Search Results

Search found 44579 results on 1784 pages for 'oracle java'.

Page 542/1784 | < Previous Page | 538 539 540 541 542 543 544 545 546 547 548 549  | Next Page >

• How do I serialise a graph in Java without getting StackOverflowException?

  - by Tim Cooper

  I have a graph structure in java, ("graph" as in "edges and nodes") and I'm attempting to serialise it. However, I get "StackOverflowException", despite significantly increasing the JVM stack size. I did some googling, and apparently this is a well known limitation of java serialisation: that it doesn't work for deeply nested object graphs such as long linked lists - it uses a stack record for each link in the chain, and it doesn't do anything clever such as a breadth-first traversal, and therefore you very quickly get a stack overflow. The recommended solution is to customise the serialisation code by overriding readObject() and writeObject(), however this seems a little complex to me. (It may or may not be relevant, but I'm storing a bunch of fields on each edge in the graph so I have a class JuNode which contains a member ArrayList<JuEdge> links;, i.e. there are 2 classes involved, rather than plain object references from one node to another. It shouldn't matter for the purposes of the question). My question is threefold: (a) why don't the implementors of Java rectify this limitation or are they already working on it? (I can't believe I'm the first person to ever want to serialise a graph in java) (b) is there a better way? Is there some drop-in alternative to the default serialisation classes that does it in a cleverer way? (c) if my best option is to get my hands dirty with low-level code, does someone have an example of graph serialisation java source-code that can use to learn how to do it?

  Read the article

• Oracle - Determine maximum supported size for regular expression

  - by FrustratedWithFormsDesigner

  I have a regular expression that throws ORA-12733, "regular expression is too long". How do I determine what the maximum supported size is? FYI: the offending regex is 892 characters. It's a generated regex, so I could change how I generate and execute it, but I would like to know what the limits to the max size are before I change how I am generating and executing. (running Oracle 10.2g) UPDATE: If it depends on the actual regex, here's the begining of it (the rest is just the same thing repeated, with different values between ^ and $): (^R_1A$|^R_2A$|^R_3A$|^R_4A$|^R_4B$|^R_5A$|^R_5B$...

  Read the article

• alias some columns names as one field in oracle's join select query

  - by Marecky

  Hi We are developing something like a social networking website. I've got task to do 'follow me' functionality. In our website objects are users, teams, companies, channels and groups (please don't ask why there are groups and teams - it is complicated for me too, but teams are releated to user's talent) Users, teams, channels, companies and groups have all their own tables. I have a query which gets me all the follower's leaders like this select --fo.leader_id, --fo.leader_type, us.name as user_name, co.name as company_name, ch.title as channel_name, gr.name as group_name, tt.name as team_name from follow_up fo left join users us on (fo.leader_id = us.id and fo.leader_type = 'user') left join companies co on (fo.leader_id = co.user_id and fo.leader_type = 'company') left join channels ch on (fo.leader_id = ch.id and fo.leader_type = 'channel') left join groups gr on (fo.leader_id = gr.id and fo.leader_type = 'group') left join talent_teams tt on (fo.leader_id = tt.id and fo.leader_type = 'team') where follower_id = 83 I need to get all fields like: user_name, company_name, channel_name, group_name, team_name as one field in SELECT's product. I have tried to alias them all the same 'name' but Oracle numbered it. Please help :)

  Read the article

• Oracle access from iOS

  - by Michael Lowman

  I'm developing an iPad app that needs read-only access to an Oracle database. Is there any way to do this? As far as I can see, the only options are using OCI, which requires a prebuilt binary in the form of the instant client (and not built for ARM), or OJDBC drivers. Both of these seem to be out of the question. In my research I have discovered that libmysqlclient compiles for arm with minimal tuning. This is a stretch, but is there any possible way to use this to my advantage? I have seen this product providing odbc connectivity through the use of a Windows gateway machine using the ODBC client libraries, but this solution really isn't an option for me at the present time. Any ideas?

  Read the article

• Where can I find good ajax support in Java/Python ?

  - by HJ-INCPP

  Hello, I want a framework (or anything) that helps me make rich client guis. I know my server-side, but I don't like programming in ajax, javascript, css etc. Something that wraps the ajax code in some objects/methods with clean syntax, would do the trick. I want to write code in java instead of defining css and html tags. Does Java Spring, JSF, Django support this ? Languages: Java, Python Thank you

  Read the article

• java is pure object oriented or not,if not why?

  - by Sanjeev

  I am confuse about this ie java is pure object oriented language but I have seen in some good books there is mantion java is not a pure object oriented but I don't get why. So please give me the answer why java is not pure object oriented language?

  Read the article

• Knowing the fundamentals of Java what is the right approach to learn Groovy?

  - by Liuh

  As my question already implies I want to learn a new language and have read several articles about groovy and its more pragmatic syntax. SO I have choosen Groovy as the language of my choice. What is a good way to learn a new language like Groovy when I already know the fundamentals of Java. When I understand correctly Groovy will be running in the Java Virtual Machine and allows me to always rely on what I know from Java when I don't know how to solve the problem in Groovy. I am looking for hints on how to organize a learning track to learn this language. I found that page explaining the differences: http://groovy.codehaus.org/Differences+from+Java But what I am looking for is more a tutorial where I can get through and get introduced to the differences.

  Read the article

• How to parse time stamps with Unicode characters in Java or Perl?

  - by ram

  I'm trying to make my code as generic as possible. I'm trying to parse install time of a product installation. I will have two files in the product, one that has time stamp I need to parse and other file tells the language of the installation. This is how I'm parsing the timestamp public class ts { public static void main (String[] args){ String installTime = "2009/11/26 \u4e0b\u5348 04:40:54"; //This timestamp I got from the first file. Those unicode charecters are some Chinese charecters...AM/PM I guess //Locale = new Locale();//don't set the language yet SimpleDateFormat df = (SimpleDateFormat)DateFormat.getDateTimeInstance(DateFormat.DEFAULT,DateFormat.DEFAULT); Date instTime = null; try { instTime = df.parse(installTime); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(instTime.toString()); } } The output I get is Parsing Failed java.text.ParseException: Unparseable date: "2009/11/26 \u4e0b\u5348 04:40:54" at java.text.DateFormat.parse(Unknown Source) at ts.main(ts.java:39) Exception in thread "main" java.lang.NullPointerException at ts.main(ts.java:45) It throws exception and at the end when I print it, it shows some proper date... wrong though. I would really appreciate if you could clarify me on these doubts How to parse timestamps that have unicode characters if this is not the proper way? If parsing is failed, how could instTime able to hold some date, wrong though? I know its some chinese,Korean time stamps so I set the locale to zh and ko as follows.. even then same error comes again Locale = new Locale("ko"); Locale = new Locale("ja"); Locale = new Locale("zh"); How can I do the same thing in Perl? I can't use Date::Manip package; Is there any other way?

  Read the article

• Oracle Triggers Query..

  - by AGeek

  Lets consider a Table STUD and a ROW-Level TRIGGER is implemented over INSERT query.. My scenario goes like this, whenever a row is inserted, a trigger is fired and it should access some script file which is placed in the hard disk, and ultimately should print the result. So, is this thing is possible? and if yes, then this thing should exist in dynamic form, i.e. if we change the content of script file, then the oracle should reflect those changes as well. I have tried doing this for java using External Procedures, but doesn't feel that much satisfied with the result that i wanted. Kindly give your point-of-view for this kind of scenario and ways that this can be implemented.

  Read the article

• Oracle TIMESTAMP w/ timezone data type confusion

  - by JuiceBox1337

  When would you use TIMESTAMP w/ timezone as opposed to TIMESTAMP w/ local time zone? When data is stored in a column of data type TIMESTAMP w/ local tz, the data is normalized to the database time zone, and the time zone displacement is not stored as part of the column data. When users retrieve the data, Oracle returns it in the users' local session time zone. Isn't that much more useful? I can't think of a reason why I'd want to use TIMESTAMP w/ timezone and get back some gobble gook with a UTC offset.

  Read the article

• What is used instead of SendMessage and PostMessage in Java to handle inter-thread communications?

  - by Kieveli

  I'm from a WinAPI / C++ background, and I'm curious as to what the Java world uses in place of a threaded message loop in a worker thread to handle communications and interactions between threads. The idea is to use a message pump in both the worker thread, and the main thread, and have them posting messages back and forth. This solution is very WinAPI / C++ centric, and probably not the preferred method of achieving this goal in Java. What is the 'Java' way to do something like this?

  Read the article

• Why is glpk-java.jar not the same across all platforms?

  - by pruefsumme

  I'm using glpk-java in one of my projects. It provides a JNI to GLPK, a free LP/MIP solver. To use it under different platforms, you need different shared libraries (libglpk.so under Linux, libglpk.dylib under Mac OS X, glpk.dll under Windows) which is fully understandable. In addition, a java library is needed: glpk-java.jar. It's created as part of the build process. I was wondering why this JAR file (which only contains .class files) is different under different platforms? I.e., I cannot use the same glpk-java.jar under Linux and Mac OS X which means that I cannot put this file under revision control.

  Read the article

• Multiple resultsets from Oracle in Odp.net,without refcursors

  - by James L

  SQL Server is able to return the results of multiple queries in a single round-trip, e.g: select a, b, c from y; select d, e, f from z; Oracle doesn't like this syntax. It is possible to use reference cursors, like this: begin open :1 for select count(*) from a; open :2 for select count(*) from b; end; However, you incur a penalty in opening/closing cursors and you can hold database locks for an extended period. What I'd like to do is retrieve the results for these two queries in one shot, using Odp.net. Is it possible?

  Read the article

• "Exception in thread "main" java.lang.NoSuchMethodError Do i miss library in the installed JDk?

  - by Ahmad

  Hello every body I was using the JDK very well writing the code then i use "javac" to compile it then "java" to run it But Recently when i write a code and compile it then if i try to run it this exception appears to me "Exception in thread "main" java.lang.NoSuchMethodError " at first i thought there is something wrong in my code , i searched in the internet for a solving for this problem but i didn't find anything may help me Then i try to run the "HelloWorld" example i made it before, it runs i copied the code and pasted it in another file and changed the name to "HelloWorld2" and compile it by "javac" and tried to run it by "java" the same exception appears i was surprised why? it is the same code then i used the "javap" which decompile the code with both i found this difference in the first one (the old one) "public static void main(java.lang.String[])"; but in the second (the new one) "public static void main(String[])"; without java.lang then i compiled the old one which works and runs by "javac" and when i try to run it, it didn't run and give me the same exception i tried with some of my old codes it run and when i compile it by "javac" it doesn't work I searched to find a solution to this problem and i found nothing

  Read the article

• how do i create a .exe that runs a java program?

  - by David

  i have a really basic java program just one .java/.class file (.java uncompiled .class compiled i guess) how do i make something that i can have run on someone elses computer?

  Read the article

• JVM specification and Java compiler code useful for SCJP preparation ?

  - by BenoitParis

  I'm preparing the SCJP exam with the almost official study book ("SCJP Sun Certified Programmer for Java 6 Exam 310-065") I understand that Java programming is writting code that fulfills a certain high-level contract; So that Java can stay platform-independent. However, I have trouble understanding and remembering things when it comes to highly specific SCJP items (and they are numerous) The book stays high-level and does not provide examples of how one compiler would handle things. This is the same thing for runtime issues (JVM level): things are too much abstract for me. Rules often seems arbitrary and therefore, with no well defined purpose, are difficult to remember. Or maybe it's that sometimes I just don't get the underlying purpose. And here is the question: Would a JVM specification and/or some java compiler code help in preparing the SCJP? Have you had the need for such material or is the book sufficient enough? Also, please share the resources you used, apart from the book.

  Read the article

• Filling a LOV in Oracle Apex based on data in another text box

  - by Martin Pugh

  I am fairly new to Oracle Apex, and have a problem. Our application currently has a method of entering data, with several text boxes and Optional List of Values. I would like to have an LOV based on information in another text box like so: select APPOINTMENT_ID PATIENT_ID from APPOINTMENT where PATIENT_ID = :P9_PAT_NUM where P9_PAT_NUM is a patient number in a text box. However, this would apparently only work if the text box has already been submitted, else it assumes the text box is null. Is there any way to get this working with an LOV, or perhaps some other method?

  Read the article

• [java] reading POST data from html form sent to serversocket.

  - by user32167

  i try to write simplest possible server app in Java, displaying html form with textarea input, which after submitting gives me possibility to parse xml typed in thet textarea. For now i build simple serversocket based server like that: import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.PrintWriter; import java.net.ServerSocket; import java.net.Socket; public class WebServer { protected void start() { ServerSocket s; String gets = ""; System.out.println("Start on port 80"); try { // create the main server socket s = new ServerSocket(80); } catch (Exception e) { System.out.println("Error: " + e); return; } System.out.println("Waiting for connection"); for (;;) { try { // wait for a connection Socket remote = s.accept(); // remote is now the connected socket System.out.println("Connection, sending data."); BufferedReader in = new BufferedReader(new InputStreamReader( remote.getInputStream())); PrintWriter out = new PrintWriter(remote.getOutputStream()); String str = "."; while (!str.equals("")) { str = in.readLine(); if (str.contains("GET")){ gets = str; break; } } out.println("HTTP/1.0 200 OK"); out.println("Content-Type: text/html"); out.println(""); // Send the HTML page String method = "get"; out.print("<html><form method="+method+">"); out.print("<textarea name=we></textarea></br>"); out.print("<input type=text name=a><input type=submit></form></html>"); out.println(gets); out.flush(); remote.close(); } catch (Exception e) { System.out.println("Error: " + e); } } } public static void main(String args[]) { WebServer ws = new WebServer(); ws.start(); } } After form (textarea with xml and one additional text input) is submitted in 'gets' String-type variable I have Urlencoded values of my variables (also displayed on the screen, it looks like that: gets = GET /?we=%3Cnetwork+ip_addr%3D%2210.0.0.0%2F8%22+save_ip%3D%22true%22%3E%0D%0A%3Csubnet+interf_used%3D%22200%22+name%3D%22lan1%22+%2F%3E%0D%0A%3Csubnet+interf_used%3D%22254%22+name%3D%22lan2%22+%2F%3E%0D%0A%3C%2Fnetwork%3E&a=fooBar HTTP/1.1 What can i do to change GET to POST method (if i simply change it in form and than put " if (str.contains("GET")){" it gives me string like gets = POST / HTTP/1.1 with no variables. And after that, how i can use xml from my textarea field (called 'we')?

  Read the article

• Why does java have an interpreter? and not a compiler?

  - by Galaxin

  Iam a newbie to java and was wondering why java have a interpreter and not a compiler? While shifting from c++ to java we come across the differences between these two Compilation process being one of them. 1.A major difference between a compiler and interpreter is that compiler compiles the whole code at once and displays all the errors at a time whereas an interpreter interprets line by line. 2.Also a compiler takes a less time to compile a code when compared to an interpreter. When java was developed for more advanced and easy features and implementations why has it been restricted to a interpreter based on above facts? Is there any special reason why this is so? If yes what is it?

  Read the article

• Loading large amounts of data to an Oracle SQL Database

  - by James

  Hey all, I was wondering if anyone had any experience with what I am about to embark on. I have several csv files which are all around a GB or so in size and I need to load them into a an oracle database. While most of my work after loading will be read-only I will need to load updates from time to time. Basically I just need a good tool for loading several rows of data at a time up to my db. Here is what I have found so far: I could use SQL Loader t do a lot of the work I could use Bulk-Insert commands Some sort of batch insert. Using prepared statement somehow might be a good idea. I guess I was wondering what everyone thinks is the fastest way to get this insert done. Any tips?

  Read the article

• ORACLE: Parameter reference in WHERE doesn't work

  - by Gainder

  Hello, I have created a simple static function in oracle 10g to get the reference of an object based on his pk. STATIC FUNCTION getRef(nome IN VARCHAR2) RETURN REF folder_typ IS fl_r REF folder_typ := null; BEGIN SELECT REF(fl) INTO fl_r FROM folder_tab fl WHERE fl.nome = nome; RETURN fl_r; END getRef; This gives me an error because it could't fetch a row. If insted of WHERE fl.nome = nome; I write WHERE fl.nome = 'folder1'; -- it works. I think im not using the parameter in the right way. How can I use it?

  Read the article

• Oracle - pl sql selecting from SYS_REFCURSOR

  - by Einstein

  I have a function that returns a SYS_REFCURSOR that has a single row but multiple columns. What I'm looking to do is to be able to have a SQL query that has nested sub-queries using the column values returned in the SYS_REFCURSOR. Alternative ideas such as types, etc would be appreciated. Code below is me writing on-the-fly and hasn't been validated for syntax. --Oracle function CREATE DummyFunction(dummyValue AS NUMBER) RETURN SYS_REFCURSOR IS RETURN_DATA SYS_REFCURSOR; BEGIN OPEN RETURN_DATA SELECT TO_CHAR(dummyValue) || 'A' AS ColumnA ,TO_CHAR(dummyValue) || 'B' AS ColumnB FROM DUAL; RETURN RETURN_DATA; END; --sample query with sub-queries; does not work SELECT SELECT ColumnA FROM DummyFunction(1) FROM DUAL AS ColumnA ,SELECT ColumnB FROM DummyFunction(1) FROM DUAL AS ColumnB FROM DUAL;

  Read the article

• how to update multiple tables in oracle DB?

  - by murali

  hi, i am using two tables in my oracle 10g. the first table having the keyword,count,id(primary key) and my second table having id, timestamp.. but i am doing any chages in the first table(keyword,count) it will reflect on the my second table timestamp.. i am using id as reference for both the tables... table1: CREATE TABLE Searchable_Keywords (KEYWORD_ID NUMBER(18) PRIMARY KEY, KEYWORD VARCHAR2(255) NOT NULL, COUNT NUMBER(18) NOT NULL, CONSTRAINT Searchable_Keywords_unique UNIQUE(KEYWORD) ); table2: CREATE TABLE Keywords_Tracking_Report (KEYWORD_ID NUMBER(18), PROCESS_TIMESTAMP TIMESTAMP(8) ); how can update one table with reference of another table.. help me plz...

  Read the article

• Inserting asyncronously into Oracle, any benefits?

  - by Karl Trumstedt

  I am using ODP.NET for loading data into Oracle. I am bulking inserts into groups of a 1000 rows each call. Is there any performance benefits in calling my load method asynchronously? So say I want to insert 10000 rows, instead of making 10 calls synchronously I make 10 calls asynchronously. My database is using ASSM right now but otherwise plenty of freelists are used of course. The database server has several cores as well. My initial tests seem to point to a performance increase, but maybe there is something I cannot see? Potential deadlock or contention issues? Of course, there is added complexity in handling transactions and such doing my load this way.

  Read the article

• Best ways to write a method that updates two objects in a multithreaded java environment?

  - by DanielHonig

  Suppose we have a class called AccountService that manages the state of accounts. AccountService is defined as interface AccountService{ public void debit(account); public void credit(account); public void transfer(Account account, Account account1); } Given this definition, what is the best way to implement transfer() so that you can guarantee that transfer is an atomic operation. I'm interested in answers that reference Java 1.4 code as well as answers that might use resources from java.util.concurrent in Java 5

  Read the article

< Previous Page | 538 539 540 541 542 543 544 545 546 547 548 549  | Next Page >