Tech Tips and Tricks
/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/ All regular expressions start and end with forward slashes to differentiate them from ordinary string expressions. Most regular expressions start matches at the first character ^ and end at the last $. Now we try to match the mailbox Continue reading Validate e-mail address with regular expression
I was searching google to find a way to show a wait page when a struts form is submitted and the response is loaded. Sometimes it is required when the page has to process a lot of information or get Continue reading Displaying a wait page for a struts action
The Jakarta Struts <html:multibox> tag can be used to display a group of checkboxes on an HTML form. The tag sets the state of the checkboxes according to the contents of an associated array. The LabelValueBean is a simple class Continue reading Using The Struts Multibox Tag With LabelValueBeans
It’s NOT the name of the member variable that counts, it’s the name of the get method. You use the part after “get” as the property name. Normally you would convert the first letter after “get” to lowercase, but if Continue reading Variable name for getters
Identifiers must start with a letter, a currency character($), or an underscore(_). Identifiers cannot start with a number. After the first character, identifiers can contain any combination of letters, currency characters, underscores, or numbers. Identifiers are case-sensitive “enum” cannot be Continue reading Legal Identifiers in Java
To increase heap size of eclipse editor, modify eclipse.ini file to the values you need -vmargs -Xms128M -Xmx512M -XX:PermSize=64M -XX:MaxPermSize=128M
[eg. of web.xml <web-app> <servlet> <servlet-name>ReadInitParams</servlet-name> <servlet-class>com.company.MyServlet</servlet-class> <display-name>Example Servlet</display-name> <init-param> <param-name>emailHost</param-name> <param-value>192.168.1.1</param-value> </init-param> </servlet> </webapp> In Servlet Code: public void init(ServletConfig config) throws ServletException { String emailHost = config.getInitParameter(“emailHost”); } or public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException Continue reading Read The Init-Params Defined In The web.xml
The difference between getAttribute() and getParameter() is that getParameter() will return the value of a parameter that was submitted by an HTML form or that was included in a query string. getAttribute() returns an object that you have set in Continue reading Difference between request.getParameter() and request.getAttribute()
To copy a file, you can use the following command: copy source.txt destination.txt To run this in Java, String[] cmd = {“copy”,”source.txt”,”destination.txt”} Runtime.getRuntime().exec(cmd); This may generate error=2. To fix this, use the complete path of copy.exe eg. C:\Windows\System32\copy.exe
If you use Hibernate in a managed environment (with JBoss or some other AS that Hibernate supoorts). Add this line to session-factory section: <property name=”hibernate.current_session_context_class” >jta </property> If you use Hibernate in a non-managed environment (standalone application with JDBC). Add Continue reading Hibernate gives “No CurrentSessionContext configured” error