by munish
    I want to know how to validate XML with XSD . XML is not of an element type but a complex type . Since validator class's validate method compare only element type. So basically I want to valide XSD's complex type with an XML. e.g. Basic XSD below xs:element name="Customer"> <xs:complexType> <xs:sequence> <xs:element name="Dob" type="xs:date" /> <xs:element name="Address"> <xs:complexType> <xs:sequence> <xs:element name="Line1" type="xs:string" /> <xs:element name="Line2" type="xs:string" /> </xs:sequence> </xs:complexType> </xs:element> </xs:sequence> </xs:complexType> </xs:element> We can assume we have multiple complex type in the Customer element. MY XML is <Address> <Line1>34 thingy street, someplace</Line1> <Line2>sometown, w1w8uu </Line2> </Address> How I validate my XML with XSD. Kindly post your suggestions in java

    Read the article

  • facebook: can't send email from app to user

    - by flybywire
    I can't send email to my app users, even though I have the permissions. I am working with the java library, although I don't think it is related to that. long uid = ...; Collection<Long> uids = new ArrayList<Long>(); uids.add(uid); FacebookXmlRestClient client = new FacebookXmlRestClient(api, secret); boolean sendEmailPerm = client.users_hasAppPermission(Permission.EMAIL,uid); System.out.println("Can send email: "+ sendEmailPerm); Collection<String> sent = client.notifications_sendTextEmail(uids, "subject", "body"); System.out.println("Succesfully sent email to: "+sent); sent = client.notifications_sendFbmlEmail(uids, "subject", "body"); System.out.println("Succesfully sent email to: "+sent); I am trying both with fbml and text email. I can also obtain the user's proxied_email property but when I send email to that address with my regular mail client is doesn't arrive. The output is: Can send email: true Succesfully sent email to: [] Succesfully sent email to: []

    Read the article

  • XMLStreamReader and a real stream

    - by Yuri Ushakov
    Update There is no ready XML parser in Java community which can do NIO and XML parsing. This is the closest I found, and it's incomplete: http://wiki.fasterxml.com/AaltoHome I have the following code: InputStream input = ...; XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance(); XMLStreamReader streamReader = xmlInputFactory.createXMLStreamReader(input, "UTF-8"); Question is, why does the method #createXMLStreamReader() expects to have an entire XML document in the input stream? Why is it called a "stream reader", if it can't seem to process a portion of XML data? For example, if I feed: <root> <child> to it, it would tell me I'm missing the closing tags. Even before I begin iterating the stream reader itself. I suspect that I just don't know how to use a XMLStreamReader properly. I should be able to supply it with data by pieces, right? I need it because I'm processing a XML stream coming in from network socket, and don't want to load the whole source text into memory. Thank you for help, Yuri.

    Read the article

  • Dymanic if statement evaluation problem with string comparison

    - by Mani
    I tried the example given in http://forums.sun.com/thread.jspa?threadID=780576&tstart=67605 to create if statement dynamically. But it is not working fine. Instead of using "age" variable as integer, i have used string in the below example. I am getting "fail" as answer instead of "success". Can anyone help me? / To change this template, choose Tools | Templates and open the template in the editor. / import java.lang.reflect.*; import bsh.Interpreter; public class Main { public static String d; public static void main(String args[]) { try { String age = "30"; String cond = "age==30"; Interpreter i = new Interpreter(); i.set("age", age); System.out.println(" sss" + i.get("age")); if((Boolean)i.eval(cond)) { System.out.println("success"); } else { System.out.println("fail"); } } catch (Throwable e) { System.err.println(e); } } } Thanks, Mani

    Read the article

  • JSESSIONID collision between two servers on same ip but different ports

    - by Steve Armstrong
    I've got a situation where I have two different webapps running on a single server, using different ports. They're both running Java's Jetty servlet container, so they both use a cookie parameter named JSESSIONID to track the session id. These two webapps are fighting over the session id. Open a Firefox tab, and go to WebApp1 WebApp1's HTTP response has a set-cookie header with JSESSIONID=1 Firefox now has a Cookie header with JSESSIONID=1 in all it's HTTP requests to WebApp1 Open a second Firefox tab, and go to WebApp2 The HTTP reqeust to WebApp2 also has a Cookie header with JSESSIONID=1, but in the doGet, when I call req.getSession(false); I get null. And if I call req.getSession(true) I get a new Session object, but then the HTTP response from WebApp2 has a set-cookie header with JSESSIONID=20 Now, WebApp2 has a working Session, but WebApp1's session is gone. Going to WebApp1 will give me a new session, blowing away WebApp2's session. Continue forever So the Sessions are thrashing between each web app. I'd really like for the req.getSession(false) to return a valid session if there's already a JSESSIONID cookie defined. One option is to basically reimplement the Session framework with a HashMap and cookies called WEBAPP1SESSIONID and WEBAPP2SESSIONID, but that sucks, and means I'll have to hack the new Session stuff into ActionServlet and a few other places. This must be a problem others have encountered. Is Jetty's HttpServletRequest.getSession(boolean) just crappy?

    Read the article

  • java.util.Map with HtmlDataTable

    - by gerry
    Hi, I'm developing an application on GlassFish v3 which uses Suns-RI of JavaEE6 and JSF2.0, etc. And the bad thing is, that no changes/switches away from Suns RI can be made (to use MyFaces or something like that). Now, the problem is, that I want to build HtmlDatatable by hand ( in Java code). The datatable should represent a java.util.Map where the first column should display the key and the second the values of the map. I've build successfully a PanelGrid from a java.util.List and used every time the "setExpressionValue" methods of UIComponent to bind the UI to the underlying List. But now, this doesn't work with the Map. Here is a snippet of my code: public HtmlDataTable getEntityDetailsDataTable() { ... Application app = FacesContext.getCurrentInstance().getApplication(); HtmlDataTable component = (HtmlDataTable)app.createComponent(HtmlDataTable.COMPONENT_TYPE); component.setValueExpression("value", ExpressionUtil.createValueExpression("#{entityTree.entity."+fieldName+".entrySet()}", Map.class)); component.setVar("param"); UIColumn column = new UIColumn(); UIOutput label1 = DynamicHtmlComponentCreator.createHtmlOutputText("#{param[key]}", String.class); column.getChildren().add(label1); UIOutput label2 = DynamicHtmlComponentCreator.createHtmlOutputText("#{param[value]}", String.class); column.getChildren().add(label2); component.getChildren().add(column); ... return component; } component.getChildren().add(column); ... return component; } So, further the problem is, that this code only prints out the content of the Map, on another page I need the values displayed in HtmlInputText elements and the whole map updated if the user clicks a i.e. "Save" button. So, further the problem is, that this code only prints out the content of the Map, on another page I need the values displayed in HtmlInputText elements and the whole map updated if the user clicks a i.e. "Save" button. If there is a workaround, to represent the Map as to Lists...please help me, because for this (map as 2 lists) I've no idea how the underlying map/database model can be updated again. Hopefully, someone can help me....

    Read the article

  • Detecting Singularities in a Graph

    - by nasufara
    I am creating a graphing calculator in Java as a project for my programming class. There are two main components to this calculator: the graph itself, which draws the line(s), and the equation evaluator, which takes in an equation as a String and... well, evaluates it. To create the line, I create a Path2D.Double instance, and loop through the points on the line. To do this, I calculate as many points as the graph is wide (e.g. if the graph itself is 500px wide, I calculate 500 points), and then scale it to the window of the graph. Now, this works perfectly for most any line. However, it does not when dealing with singularities. If, when calculating points, the graph encounters a domain error (such as 1/0), the graph closes the shape in the Path2D.Double instance and starts a new line, so that the line looks mathematically correct. Example: However, because of the way it scales, sometimes it is rendered correctly, sometimes it isn't. When it isn't, the actual asymptotic line is shown, because within those 500 points, it skipped over x = 2.0 in the equation 1 / (x-2), and only did x = 1.98 and x = 2.04, which are perfectly valid in that equation. Example: In that case, I increased the window on the left and right one unit each. My question is: Is there a way to deal with singularities using this method of scaling so that the resulting line looks mathematically correct? I myself have thought of implementing a binary search-esque method, where, if it finds that it calculates one point, and then the next point is wildly far away from the last point, it searches in between those points for a domain error. I had trouble figuring out how to make it work in practice, however. Thank you for any help you may give!

    Read the article

  • Google Web Toolkit Asynchronous Call from a Service Implementation

    - by Thor Thurn
    I'm writing a simple Google Web Toolkit service which acts as a proxy, which will basically exist to allow the client to make a POST to a different server. The client essentially uses this service to request an HTTP call. The service has only one asynchronous method call, called ajax(), which should just forward the server response. My code for implementing the call looks like this: class ProxyServiceImpl extends RemoteServiceServlet implements ProxyService { @Override public Response ajax(String data) { RequestBuilder rb = /*make a request builder*/ RequestCallback rc = new RequestCallback() { @Override public void onResponseReceived(Response response) { /* Forward this response back to the client as the return value of the ajax method... somehow... */ } }; rb.sendRequest(data, requestCallback); return /* The response above... except I can't */; } } You can see the basic form of my problem, of course. The ajax() method is used asynchronously, but GWT decides to be smart and hide that from the dumb old developer, so they can just write normal Java code without callbacks. GWT services basically just do magic instead of accepting a callback parameter. The trouble arises, then, because GWT is hiding the callback object from me. I'm trying to make my own asynchronous call from the service implementation, but I can't, because GWT services assume that you behave synchronously in service implementations. How can I work around this and make an asynchronous call from my service method implementation?

    Read the article

  • Scala wont pattern match with java.lang.String and Case Class

    - by Stefan
    Hello fellow Scala Programmers I have been working with Scala for some month now, however I have a problem with some properly basic stuff, I am hoping you will help my out with it. case class PersonClass(name: String, age: Int) object CaseTester { def main(args:Array[String]) { val string = "hej" string match { case e:String => println(string) case PersonClass => println(string) } } } When I am doing like this I get error: pattern type is incompatible with expected type; found : object PersonClass required: java.lang.String case PersonClass = println(string) And if I then change the second line in the pattern matching to the following: case e:PersonClass => println(string) I then get the error: error: scrutinee is incompatible with pattern type; found : PersonClass required: java.lang.String case e:PersonClass = println(string) However if I change the string definition to the following it compiles fine in both cases. val string:AnyRef = "hej"

    Read the article

  • Hibernate and parent/child relations

    - by Marco
    Hi to all, I'm using Hibernate in a Java application, and i feel that something could be done better for the management of parent/child relationships. I've a complex set of entities, that have some kind of relationships between them (one-to-many, many-to-many, one-to-one, both unidirectional and bidirectional). Every time an entity is saved and it has a parent, to estabilish the relationship the parent has to add the child to its collection (considering a one-to-may relationship). For example: Parent p = (Parent) session.load(Parent.class, pid); Child c = new Child(); c.setParent(p); p.getChildren().add(c); session.save(c); session.flush(); In the same way, if i remove a child then i have to explicitly remove it from the parent collection too. Child c = (Child) session.load(Child.class, cid); session.delete(c); Parent p = (Parent) session.load(Parent.class, pid); p.getChildren().remove(c); session.flush(); I was wondering if there are some best practices out there to do this jobs in a different way: when i save a child entity, automatically add it to the parent collection. If i remove a child, automatically update the parent collection by removing the child, etc. For example, Child c = new Child(); c.setParent(p); session.save(c); // Automatically update the parent collection session.flush(); or Child c = (Child) session.load(Child.class, cid); session.delete(c); // Automatically updates its parents (could be more than one) session.flush(); Anyway, it would not be difficult to implement this behaviour, but i was wondering if exist some standard tools or well known libraries that deals with this issue. And, if not, what are the reasons? Thanks

    Read the article

  • Xpath: Selecting all of an element type?

    - by Johannes
    I'm just starting to learn Xpath, I'm trying to write a line of code that will select all of the actors in EACH movie parent (through Java!). Below, I have an example of one movie, but there are multiple <Movie> elements, each with <Actor> elements. <Movie Genre = 'Other'> <Title>Requiem For A Dream</Title> <ReleaseYear>2000</ReleaseYear> <Director>Darren Aronofsky</Director> <Actor Character = 'Sara Goldfarb'>Ellen Burstyn</Actor> <Actor Character = 'Harry Goldfarb'>Jared Leto</Actor> <Actor Character = 'Marion Silver'>Jennifer Connelly</Actor> <Actor Character = 'Tyrone C. Love'>Marlon Wayans</Actor> </Movie> Currently, I can only select the first <Actor> element of each <Movie> element -- is it possible to select all of them without using a for loop? Here is my current line of code that displays the first <Actor> element of every <Movie> element: System.out.println("Starring: " + xpath.evaluate("Actor", movieNode) + " as " + xpath.evaluate("Actor/@Character", movieNode) + "\n"); Any and all help if much appreciated!

    Read the article

  • Looking for a good dev environment for OSGi bundles

    - by Riduidel
    Hi, I'm currently investigating in the field of dev environment for OSGi bundles. My goal is to find a way to develop, test and debug with ease the bundles I'll be coding. Besides, I have some "cultural" requirements. I want to be able to use java continuous integration servers (typically, Hudson) As a consequence of that first requirement, I want to have a repeatable, one-click build process. My typical tool for that is maven. And finally, being long-term Eclipse user, and having the m2eclipse at hand to merge my eclipse env with my maven one, I obviously want to be able to test and debug with that IDE. So far, here are the infos I know I can use (and have already tested) maven-bundle-plugin, maven-ipojo-plugin which both offer clean packaging facilities I have tested maven pax (and eclipse pax) and am not really satisfied with both : maven pax generates a very heavy project, where adding dependencies is very error-prone (the maven pax:import-bundle command line, with all its arguments, is a hell per se) I have taken a look at Karaf, which seems to have some nice direct maven provisionning, but I don't know how to integrate it with my Eclipse, besides using the traditionnal JPDA bridge. However, it seems to be more production-oriented than dev-oriented, and as such may require heavy configuration to fit my need (although the reading of its user manual doesn't revedal that). Have you got any ideas ? Some maven/eclipse plugins ?

    Read the article

  • Lazy non-modifiable list

    - by mindas
    I was looking for a decent implementation of a generic lazy non-modifiable list implementation to wrap my search result entries. The unmodifiable part of the task is easy as it can be achieved by Collections.unmodifiableList() so I only need to sort out the the lazy part. Surprisingly, google-collections doesn't have anything to offer; while LazyList from Apache Commons Collections does not support generics. I have found an attempt to build something on top of google-collections but it seems to be incomplete (e.g. does not support size()), outdated (does not compile with 1.0 final) and requiring some external classes, but could be used as a good starting point to build my own class. Is anybody aware of any good implementation of a LazyList? If not, which option do you think is better: write my own implementation, based on google-collections ForwardingList, similar to what Peter Maas did; write my own wrapper around Commons Collections LazyList (the wrapper would only add generics so I don't have to cast everywhere but only in the wrapper itself); just write something on top of java.util.AbstractList; Any other suggestions are welcome.

    Read the article

  • What does flushing thread local memory to global memory mean?

    - by Jack Griffith
    Hi, I am aware that the purpose of volatile variables in Java is that writes to such variables are immediately visible to other threads. I am also aware that one of the effects of a synchronized block is to flush thread-local memory to global memory. I have never fully understood the references to 'thread-local' memory in this context. I understand that data which only exists on the stack is thread-local, but when talking about objects on the heap my understanding becomes hazy. I was hoping that to get comments on the following points: When executing on a machine with multiple processors, does flushing thread-local memory simply refer to the flushing of the CPU cache into RAM? When executing on a uniprocessor machine, does this mean anything at all? If it is possible for the heap to have the same variable at two different memory locations (each accessed by a different thread), under what circumstances would this arise? What implications does this have to garbage collection? How aggressively do VMs do this kind of thing? Overall, I think am trying to understand whether thread-local means memory that is physically accessible by only one CPU or if there is logical thread-local heap partitioning done by the VM? Any links to presentations or documentation would be immensely helpful. I have spent time researching this, and although I have found lots of nice literature, I haven't been able to satisfy my curiosity regarding the different situations & definitions of thread-local memory. Thanks very much.

    Read the article

  • Define a swig interface file for generation of wrapper to every type from some header file

    - by Dmitriy Matveev
    Hi! We're using some C library in our Java project. Several years ago some other developer which has retired few years ago (as always) has created all the wrappers for us. The wrappers were generated by the swig, but the interface file is lost now. The basic idea of library and the wrappers for it is following: There only one function which returns pointer to some complex object. And there are wrapper for that function. The complex object is a tree-like structure with dozens of node kinds and types (C structures) used to represent them. There are hundreds of wrappers for every field of every type and we're trying to use them all. The library was updated some time ago and now there are some new data we unaware of which yet, but would like to use. This data is contained in some of the objects indirectly contained or referenced from the object created by the function we call (Some new fields and types were added). I know that I shouldn't make any changes to the wrappers by hand and should rather modify the interface, but as I already wrote it's missing. For now I only want to generate wrappers some few types which are added/changed and them to our old wrappers, but later I want to start creation of interface file which will define "what and how should be wrapped". All the definitions necessary for us are defined in single header file. Is it possible to tell swig to generate wrappers for every type in this header? If so, how can I write such interface file?

    Read the article

  • What's wrong with this code

    - by javacode
    I am getting the compiler error. Can anybody debug this? import javax.mail.*; import javax.mail.internet.*; import java.util.*; public class SendMail { public static void main(String [] args) { SendMail sm=new SendMail(); sm.postMail("[email protected]","hi","hello","[email protected]"); } public void postMail( String recipients[ ], String subject, String message , String from) throws MessagingException { boolean debug = false; //Set the host smtp address Properties props = new Properties(); props.put("mail.smtp.host", "webmail.emailmyname.com"); // create some properties and get the default Session Session session = Session.getDefaultInstance(props, null); session.setDebug(debug); // create a message Message msg = new MimeMessage(session); // set the from and to address InternetAddress addressFrom = new InternetAddress(from); msg.setFrom(addressFrom); InternetAddress[] addressTo = new InternetAddress[recipients.length]; for (int i = 0; i < recipients.length; i++) { addressTo[i] = new InternetAddress(recipients[i]); } msg.setRecipients(Message.RecipientType.TO, addressTo); // Optional : You can also set your custom headers in the Email if you Want msg.addHeader("MyHeaderName", "myHeaderValue"); // Setting the Subject and Content Type msg.setSubject(subject); msg.setContent(message, "text/plain"); Transport.send(msg); } }

    Read the article

  • RegularExpression-esque search matching Objects in List

    - by Pindatjuh
    I'm currently working on an implementation of the following idea, and I was wondering if there is any literature on this subject. Working with Java, but the principle applies on any language with a decent type-system, I like to implement: matching Objects from a List using a RegularExpression-esque search: So let's say I have a List containing List<Object> x = new ArrayList<Object>(); x.add(new Object()); x.add("Hello World"); x.add("Second String"); x.add(5); // Integer (auto-boxing) x.add(6); // Integer Then I create a "Regular Expression" (not working with a stream of characters, but working with a stream of Objects), and instead of character-classes, I use type-system properties: [String][Integer] And this would match one sublist: {Match["Second String", 5]}. The expression: [String:length()<15] Will match two sublist (each of length 1) containing a String which instance is passing the expression instance.length() < 5: {Match["Hello World"],Match["Second String"]}. [Object][Object] Matches any pair in the List: {Match[Object,"Hello World"],Match["Second String", 5]}, in a streamed manner (no overlapping matches). Ofcourse, my implementation will have grouping, lookahead/lookbehinds and is hierarchical (i.e. matching n elements from Lists in Lists), etc. The above merely illustrates the concept. Is there a name for this principle, and is there literature available on it?

    Read the article

  • Modeling multiple polymorphic relationships using Hibernate

    - by f-potter
    Ruby on Rails has polymorphic relations which are really useful for implementing functionality such as commenting, tagging and rating to name a few. We can have a comment, tag or rating class which has a many to one polymorphic relationship with a commentable, taggable and rateable object. Also, a given domain object can choose to implement any combination of such relations. So, it can for example be commentable, taggable and rateable at the same time. I couldn't think up of a straightforward way to duplicate this functionality in Hibernate. Ideally, there would be a Comment class which will have a many to one relationship with a Commentable class and a Commentable class will conversely have a one to many relationship with Comments. It will be ideal if the concrete domain classes can inherit from a number of such classes, say Commentable and Taggable. Things seem a little complicated as a Java class can only extend one other class and some code might end up being duplicated across a number of classes. I wanted to know what are the best practices for modeling such relationships neatly and concisely using Hibernate?

    Read the article

  • How do I read text from a serial port?

    - by user2164
    I am trying to read data off of a Windows serial port through Java. I have the javax.comm libraries and am able to get some data but not correct data. When I read the port into a byte array and convert it to text I get a series of characters but no real text string. I have tried to specify the byte array as being both "UTF-8" and "US-ASCII". Does anyone know how to get real text out of this? Here is my code: while (inputStream.available() > 0) { int numBytes = inputStream.read(readBuffer); System.out.println("Reading from " + portId.getName() + ": "); System.out.println("Read " + numBytes + " bytes"); } System.out.println(new String(readBuffer)); System.out.println(new String(readBuffer, "UTF-8")); System.out.println(new String(readBuffer, "US-ASCII")); the output of the first three lines will not let me copy and paste (I assume because they are not normal characters). Here is the output of the Hex: 78786000e67e9e60061e8606781e66e0869e98e086f89898861878809e1e9880 I am reading from a Hollux GPS device which does output in string format. I know this for sure because I did it through C#. The settings that I am using for communication which I know are right from the work in the C# app are: Baud Rate: 9600 Databits: 8 Stop bit: 1 parity: none

    Read the article

< Previous Page | 645 646 647 648 649 650 651 652 653 654 655 656  | Next Page >