Search Results

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

Page 347/1332 | < Previous Page | 343 344 345 346 347 348 349 350 351 352 353 354  | Next Page >

• Beginning GWT and Java - wich is the best route when coming from LAMP background?

  - by Cambiata

  Hi! I've worked a lot with php/mysql on linux servers, including frameworks, orm etc. Now I want to give GWT and Java a try! Installing GWT SDK, Eclipse plugin etc and running a "Hello world" is no problem... The server is running automagically in the background... But when it comes to setting it up my self, there seems to be confusingly many options. Jetty? Tomcat? Glassfish? How are those related/combinable to/with Apache? Are there any good resources or tutorials for setting up java development and server environments suited for one like me with PHP background? Maybe pointing out the possiblities of running PHP and Java on the same server? Regards / Jonas

  Read the article

• How does memory management in Java and C# differ?

  - by David Johnstone

  I was reading through 2010 CWE/SANS Top 25 Most Dangerous Programming Errors and one of the entries is for Buffer Copy without Checking Size of Input. It suggests using a language with features to prevent or mitigate this problem, and says: For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. I was not aware that Java and C# differed in any meaningful way with regard to memory management. How is it that Java is not subject to buffer overflows, while C# only protects against overflows? And how is it possible to disable this protection in C#?

  Read the article

• How to match ColdFusion encryption with Java 1.4.2?

  - by JohnTheBarber

  * sweet - thanks to Edward Smith for the CF Technote that indicated the key from ColdFusion was Base64 encoded. See generateKey() for the 'fix' My task is to use Java 1.4.2 to match the results a given ColdFusion code sample for encryption. Known/given values: A 24-byte key A 16-byte salt (IVorSalt) Encoding is Hex Encryption algorithm is AES/CBC/PKCS5Padding A sample clear-text value The encrypted value of the sample clear-text after going through the ColdFusion code Assumptions: Number of iterations not specified in the ColdFusion code so I assume only one iteration 24-byte key so I assume 192-bit encryption Given/working ColdFusion encryption code sample: <cfset ThisSalt = "16byte-salt-here"> <cfset ThisAlgorithm = "AES/CBC/PKCS5Padding"> <cfset ThisKey = "a-24byte-key-string-here"> <cfset thisAdjustedNow = now()> <cfset ThisDateTimeVar = DateFormat( thisAdjustedNow , "yyyymmdd" )> <cfset ThisDateTimeVar = ThisDateTimeVar & TimeFormat( thisAdjustedNow , "HHmmss" )> <cfset ThisTAID = ThisDateTimeVar & "|" & someOtherData> <cfset ThisTAIDEnc = Encrypt( ThisTAID , ThisKey , ThisAlgorithm , "Hex" , ThisSalt)> My Java 1.4.2 encryption/decryption code swag: package so.example; import java.security.*; import javax.crypto.Cipher; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; import org.apache.commons.codec.binary.*; public class SO_AES192 { private static final String _AES = "AES"; private static final String _AES_CBC_PKCS5Padding = "AES/CBC/PKCS5Padding"; private static final String KEY_VALUE = "a-24byte-key-string-here"; private static final String SALT_VALUE = "16byte-salt-here"; private static final int ITERATIONS = 1; private static IvParameterSpec ivParameterSpec; public static String encryptHex(String value) throws Exception { Key key = generateKey(); Cipher c = Cipher.getInstance(_AES_CBC_PKCS5Padding); ivParameterSpec = new IvParameterSpec(SALT_VALUE.getBytes()); c.init(Cipher.ENCRYPT_MODE, key, ivParameterSpec); String valueToEncrypt = null; String eValue = value; for (int i = 0; i < ITERATIONS; i++) { // valueToEncrypt = SALT_VALUE + eValue; // pre-pend salt - Length > sample length valueToEncrypt = eValue; // don't pre-pend salt Length = sample length byte[] encValue = c.doFinal(valueToEncrypt.getBytes()); eValue = Hex.encodeHexString(encValue); } return eValue; } public static String decryptHex(String value) throws Exception { Key key = generateKey(); Cipher c = Cipher.getInstance(_AES_CBC_PKCS5Padding); ivParameterSpec = new IvParameterSpec(SALT_VALUE.getBytes()); c.init(Cipher.DECRYPT_MODE, key, ivParameterSpec); String dValue = null; char[] valueToDecrypt = value.toCharArray(); for (int i = 0; i < ITERATIONS; i++) { byte[] decordedValue = Hex.decodeHex(valueToDecrypt); byte[] decValue = c.doFinal(decordedValue); // dValue = new String(decValue).substring(SALT_VALUE.length()); // when salt is pre-pended dValue = new String(decValue); // when salt is not pre-pended valueToDecrypt = dValue.toCharArray(); } return dValue; } private static Key generateKey() throws Exception { // Key key = new SecretKeySpec(KEY_VALUE.getBytes(), _AES); // this was wrong Key key = new SecretKeySpec(new BASE64Decoder().decodeBuffer(keyValueString), _AES); // had to un-Base64 the 'known' 24-byte key. return key; } } I cannot create a matching encrypted value nor decrypt a given encrypted value. My guess is it's something to do with how I'm handling the initial vector/salt. I'm not very crypto-savvy but I'm thinking I should be able to take the sample clear-text and produce the same encrypted value in Java as ColdFusion produced. I am able to encrypt/decrypt my own data with my Java code (so I'm consistent) but I cannot match nor decrypt the ColdFusion sample encrypted value. I have access to a local webservice that can test the encrypted output. The given ColdFusion output sample passes/decrypts fine (of course). If I try to decrypt the same sample with my Java code (using the actual key and salt) I get a "Given final block not properly padded" error. I get the same net result when I pass my attempt at encryption (using the actual key and salt) to the test webservice. Any Ideas?

  Read the article

• How do I pipe the Java console output to a file?

  - by Ced

  I found a bug in an application that completely freezes the JVM. The produced stacktrace would provide valuable information for the developers and I would like to retrieve it from the Java console. When the JVM crashes, the console is frozen and I cannot copy the contained text anymore. Is there way to pipe the Java console directly to a file or some other means of accessing the console output of a Java application? Update: I forgot to mention, without changing the code. I am a manual tester. Update 2: This is under Windows XP and it's actually a web start application. Piping the output of javaws jnlp-url does not work (empty file).

  Read the article

• How can I use Java to communicate to device through USB port?

  - by Bopha

  I just recently learn Java and try to communicate to the device through USB port connection. I've have used C# with OpenNETCF which allows me to send file and retrieve file on the device through USB port; how can I achieve this with java? I seearch on stackoverflow thread, http://stackoverflow.com/questions/544507/how-to-communicate-with-a-usb-device-under-windows-and-java, the comment made by christoffer is to hack the native code, but I don't quite which native code api that he referred to. RAPI, maybe?

  Read the article

• How to do a true Java ping from Windows?

  - by stjowa

  I have a device on a network that I am attempting to ping through my Java program. Through my windows command prompt, I can ping the device address fine and do a tracert on the address fine. Online, I have seen that in order to do a ping through Java you have to do the following: InetAddress.getByName(address).isReachable(timeout); But, when I use this code on my device address, it always returns false in my program. I am using the correct IPv4 address with a good timeout value. Also, if I use a localhost address, it works fine. Why can I ping the device through cmd, but not through my program? I have heard in various places that this is not a true ping. Is there a better way to emulate a ping in Java? Thanks

  Read the article

• Quaere - Anyone using it yet? (LINQ to Objects for Java)

  - by Marty Pitt

  Hi there I'm a .NET guy originally, working in Java recently, and finding I'm really missing LINQ to Objects, specifically for performing filtering against collections. A few people here on Stack Overflow have answered the "LINQ for Java?" question with a single word : Quaere However, on the site it clearly states "Pre-Beta", and there's been no commits to their code for over a year, so I'm guessing the project is pretty much dead. Is anyone actually using this, and / or have any experience with it? The second most common answer appears to be "use Google Collections". Is this the most appropriate Java way? Cheers Marty

  Read the article

• What is the ratio of Java programmers to C#.net programmers?

  - by Vaccano

  How many Java Programmers are there to every C# programmer? I have a coworker that says it was 3:1 (3 Java to 1 C#) but it is now more like 2:1 (2 java to 1 C#) Is this valid? Is there somewhere I could go for this info? Edit: This question needs to be a bit more limited in scope. I am referring to US programmers and those who would consider their career to be more focused in one side than the other. (If you are evenly balanced then you would cancel out.)

  Read the article

• What is the purpose of Java's unary plus operator?

  - by Syntactic

  Java's unary plus operator appears to have come over from C, via C++. As near as I can tell, it has the following effects: promotes its operand to int, if it's not already an int or wider unboxes its operand, if it's a wrapper object complicates slightly the parsing of evil expressions containing large numbers of consecutive plus signs It seems to me that there are better (or, at least, clearer) ways to do all of these things. In this SO question, concerning the counterpart operator in C#, someone said that "It's there to be overloaded if you feel the need." But in Java, one cannot overload any operator. So does this operator exist in Java just because it existed in C++?

  Read the article

• Why does Java not have any destructor like C++?

  - by Abhishek Jain

  Java has its own garbage collection implementation so it does not require any destructor like C++ . This makes Java developer lazy in implementing memory management. And Garbage Collection is very expensive. Still we can have destructor along with garbage collector where developer can free resources and which can save garbage collector's work. This might improves the performance of application. Why does Java not provide any destructor kind of mechanism? Developer does not have control over GC but he/she can control or create object. Then why not give them ability to destruct the objects?

  Read the article

• Possible to access gdata api when using Java App Engine?

  - by PCBEEF

  I have a dilemma where I want to create an application that manipulates google contacts information. The problem comes down to the fact that Python only supports version 1.0 of the api whilst Java supports 3.0. I also want it to be web-based so I'm having a look at google app engine, but it seems that only the python version of app engine supports the import of gdata apis whilst java does not. So its either web based and version 1.0 of the api or non-web based and version 3.0 of the api. I actually need version 3.0 to get access to the extra fields provided by google contacts. So my question is, is there a way to get access to the gdata api under Google App Engine using Java? If not is there an ETA on when version 3.0 of the gdata api will be released for python? Cheers.

  Read the article

• Java desktop app: How to maximize tray application when hotkey pressed?

  - by David

  I need to write a program that, when minimized, lives in the System Tray, and I'll use Java 6's SystemTray API to do that. How can I make that application comes to the foreground when the user presses some hotkey? For example, the app is running but minimized. When the user presses CTRL-SHIFT-Y or something (or, like Google Desktop's search, CTRL twice) and the application is maximized. EDIT: I know about how to bring a Java window to the foreground. I'm asking more specifically about how to make a running Java app listen for a hotkey.

  Read the article

• when is java faster than c++ (or when is JIT faster then precompiled)?

  - by kostja

  I have heard that under certain circumstances, Java programs or rather parts of java programs are able to be executed faster than the "same" code in C++ (or other precompiled code) due to JIT optimizations. This is due to the compiler being able to determine the scope of some variables, avoid some conditionals and pull similar tricks at runtime. Could you give an (or better - some) example, where this applies? And maybe outline the exact conditions under which the compiler is able to optimize the bytecode beyond what is possible with precompiled code? NOTE : This question is not about comparing Java to C++. Its about the possibilities of JIT compiling. Please no flaming. I am also not aware of any duplicates. Please point them out if you are.

  Read the article

• Which rdfa parser for java that supports currently used rdfa attributes?

  - by lennyks

  I am building an app in Java using Jena for semantic information scraping. I am looking for a RDFa parser that would allow me to correctly extract all the rdfa statements. Specifically, one that extracts info about namespaces used and presuming that rdfa tags are correct in the page produces correct triples, ones that distinguish between object and data properties. I went through all rdfa parsers from the site http://rdfa.info/wiki/Consume for Java. They all struggle to extract any rdfa statements and if they do not crash, Jena RDFa parser shows plenty of errors and then dies a terrible death, the data is of little use as it is incorrectly processed and generally mixed up. I am newbie in this area so please be gentle:) I was also thinking of using a library written in different language but then again I don't really know how to plug it into Java code. Any suggestions?

  Read the article

• After Port Forwarding, how to get my external IP in Java ?

  - by Frank

  I set up a static IP and did port forwarding on my notebook, and now I have a static IP address, but it's relatively static, every time I re-start the machine, I get another address, and since I have a "static" IP I can now do Paypal IPN messaging. But how can I get this static IP from my Java program ? One way I can think of is to visit : http://portforward.com/ and on that page it tells me what my external IP is, so I can extract it with Java code, is there any other way that I can do in my Java code to get this info ?

  Read the article

• Java class Class<T> and static method Class.forName() drive me crazy.

  - by matt

  Hi, this code doesn't compile. i'm wandering what i am doing wrong: private static Importable getRightInstance(String s) throws Exception { Class<Importable> c = Class.forName(s); Importable i = c.newInstance(); return i; } where Importable is an interface and the string s is the name of an implementing class. The compiler says: ./Importer.java:33: incompatible types found : java.lang.Class<capture#964 of ?> required: java.lang.Class<Importable> Class<Importable> c = Class.forName(format(s)); thanks for any help!

  Read the article

• Suggest a open source project which heavily uses java concurrency utilities?

  - by user49767

  I have done good amount of Java programming, but yet to master Threading & Concurrency. I would like to become an expert programmer in threading & concurrency. I have also took a short at Tomcat code, I was able to understand, but looking even more complex project. Could you suggest any open source project which heavily uses java threading & concurrency utilities? Note : I have also reading java.util.concurrent package source code, but eager to learn from Application perspective, than creating my own threading utilities.

  Read the article

• Preferred data-format for user-data in java applications?

  - by Frederik Wordenskjold

  I'm currently developing a desktop application in java, which stores user data such as bookmarks for ftp-servers. When deciding how to save these informations, I ended up using xml, simply because I like the way xpath works. I was thinking about json too, which seems more lightweight. What is your preferred way to store data in java desktop applications (in general) and why? What about java-persistence, does that have any advantages worth noting? And how much does the size of user data matter? Its not always possible to store data in a database (or preferable), and in my experience xml does not scale well. Let me know what you think!

  Read the article

• How can I do printing in Java with layouts instead of low level coordinates?

  - by Jonas

  I need to to some printing from my Java Swing application. I have tried to use Java Tutorials, but everything is very low level, and time-consuming. I have to specify the coordinates for every line that I want to print. It it also very lowlevel to use text, because I have to use FontMetrics and calculate what space all text fills up. Is there any easier way to to printing in Java? I would like to design the documents with something like layout managers instead. Any good library or API?

  Read the article

• How to save optimized png images with java's ImageIO?

  - by Christoph

  I am generating lots of images in java and saving them through the ImageIO.write method like this: final BufferedImage img = createSomeImage(); ImageIO.write( img, "png", new File( "/some/file.png" ); I was happy with the results until Google's firefox addon 'Page Speed' told me that i can save up to 60% of the size if i optimize the images. The images are QR codes, their size is around 900B each and the firefox-plugin optimized versions are around 300B. I'd like to save such optimized 300B Images directly from java. So here my question again: How to save optimized png images with java's ImageIO?

  Read the article

• Running Python code from Java program, shoudl i be doing this?

  - by Space Rocker

  i have a scenario where i draw a network and set all it's paraments on swing based gui, after that i have to translate this network into a python based script which another framework reads and realize this network in the form of virtual machines. As an example have look here: from mininet.topo import Topo, Node class MyTopo( Topo ): def *__init__*( self, enable_all = True ): super( MyTopo, self ).__init__() Host = 1 Switch = 2 self.add_node( Switch, Node( is_switch=True ) ) self.add_node( Host, Node( is_switch=False ) ) self.add_edge( Host, Switch ) self.enable_all() topos = { 'mytopo': ( lambda: MyTopo() ) } It simply connects a host to a switch and realize this topology on mininet framework. Now for now in order to realize the drawn network on java GUI here is what i am doing: I simply take the information from GUI and creates a new python file like the one above using java code and then run this file in mininet, which works fine somehow. I want to know, is this the correct and robust way how i am doing this or should i be looking further into java-python bridge like scenarios to be more effective or so as to say more professional.

  Read the article

• how to import Java class with Python using Eclipse?

  - by JChao

  Hi, I'm trying to write Jython where the Python file imports classes from Java I'm using Eclipse with PyDev. My Python code looks like: from eclipsejavatest import eclipseJavaTest from eclipsejavatest import JavaClass class eclipsePyPrint(eclipseJavaTest): def eclipsepyMain(self): print "python main method" eclipseJavaTest.printerCount(4) print eclipseJavaTest.gotoPython() eclipseJavaTest.printerSentence() samplepyClass = JavaClass("Jython plain") samplepyClass.setName("jython fancy") print samplepyClass.getName() but I'm getting the error ImportError: No module named eclipsejavatest The Python project references the Java project. I've tried exporting the Java project and adding the .jar to the Jython Class Path for the Python project. I'm not sure what to do to get this to work.

  Read the article

• What's a good way to encrypt data using an asymmetric key, that's available to both java and ruby?

  - by Michael Campbell

  I have a customer that wants to encrypt some data in his database (not passwords; this needs actual encryption, not hashing). The application which will be doing the encrypting/writing is in Java, but the process which will DECRYPT it is behind a secure firewall, and is written in ruby. The idea was to use a public/private key scheme; the java system would encrypt it with the public key, then the process on his local box would use the private key to decrypt it as needed. I'm looking for any experience anyone has doing something like that; my main question is what sorts of libraries on java and ruby can interoperate with the same keys and data.

  Read the article

• How can I modify an Android bitmap in C++ (JNI/NDK) so that I can use on the Java side?

  - by HardCoder

  I call a C++ function over JNI and pass a RGBA_8888 bitmap, lock it, change the values, unlock it, return and then display it in Java with this C++ code: AndroidBitmap_getInfo(env, map, &info) < 0); AndroidBitmap_lockPixels(env, map, (void**)&pixel); for(i=info.width*info.height-1;i>=0;i--) { pixel[i] = 0xf1f1f1f1; } AndroidBitmap_unlockPixels(env, map); The problem I have is that the bitmaps looks not as I expect it and the pixel values (verified with getPixel) are not the same when I check them in Java from what I set them in C++. When I set the bitmap values to 0xffffffff I get the correct value in Java, but for many others I don't. 0xf1f1f1f1 for example turns into 0xF1FFFFFF. What do I have to do to make it work ? PS: I am using Android 2.3.4

  Read the article

• How to include named capture groups in java regex?

  - by jrummell

  I'm new to regex in Java and I can't figure out how to include named capture groups in an expression. I'm writing a ScrewTurn Image Converter for Confluence's Universal Wiki Converter. This is what I have: String image = "\\[image(?<align>auto)?\\|\\|{UP\\(((?<namespace>\\w+)\\.)?(?<pagename>[\\w-]+)\\)}(?<filename>[\\w- ]+\\.[\\w]+)\\]"; Pattern imagePattern = Pattern.compile(image, Pattern.CASE_INSENSITIVE); It's throwing this exception in Pattern.comiple(): java.util.regex.PatternSyntaxException: Unknown look-behind group near index 19 \[image(?<align>auto)?\|\|{UP\(((?<namespace>\w+)\.)?(?<pagename>[\w-]+)\)}(?<filename>[\w- ]+\.[\w]+)\] ^ I've used named capture groups like this before in C# (?<namedgroup>asdf), but not in Java. What am I missing?

  Read the article

< Previous Page | 343 344 345 346 347 348 349 350 351 352 353 354  | Next Page >