Search Results

Search found 33603 results on 1345 pages for 'java champion stephen chin'.

Page 117/1345 | < Previous Page | 113 114 115 116 117 118 119 120 121 122 123 124  | Next Page >

  • Generics and reflection in Java

    - by Ragesh
    This is probably a very basic question, but I'm really new to generics in Java and I'm having a hard time altering my thought process from the way things are done in C#, so bear with me. I'm trying to build a generic repository in Java. I've created an IRepository interface that looks like this: public interface IRepository<T extends IEntity> And a Repository class that looks like this: public class Repository<T extends IEntity> implements IRepository<T> Now, from within the constructor of my Repository class, I'd like to be able to "divine" the exact type of T. For example, if I instantiated a repository like this: IRepository<MyClass> repo = new Repository<MyClass>(); I'd like to know that T is actually MyClass. This is trivial in C#, but obviously generics are a totally different beast in Java and I can't seem to find anything that would help me do this.

    Read the article

  • Archiving Database Tables using Java

    - by HonorGod
    My application demands archiving database tables between sybase and db2 and vice-a-versa and within(db2 to db2 and sybase to sybase) using java. I am trying to understand the best strategies around in terms performance, implementation, ease of use and scalability. Here is my current process - source and destination tables with the acceptable parameters (from java) are defined within xml. the application reads the source and destination configurations and execute them sequentially. destination is sometime optional when source is just deleting data from a specific table or when the source is just calling a stored procedure. dataset between source and destination is extremely large (in millions) From top of my head, it looks like I can define dependencies between multiple source and destination combination and have them execute in parallel in multiple treads. But will this improve any performance(i hope it will)? Are there any open-source frameworks for data archiving using java? Any other thoughts on the implements side will be really helpful. Thanks

    Read the article

  • PL/SQL exception and Java programs

    - by edwards
    Hi Business logic is coded in pl/sql packages procedures and functions. Java programs call pl/sql packages procedures and functions to do database work. pl/sql programs store exceptions into Oracle tables whenever an exception is raised. How would my java programs get the exceptions since the exception instead of being propagated from pl/sql to java is getting persisted to a oracle table and the procs/functions just return 1 or 0. Sorry folks i should have added this constraint much earlier and avoided this confusion. As with many legacy projects we don't have the freedom to modify the stored procedures.

    Read the article

  • java cannot reserver heap size error on windows server

    - by Prad
    HI, I have the following configuration: Server : windows 2003 server (32 bit) java version: 1.5_0_22 I get the following error when executing from command line ( my code is based off eclipse wihch gives the same error) java -XX:MaxPermSize=256m -Xmx512m Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. The server has over 20GB physical memory with over 19 GB free right now. It does not give an error upto -Xmx486m I have read other articles about contiguous memory space. There is hardly anything running on this server. Can I validae this in any way? Thanks

    Read the article

  • Calling consecutive java tasks in a shell script

    - by Bigtwinz
    Hi all, This may be a rudimentary question but the answer was not readily available. I'd like to create a shell script that calls 3 tasks consecutively, but wait till the previous task is complete. Like so: a. call first Java program via ant b. call third party Java application c. call third Java program via ant I'm wondering if there is a way to check and ensure a. is done before b. is called and same for b. and c. thanks

    Read the article

  • Getter/Setter from separate class file in Java

    - by Crystal
    I'm new to Java and for a HW assignment, we had to create a Person class that has a constructor, getter/setter for the attributes of firstName, lastName, phone. That is in a separate file from an old HW assignment (Person.java). Now we have to use that Person class in our new HW assignment (LoanApplication.java). So if one of the attributes is private Person client do I need to create getter/setters or a constructor again? Otherwise, how does each LoanApplicaiton instance know which Person attribute it is to go with? How does the JVM know that it can use the Person.class even though my LoanApplicaiton.class does not extend Person.class? Thanks.

    Read the article

  • Java Enum Newbie Question

    - by ikurtz
    i have a situation where i need the Checker enum below used in multiple classes: package Sartre.Connect4; public enum Checker { EMPTY, RED, YELLOW } so i put the Checker in a Checker.java file and then from the classes that need it i simply do the following: example: public Cell(){ currentCell = Checker.EMPTY; } example: public Cell(Checker checker){ currentCell = checker; } and the code compiles fine and runs fine also. so what is my question? well being new to Java i am just wondering if the way i use Checker without encapsulating it in a class is a sound implementation? it may be because of The enum declaration defines a class (called an enum type). as noted in Java docs enum tutorial page. thank you for your insight into this matter.

    Read the article

  • Trouble understanding Java map Entry sets

    - by Jake Sellers
    I'm looking at a java hangman game here: https://github.com/leleah/EvilHangman/blob/master/EvilHangman.java The code in particular is this: Iterator<Entry<List<Integer>, Set<String>>> k = partitions.entrySet().iterator(); while (k.hasNext()) { Entry<?, ?> pair = (Entry<?, ?>)k.next(); int sizeOfSet = ((Set<String>)pair.getValue()).size(); if (sizeOfSet > biggestPartitionSize) { biggestPartitionSize = sizeOfSet; } } Now my question. My google foo is weak I guess, I cannot find much on Entry sets other than the java doc itself. Is is just a temporary copy of the map? And I cannot find any info at all on the syntax: Entry<?, ?> Can anyone explain or point me toward an explanation of what is going on with those question marks? Thanks in advanced.

    Read the article

  • What are the things Java got right?

    - by hamletdarcy
    What are the things that Java (the language and platform) got categorically right? In other words, what things are more recent programming languages preserving and carrying forward? Some easy answer are: garbage collection, a VM, lack of pointers, classloaders, reflection(?) What about language based answers? Please don't list the things Java did wrong, just right. (note by Mark Harrison) This is an interesting and useful question, especially for those of us who don't use java regularly. I'm voting for reopening. Please don't close as argumentative, as it doesn't seem to be causing any arguments.

    Read the article

  • Why do date manipulation in Java with milliseconds?

    - by staticsan
    I was recently faced with the problem of calculating the number of days from two dates in Java (without using joda, I'm afraid). Searching on the 'net shows most answers to this question say to get the milliseconds of the two days and convert that to days, which I found appalling. However, a scant few show a different approach: use a temporary variable to count how many times it takes adding 1 day to the first date to get to the second. This leaves the conversions to the code that does it best: the library. Why do so many people advocate the first? In another project, I had previously encountered numerous subtle date calculation problems involving time-zones, daylight-saving and once even leap years using seconds to do date comparisions and calculations. All these went away when all the comparison and calculation code was rewitten to use the language libraries. (This was in PHP, though, where the libraries are structured quite differently to Java.) So I'm understandably reluctant to use this "common wisdom" in the world of Java about comparing dates.

    Read the article

  • Why is memory management so visible in Java?

    - by Emil
    I'm playing around with writing some simple Spring-based web apps and deploying them to Tomcat. Almost immediately, I run into the need to customize the Tomcat's JVM settings with -XX:MaxPermSize (and -Xmx and -Xms); without this, the server easily runs out of PermGen space. Why is this such an issue for Java compared to other garbage collected languages? Comparing counts of "tune X memory usage" for X in Java, Ruby, Perl and Python, shows that Java has easily an order of magnitude more hits in Google than the other languages combined.

    Read the article

  • Inheriting from multiple classes in Java (and possibly not using interface)

    - by sheidaei
    So, let's say we have classes A, B and C and I want to inherit from all those classes and have another class called D, it can be done using implements and interfaces in Java. But let's say we don't want to use this simple solution, would you be able to inherit class D from classes A, B and C in any other way in Java? (This question might be related to design patterns, it has been brought up after challenging my colleague at lunch discussing design patterns) I don't think there is any other way to have multiple inheritance in Java other than using multiple interfaces.

    Read the article

  • After C++ - Python or Java?

    - by carleeto
    I'm fast approaching the point in my coding where I would like to quickly write object oriented code in languages other than C++ for a variety of reasons. After a lot of research, my choices have pretty much narrowed down to Python and Java. I'm leaning towards Python because of its relationship to C, but with Java, from what I can see, I get a good introduction to using and creating test suites with Eclipse - there is also Processing which is pulling me towards Java. I'm not the kind of guy to tackle two languages at once, so which one would you recommend and why? What I want at the end is to have an additional language I can use for rapid development. Ease of learning isn't important to me as I'm willing to put in the time regardless. Ability to use the new language widely is.

    Read the article

  • Java serial comm notifyOnDataAvailable configure receive buffer size?

    - by fred basset
    Hi All, I have a Java serial driver that's using the notifyOnDataAvailable mode to enable async. receive notification. I see an occasional problem where the SerialPortEvent.DATA_AVAILABLE serial event is not called until a relatively large no. of characters have been received (e.g. 34). The problem is that the sender sent a 20 byte packet, so the Java receiver did not send an ACK until the sender did a retry of the 20 byte send. Is there any way in Java COMM to configure the size of the receive buffer?

    Read the article

  • Java Interface Reflection Alternatives

    - by Phaedrus
    I am developing an application that makes use of the Java Interface as more than a Java interface, i.e., During runtime, the user should be able to list the available methods within the interface class, which may be anything: private Class<? extends BaseInterface> interfaceClass. At runtime, I would like to enum the available methods, and then based on what the user chooses, invoke some method. My question is: Does the Java "Interface" architecture provide any method for me to peek and invoke methods without using the Reflection API? I wish there were something like this (Maybe there is): private Interface<? extends BaseInterface> interfaceAPI; public void someMethod(){ interfaceAPI.listMethods(); interfaceAPI.getAnnotations(); } Maybe there is some way to use Type Generics to accomplish what I want? Thanks, Phaedrus

    Read the article

  • Java Swing- Create a function to add elements to JScrollPanel

    - by battousai622
    I want to create a function so that i can call add JLabel's, etc inside the JScrollPanel. I am not sure what the command is in NetBeans. I tried doing JScrollPanel - events - container - componentAdded to create the code below. But nothing shows up when i add code to that function. private void initComponents() { scrollPanel = new javax.swing.JScrollPane(); scrollPanel.addContainerListener(new java.awt.event.ContainerAdapter() { public void componentAdded(java.awt.event.ContainerEvent evt) { scrollPanelComponentAdded(evt); } } private void scrollPanelComponentAdded(java.awt.event.ContainerEvent evt) { System.out.println("main"); } Any help would be great, thanks.

    Read the article

  • Java 7 New Features

    - by John W.
    I have done some good reading on the new java.util.concurrent features being introduced with the java 7 release. For instance, Phaser, TransferQueue and the more exciting Fork Join Framework. I recently saw a power point made by Josh Bloch about even more features that are going to be introduced however that link has been lost. For example I remember one change is being able to build a Map the same way you can build an array for: Map myMap = {"1,Dog","2,Cat"}; and so forth (this may not be 100% correct but the idea is there) Does anyone know of a list or just can name some new things to look forward to? Note: I did see a question asked http://stackoverflow.com/questions/213958/new-features-in-java-7 however it was asked ~2 years ago and I am sure the list of updates are more concrete. Thanks!

    Read the article

  • Can you call compiled JRuby classes from java?

    - by John Baker
    So I came up with the general idea to write some code in JRuby, then access all the classes via Java. I have no idea if this is at all possible but I wanted to ask anyway. Lets say I have some JRuby code: class adder def addme return 22 end end If I compiled this with jrubyc is there any way I could then possibly do something like this in java: import adder; class anything { void testMethod() { adder a = new adder(); int x = a.addme(); } } After looking at it now it sort of makes me think that Java will have zero idea what sort of item test addme is going to return so that might not work. I don't know but I wanted to throw it out there anyway. Thanks

    Read the article

  • Java training for .NET developers?

    - by C Keene
    We are working with a large retail bank on training 40-50 .Net developers to use Java. They are familiar with C# and .Net framework and have built dozens of "run the business" style apps in .Net. We need advice on how to provide basic Java familiarity, with a focus on back end logic, security and transaction management. Back end is Spring/Hibernate, front end is Ajax (Dojo). Are there any online, self-paced, Java courses that would be good for C#/.Net developers to get up to speed quickly?

    Read the article

  • execute external command / application from java

    - by IttayD
    I'm looking for a package to support reliably executing external processes from Java. My criteria: Abstract over OS. So if I want to run 'foo', it will look for 'foo.bat', 'foo.exe' under windows and 'foo' under other OSs (or, have a way of passing a map of os-command) Being able to execute Java classes by simply giving the class name and arguments (so the package locates the java command, copies jvm flags and then executes) Process stdout and stderr properly Watchdog / Monitoring capabilities I've looked at commons-exec but it looks like it answers only 3 & 4. Ant has support for execution but looks like an overkill to use it for this purpose only.

    Read the article

  • Take input through Buttons in java

    - by stash211
    I understand that the title might not be descriptive enough, but I'm making a magic square game in Java and basically, I'm trying to replicate user input as found in the sudoku game here: http://www.websudoku.com/. What I have is a n x n grid of Buttons (not JButton) as the board and what I want the user to be able to do is when the user clicks on one of the buttons, similar to the game above, it allows the user to type in his guess in the button itself instead of popping up a dialog box with an input field of some sort. I don't know where to start, I am a beginner in Java (not very beginner, but my knowledge with the various Java APIs is very limited), so I'm trying to find out if this would be possible and if it is, how would I go about doing it? Thanks for any help.

    Read the article

  • Get all variables of javascript in JAVA

    - by Parhs
    Hello... I am using rhino and Scripting for the Java Platform in order to allow the user extend my application. However the user can write some cases eg (ASTO.value>440) || (ASTO.bellowNormal) etc... The problem is that before running the script from my JAVA application using ScriptEngine i want to get the names of all the variables! Because i should know which variables are required for the script to run... I know that a regular expression would do the job but i amnt sure... Please i somebody could help me figure out the java regexp to get the variables i would really appriciate it..

    Read the article

  • Clearcase and java process : changing view does not apply

    - by user1432310
    i have a simple application, which receives input from a user for a CC stream name, and is suppose to return the content of a specific file from this stream repository. I have tried doing this using a simple shell script: user enters stream name, java receives stream name, runs a process which runs a script "myccscript.sh" which contains "myinput=$1; cleartool setview $myinput" (or something like that). then i try reading the file and printing it's content in the java side. BUT, after the process is finished - the view is not the view from the user input - that environment was probably only valid for the process Ive created. how do i change the clearcase view to the main java process? Thanks!

    Read the article

  • IP Address not obtained in java

    - by nilesh
    This code used to return my local ip address as 192.xxx.x.xxx but now it is returning 127.0.0.1 . Please help me why the same code is returning different value. Is there something that I need to watch at linux OS. import java.util.*; import java.lang.*; import java.net.*; public class GetOwnIP { public static void main(String args[]) { try{ InetAddress ownIP=InetAddress.getLocalHost(); System.out.println("IP of my system is := "+ownIP.getHostAddress()); }catch (Exception e){ System.out.println("Exception caught ="+e.getMessage()); } } }

    Read the article

  • Why Java cannot find my constructor?

    - by Roman
    Well, maybe it is a stupid question, but I cannot resolve this problem. In my ServiceBrowser class I have this line: ServiceResolver serviceResolver = new ServiceResolver(ifIndex, serviceName, regType, domain); And compiler complains about it. It says: cannot find symbol symbol : constructor ServiceResolver(int,java.lang.String,java.lang.String,java.lang.String) This is strange, because I do have a constructor in the ServiceResolver: public void ServiceResolver(int ifIndex, String serviceName, String regType, String domain) { this.ifIndex = ifIndex; this.serviceName = serviceName; this.regType = regType; this.domain = domain; } ADDED: I removed void from the constructor and it works! Why?

    Read the article

< Previous Page | 113 114 115 116 117 118 119 120 121 122 123 124  | Next Page >