Search Results

Search found 37456 results on 1499 pages for 'java util logging'.

Page 227/1499 | < Previous Page | 223 224 225 226 227 228 229 230 231 232 233 234  | Next Page >

  • How to detect invalid image URL with JAVA?

    - by Cataclysm
    I have a method to download image from URL. As like below.. public static byte[] downloadImageFromURL(final String strUrl) { InputStream in; ByteArrayOutputStream out = new ByteArrayOutputStream(); try { URL url = new URL(strUrl); in = new BufferedInputStream(url.openStream()); byte[] buf = new byte[2048]; int n = 0; while (-1 != (n = in.read(buf))) { out.write(buf, 0, n); } out.close(); in.close(); } catch (IOException e) { return null; } return out.toByteArray(); } I have an image url and it is valid. for example. https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTxfYM-hnD-Z80tgWdIgQKchKe-MXVUfTpCw1R5KkfJlbRbgr3Zcg My problem is I don't want to download if image is really not exists.Like .... https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTxfYM-hnD-Z80tgWdIgQKchKe-MXVUfTpCw1R5KkfJlbRbgr3Zcgaaaaabbbbdddddddddddddddddddddddddddd This image shouldn't be download by my method. So , how can I know the giving image URL is not really exists. I don't want to validate my URL (I think that may not my solution ). So, I googled for that. From this article ... How to check if a URL exists or returns 404 with Java? and Java check if file exists on remote server using its url But this con.getResponseCode() will always return status code "200". This mean my method will also download invalid image urls. So , I output my bufferStream as like... System.out.println(in.read(buf)); Invalid image URL produces "43". So , I add these lines of codes in my method. if (in.read(buf) == 43) { return null; } It is ok. But I don't think that will always satisfy. Has another way to get it ? am I right? I would really appreciate any suggestions. This problem may struct my head. Thanks for reading my question.

    Read the article

  • Generic solution to deselect buttons in java

    - by Hectoret
    In a set of radio buttons of the same group, only one can be selected at the same time. I would like to have the same behaviour with a normal button. Imagine there's a row of 3 buttons. When a button is selected it changes: but.setSelected(true) and the other two buttons should be NOT selected: but.setSelected(false) Now, is there a generic, simple and clean solution to accomplish that in Java (Swing) ?

    Read the article

  • Java threads for the beginner

    - by Boba
    I've been trying to explain Java threading to a colleague who has never been exposed to multi-threaded applications, but apparently I'm not a very good teacher. Can anyone recommend a good online or offline resource that can explain threading in a simple, step-by-step manner? I know it's a complex topic, but surely there exists an article, book, or other explanation that can result in an "Aha! I get it, finally!" moment.

    Read the article

  • Java Applet flickers on redraw();

    - by Dan
    OK so here's my code: http://www.so.pastebin.com/08ghTkQL When I press UP, DOWN, LEFT, or RIGHT... the applet redraws itself and positions the new player... sometimes when I do this (pressing buttons), the whole java applet flickers.... how do I stop this? Thank you.

    Read the article

  • Java checking connection via socket continuously

    - by Onca
    I'm developing a multiclient-server program with Java based on GUI and database. The demand regarding the program from the client side is to make sure all the time that there is a connection to the server, and if the connection is lost (server goes down/problem with socket or stream) it should be notified. In other words I need a solution for continuously checking the connection to the server. What is the best way to do that ?

    Read the article

  • visualizing enter symbol in java (Serif/SansSerif preferred)

    - by Tom
    How can I display the graphical "enter symbol" within java applet using fonts? I want to show "?", which is U+21B5 DOWNWARDS ARROW WITH CORNER LEFTWARDS. – I want to draw this to applet's screen so that it works in WIN, LINUX, MACOSX, etc. Is there a font available that makes this possible or should I draw it manually somehow? g2d.setFont("SymbolFont??which one"); g2d.drawString(myenterSymbolHere,x,Y);

    Read the article

  • Rsyslogd not listening on port

    - by amorfis
    I installed rsyslogd on ubuntu server, started it and everything looks fine, but the port the server should listen on is not opened. ubuntu@node7:~$ sudo service rsyslog restart rsyslog stop/waiting rsyslog start/running, process 14114 Netstat shows it is not listening: ubuntu@node7:~$ netstat -tlan Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 320 172.22.0.17:22 10.8.8.38:61335 ESTABLISHED tcp6 0 0 :::22 :::* LISTEN tcp6 0 0 :::2776 :::* LISTEN tcp6 0 0 :::2777 :::* LISTEN tcp6 0 0 172.22.0.17:2777 172.22.0.11:56554 ESTABLISHED tcp6 0 0 172.22.0.17:2776 172.22.0.11:39780 ESTABLISHED This is how /etc/rsyslog.conf looks like (most comments omitted): ubuntu@node7:~$ cat /etc/rsyslog.conf ################# #### MODULES #### ################# $ModLoad imuxsock # provides support for local system logging $ModLoad imklog # provides kernel logging support (previously done by rklogd) $ModLoad imtcp $InputTCPServerRun 514 ########################### #### GLOBAL DIRECTIVES #### ########################### $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat $RepeatedMsgReduction on $WorkDirectory /var/spool/rsyslog $FileOwner syslog $FileGroup adm $FileCreateMode 0640 $DirCreateMode 0755 $Umask 0022 $PrivDropToUser syslog $PrivDropToGroup adm $IncludeConfig /etc/rsyslog.d/*.conf In /etc/rsyslog.d/35-server-per-host.conf I have following lines, and I suspect this can be the cause. What does it mean? # Stop processing of all non-local messages. You can process remote messages # on levels less than 35. :fromhost-ip,!isequal,"127.0.0.1" ~ and if it is, how could I change it to have server listening and receiving and logging messages? UPDATE: I commented out suspected line, but still it's not listening on port 514

    Read the article

  • Uncompress GZIPed HTTP Response in Java

    - by bill0ute
    Hi, I'm trying to uncompress a GZIPed HTTP Response by using GZIPInputStream. However I always have the same exception when I try to read the stream : java.util.zip.ZipException: invalid bit length repeat My HTTP Request Header: GET www.myurl.com HTTP/1.0\r\n User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; fr; rv:1.9.2) Gecko/20100115 Firefox/3.6\r\n Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n Accept-Language: fr,fr-fr;q=0.8,en-us;q=0.5,en;q=0.3\r\n Accept-Encoding: gzip,deflate\r\n Accept-Charset: ISO-8859-1,UTF-8;q=0.7,*;q=0.7\r\n Keep-Alive: 115\r\n Connection: keep-alive\r\n X-Requested-With: XMLHttpRequest\r\n Cookie: Some Cookies\r\n\r\n At the end of the HTTP Response header, I get path=/Content-Encoding: gzip, followed by the gziped response. I tried 2 similars codes to uncompress : GZIPInputStream gzip = new GZIPInputStream (new ByteArrayInputStream (tBytes)); StringBuffer szBuffer = new StringBuffer (); byte tByte [] = new byte [1024]; while (true) { int iLength = gzip.read (tByte, 0, 1024); // <-- Error comes here if (iLength < 0) break; szBuffer.append (new String (tByte, 0, iLength)); } And this one that I get on this forum : InputStream gzipStream = new GZIPInputStream (new ByteArrayInputStream (tBytes)); Reader decoder = new InputStreamReader (gzipStream, "UTF-8");//<- I tried ISO-8859-1 and get the same exception BufferedReader buffered = new BufferedReader (decoder); I guess this is an encoding error. Best regards, bill0ute

    Read the article

  • Java synchronized seems ignored

    - by viraptor
    Hi, I've got the following code, which I expected to deadlock after printing out "Main: pre-sync". But it looks like synchronized doesn't do what I expect it to. What happens here? import java.util.*; public class deadtest { public static class waiter implements Runnable { Object obj; public waiter(Object obj) { this.obj = obj; } public void run() { System.err.println("Thead: pre-sync"); synchronized(obj) { System.err.println("Thead: pre-wait"); try { obj.wait(); } catch (Exception e) { } System.err.println("Thead: post-wait"); } System.err.println("Thead: post-sync"); } } public static void main(String args[]) { Object obj = new Object(); System.err.println("Main: pre-spawn"); Thread waiterThread = new Thread(new waiter(obj)); waiterThread.start(); try { Thread.sleep(1000); } catch (Exception e) { } System.err.println("Main: pre-sync"); synchronized(obj) { System.err.println("Main: pre-notify"); obj.notify(); System.err.println("Main: post-notify"); } System.err.println("Main: post-sync"); try { waiterThread.join(); } catch (Exception e) { } } } Since both threads synchronize on the created object, I expected the threads to actually block each other. Currently, the code happily notifies the other thread, joins and exits.

    Read the article

  • Synchronization of Nested Data Structures between Threads in Java

    - by Dominik
    I have a cache implementation like this: class X { private final Map<String, ConcurrentMap<String, String>> structure = new HashMap...(); public String getValue(String context, String id) { // just assume for this example that there will be always an innner map final ConcurrentMap<String, String> innerStructure = structure.get(context); String value = innerStructure.get(id); if(value == null) { synchronized(structure) { // can I be sure, that this inner map will represent the last updated // state from any thread? value = innerStructure.get(id); if(value == null) { value = getValueFromSomeSlowSource(id); innerStructure.put(id, value); } } } return value; } } Is this implementation thread-safe? Can I be sure to get the last updated state from any thread inside the synchronized block? Would this behaviour change if I use a java.util.concurrent.ReentrantLock instead of a synchronized block, like this: ... if(lock.tryLock(3, SECONDS)) { try { value = innerStructure.get(id); if(value == null) { value = getValueFromSomeSlowSource(id); innerStructure.put(id, value); } } finally { lock.unlock(); } } ... I know that final instance members are synchronized between threads, but is this also true for the objects held by these members? Maybe this is a dumb question, but I don't know how to test it to be sure, that it works on every OS and every architecture.

    Read the article

  • Provisioning Api using java

    - by user268515
    Hi i'm working in java and tried to retrieve all the user in the domain for that i used Provisionin api............ Its working good But my idea is to Use 2-legged OAuth to retrieve the users from the domain Is it Possible? I dont how to specify the URL please Help me And i triede the following the program final String CONSUMER_KEY = "xxxxxxxxxx.com"; final String CONSUMER_SECRET = "12345678122154154df9"; final String DOMAIN = "xxxxxxxxxx.com"; GoogleOAuthParameters oauthParameters = new GoogleOAuthParameters(); oauthParameters.setOAuthConsumerKey(CONSUMER_KEY); oauthParameters.setOAuthConsumerSecret(CONSUMER_SECRET); oauthParameters.setOAuthType(OAuthType.TWO_LEGGED_OAUTH); OAuthHmacSha1Signer signer = new OAuthHmacSha1Signer(); URL feedUrl = new URL("https://apps-apis.google.com/a/feeds/" + DOMAIN + "/user/2.0/[email protected]"); userService = new UserService("Myapplication"); userService.setOAuthCredentials(oauthParameters, signer); userService.useSsl(); UserFeed allUsers = new UserFeed(); UserFeed allpage; Link nextLink; do { allpage = userService.getFeed(feedUrl, UserFeed.class); allUsers.getEntries().addAll(allpage.getEntries()); nextLink = allpage.getLink(Link.Rel.NEXT, Link.Type.ATOM); if (nextLink != null) { feedUrl = new URL(nextLink.getHref()); } }while (nextLink != null); return allUsers; } Its returing the error as com.google.gdata.util.AuthenticationException: Unknown authorization header

    Read the article

  • converting a Tree to newick format. java

    - by Esmond
    I'm having problems converting a binary rooted tree to newick format. The full explanation for such a format can be found: http://code.google.com/p/mrsrf/wiki/NewickTree An example of a newick format would be as follows: for a tree T such as http://www.cs.mcgill.ca/~cs251/OldCourses/1997/topic8/images/completetreetwo.gif the newick representation would be: (((8,9),(10,11)),((12,13),(14,15))) the internal node will become the commas while the leaves will be retained. such trees have internal nodes which will always have 2 children. I have a problem using recursion to come out with this newick format. The output contains far too many nodes and braces. Any comments to resolve this problem is appreciated or even an iterative algorithm would be welcomed import java.util.Stack; public class Tree { .... public String inOrderNewick(Node root, String output) throws ItemNotFoundException { if (root.hasChild()) { output += "("; output += inOrderNewick(root.child1, output); output += ","; output += inOrderNewick(root.child2, output); output += ")"; return output; } else { output += root.getSeq(); return output; } } }

    Read the article

  • Why wont this compile its killing me. (java)

    - by Ryan The Leach
    import java.util.*; public class Caesar { public static void main(String [] args) { final boolean DEBUG = false; System.out.println("Welcome to the Caesar Cypher"); System.out.println("----------------------------"); Scanner keyboard = new Scanner (System.in); System.out.print("Enter a String : "); String plainText = keyboard.nextLine(); System.out.print("Enter an offset: "); int offset = keyboard.nextInt(); String cipherText = ""; for(int i=0;i<plainText.length();i++) { int chVal = plainText.charAt(i); if (DEBUG) {int debugchVal = chVal;} chVal +=offset; if (DEBUG) {System.out.print(chVal + "\t");} while (chVal <32 || chVal > 127) { if (chVal < 32) chVal += 96; if (chVal > 127) chVal -= 96; if(DEBUG) {System.out.print(chVal+" ");} } if (DEBUG) {System.out.println();} char c = (char) chVal; cipherText = cipherText + c; if (DEBUG) {System.out.println(i + "\t" + debugchVal + "\t" + chVal + "\t" + c + "\t" + cipherText);} } System.out.println(cipherText); } }

    Read the article

  • Append data to same text file using java

    - by Manu
    SimpleDateFormat formatter = new SimpleDateFormat("ddMMyyyy_HHmmSS"); String strCurrDate = formatter.format(new java.util.Date()); String strfileNm = "Customer_" + strCurrDate + ".txt"; String strFileGenLoc = strFileLocation + "/" + strfileNm; String Query1="select '0'||to_char(sysdate,'YYYYMMDD')||'123456789' class_code from dual"; String Query2="select '0'||to_char(sysdate,'YYYYMMDD')||'123456789' class_code from dual"; try { Statement stmt = null; ResultSet rs = null; Statement stmt1 = null; ResultSet rs1 = null; stmt = conn.createStatement(); stmt1 = conn.createStatement(); rs = stmt.executeQuery(Query1); rs1 = stmt1.executeQuery(Query2); File f = new File(strFileGenLoc); OutputStream os = (OutputStream)new FileOutputStream(f,true); 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.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; } The above code is working fine. it writes the content of "rs" resultset data in text file Now what i want is ,i need to append the the content in "rs2" resultset to the "same text file"(ie . i need to append "rs2" content with "rs" content in the same text file)..

    Read the article

  • java - coding errors causing endless loop

    - by Daniel Key
    Im attempting to write a program that takes a population's birthrate and deathrate and loops the annual population until it either reaches 0 or doubles. My problem it that it continuously loops an endless amount of illegible numbers and i cant fix it. please help. //***************************************** //This program displays loop statements //Written by: Daniel Kellogg //Last Edited: 9/28/12 //**************************************** import java.util.Scanner; public class Hwk6 { public static void main (String[] args) { int currentYear, currentPopulation; double birthRate, deathRate; Scanner stdin = new Scanner(System.in); System.out.println("\nPopulation Estimator\n"); System.out.println("Enter Year"); currentYear = stdin.nextInt(); System.out.println("Enter Current Population"); currentPopulation = stdin.nextInt(); System.out.println("Enter Birthrate of Population"); birthRate = stdin.nextDouble(); System.out.println("Enter Deathrate of Population"); deathRate = stdin.nextDouble(); int counter = currentPopulation; System.out.println("Population: "); while (currentPopulation != -1) while (counter < currentPopulation * 2) { System.out.print(counter + " "); counter = counter + (int)(counter * birthRate - counter * deathRate); } System.exit(0); } }

    Read the article

  • Help with Hashmaps in Java

    - by Crystal
    I'm not sure how I use get() to get my information. Looking at my book, they pass the key to get(). I thought that get() returns the object associated with that key looking at the documentation. But I must be doing something wrong here.... Any thoughts? import java.util.*; public class OrganizeThis { /** Add a person to the organizer @param p A person object */ public void add(Person p) { staff.put(p, p.getEmail()); System.out.println("Person " + p + "added"); } /** * Find the person stored in the organizer with the email address. * Note, each person will have a unique email address. * * @param email The person email address you are looking for. * */ public Person findByEmail(String email) { Person aPerson = staff.get(email); return aPerson; } private Map<Person, String> staff = new HashMap<Person, String>(); public static void main(String[] args) { OrganizeThis testObj = new OrganizeThis(); Person person1 = new Person("J", "W", "111-222-3333", "[email protected]"); testObj.add(person1); System.out.println(testObj.findByEmail("[email protected]")); } }

    Read the article

  • Why doesn't java.util.Set have get(int index)?

    - by Marty Pitt
    I'm sure there's a good reason, but could someone please explain why the java.util.Set interface lacks get(int Index), or any similar get() method? It seems that sets are great for putting things into, but I can't find an elegant way of retrieving a single item from it. If I know I want the first item, I can use set.iterator().next(), but otherwise it seems I have to cast to an Array to retrieve an item at a specific index? What are the appropriate ways of retrieving data from a set? (other than using an iterator) I'm sure the fact that it's excluded from the API means there's a good reason for not doing this -- could someone please enlighten me? EDIT: Some extremely great answers here, and a few saying "more context". The specific scneario was a dbUnit test, where I could reasonalby assert that the returned set from a query had only 1 item, and I was trying to access that item. However, the question is more valid without the scenario, as it remains more focussed : What's the difference between set & list. Thanks to all for the fantastic answers below.

    Read the article

  • need help with Java solution /newbie

    - by Racket
    Hi, I'm new to programming in general so i'm trying to be as specific as possible in this question. There's this book that i'm doing some exercises on. I managed to do more than half of what they say, but it's just one input that I have been struggling to find out. I'll write the question and thereafter my code, "Write an application that creates and prints a random phone number of the form XXX-XXX-XXXX. Include the dashes in the output. Do not let the first three digits contain an 8 or 9 (but don't be more restrictive than that), and make sure that the second set of three digits is not greater than 742. Hint: Think through the easiest way to construct the phone number. Each diigit does not have to be determined separately." OK, the highlighted sentence is what i'm looking at. Here's my code: import java.util.Random; public class PP33 { public static void main (String[] args) { Random rand = new Random(); int num1, num2, num3; num1 = rand.nextInt(900) + 100; num2 = rand.nextInt(643) + 100; num3 = rand.nextInt(9000) + 1000; System.out.println(num1+"-"+num2+"-"+num3); } } How am I suppose to do this? I'm on chapter 3 so we have not yet discussed if statements etcetera, but Aliases, String class, Packages, Import declaration, Random Class, Math Class, Formatting output (decimal- & numberFormat), Printf, Enumeration & Wrapper classes + autoboxing. So consider answer the question based only on these assumptions, please. The code doesn't have any errors. Thank you!

    Read the article

  • Java HashMap containsKey always false

    - by Dennis
    I have the funny situation, that I store a Coordinate into a HashMap<Coordinate, GUIGameField>. Now, the strange thing about it is, that I have a fragment of code, which should guard, that no coordinate should be used twice. But if I debug this code: if (mapForLevel.containsKey(coord)) { throw new IllegalStateException("This coordinate is already used!"); } else { ...do stuff... } ... the containsKey always returns false, although I stored a coordinate with a hashcode of 9731 into the map and the current coord also has the hashcode 9731. After that, the mapForLevel.entrySet() looks like: (java.util.HashMap$EntrySet) [(270,90)=gui.GUIGameField@29e357, (270,90)=gui.GUIGameField@ca470] What could I have possibly done wrong? I ran out of ideas. Thanks for any help! public class Coordinate { int xCoord; int yCoord; public Coordinate(int x, int y) { ...store params in attributes... } ...getters & setters... @Override public int hashCode() { int hash = 1; hash = hash * 41 + this.xCoord; hash = hash * 31 + this.yCoord; return hash; } }

    Read the article

< Previous Page | 223 224 225 226 227 228 229 230 231 232 233 234  | Next Page >