Search Results

Search found 55248 results on 2210 pages for 'java memory model'.

Page 540/2210 | < Previous Page | 536 537 538 539 540 541 542 543 544 545 546 547  | Next Page >

• Which options do I have for Java process communication?

  - by Dmitriy Matveev

  We have a place in a code of such form: void processParam(Object param) { wrapperForComplexNativeObject result = jniCallWhichMayCrash(param); processResult(result); } processParam - method which is called with many different arguments. jniCallWhichMayCrash - a native method which is intended to do some complex processing of it's parameter and to create some complex object. It can crash in some cases. wrapperForComplexNativeObject - wrapper type generated by SWIG processResult - a method written in pure Java which processes it's parameter by creation of several kinds (by the kinds I'm not meaning classes, maybe some like hierarchies) of objects: 1 - Some non-unique objects which are referencing each other (from the same hierarchy), these objects can have duplicates created from the invocations of processParam() method with different parameter values. Since it's costly to keep all the duplicates it's necessary to cache them. 2 - Some unique objects which are referencing each other (from the same hierarchy) and some of the objects of 1st kind. After processParam is executed for each of the arguments from some set the data created in processResult will be processed together. The problem is in fact that jniCallWhichMayCrash method may crash the entire JVM and this will be very bad. The reason of crash may be such that it can happen for one argument value and not for the other. We've decided that it's better to ignore crashes inside of JVM and just skip some chunks of data when such crashes occur. In order to do this we should run processParam function inside of separate process and pass the result somehow (HOW? HOW?! This is a question) to the main process and in case of any crashes we will only lose some part of data (It's ok) without lose of everything else. So for now the main problem is implementation of transport between different processes. Which options do I have? I can think about serialization and transmitting of binary data by the streams, but serialization may be not very fast due to object complexity. Maybe I have some other options of implementing this?

  Read the article

• Passing the Class<T> in java of a generic list?

  - by Rob Stevenson-Leggett

  I have a method for reading JSON from a service, I'm using Gson to do my serialization and have written the following method using type parameters. public T getDeserializedJSON(Class<T> aClass,String url) { Reader r = getJSONDataAsReader(url); Gson gson = new Gson(); return gson.fromJson(r, aClass); } I'm consuming json which returns just an array of a type e.g. [ { "prop":"value" } { "prop":"value" } ] I have a java class which maps to this object let's call it MyClass. However to use my method I need to do this: RestClient<ArrayList<MyClass>> restClient = new RestClient<ArrayList<MyClass>>(); ArrayList<MyClass> results = restClient.getDeserializedJSON(ArrayList<MyClass>.class, url); However, I can't figure out the syntax to do it. Passing just ArrayList.class doesn't work. So is there a way I can get rid of the Class parameter or how do I get the class of the ArrayList of MyClass?

  Read the article

• Need a Concatenating VBA code to prevent memory issue workaround

  - by doharr

  My set up: Have 50,000 rows of data. ( My row count will increase in the future. So might as well say I have a full worksheet of 64000+ rows.) All Data is TEXT, no formulas, etc. Column A is open Columns B thru AC contain the Data that needs to be concatenated The Data in the rows once concatenated to Column A will contain 60,000 digits or 6kb in file size. After additional maniuplation each cell will become a file. I have tried concatenating in Excel and I run into memory issues. The memory issue is when I Select and fill down the concatenating function into the worksheet. It crashes at the 8200 +/-row. My system is 2gb of ram, windows xp professional and Excel 2003. Have 4GB of disk space Hoping to find a VBA code that will conserve memory, and not crash like it does in excel. Thank you

  Read the article

• UIButton setBackgroundImage consumes doesn't release memory?

  - by just_another_coder

  My UIButton has it's background image set like this: [myImageButton setBackgroundImage:[UIImage imageNamed:myImageName] forState:UIControlStateNormal]; myImageButton is a retained property of the class, and is setup with IB. No where else is it accessed in the app. myImageName is simply an NSString with a filename like @"myImage_number_1.png" I am loading large images, 1024 x 1024 in size. When the view is shown, it changes the image with the above statement, then available memory decreases. After I see the view about 7-9 different times, the app crashes with a memory warning. I thought the method would free up the loaded image. The view itself is only instantiated and allocated one time, so it's not in the retain/release cycle if the view controller. Is there something about this setBackgroundImage I don't know that causes it to not release memory?

  Read the article

• How Do I Parse this XML in Java SAX?

  - by Tiever

  I am using the SAX parser in java. I am not sure: 1) What classes I need for this kind of situation? I am guessing I want to have Classes for (please let me know if my thoughts are completely wrong): -FosterHome (Contains an Arraylist of Family and Child) -Family (Contains ArrayList for Child and a String fro parent) -Child (contains ArrayList for ChildID) 2) How to handle this situation in the startElement and endElement method What complicates is due to the ChildID appearing in both the ChildList and the RemainingChildList. Appreciate anyone who can help me out. <FosterHome> <Orphanage>Happy Days Daycare</Orphanage> <Location>Apple Street</Location> <Families> <Family> <Parent>Adams</ParentID> <ChildList> <ChildID>Child1</ChildID> <ChildID>Child2</ChildID> </ChildList> </Family> <Family> <Parent>Adams</ParentID> <ChildList> <ChildID>Child3</ChildID> <ChildID>Child4</ChildID> </ChildList> </Family> </Families> <RemainingChildList> <ChildID>Child5</ChildID> <ChildID>Child6</ChildID> </RemainingChildList> </FosterHome>

  Read the article

• Django ForeignKey _set on an inherited model

  - by neolaser

  I have two models Category and Entry. There is another model ExtEntry that inherits from Entry class Category(models.Model): title = models.CharField('title', max_length=255) description = models.TextField('description', blank=True) ... class Entry(models.Model): title = models.CharField('title', max_length=255) categories = models.ManyToManyField(Category) ... class ExtEntry(Entry): groups= models.CharField('title', max_length=255) value= models.CharField('title', max_length=255) ... I am able to use the Category.entry_set but I want to be able to do Category.blogentry_set but it is not available. If this is not available,then I need another method to get all ExtEntryrelated to one particular Category Thanks

  Read the article

• Silverlight Memory Usage

  - by peter

  Hi All, Is there a way to measure the current memory usage of the silverlight plug-in from within the client side C# code? I am isolating a memory leak and it would be good to know the current memory usage of the plug-in. For instance it could be logged to a file before I clicked a button that it was using '60 mb' and after I clicked the button it was using '70 mb' etc. I could then gradually add in controls and use this technique to quantify the leak. Thanks.

  Read the article

• How to call a method in another class in Java?

  - by Puchatek

  Currently I have two classes. a classroom class and a School class. I would like to write a method in the School class to call public void setTeacherName(String newTeacherName) from the classroom class. public class classroom { private String classRoomName; private String teacherName; public void setClassRoomName(String newClassRoomName) { classRoomName = newClassRoomName; } public String returnClassRoomName() { return classRoomName; } public void setTeacherName(String newTeacherName) { teacherName = newTeacherName; } public String returnTeacherName() { return teacherName; } } import java.util.ArrayList; public class School { private ArrayList<classroom> classrooms; private String classRoomName; private String teacherName; public School() { classrooms = new ArrayList<classroom>(); } public void addClassRoom(classroom newClassRoom, String theClassRoomName) { classrooms.add(newClassRoom); classRoomName = theClassRoomName; } // how to write a method to add a teacher to the classroom by using the classroom parameter // and the teachers name }

  Read the article

• How to add model entity property in WCF RIA service

  - by Oblomingo

  I'm developing silverlight app with WCF Ria service. I'm using MS SQL database and Entity Framework as ORM framework (Database first method). Model with domain service are in separate project - App1.Data. Silverlight and generated model proxy classes are in App1 project. I want to add property to model entity class EntityClass to get this property on client side. So I did it that way - added this class to project App1.Data: public partial class EntityClass { [DataMember] public List<EntityClass2> PropertyName {get; set;} } After rebuilding EntityClass proxy on client side doesn't have this new property. Where is my mistake?

  Read the article

• Per Process Memory Calculation Alogrithm in Linux (say kernel 2.6 and above)

  - by Vaibhav Singh

  How do you calculate the linux process's Acutal Memory Usage and Not Virtual Memory Usage through the information supplied by /proc//smaps or maps or status or stat. To be more precise I need the heap usage only. I need to do this on an PowerPc based embedded system and hence I do not have utilities like exmap, valgrind etc. I understand the concepts of shared/non shared memory. I have read through the other topics given in this forum about the same but they talk more using the tools mentioned. What I need is the native way of calculation done by the same tools so that I may write a shell script for the same.

  Read the article

• Java: Cleaing up connection reset (but not by peer).

  - by Zombies

  There seems to be some confusion as well contradicting statements on various SO answers: http://stackoverflow.com/questions/585599/whats-causing-my-java-net-socketexception-connection-reset . You can see here that the accepted answer states that the connecteion was closed by other side. But this is not true, closing a connection doesn't cause a connection reset. It is cauesed by "an underlying TCP/IP error." What I want to know is if a SocketException: Connection reset means really besides "unerlying TCP/IP Error." What really causes this? As I doubt it has anything to do with the connection being closed (since closing a connection isn't an exception worthy flag, and reading from a closed connection is, but that isn't an "underlying TCP/IP error." My hypothesis is this Connection reset is caused from a server's failure to acknowledge an ACK packet (either wholly or just improperly as per TCP/IP). And that a SocketTimeoutException is generated only when no data is generated to be read (since this is thrown during a read after a certain duration, and read is waiting for data, but is not concerned with ACK packets). In other words, read() throws SocketTimeoutException if it didn't read any bytes of actual data (DATA LAYER) in its allotted time.

  Read the article

• How to specify hash algorithm when updating LDAP via Java?

  - by JuanZe

  Is there a way to specify the hash algorithm (MD5, SHA1, etc.) to use for storing the passwords when you update an Open LDAP directory using Java APIs with code like this: private void resetPassword(String principal, String newPassword) throws NamingException { InitialDirContext ctxAdmin = null; Hashtable<String, String> ctxData = new Hashtable<String, String>(); ctxData.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory"); ctxData.put(Context.PROVIDER_URL, "ldap://myserver:389"); ctxData.put(Context.SECURITY_AUTHENTICATION, "simple"); ctxData.put(Context.SECURITY_PRINCIPAL, "admin_dn"); ctxData.put(Context.SECURITY_CREDENTIALS, "admin_passwd"); InitialDirContext ctxAdmin = new InitialDirContext(ctxData); if (newPassword == null || newPassword.equals("")) { String msg = "Password can't be null"; throw new NamingException(msg); } else { if (principal == null || principal.equals("")) { String msg = "Principal can't be null"; throw new NamingException(msg); } else { if (ctxAdmin == null) { String errCtx = "Can't get LDAP context"; throw new NamingException(errCtx); } } } BasicAttribute attr = new BasicAttribute("userpassword", newPassword); ModificationItem modItem = new ModificationItem(DirContext.REPLACE_ATTRIBUTE, attr); ModificationItem[] items = new ModificationItem[1]; items[0] = modItem; ctxAdmin.modifyAttributes("cn=" + principal + ",ou=Users,dc=com", items); }

  Read the article

• How to call a method in another class using the arraylist index in java?

  - by Puchatek

  Currently I have two classes. A Classroom class and a School class. public void addTeacherToClassRoom(Classroom myClassRoom, String TeacherName) I would like my method addTeacherToClassRoom to use the Classroom Arraylist index number to setTeacherName e.g. int 0 = maths int 1 = science I would like to setTeacherName "Daniel" in int 1 science. many, thanks public class Classroom { private String classRoomName; private String teacherName; public void setClassRoomName(String newClassRoomName) { classRoomName = newClassRoomName; } public String returnClassRoomName() { return classRoomName; } public void setTeacherName(String newTeacherName) { teacherName = newTeacherName; } public String returnTeacherName() { return teacherName; } } import java.util.ArrayList; public class School { private ArrayList<Classroom> classrooms; private String classRoomName; private String teacherName; public School() { classrooms = new ArrayList<Classroom>(); } public void addClassRoom(Classroom newClassRoom, String theClassRoomName) { classrooms.add(newClassRoom); classRoomName = theClassRoomName; } public void addTeacherToClassRoom(Classroom myClassRoom, String TeacherName) { myClassRoom.setTeacherName(TeacherName); } }

  Read the article

• PDFBox Pagebreak strange Nullpointer exception

  - by schneiti

  I currently try printing out text on multiple pages. For this, I count the number of rows and when they reach a fixed amount a method called pagebreakis executed. After the first pagebreak, when I try setting a font using contentstream.setFont(PDType1Font.HELVETICA, 12); it yields the following errormessage occuring at the described setFont-row. java.lang.NullPointerException at org.apache.pdfbox.pdmodel.edit.PDPageContentStream.setFont(PDPageContentStream.java:321) at com.xy.deu.xy.abc.db.schemavergleich.PDFDocumenter.drawBGCS(PDFDocumenter.java:781) at com.xy.deu.xy.abc.db.schemavergleich.PDFDocumenter.createPDFDocumentation(PDFDocumenter.java:205) at com.xy.deu.xy.abc.db.schemavergleich.MainClass.createPDFandOutput(MainClass.java:361) at com.xy.deu.xy.abc.db.schemavergleich.MainClass.start(MainClass.java:231) at com.xy.deu.xy.abc.db.schemavergleich.MainClass.main(MainClass.java:180) Below is the code that gets executed as the error occurs. ... // If Table gets to long for a page -> pagebreak: if(currentLines > 37) { pageBreak(currentLinePos); // TODO Currently causing app to crash } ... private void pageBreak(int currentLine) throws Exception { contentStream.endText(); contentStream.close(); // Create new page page = new PDPage(PDPage.PAGE_SIZE_A4); doc.addPage( page ); // Create a new font object selecting one of the PDF base fonts font = PDType1Font.HELVETICA; // Start a new content stream which will "hold" the to be created content contentStream = new PDPageContentStream(doc, page); currentLines = 0; mediabox = page.findMediaBox(); contentStream.beginText(); contentStream.moveTextPositionByAmount(startX, startY); contentStream.setFont(PDType1Font.HELVETICA, 12); } Now comes the strange thing: Debugging yields into nothing that is not set. I'll attach a screenshot for you right at the position where the error occurs:

  Read the article

• Rails model to represent multiple fields

  - by Tristan O'Neil

  I'm developing a rails project where I have one data model with multiple fields that are collection selects. I'd like to create another model to represent all of these collection select fields. So, for instance, my main data model has three collection select fields -- one for county, one for category, and one for classification. I could separate these into three separate data models, but that seems redundant since they all share the same characteristics. They have a type and a value, like a county is a county and it has a value of let's say Sonoma, just as category has a type of category and a value of let's say Winery. If you've ever used Drupal, I'm basically looking for the behavior of the taxonomy functionality. So you see my dilemma: I need to separate these fields into three separate fields but they have very similar data structures. Any suggestions would be greatly appreciated.

  Read the article

• create a model in create action from a class

  - by Pontek

  As a newbie to rails I can't find how to solve my issue ^^ I want to create a VideoPost from a form with a text field containing a video url (like youtube) I'm getting information on the video thanks to the gem https://github.com/thibaudgg/video_info And I want to save thoses information using a model of mine (VideoInformation). But I don't know how the create process should work. Thanks for any help ! I'm trying to create a VideoPost in VideoPostsController like this : def create video_info = VideoInfo.new(params[:video_url]) video_information = VideoInformation.create(video_info) #undefined method `stringify_keys' for #<Youtube:0x00000006a24120> if video_information.save @video_post = current_user.video_posts.build(video_information) end end My VideoPost model : # Table name: video_posts # # id :integer not null, primary key # user_id :integer # video_information_id :integer # created_at :datetime not null # updated_at :datetime not null My VideoInformation model (which got same attributes name than VideoInfo gem) : # Table name: video_informations # # id :integer not null, primary key # title :string(255) # description :text # keywords :text # duration :integer # video_url :string(255) # thumbnail_small :string(255) # thumbnail_large :string(255) # created_at :datetime not null # updated_at :datetime not null

  Read the article

• How to have variables with dynamic data types in Java?

  - by Nazgulled

  Hi, I need to have a UserProfile class that it's just that, a user profile. This user profile has some vital user data of course, but it also needs to have lists of messages sent from the user friends. I need to save these messages in LinkedList, ArrayList, HashMap and TreeMap. But only one at a time and not duplicate the message for each data structure. Basically, something like a dynamic variable type where I could pick the data type for the messages. Is this, somehow, possible in Java? Or my best approach is something like this? I mean, have 2 different classes (for the user profile), one where I host the messages as Map<K,V> (and then I use HashMap and TreeMap where appropriately) and another class where I host them as List<E> (and then I use LinkedList and ArrayList where appropriately). And probably use a super class for the UserProfile so I don't have to duplicate variables and methods for fields like data, age, address, etc... Any thoughts?

  Read the article

• Why aren't my threads start at the same time? Java

  - by Ada

  Hi, I have variable number of threads which are used for parallel downloading. I used this, for(int i = 0; i< sth; i++){ thrList.add(new myThread (parameters)); thrList.get(i).start(); thrList.get(i).join(); } I don't know why but they wait for each other to complete. When using threads, I am supposed get mixed print outs, since right then there are several threads running that code. However, when I print them out, they are always in order and one thread waits for the previous one to finish first. I only want them to join the main thread, not wait for each other. I noticed that when I measured time while downloading in parallel. How can I fix this? Why are they doing it in order? In my .java, there is MyThread class with run and there is Downloader class with static methods and variables. Would they be the cause of this? The static methods and variables? How can I fix this problem?

  Read the article

• php most memory efficient way to return files

  - by bumperbox

  so i have a bunch of files, some can be up to 30-40mb and i want to use php to handle security of the files, so i can control who has access to them that means i have a script sort of like this rough example $has_permission = check_database_for_permission($user, filename); if ($has_permission) { header('Content-Type: image/jpeg'); readfile ($filename); exit; } else { // return 401 error } i would hate for every request to load the full file into memory, as it would soon chew up all the memory on my server with a few simultaneous requests so a couple of questions is readfile the most memory efficient way of doing this? is there some better method of achieving the same outcome, that i am overlooking? server: apache/php5 thanks

  Read the article

• How to implement the API/SPI Pattern in Java?

  - by Adam Tannon

  I am creating a framework that exposes an API for developers to use: public interface MyAPI { public void doSomeStuff(); public int getWidgets(boolean hasRun); } All the developers should have to do is code their projects against these API methods. I also want them to be able to place different "drivers"/"API bindings" on the runtime classpath (the same way JDBC or SLF4J work) and have the API method calls (doSomeStuff(), etc.) operate on different 3rd party resources (files, servers, whatever). Thus the same code and API calls will map to operations on different resources depending on what driver/binding the runtime classpath sees (i.e. myapi-ftp, myapi-ssh, myapi-teleportation). How do I write (and package) an SPI that allows for such runtime binding, and then maps MyAPI calls to the correct (concrete) implementation? In other words, if myapi-ftp allows you to getWidgets(boolean) from an FTP server, how would I could this up (to make use of both the API and SPI)? Bonus points for concrete, working Java code example! Thanks in advance!

  Read the article

• Is there a Java data structure that is effectively an ArrayList with double indicies and built-in in

  - by Bob Cross

  I am looking for a pre-built Java data structure with the following characteristics: It should look something like an ArrayList but should allow indexing via double-precision rather than integers. Note that this means that it's likely that you'll see indicies that don't line up with the original data points (i.e., asking for the value that corresponds to key "1.5"). As a consequence, the value returned will likely be interpolated. For example, if the key is 1.5, the value returned could be the average of the value at key 1.0 and the value at key 2.0. The keys will be sorted but the values are not ensured to be monotonically increasing. In fact, there's no assurance that the first derivative of the values will be continuous (making it a poor fit for certain types of splines). Freely available code only, please. For clarity, I know how to write such a thing. In fact, we already have an implementation of this and some related data structures in legacy code that I want to replace due to some performance and coding issues. What I'm trying to avoid is spending a lot of time rolling my own solution when there might already be such a thing in the JDK, Apache Commons or another standard library. Frankly, that's exactly the approach that got this legacy code into the situation that it's in right now.... Is there such a thing out there in a freely available library?

  Read the article

• Force freeing memory in PHP

  - by DBa

  Hi everybody, in a PHP program, I sequentially read a bunch of files (with file_get_contents), gzdecode them, json_decode the result, analyze the contents, throw the most of it away, and store about 1% in an array. Unfortunately, with each iteration (I traverse over an array containing the filenames), there seems to be some memory lost (according to memory_get_peak_usage, about 2-10 MB each time). I have double- and triplechecked my code, I am not storing unneded data in the loop (and the needed data hardly exceeds about 10MB overall), but I am frequently rewriting (actually, strings in an array). Apparently, PHP does not free the memory correctly, thus using more and more RAM until it hits the limit. Is there any way to do a forced garbage collection? Or, at least, to find out where the memory is used? Thanks in advance, Dmitri

  Read the article

• ASP.NET MVC 2 model properties binding order

  - by bniwredyc

  Is there a way to change order in which the default binder binds property values of model? For example I have model class A: class A { public string A1 {get; set;} public string A2 {get; set;} } and action DoSomethig: public ActionResult DoSomething(A model) { ... } I want that A2 property has been bound before the A1 property. Is it possible? Or I need to write custom binder?

  Read the article

• Java error - not a statement, what does this mean?

  - by user2898828

  I am trying to get my code to create the new constructor objects which I require to create a mobile phone object. I have tried naming the constuctor fields to create the object. when I compile my code on this line this.Mobile samsungPhone = new Mobile("Samsung", 1, 2, "verizon", 3 "GPS"); I get this error: not a statement, what does this mean?? UPDATED CODE! my code: /** * to write a simple java class Mobile that models a mobile phone. * * @author (Lewis Burte-Clarke) * @version (14/10/13) */ public class Mobile { // type of phone private String phonetype; // size of screen in inches private int screensize; // menory card capacity private int memorycardcapacity; // name of present service provider private String serviceprovider; // type of contract with service provider private int typeofcontract; // camera resolution in megapixels private int cameraresolution; // the percentage of charge left on the phone private int checkcharge; // wether the phone has GPS or not private String GPS; // instance variables - replace the example below with your own private int x; // The constructor method public Mobile(String mobilephonetype, int mobilescreensize, int mobilememorycardcapacity,int mobilecameraresolution,String mobileGPS, String newserviceprovider) { this.phonetype = mobilephonetype; this.screensize = mobilescreensize; this.memorycardcapacity = mobilememorycardcapacity; this.cameraresolution = mobilecameraresolution; this.GPS = mobileGPS; this.serviceprovider = newserviceprovider; this.typeofcontract = 12; this.checkcharge = checkcharge; // you do not use this ones during instantiation,you can remove them if you do not need or assign them some default values Mobile samsungPhone = new Mobile("Samsung", 1, 2, "verizon", 3, "GPS"); 1024 = screen size; 2 = memory card capacity; 3=resolution; GPS = gps; "verizon"=service provider; typeofcontract = 12; checkcharge = checkcharge; } } // A method to display the state of the object to the screen public void displayMobileDetails() { System.out.println("phonetype: " + phonetype); System.out.println("screensize: " + screensize); System.out.println("memorycardcapacity: " + memorycardcapacity); System.out.println("cameraresolution: " + cameraresolution); System.out.println("GPS: " + GPS); System.out.println("serviceprovider: " + serviceprovider); System.out.println("typeofcontract: " + typeofcontract); } } class mymobile { public static void) { Mobile Samsung = new Mobile("Samsung", 1, 2, "verizon", 3, "GPS"); Mobile Blackberry = new Mobile("Blackberry", "3.", "4","8", "GPS"); Samsung.displayMobileDetails(); Blackberry.displayMobileDetails(); } } any answers and replies would be greatly appreciated!

  Read the article

• Learning Java and logic using debugger. Did I cheat?

  - by centr0

  After a break from coding in general, my way of thinking logically faded (as if it was there to begin with...). I'm no master programmer. Intermediate at best. I decided to see if i can write an algorithm to print out the fibonacci sequence in Java. I got really frustrated because it was something so simple, and used the debugger to see what was going on with my variables. solved it in less than a minute with the help of the debugger. Is this cheating? When I read code either from a book or someone else's, I now find that it takes me a little more time to understand. If the alghorithm is complex (to me) i end up writing notes as to whats going on in the loop. A primitive debugger if you will. When you other programmers read code, do you also need to write things down as to whats the code doing? Or are you a genius and and just retain it?

  Read the article

< Previous Page | 536 537 538 539 540 541 542 543 544 545 546 547  | Next Page >