Search Results

Search found 33141 results on 1326 pages for 'java opts'.

Page 643/1326 | < Previous Page | 639 640 641 642 643 644 645 646 647 648 649 650  | Next Page >

  • Elegantly handling constraint violations in EJB/JPA environment?

    - by hallidave
    I'm working with EJB and JPA on a Glassfish v3 app server. I have an Entity class where I'm forcing one of the fields to be unique with a @Column annotation. @Entity public class MyEntity implements Serializable { private String uniqueName; public MyEntity() { } @Column(unique = true, nullable = false) public String getUniqueName() { return uniqueName; } public void setUniqueName(String uniqueName) { this.uniqueName = uniqueName; } } When I try to persist an object with this field set to a non-unique value I get an exception (as expected) when the transaction managed by the EJB container commits. I have two problems I'd like to solve: 1) The exception I get is the unhelpful "javax.ejb.EJBException: Transaction aborted". If I recursively call getCause() enough times, I eventually reach the more useful "java.sql.SQLIntegrityConstraintViolationException", but this exception is part of the EclipseLink implementation and I'm not really comfortable relying on it's existence. Is there a better way to get detailed error information with JPA? 2) The EJB container insists on logging this error even though I catch it and handle it. Is there a better way to handle this error which will stop Glassfish from cluttering up my logs with useless exception information? Thanks.

    Read the article

  • Selenium and Firefox 9's "Will you help improve Mozilla Firefox" popup

    - by Rup
    I'm trying to test a Java web app using Selenium 2.16.1. When Selenium opens Firefox, I see a band at the top of the page with message "Will you help improve Mozilla Firefox" For some reason this breaks selenium.click("id=submit"); selenium.waitForPageToLoad("60000"); which is trying to log in - it becomes a no-op, and the test fails because it's then expecting to have logged in. If I break on the click line and clear the 'will you help' band before continuing then the form submit succeeds. Is there a way to suppress this band from appearing? (I expect that would mean setting a property in Firefox's default profile - where do I find that?) Or is there a way to get Selenium to spot and dismiss this first? Thanks! I'm using Firefox 9.0.1. Solved - thanks Danny! Just in case it isn't clear from the answers and comments below: This was an issue with 2.16.1 and IMO the best solution is to upgrade to 2.17 or later.

    Read the article

  • Covariance and Contravariance inference in C# 4.0

    - by devoured elysium
    When we define our interfaces in C# 4.0, we are allowed to mark each of the generic parameters as in or out. If we try to set a generic parameter as out and that'd lead to a problem, the compiler raises an error, not allowing us to do that. Question: If the compiler has ways of inferring what are valid uses for both covariance (out) and contravariance(in), why do we have to mark interfaces as such? Wouldn't it be enough to just let us define the interfaces as we always did, and when we tried to use them in our client code, raise an error if we tried to use them in an un-safe way? Example: interface MyInterface<out T> { T abracadabra(); } //works OK interface MyInterface2<in T> { T abracadabra(); } //compiler raises an error. //This makes me think that the compiler is cappable //of understanding what situations might generate //run-time problems and then prohibits them. Also, isn't it what Java does in the same situation? From what I recall, you just do something like IMyInterface<? extends whatever> myInterface; //covariance IMyInterface<? super whatever> myInterface2; //contravariance Or am I mixing things? Thanks

    Read the article

  • how to use "tab space" while writing in text file

    - by Manu
    SimpleDateFormat formatter = new SimpleDateFormat("ddMMyyyy_HHmmSS"); String strCurrDate = formatter.format(new java.util.Date()); String strfileNm = "Cust_Advice_" + strCurrDate + ".txt"; String strFileGenLoc = strFileLocation + "/" + strfileNm; String strQuery="select name, age, data from basetable; try { stmt = conn.createStatement(); System.out.println("Query is -> " + strQuery); rs = stmt.executeQuery(strQuery); File f = new File(strFileGenLoc); OutputStream os = (OutputStream)new FileOutputStream(f); String encoding = "UTF8"; OutputStreamWriter osw = new OutputStreamWriter(os, encoding); BufferedWriter bw = new BufferedWriter(osw); while (rs.next() ) { bw.write(rs.getString(1)==null? "":rs.getString(1)); bw.write(" "); bw.write(rs.getString(2)==null? "":rs.getString(2)); bw.write(" "); } bw.flush(); bw.close(); } catch (Exception e) { System.out.println( "Exception occured while getting resultset by the query"); e.printStackTrace(); } finally { try { if (conn != null) { System.out.println("Closing the connection" + conn); conn.close(); } } catch (SQLException e) { System.out.println( "Exception occured while closing the connection"); e.printStackTrace(); } } return objArrayListValue; } i need "one tab space" in between each column(while writing to text file). like manu 25 data1 manc 35 data3 in my code i use bw.write(" ") for creating space between each column. how to use "one tab space" in that place instead of giving "space".

    Read the article

  • Best architecture for a social media app

    - by Sky
    Hey guys, Im working on promising project that develops a new social media app for web and mobile. We are at begin defining functionalities. Nevertheless, I'm thinking ahead on architecture. So I'm asking: 1 - Whats the best plataform to develop the core of this aplication that will have a Rest API interface. 2 - Whats the best database that will scale and grow with my application. As far as I researched, these were the answers I found most interesting: For database: Cassandra NoSQL DB, amazing scalabilty, amazing write performance, good read performance (will be improved on 0.6). I think i will choose that one. Zookeer for transactions on Cassandra. I think that 2 technologies rly good for that propose. What do you think guys? On the front end that will serve the REST API, i dont have a final candidate. For this one i have questions based on Perfomance X Scalabilty X Fast Development/Maintenance. Java or .Net As far as I researched, brings the best balance of this requisits. Python, pearl and Rail, has the best (Fast Development/Maintenance), but sux on all other. C or C++ I dont even consider, because its (Fast Development/Maintenance) sux... So what do you guy think about it?

    Read the article

  • Perl Script in background

    - by himz
    I have a perl script i made to automatically telnet into different servers . but its interface is only command line. To make it more user friendly for general windows users , i need to make GUI for it . My idea is to make GUI in a language like VB,java ,etc and let that call perl script . my script will run in background in a command prompt and whatever the result it displays back in GUI. Got some success. GUI in vb ,I run an instance of CMD in background ,run perl script in that .But that is wer program fails .As perl script runs in a thread for perl , i only get the output when script completes(rather say when it timeout). i need a mechanism where i can interact with the perl script , take output of script and show to user , then take input from user and so on . Please can you all suggest me some way to actually make this happen. PS: No limitation on using any language for GUI (as core work is done by perl script,GUI only there to give appropriate commands to script) Thanks in advance

    Read the article

  • .apk signing fails even with Sun JDK (java.lang.NoClassDefFoundError: com.android.jarutils.DebugKeyP

    - by ianweller
    I'm having an interesting problem signing my Android application, whether or not I'm using a debug key. Regardless of the JDK I have installed to /usr/bin/{java,keytool,jarsigner} (OpenJDK or Sun's JDK) it will always give the following output after compiling successfully: -package-debug-sign: [apkbuilder] Creating RemoteNotify-debug-unaligned.apk and signing it with a debug key... BUILD FAILED /home/ianweller/AndroidSDK/platforms/android-7/templates/android_rules.xml:281: The following error occurred while executing this line: /home/ianweller/AndroidSDK/platforms/android-7/templates/android_rules.xml:152: java.lang.NoClassDefFoundError: com.android.jarutils.DebugKeyProvider The application was built and signed just fine by Eclipse with the ADT plugin (even without Sun's JDK installed). I'm on Fedora 12. I'm wanting to get my code out of Eclipse and move it into a git repository, but being unable to build it from ant will not allow this to happen.

    Read the article

  • Ideas for a rudimentary software licensing implementation

    - by Ross
    I'm trying to decide how to implement a very basic licensing solution for some software I wrote. The software will run on my (hypothetical) clients' machines, with the idea being that the software will immediately quit (with a friendly message) if the client is running it on greater-than-n machines (n being the number of licenses they have purchased). Additionally, the clients are non-tech-savvy to the point where "basic" is good enough. Here is my current design, but given that I have little to no experience in the topic, I wanted to ask SO before I started any development on it: A remote server hosts a MySQL database with a table containing two columns: client-key and license quantity The client-side application connects to the MySQL database on startup, offering it's client-key that I've put into a properties file packaged into the distribution (I would create a new distribution for each new client) Chances are, I'll need a second table to store validation history, so that with some short logic, the software can decide if it can be run on a given machine (maybe a sliding window of n machines using the software per 24 hours) If the software cannot establish a connection to the MySQL database, or decides that it's over the n allowed machines per day, it closes The connection info for the remote server hosting the MySQL database should be hard-coded into the app? (That sounds like a bad idea, but otherwise they could point it to some other always-validates-to-success server) I think that about covers my initial design. The intent being that while it certainly isn't full-proof, I think I've made it at least somewhat difficult to create an easily-sharable cracking solution. Also, I can easily adjust the license amount for a given client/key pair. I gotta figure this has been done a million times before, so tell me about a better solution that's just as simple to implement and provides the same (low) amount of security. In the event that external libraries are used, I prefer Java, as that's what the software has been written in.

    Read the article

  • Unable to upload large files on FTP using Apache commons-net-3.1

    - by Nitin
    I am trying to upload the one large file ( more than 8 MB) using storeFile(remote, local) method of FTPClient but it results false.It get uploaded with some extra bytes.Following is the code with Output: public class Main { public static void main(String[] args) { FTPClient client = new FTPClient(); FileInputStream fis = null; try { client.connect("208.106.181.143"); client.setFileTransferMode(client.BINARY_FILE_TYPE); client.login("abc", "java"); int reply = client.getReplyCode(); System.out.println("Received Reply from FTP Connection:" + reply); if(FTPReply.isPositiveCompletion(reply)){ System.out.println("Connected Success"); } client.changeWorkingDirectory("/"+"Everbest"+"/"); client.makeDirectory("ETPSupplyChain5.3-EvbstSP3"); client.changeWorkingDirectory("/"+"Everbest"+"/"+"ETPSupplyChain5.3-EvbstSP3"+"/"); FTPFile[] names = client.listFiles(); String filename = "E:\\Nitin\\D-Drive\\Installer.rar"; fis = new FileInputStream(filename); boolean result = client.storeFile("Installer.rar", fis); int replyAfterupload = client.getReplyCode(); System.out.println("Received Reply from FTP Connection replyAfterupload:" + replyAfterupload); System.out.println("result:"+result); for (FTPFile name : names) { System.out.println("Name = " + name); } client.logout(); fis.close(); client.disconnect(); } catch (SocketException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } o/p: Received Reply from FTP Connection:230 Connected Success 32 /Everbest/ETPSupplyChain5.3-EvbstSP3 Received Reply from FTP Connection replyAfterupload:150 result:false

    Read the article

  • Help with Neuroph neural network

    - by user359708
    For my graduate research I am creating a neural network that trains to recognize images. I am going much more complex than just taking a grid of RGB values, downsampling, and and sending them to the input of the network, like many examples do. I actually use over 100 independently trained neural networks that detect features, such as lines, shading patterns, etc. Much more like the human eye, and it works really well so far! The problem is I have quite a bit of training data. I show it over 100 examples of what a car looks like. Then 100 examples of what a person looks like. Then over 100 of what a dog looks like, etc. This is quite a bit of training data! Currently I am running at about one week to train the network. This is kind of killing my progress, as I need to adjust and retrain. I am using Neuroph, as the low-level neural network API. I am running a dual-quadcore machine(16 cores with hyperthreading), so this should be fast. My processor percent is at only 5%. Are there any tricks on Neuroph performance? Or Java peroformance in general? Suggestions? I am a cognitive psych doctoral student, and I am decent as a programmer, but do not know a great deal about performance programming.

    Read the article

  • How to create a Binary Tree from a General Tree?

    - by mno4k
    I have to solve the following constructor for a BinaryTree class in java: BinaryTree(GeneralTree<T> aTree) This method should create a BinaryTree (bt) from a General Tree (gt) as follows: Every Vertex from gt will be represented as a leaf in bt. If gt is a leaf, then bt will be a leaf with the same value as gt If gt is not a leaf, then bt will be constructed as an empty root, a left subTree (lt) and a right subTree (lr). Lt is a stric binary tree created from the oldest subtree of gt (the left-most subtree) and lr is a stric binary tree created from gt without its left-most subtree. The frist part is trivial enough, but the second one is giving me some trouble. I've gotten this far: public BinaryTree(GeneralTree<T> aTree){ if (aTree.isLeaf()){ root= new BinaryNode<T>(aTree.getRootData()); }else{ root= new BinaryNode<T>(null); // empty root LinkedList<GeneralTree<T>> childs = aTree.getChilds(); // Childs of the GT are implemented as a LinkedList of SubTrees child.begin(); //start iteration trough list BinaryTree<T> lt = new BinaryTree<T>(childs.element(0)); // first element = left-most child this.addLeftChild(lt); aTree.DeleteChild(hijos.elemento(0)); BinaryTree<T> lr = new BinaryTree<T>(aTree); this.addRightChild(lr); } } Is this the right way? If not, can you think of a better way to solve this? Thank you!

    Read the article

  • Create image from scratch with JMagick

    - by Michael IV
    I am using Java port of ImageMagick called JMagick .I need to be able to create a new image and write an arbitrary text chunk into it.The docs are very poor and what I managed to get so far is to write text into the image which comes from IO.Also , in all the examples I have found it seems like the very first operation ,before writing new image data , is always loading of an existing image into ImageInfo instance.How do I create an image from scratch with JMagick and then write a text into it? Here is what I do now : try { ImageInfo info = new ImageInfo(); info.setSize("512x512"); info.setUnits(ResolutionType.PixelsPerInchResolution); info.setColorspace(ColorspaceType.RGBColorspace); info.setBorderColor(PixelPacket.queryColorDatabase("red")); info.setDepth(8); BufferedImage img = new BufferedImage(512,512,BufferedImage.TYPE_4BYTE_ABGR); byte[] imageBytes = ((DataBufferByte) img.getData().getDataBuffer()).getData(); MagickImage mimage = new MagickImage(info,imageBytes); DrawInfo aInfo = new DrawInfo(info); aInfo.setFill(PixelPacket.queryColorDatabase("green")); aInfo.setUnderColor(PixelPacket.queryColorDatabase("yellow")); aInfo.setOpacity(0); aInfo.setPointsize(36); aInfo.setFont("Arial"); aInfo.setTextAntialias(true); aInfo.setText("JMagick Tutorial"); aInfo.setGeometry("+40+40"); mimage.annotateImage(aInfo); mimage.setFileName("text.jpg"); mimage.writeImage(info); } catch (MagickException ex) { Logger.getLogger(LWJGL_IDOMOO_SIMPLE_TEST.class.getName()).log(Level.SEVERE, null, ex); } It doesn't work , the JVM crashes with access violation as it probably expects for the input image from IO.

    Read the article

  • Overriding equals method without breaking symmetry in a class that has a primary key

    - by Kosta
    Hi, the answer to this question is probably "not possible", but let me ask regardless :) Assuming we have a very simple JAVA class that has a primary key, for example: class Person { String ssid; String name; String address; ... } Now, I want to store people in a collection, meaning I will have to override the equals method. Not a completely trivial matter, but on a bare basis I will have something along the lines of: @Override public boolean equals (Object other) { if(other==this) return true; if(!other.getClass().equals(this.getClass()) return false; Person otherPerson = (Person)other; if(this.ssid.equals(otherPerson.getSsid()) return true; } Excuse any obvious blunders, just typing this out of my head. Now, let's say later on in the application I have a ssid I obtained through user input. If I want to compare my ssid to a Person, I would have to call something like: String mySsid = getFromSomewhere(); Person myPerson = getFromSomewhere(); if(myPerson.equals(new Person(mySsid)) doSomething(); This means I have to create a convenience constructor to create a Person based on ssid (if I don't already have one), and it's also quite verbose. It would be much nicer to simply call myPerson.equals(mySsid) but if I added a string comparison to my Person equals class, that would break the symmetry property, since the String hasn't got a clue on how to compare itself to a Person. So finally, the big question, is there any way to enable this sort of "shorthand" comparisons using the overriden equals method, and without breaking the symmetry rule? Thanks for any thoughts on this!

    Read the article

  • Calling an Oracle PL/SQL procedure with Custom Object return types from 0jdbc6 JDBCthin drivers

    - by Andrew Harmel-Law
    I'm writing some JDBC code which calls a Oracle 11g PL/SQL procdedure which has a Custom Object return type. Whenever I try an register my return types, I get either ORA-03115 or PLS-00306 as an error when the statement is executed depending on the type I set. An example is below: PLSQL Code: Procedure GetDataSummary (p_my_key IN KEYS.MY_KEY%TYPE, p_recordset OUT data_summary_tab, p_status OUT VARCHAR2); Java Code: String query = "beginmanageroleviewdata.getdatasummary(?, ?, ?); end;"); CallableStatement stmt = conn.prepareCall(query); stmt.setInt(1, 83); stmt.registerOutParameter(2, OracleTypes.CURSOR); // Causes error: PLS-00306 stmt.registerOutParameter(3, OracleTypes.VARCHAR); stmt.execute(stmt); // Error mentioned above thrown here. Can anyone provide me with an example showing how I can do this? I guess it's possible. However I can't see a rowset OracleType. CURSOR, REF, DATALINK, and more fail. Apologies if this is a dumb question. I'm not a PL/SQL expert and may have used the wrong terminology in some areas of my question. (If so, please edit me). Thanks in advance. Regs, Andrew

    Read the article

  • SWT: problems with clicking button after using setEnabled() on Linux

    - by Laimoncijus
    Hi, I have a strange case with SWT and Button after using setEnabled() - seems if I disable and enable button at least once - I cannot properly click with mouse on it anymore... Already minify code to very basic: import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class TestButton { public TestButton() { Display display = new Display(); Shell shell = new Shell(display); GridLayout mainLayout = new GridLayout(); shell.setLayout(mainLayout); shell.setSize(100, 100); Button testButton = new Button(shell, SWT.PUSH); testButton.addSelectionListener(new TestClickListener()); testButton.setText("Click me!"); //testButton.setEnabled(false); //testButton.setEnabled(true); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); } class TestClickListener implements SelectionListener { @Override public void widgetDefaultSelected(SelectionEvent e) { } @Override public void widgetSelected(SelectionEvent e) { System.out.println("Click!"); } } public static void main(String[] args) { new TestButton(); } } When I keep these 2 lines commented out - I can properly click on a button and always get "Click!" logged, but if I uncomment them - then I can't click on button properly with mouse anymore - button visually seems to be clicked, but nothing is logged... Am I doing something wrong here? Or maybe it's some kind of bug on Linux platform? Because on Mac running the same code I never experienced such problems... Thanks for any hint! P.S. Running code on Ubuntu 9.10, Gnome + Compiz, Sun Java 1.6.0.16

    Read the article

  • java.lang.Void in C#?

    - by user313661
    Hi, I am currently working with .Net 2.0 and have an interface whose generic type is used to define a method's return type. Something like interface IExecutor<T> { T Execute() { ... } } My problem is that some classes that implement this interface do not really need to return anything. In Java you can use java.lang.Void for this purpose, but after quite a bit of searching I found no equivalent in C#. More generically, I also did not find a good way around this problem. I tried to find how people would do this with delegates, but found nothing either - which makes me believe that the problem is that I suck at searching :) So what's the best way to solve this? How would you do it? Thanks!

    Read the article

  • Spring 2.5 managed servlets: howto?

    - by EugeneP
    Correct me if anything is wrong. As I understand, all Spring functionality, namely DI works when beans are got thru Spring Context, ie getBean() method. Otherwise, none can work, even if my method is marked @Transactional and I will create the owning class with a new operator, no transaction management will be provided. I use Tomcat 6 as a servlet container. So, my question is: how to make Servlet methods managed by Spring framework. The issue here is that I use a framework, and its servlets extend the functionality of basic java Servlets, so they have more methods. Still, web.xml is present in an app as usual. The thing is that I do not control the servlets creation flow, I can only override a few methods of each servlet, the flow is basically written down in some xml file, but I control this process using a graphical gui. So, basically, I only add some code to a few methods of each Servlet. How to make those methods managed by Spring framework? The basic thing I need to do is making these methods transactional (@Transactional).

    Read the article

  • Urgent: Sort HashSet() function data in sequence

    - by vincent low
    i am new to java, the function i like to perform is something like: i will load a series of data from a file, into my hashSet() function. the problem is, i able to enter all the data in sequence, but i cant retrieve it out in sequence base on the account name in the file. any 1 can help to give a comment? below is my code: public Set retrieveHistory(){ Set dataGroup = new HashSet(); try{ File file = new File("C:\\Documents and Settings\\vincent\\My Documents\\NetBeansProjects\\vincenttesting\\src\\vincenttesting\\vincenthistory.txt"); BufferedReader br = new BufferedReader(new FileReader(file)); String data = br.readLine(); while(data != null){ System.out.println("This is all the record:"+data); Customer cust = new Customer(); //break the data based on the , String array[] = data.split(","); cust.setCustomerName(array[0]); cust.setpassword(array[1]); cust.setlocation(array[2]); cust.setday(array[3]); cust.setmonth(array[4]); cust.setyear(array[5]); cust.setAmount(Double.parseDouble(array[6])); cust.settransaction(Double.parseDouble(array[7])); dataGroup.add(cust); //then proced to read next customer. data = br.readLine(); } br.close(); }catch(Exception e){ System.out.println("error" +e); } return dataGroup; } public static void main(String[] args) { FileReadDataModel fr = new FileReadDataModel(); Set customerGroup = fr.retrieveHistory(); System.out.println(e); for(Object obj : customerGroup){ Customer cust = (Customer)obj; System.out.println("Cust name :" +cust.getCustomerName()); System.out.println("Cust amount :" +cust.getAmount()); }

    Read the article

  • Basic File upload in GWT

    - by Maksim
    I'm trying to figure out how to upload one file using GWTs FileUpload widget. I'm using GWT and Google AppEngine with Java but I would like to upload file to my own Linux server. I have the following code already but now I can't figure out how to submit my file to the Google AppServer server and save it to another server: public class FileUploader{ private ControlPanel cp; private FormPanel form = new FormPanel(); private FileUpload fu = new FileUpload(); public FileUploader(ControlPanel cp) { this.cp = cp; this.cp.setPrimaryArea(getFileUploaderWidget()); } @SuppressWarnings("deprecation") public Widget getFileUploaderWidget() { form.setEncoding(FormPanel.ENCODING_MULTIPART); form.setMethod(FormPanel.METHOD_POST); // form.setAction(/* WHAT SHOULD I PUT HERE */); VerticalPanel holder = new VerticalPanel(); fu.setName("upload"); holder.add(fu); holder.add(new Button("Submit", new ClickHandler() { public void onClick(ClickEvent event) { GWT.log("You selected: " + fu.getFilename(), null); form.submit(); } })); form.addSubmitHandler(new FormPanel.SubmitHandler() { public void onSubmit(SubmitEvent event) { if (!"".equalsIgnoreCase(fu.getFilename())) { GWT.log("UPLOADING FILE????", null); // NOW WHAT???? } else{ event.cancel(); // cancel the event } } }); form.addSubmitCompleteHandler(new FormPanel.SubmitCompleteHandler() { public void onSubmitComplete(SubmitCompleteEvent event) { Window.alert(event.getResults()); } }); form.add(holder); return form; } } Now, what do I need to do next? What do i need to put in web.xml and how do I write my servlet so i can store file and return url of that object (if possible)

    Read the article

  • Android Debugging InetAddress.isReachable

    - by badMonkey
    I am trying to figure out how to tell if a particular ipaddress is available in my android app during debugging ( I haven't tried this on an actual device ). From reading it appears that InetAddress.isReachable should do this for me. Initially I thought that I could code something like: InetAddress address = InetAddress.getByAddress( new byte[] { (byte) 192, (byte) 168, (byte) 254, (byte) 10 ); success = address.isReachable( 3000 ); This returns false even though I am reasonably sure it is a reachable address. I found that if I changed this to 127, 0, 0, 1 it returned success. My next attempt was same code, but I used the address I got from a ping of www.google.com ( 72.167.164.64 as of this writing ). No success. So then I tried a further example: int timeout = 2000; InetAddress[] addresses = InetAddress.getAllByName("www.google.com"); for (InetAddress address : addresses) { if ( address.isReachable(timeout)) { success = true; // just set a break point here } } I am relatively new to Java and Android so I suspect I am missing something, but I can't find anything that would indicate what that is.

    Read the article

  • Correct Interactive Website System Design Concepts / Methods?

    - by Xandel
    Hi all, I hope this question isn't too open ended, but a nudge in the right direction is all I need! I am currently building an online accounting system - the idea is that users can register, log in, and then create customers, generate invoices and other documents and eventually print / email those documents out. I am a Java programmer but unfortunately haven't had too much experience in web projects and their design concepts... This is what I have got thus far - A Tomcat web server which loads Spring. Spring handles my DAO's and required classes for the business logic. Tomcat serves JSP's containing the pages which make up the website. To make it interactive I have used JavaScript in the pages (jQuery and its AJAX calls) to send and receive JSON data (this is done by posting to a page which calls a handleAction() method in one of my classes). My question is, am I tackling this project in the right way? Am I using the right tools and methods? I understand there are literally countless ways of tackling any project but I would really love to get feedback with regards to tried and tested methods, general practices etc. Thanks in advance! Xandel

    Read the article

  • What is the correct way to handle object which is instance of class in apache.xerces?

    - by Roman
    Preface: I'm working on docx parser for java. docx format is based on xml. When I read document its parts are being unmarshalled (with JAXB). And I get a tree of certain elements based on xml markup. Almost problem: But some elements (which are at very deep xml level) returned not as certain class from docx spec (i.e. CTStyle, CTDrawing, CTInline etc) but as Object. Those objects are indeed instances of xerces classes, e.g. ElementNSImpl. Problem: How should I handle these objects. The simplest approach is: CTGraphicData gData = getGraphicData (); Object obj = gData.getAny().get(0); ElementNSImpl element = (ElementNSImpl)obj; But it doesn't seem to be a good solution. I've never worked with xerces directly. What is the better way to do this casting? (If anyone also give me a tip about right way to iterate through nodes it would be great).

    Read the article

  • compareTo and nested Enums

    - by echox
    Hi, in "A Programmers Guide to Java SCJP Certification" I found an example which I can't follow. This the given enum: enum Scale3 { GOOD(Grade.C), BETTER(Grade.B), BEST(Grade.A); enum Grade {A, B, C} private Grade grade; Scale3(Grade grade) { this.grade = grade; } public Grade getGrade() { return grade; } } This is the given expression: Scale3.GOOD.getGrade().compareTo(Scale3.Grade.A) > 0; I don't understand why this expression will be true? The return value will be 2. compareTo() will return a value 0 if the given object is "less" than the object. Scale3.Grade.A is the "biggest" element of Grades, its ordinal number is 0. Scale3.GOOD is the "biggest" element of Scale3, its ordinal number is also 0. The constructor of Scale3 is called with Scale3.Grade.C, which ordinal number is 2. So the given expression is equal to the following code: Scale3.Grade.C.compareTo(Scale3.Grade.A) > 0; A is "bigger" than C, so shouldn't be the result < 0?

    Read the article

  • Question about the Cloneable interface and the exception that should be thrown

    - by Nazgulled
    Hi, The Java documentation says: A class implements the Cloneable interface to indicate to the Object.clone() method that it is legal for that method to make a field-for-field copy of instances of that class. Invoking Object's clone method on an instance that does not implement the Cloneable interface results in the exception CloneNotSupportedException being thrown. By convention, classes that implement this interface should override Object.clone (which is protected) with a public method. See Object.clone() for details on overriding this method. Note that this interface does not contain the clone method. Therefore, it is not possible to clone an object merely by virtue of the fact that it implements this interface. Even if the clone method is invoked reflectively, there is no guarantee that it will succeed. And I have this UserProfile class: public class UserProfile implements Cloneable { private String name; private int ssn; private String address; public UserProfile(String name, int ssn, String address) { this.name = name; this.ssn = ssn; this.address = address; } public UserProfile(UserProfile user) { this.name = user.getName(); this.ssn = user.getSSN(); this.address = user.getAddress(); } // get methods here... @Override public UserProfile clone() { return new UserProfile(this); } } And for testing porpuses, I do this in main(): UserProfile up1 = new UserProfile("User", 123, "Street"); UserProfile up2 = up1.clone(); So far, no problems compiling/running. Now, per my understanding of the documentation, removing implements Cloneable from the UserProfile class should throw an exception in up1.clone() call, but it doesn't. I've read around here that the Cloneable interface is broken but I don't really know what that means. Am I missing something?

    Read the article

< Previous Page | 639 640 641 642 643 644 645 646 647 648 649 650  | Next Page >