Search Results

Search found 32961 results on 1319 pages for 'java'.

Page 894/1319 | < Previous Page | 890 891 892 893 894 895 896 897 898 899 900 901  | Next Page >

  • Passing arguments between classes - use public properties or pass a properties class as argument?

    - by devoured elysium
    So let's assume I have a class named ABC that will have a list of Point objects. I need to make some drawing logic with them. Each one of those Point objects will have a Draw() method that will be called by the ABC class. The Draw() method code will need info from ABC class. I can only see two ways to make them have this info: Having Abc class make public some properties that would allow draw() to make its decisions. Having Abc class pass to draw() a class full of properties. The properties in both cases would be the same, my question is what is preferred in this case. Maybe the second approach is more flexible? Maybe not? I don't see here a clear winner, but that sure has more to do with my inexperience than any other thing. If there are other good approaches, feel free to share them. Here are both cases: class Abc1 { public property a; public property b; public property c; ... public property z; public void method1(); ... public void methodn(); } and here is approach 2: class Abc2 { //here we make take down all properties public void method1(); ... public void methodn(); } class Abc2MethodArgs { //and we put them here. this class will be passed as argument to //Point's draw() method! public property a; public property b; public property c; ... public property z; } Also, if there are any "formal" names for these two approaches, I'd like to know them so I can better choose the tags/thread name, so it's more useful for searching purposes. That or feel free to edit them.

    Read the article

  • Android: Prompt user to save changes when Back button is pressed

    - by chriskopec
    I have an activity that contains several user editable items (an EditText field, RatingBar, etc). I'd like to prompt the user if the back/home button is pressed and changes have been made that have not yet been saved. After reading through the android documentation, it seems like this piece of code should go in the onPause method. I've tried putting an AlertDialog in the onPause however the dialog gets shown and then immediately tears down because nothing is there to block the pause from completing. This is what I've come up with so far: @Override protected void onPause() { super.onPause(); AlertDialog ad = new AlertDialog.Builder(this).setMessage( R.string.rating_exit_message).setTitle( R.string.rating_exit_title).setCancelable(false) .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { // User selects OK, save changes to db } }).setNeutralButton(android.R.string.cancel, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { // User selects Cancel, discard all changes } }).show(); } Am I on the right track or is there another way to accomplish what I'm trying to do here? Any help would be great!

    Read the article

  • Implementing deadlock condition

    - by Bhaskar
    I am trying to implementing deadlock condition but somehow I am not able to get it working. Both the threads Thread1 and Thread2 are entering in the run function but only one of them enters in Sub/Sum depending on who entered run first. Example : if Thread2 entered run first the it will call sub() and Thread1 never calls sum(). I have also added sleep time so that Thread2 sleeps before calling sum() and Thread1 gets enough time to enter Sum() but Thread1 never enters. public class ExploringThreads { public static void main(String[] args) { // TODO Auto-generated method stub threadexample a1 = new threadexample(); Thread t1 = new Thread(a1, "Thread1"); Thread t2 = new Thread(a1,"Thread2"); t1.start(); t2.start(); } } class threadexample implements Runnable{ public int a = 10; public void run(){ if(Thread.currentThread().getName().equals("Thread1")) sum(); else if(Thread.currentThread().getName().equals("Thread2")) sub(); } public synchronized void sum() { try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(Thread.currentThread().getName()+"In Sum"); sub(); } public synchronized void sub() { try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(Thread.currentThread().getName()+"In Sub"); sum(); } }

    Read the article

  • Use of mouselisteners in a jTable

    - by eli1987
    I have a jTable with columns 'Job_no' and 'Status'with values such as: Job_no Status 1 Active 2 Pending 3 Pending I would like it so that if a user clicks on a Status say in this case the first 'Pending'(where Job_no = 2) an inputDialog pops up allowing the user to change the status of the cell clicked-how can I do this? Bear in mind you will also have to retrieve the Job_no(that corresponds to that status) somehow, and that, though I'm OK with JOptionPane's, I'm new to JTables. I'm using JDBC(mySQL) and have a table 'Jobs' which amongst other things, has column Job_no and status. Thanks for your help.

    Read the article

  • RAD - Websphere Application server won't start

    - by Caroline
    I am having issues with RAD7. My server will not start for me today. I am working from home and connected to the VPN. Everything works except my server in RAD. It worked fine yesterday in work and had previously worked when I was at home but that was a few weeks ago. Are there any settings that I should look out for? I have disabled my proxy settings in RAD and turned off everything in my firewall. I can ping all the DBs that the server is connecting to. I have even removed all the projects from the server and it will still not start. It keeps trying and then times out after 300s. Any suggestions?

    Read the article

  • Can I have two names for the same variable?

    - by Roman
    The short version of the question: I do: x = y. Then I change x, and y is unchanged. What I want is to "bind" x and y in such a way that I change y whenever I change x. The extended version (with some details): I wrote a class ("first" class) which generates objects of another class ("second" class). In more details, every object of the second class has a name as a unique identifier. I call a static method of the first class with a name of the object from the second class. The first class checks if such an object was already generated (if it is present in the static HashMap of the first class). If it is already there, it is returned. If it is not yet there, it is created, added to the HashMap and returned. And then I have the following problem. At some stage of my program, I take an object with a specific name from the HashMap of the first class. I do something with this object (for example change values of some fields). But the object in the HashMap does not see these changes! So, in fact, I do not "take" an object from the HashMap, I "create a copy" of this object and this is what I would like to avoid.

    Read the article

  • how to implement this observer pattern?

    - by lethal
    Hello. I have 4 classes, that describe state diagram. Node, Edge, ComponentOfNode, ComponentOfEdge. ComponentOfEdge compounds from ComponentsOfNode. Node can have 0..n outgoing edges. Edge can have only 2 nodes. Edge should be able to offer ComponentOfNode, but only from nodes that Edge has, in form ComponentOfEdge. The user can change ComponentsOfNode. I need this change spreads to all Edge. Hw to do it? I expect the observer should be used. Can you give me example in pseudocode please?

    Read the article

  • Hibernate Persistence problems with Bean Mapping (Dozer)

    - by BuffaloBuffalo
    I am using Hibernate 3, and having a particular issue when persisting a new Entity which has an association with an existing detached entity. Easiest way to explain this is via code samples. I have two entities, FooEntity and BarEntity, of which a BarEntity can be associated with many FooEntity: @Entity public class FooEntity implements Foo{ @Id private Long id; @ManyToOne(targetEntity = BarEntity.class) @JoinColumn(name = "bar_id", referencedColumnName = "id") @Cascade(value={CascadeType.ALL}) private Bar bar; } @Entity public class BarEntity implements Bar{ @Id private Long id; @OneToMany(mappedBy = "bar", targetEntity = FooEntity.class) private Set<Foo> foos; } Foo and Bar are interfaces that loosely define getters for the various fields. There are corresponding FooImpl and BarImpl classes that are essentially just the entity objects without the annotations. What I am trying to do is construct a new instance of FooImpl, and persist it after setting a number of fields. The new Foo instance will have its 'bar' member set to an existing Bar (runtime being a BarEntity) from the database (retrieved via session.get(..)). After the FooImpl has all of its properties set, Apache Dozer is used to map between the 'domain' object FooImpl and the Entity FooEntity. What Dozer is doing in the background is instantiating a new FooEntity and setting all of the matching fields. BarEntity is cloned as well via instantiation and set the FooEntity's 'bar' member. After this occurs, passing the new FooEntity object to persist. This throws the exception: org.hibernate.PersistentObjectException: detached entity passed to persist: com.company.entity.BarEntity Below is in code the steps that are occurring FooImpl foo = new FooImpl(); //returns at runtime a persistent BarEntity through session.get() Bar bar = BarService.getBar(1L); foo.setBar(bar); ... //This constructs a new instance of FooEntity, with a member 'bar' which itself is a new instance that is detached) FooEntity entityToPersist = dozerMapper.map(foo, FooEntity.class); ... session.persist(entityToPersist); I have been able to resolve this issue by either removing or changing the @Cascade annotation, but that limits future use for say adding a new Foo with a new Bar attached to it already. Is there some solution here I am missing? I would be surprised if this issue hasn't been solved somewhere before, either by altering how Dozer Maps the children of Foo or how Hibernate reacts to a detached Child Entity.

    Read the article

  • Does it mean JVM Suspended?

    - by Joe.wang
    When my application run . I got a message says : Ping: Timed out waiting for signal from JVM. The JVM was launched with debug options so this may be because the JVM is currently suspended by a debugger. Any future timeouts during this JVM invocation will be silently ignored. What does that mean? It seems it will block any web request from outside? because when I upload a file to it, it failed. help me .

    Read the article

  • Does thread pool size keep growing for scheduledthreadpoolexecutor?

    - by Sourajit Basak
    Imagine a situation where tasks are being added to scheduledthreadpoolexecutor. Each of these tasks will keep on running at different periodic intervals. Although all such tasks will not be running at the same time because each is set at different intervals, there may be a situation where a high number of threads are competing for execution. Is there any restriction on total number of threads ? It seems there is a restriction on the total number of idle threads. And does this concept of idle thread imply that long running tasks (thread) may be destroyed and recreated when needed ?

    Read the article

  • How to define a class with variable properties?

    - by user1723326
    I'm making a database program. I want the user to be able to define their own columns, as many as they want. How would I then define each record in its class file?(Since the properties would be different user to user) EDIT: It's part of a school assignment-it's going to hold different scores and the likes for the teacher for different students they can add, but they will also be able to add a new assignment, test(a column) .

    Read the article

  • arrayListOutOfBoundsException... Please Help?

    - by Jacob
    This is my class Debugger. Can anyone try and run it and see whens wrong? Ive spent hours on it already. :( public class Debugger { private String codeToDebug = ""; public Debugger(String code) { codeToDebug = code; } /** * This method itterates over a css file and adds all the properties to an arraylist */ public void searchDuplicates() { boolean isInside = false; ArrayList<String> methodStorage = new ArrayList(); int stored = 0; String[] codeArray = codeToDebug.split(""); try { int i = 0; while(i<codeArray.length) { if(codeArray[i].equals("}")) { isInside = false; } if(isInside && !codeArray[i].equals(" ")) { boolean methodFound = false; String method = ""; int c = i; while(!methodFound) { method += codeArray[c]; if(codeArray[c+1].equals(":")) { methodFound = true; } else { c++; } } methodStorage.add(stored, method); System.out.println(methodStorage.get(stored)); stored++; boolean stillInside = true; int skip = i; while(stillInside) { if(codeArray[skip].equals(";")) { stillInside = false; } else { skip++; } } i = skip; } if(codeArray[i].equals("{")) { isInside = true; } i++; } } catch(ArrayIndexOutOfBoundsException ar) { System.out.println("------- array out of bounds exception -------"); } } /** * Takes in String and outputs the number of characters it contains * @param input * @return Number of characters */ public static int countString(String input) { String[] words = input.split(""); int counter = -1; for(int i = 0; i<words.length; i++){ counter++; } return counter; } public static void main(String[] args) { Debugger h = new Debugger("body {margin:;\n}"); h.searchDuplicates(); } }

    Read the article

  • Creating objects makes the VM faster?

    - by Sudhir Jonathan
    Look at this piece of code: MessageParser parser = new MessageParser(); for (int i = 0; i < 10000; i++) { parser.parse(plainMessage, user); } For some reason, it runs SLOWER (by about 100ms) than for (int i = 0; i < 10000; i++) { MessageParser parser = new MessageParser(); parser.parse(plainMessage, user); } Any ideas why? The tests were repeated a lot of times, so it wasn't just random. How could creating an object 10000 times be faster than creating it once?

    Read the article

  • change a frame's attribute by pressing a button

    - by asavu
    Hi. Suppose we have a JFrame named frame1 with a String attribute named credentials set inittially to null. I have a jButton named button1 attached to the frame and I want to change the frame1 String credentials attribute by pressing button1. I need some piece of advice regarding the ActionListener code especially. Could you guys pls help me? Thank you.

    Read the article

  • GET is not working for firstResource Rest example

    - by Anandan
    Hi, I am newbie to rest. I am using the following code example to understand the RESTlet. http://www.restlet.org/documentation/1.1/firstResource I am using RESTClient addon to firefox for testing. When i do GET on http://localhost/rest, i get a response "ok". But when i do GET on http://localhost/items, I get an error "404 Not found" Here's the sample code: public synchronized Restlet createRoot() { Router router = new Router(getContext()); router.attach("/items", ItemsResource.class); router.attach("/items/{itemName}", ItemResource.class); Restlet restlet = new Restlet() { @Override public void handle(Request request, Response response) { StringBuilder stringBuilder = new StringBuilder(); stringBuilder.append("ok"); response.setEntity(new StringRepresentation(stringBuilder .toString(), MediaType.TEXT_HTML)); } }; router.attach("/rest", restlet); return router; } ItemResource is same as provided in the link. and I use tomcat to run the servlet. Why am I getting the "Not found" error? Am i missing something here? Thanks & Regards, Anandan

    Read the article

  • Jaxb to generate the XML directly to the OutputStream

    - by sonu
    Hi, I have a 500Mb csv file. I need to convert it into XML file. I am using the Jaxb to created the xml file. It is working fine for small amout of data. but for large amout of data like 300 mb it is throwing out of memory exception. Can anyone tell me that How can I create each element and write it into a file without creating the whole tree using the jaxb?" Thanks Sonu

    Read the article

  • Complete list of Fonts which support

    - by Yan Cheng CHEOK
    Currently, if I change the locale setting of my application by Locale.setDefault(Locale.ENGLISH); Locale.setDefault(Locale.SIMPLIFIED_CHINESE); What I understand from this JFreeChart forum is that, I am not using correct font. Once you get the reference of the LegentTitle, you can set it to any font. Apparently, JFreeChart's default is "Tahoma" and it doesn't support Chinese characters. May I know, how I can programmatic determine, as list of available Fonts in my system, which support Chinese? I can hard code it to Serif (It fully support Chinese, doesn't it?), its look n feel doesn't looks good to me. I would like to have more choices.

    Read the article

< Previous Page | 890 891 892 893 894 895 896 897 898 899 900 901  | Next Page >