Question of the Week Archive

Question of the Week presents answers to key questions posed by the developer community. The intent is to pass this important, but not always easy-to-find, information on to Java Developer Connection^SM (JDC) members. The questions are selected from the JDC Forums and special interest lists generally because: they are frequently asked, they are significant or timely, or the answers are not easily accessible.

Question of the week No.186: How does J2EE^TM SDK provide a JNDI DataSource?

Question of the week No.185: How can I process a file upload from the browser?

Question of the week No.184: Can Java^TM technology beat Perl with pattern matching in large files?

Question of the week No.183: When should I use NIO?

Question of the week No.182: Is a singleton a single instance per application?

Question of the week No.181: What is the relationship between Xerces and JAXP?

Question of the week No.180: Is there a method to cache the ResultSet?

Question of the week No.179: Why doesn't request.getParameter return the correct data?

Question of the week No.178: Is it possible with SQL to store a String containing a single quotes?

Question of the week No.177: How do I standardize times across time zones?

Question of the week No.176: there something other than StringTokenizer I can use to split tokens in a String?

Question of the week No.175: Is there a way to customize the display of caught exceptions?

Question of the week No.174: Are there new J2SE^TM features that enable high-performance I/O code?

Question of the week No.173: How do I point in the import statement to another subdirectory?

Question of the week No.172: How do I know when to use Date, Calendar, or GregorianCalendar?

Question of the week No.171: How can I can encode the output of a file to be written in a UTF-16 encoding?

Question of the week No.170: How can I sort a hash table based on values?

Question of the week No.169: How do I use HTTPS (SSL over HTTP) with the Java^TM Embedded Server (JES)?

Question of the week No.168: How do I get the JTextArea to come up as a seperate frame without a main statement, and how is the JTextArea supposed to paint itself without the pack() for the inner TextArea class?

Question of the week No.167: How can I sign and use an applet using a self-signed cert or CA authorized in the J2SE^TM 1.3 plugin?

Question of the week No.166: How do I write an application for the upcoming J2ME^TM Personal Profile?

Question of the week No.165: What is the difference between throw and throws?

Question of the week No.164: How do I use the StringTokenizer class to parse a String?

Question of the week No.163: How can I execute DOS commands from a Java^TM application?

Question of the week No.162: Preventing JTextArea changes size with dynamic data

Question of the week No.161: How can I use an obfuscator with the J2ME^TM Wireless Toolkit?

Question of the week No.160: How do you protect your code from decompilers?

Question of the week No.159: Where are device-specific things implemented in J2ME^TM?

Question of the week No.158: How can I use synchronization on a string?

Question of the week No.157: How do I open a URL connection to a https server?

Question of the week No.156: Is a gateway required to have a hard disk to run Java Embedded Server^TM Software?

Question of the week No.155: How do you create a structure like a HashMap with case insensitive keys?

Question of the week No.154: How can I manually kill threads?

Question of the week No.153: How can I calculate the number of bytes that come in over an InputStream opened with the openInputStream() method of an HttpConnection object in MIDP?

Question of the week No.152: Why does the Calendar class appear to return wrong values for the current date?

Question of the week No.151: What is the best way to round to two decimal places?

Question of the week No.150: What is a tag body?

Question of the week No.149: How can I build the J2ME^TM CDC/Foundation Profile 1.0 FCS using RedHat Linux 7.1?

Question of the week No.148: How do you decode a mathematical expression?

Question of the week No.147: What is a DomParser/SaxParser?

Question of the week No.146: What's the difference between EJB^TM and JSP^TM sessions?

Question of the week No.145: How can I search for and assign a value to HTML?

Question of the week No.144: How Can I Emulate an HTML form in a J2ME^TM application?

Question of the week No.143: How can I get the attributes of the uid using JNDI?

Question of the week No.142: How can I add days to DateString?

Question of the week No.141: How can I store values to a file that is created automatically?

Question of the week No.140: Can I send an HTTP request to a servlet from a normal class without having to use a browser to send the HTTP requests?

Question of the week No.139: Is it possible with SQL to store a String with a single quote?

Question of the week No.138: What is the best method of pooling objects?

Question of the week No.137: How do the event delivery methods work in MIDP?

Question of the week No.136: Is there a simple way to retrieve the column name from a result set as well as its associated data?

Question of the week No.135: What's happening to my process output?

Question of the week No.134: How can I improve transfer rates through a socket?

Question of the week No.133: How does one send OOB (Out Of Band) data using java.net.Socket?

Question of the week No.132: How can I use HTTPS with the Java Embedded Server^TM (JES) technology?

Question of the week No.131: How do you convert from one code page to another?

Question of the week No.130: Why am I getting PortInUseException on Solaris^TM operating environment when the serial port seems to be available?

Question of the week No.129: What is Unicode?

Question of the week No.128: How do you download a new MIDlet?

Question of the week No.127: How can I cast an array?

Question of the week No.126: What's the difference between a JVM and a CVM?

Question of the week No.125: How can I log in a distributed environment?

Question of the week No.124: How do I make a ProgressMonitor modal?

Question of the week No.123: What is the correct way to nest JAR files for Java Embedded Server^TM 2.0?

Question of the week No.122: How to check if a string is numeric?

Question of the week No.121: How can I hide calls to servlets and their parameters in the address and status bar?

Question of the week No.120: How can I convert a date in String format to a Date object?

Question of the week No.119: How to connect to database using SQLJ from servlet?

Question of the week No.118: How can I open a raw socket connection under MIDP?

Question of the week No.117: Is it possible to create vertical tabbed panes using Project Swing?

Question of the week No.116: How do I handle the lifecycle of bundles and services in the JES 2.0 framework?

Question of the week No.115: How can I access native fonts with JDK^TM 1.2?

Question of the week No.114: Why use Class.forName()?

Question of the week No.113: Can a MIDlet spawn or download another MIDlet?

Question of the week No.112: Is Java Card^TM technology as secure as standard smart card technology?

Question of the week No.111: How can I implement the Singleton pattern in the Java^TM programming language?

Question of the week No.110: How do objectinputstream, inputstream, and fileinputstream differ?

Question of the week No.109: Can I dynamically download code on KVM and MIDP?

Question of the week No.108: How can I convert an array of objects in to an ArrayList and then into a Hashset?

Question of the week No.107: How can I calculate the bytes occupied by an object?

Question of the week No.106: How can I sort objects with Comparator?

Question of the week No.105: How to change List to String[]?

Question of the week No.104: What class called my method?

Question of the week No.103: Is there a way to find out how many fields are in a record from the result set?

Question of the week No.102: How can I get values from an HTML form using JavaServer Pages^TM?

Question of the week No.101: Why does Node.getNodeValue() method return null?

Question of the week No.100: What does the property="*" mean?

Question of the week No.99: How can I create a digital certificate and sign an applet?

Question of the week No.98: How do I read and write objects from a serialized file?

Question of the week No.97: What's the diffence between green threads and native threads?

Question of the week No.96: What's the difference between JavaServer Pages^TM include tags?

Question of the week No.95: How can an Iterator be changed into an Enumeration?

Question of the week No.94: How can applets communicate with each other?

Question of the week No.93: How do I add a Security Provider?

Question of the week No.92: How can I implement the SOCKS protocol without going to an outside library?

Question of the week No.91: Is it possible to convert a String into a Key object?

Question of the week No.90: How can I convert String to int in JavaServer Pages^TM?

Question of the week No.89 What is the difference in results using String versus StringBuffer?

Question of the week No.88 How can JSP be debugged at runtime?

Question of the week No.87 How can a jstring object be created from char *?

Question of the week No.86 Is it possible to build a valid line of Java^TM code in a string and then execute it at run time?

Question of the week No.85 How can a servlet be set up to work through a proxy server?

Question of the week No.84 How does communication take place in business-to-business e-commerce via XML over HTTP?

Question of the week No.83 Can I read and write serialized objects between JDK 1.1 and 1.2?

Question of the week No.82 How do I create an array of objects where the objects contain other arrays?

Question of the week No.81 How can an inner class be accessed from another class?

Question of the week No.80 Destroy function {connection.close()}

Question of the week No.79 Code Optimization

Question of the week No.78 How to Decrypt Email Messages

Question of the week No.77 Using the Collections Framework with Java^TM 1.1

Question of the week No.76 Accessing Images in JAR Files

Question of the week No.75 What is a "Peer"?

Question of the week No.74 How can files be attached to e-mail using JavaMail^TM?

Question of the week No.73 How do access JDBC^TM from JavaServer Pages^TM?

Question of the week No.72 How can a Canvas3D object be created with Java 3D^TM?

Question of the week No.71 Is it possible to obtain and save individual frames from an AVI movie with the Java^TM Media Framework?

Question of the week No.70 How can a BufferedImage be resized with Java2D^TM?

Question of the week No.69 How can a second tabbed page be created the on the fly?

Question of the week No.68 How to Start Executable Files from Java^TM Applications?

Question of the week No.67 How Does a Developer Get Started with KVM?

Question of the week No.66 Servlet Configuration Questions

Question of the week No.65 How can Chinese Text be Displayed in the Java^TM 2 Programming Language?

Question of the week No.64 Questions about Java^TM Runtime Environments.

Question of the week No.63 How can an applet be made from JavaBeans^TM?

Question of the week No.62 How to bring up an iconified JFrame?

Question of the week No.61 Which method can be used to handle servlet requests?

Question of the week No.60 How to synchronize collections?

Question of the week No.59 How to signal another object?

Question of the week No.58 How to share objects among servlets?

Question of the week No.57 How to find the visible JTable Rows?

Question of the week No.56 How to redirect a request from a servlet to JSP?

Question of the week No.55 How to obtain default character encoding?

Question of the week No.54 Cookies Created by Servlet.

Question of the week No.53 Applet to Servlet Communication.

Question of the week No.52 Offscreen Graphics without a Window.

Question of the week No.51 How to lock columns in a JTable so they are not scrollable?

Question of the week No.50 How to use a horizontal scollbar so that I can see all the columns in a JTable?

Question of the week No.49 How to add a JPanel containing an image to a JDesktopPane and have it appear above the image and remain?

Question of the week No.48 How to get a Java^TM applet to open a new browser window?

Question of the week No.47 JTextArea Focus and Flickering?

Question of the week No.46 How to make an event log?

Question of the week No.45 How to show a JFrame that tells the user to wait while loading a file?

Question of the week No.44 How to draw image data to an array, then display it?

Question of the week No.43 How to know what directory an application written in the Java ^TM programming language has been loaded from?

Question of the week No.42 How to release the resources that the instance of Thread occupies?

Question of the week No.41 Why do threads sometimes stay alive when the browser window is minimized?

Question of the week No.40 How to save a picture drawn on a Canvas object, into a Jpeg file?

Question of the week No.39 How to control the accuracy of Timer and Threads?

Question of the week No.38 When selecting an item from choice, how do I display the table fields?

Question of the week No.37 How can the content of a JList be changed everytime it is queried from a database?

Question of the week No.36 Can you put an ALT message in the applet tag?

Question of the week No.35 Memory inspection/leak detectors

Question of the week No.34 How to add a popup listener to a row in a JTable

Question of the week No.33 How to reduce the lease time of my RMI objects

Question of the week No.32 How to find out which Swing Component has focus?

Question of the week No.31 How to control the close operations on a JInternalFrame window?

Question of the week No.30 How to print the contents of a large JTable?

Question of the week No.29 How to render simple HTML using JEditorPane?

Question of the week No.28 How to store an encrypted password?

Question of the week No.27 How to calculate the minimum amount of memory needed to run my application?

Question of the week No.26 How to restore an iconfied JFrame to its normal state?

Question of the week No.25 How to print a report in batch mode using the java.awt.print API?

Question of the week No.24 How to implement a splash screen for my application?

Question of the week No.23 How to clear data entered into a JTable?

Question of the week No.22 How to use the NewAudioClip method to read a local audio file?

Question of the week No.21 How to launch a Java 2 application from a Windows NT icon?

Question of the week No.20 How to speed up printing in my JDK 1.2 Swing application?

Question of the week No.19 How to debug Swing events?

Question of the week No.18 How to configure callbacks in Java IDL?

Question of the week No.17 How to change a Swing font across my whole application?

Question of the week No.16 How to remove the "X" closing button from a dialog box?

Question of the week No.15 How to launch a web browser from my Java application?

Question of the week No.14 How to convert my Swing code to use new package names?

Question of the week No.13 Where to get technical information about Enterprise JavaBeans^TM?

Question of the week No.12 When I click a JComboBox in my applet and select an element, JComboBox never changes.

Question of the week No.11 Problems setting a security manager when using JDBC^TM in JDK^TM 1.2 Beta 4.

Question of the week No.10 How do you hide columns and rows in a JTable component?

Question of the week No.9 How do you set ODBC options using the JDBC^TM Database Access API?

Question of the week No.8 How do you ignore user input in a Swing application?

Question of the week No.7 How to access the Java^TM console from the Java^TM Plug-in?

Question of the week No.6 Missing servlet classes in JDK ^TM 1.2 Beta 4

Question of the week No.5 How do you send an image file by JavaMail?

Question of the week No.4 A problem with class searching in JDK ^TM1.2 Beta 4

Question of the week No.3 Where does Java^TM Studio^TM 1.0 generate its source code?

Question of the week No.2 JDK^TM 1.2 Beta 4 and the classes.zip file

Question of the week No.1 Drag and Drop in JDK^TM 1.2 Beta 4