JavaScript - Why to use "var that = this;"

Now a days most of JavaScript files are following Object Oriented Approach.

In simple words, it means it is possible to call super methods using child classes.

So not to lose a reference of function which is calling other one, that is smartly getting used.

Below are good examples explaining about that to refer this:

Keep sharing….!

III

Best Regards,

Abhijeet Rathod.

------------------------------

When 'I' is replaced by 'We',

Even illness becomes wellness.

------------------------------

WebLogic 10.3.x Error : NoSuchMethodError for javax.persistence.spi.PersistenceUnitInfo.getSharedCacheMode()Ljavax/persistence/SharedCacheMode

As of now mostly trend is using newer frameworks or migrating from older framework to newer one.

One of the classic situation we started facing with Application Deployment once we have done migration.

Technology Stack we are using in our Applications is as below:

·         Java 7
·         JPA 2.0
·         Spring 3.0
·         Hibernate 3.0
·         EJB 3.0
·         Oracle 11g

While deploying we are getting below exception:

Caused By: java.lang.NoSuchMethodError: javax.persistence.spi.PersistenceUnitInfo.getSharedCacheMode()Ljavax/persistence/SharedCacheMode; at org.hibernate.ejb.util.LogHelper.logPersistenceUnitInfo(LogHelper.java:39) at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:516) at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:73) at weblogic.deployment.PersistenceUnitInfoImpl.createEntityManagerFactory(PersistenceUnitInfoImpl.java:352) at weblogic.deployment.PersistenceUnitInfoImpl.createEntityManagerFactory(PersistenceUnitInfoImpl.java:332)

In development environment we are using below for deployment:

·         WebLogic 12
·         Oracle 11g

So what is cause for this?

·         Pre-Production and Production environment having:

o   WebLogic 10.3.5

o   Oracle 11g

As database point of view there is no issue.

So it's mostly application server compatibility issue.

JPA Jars which WebLogic 10.3.5 is having are of different versions than application requires.

So as to resolve this issues, following are 2 possible solutions:

·         Application Level Changes:

o   Adding ANTLR specific changes to be done in weblogic-application.xml file located under META-INF.

<?xml version="1.0" encoding="UTF-8"?> <weblogic-application xmlns="http://www.oracle.com/technology/weblogic/wls_10.3.2.0.html" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">        <!--  This is needed since WL has a different version of antlr jar-->     <prefer-application-packages>         <package-name>antlr.*</package-name>     </prefer-application-packages>     </weblogic-application>

o   Adding JPA specific JARs to application WAR/EAR only.

§  Hibernate-jpa-api.jar

§  Weblogic-fullclient.jar

·         WebLogic Level – Configuration changes:

--

III  Best Regards,

III  Abhijeet.

Keyboard Shorcuts (Microsoft Windows)

1. CTRL+C (Copy)
2. CTRL+X (Cut)
3. CTRL+V (Paste)
4. CTRL+Z (Undo)
5. DELETE (Delete)
6. SHIFT+DELETE (Delete the selected item permanently without placing the item in the Recycle Bin)
7. CTRL while dragging an item (Copy the selected item)
8. CTRL+SHIFT while dragging an item (Create a shortcut to the selected item)
9. F2 key (Rename the selected item)
10. CTRL+RIGHT ARROW (Move the insertion point to the beginning of the next word)
11. CTRL+LEFT ARROW (Move the insertion point to the beginning of the previous word)
12. CTRL+DOWN ARROW (Move the insertion point to the beginning of the next paragraph)
13. CTRL+UP ARROW (Move the insertion point to the beginning of the previous paragraph)
14. CTRL+SHIFT with any of the arrow keys (Highlight a block of text) SHIFT with any of the arrow keys (Select more than one item in a window or on the desktop, or select text in a document)
15. CTRL+A (Select all)
16. F3 key (Search for a file or a folder)
17. ALT+ENTER (View the properties for the selected item)
18. ALT+F4 (Close the active item, or quit the active program)
19. ALT+ENTER (Display the properties of the selected object)
20. ALT+SPACEBAR (Open the shortcut menu for the active window)
21. CTRL+F4 (Close the active document in programs that enable you to have multiple documents opensimultaneou sly)
22. ALT+TAB (Switch between the open items)
23. ALT+ESC (Cycle through items in the order that they had been opened)
24. F6 key (Cycle through the screen elements in a window or on the desktop)
25. F4 key (Display the Address bar list in My Computer or Windows Explorer)
26. SHIFT+F10 (Display the shortcut menu for the selected item) 27. ALT+SPACEBAR (Display the System menu for the active window)
28. CTRL+ESC (Display the Start menu)
29. ALT+Underlined letter in a menu name (Display the corresponding menu) Underlined letter in a command name on an open menu (Perform the corresponding command)
30. F10 key (Activate the menu bar in the active program)
31. RIGHT ARROW (Open the next menu to the right, or open a submenu)
32. LEFT ARROW (Open the next menu to the left, or close a submenu)
33. F5 key (Update the active window)
34. BACKSPACE (View the folder onelevel up in My Computer or Windows Explorer)
35. ESC (Cancel the current task)
36. SHIFT when you insert a CD- ROMinto the CD-ROM drive (Prevent the CD-ROM from automatically playing)

Dialog Box - Keyboard Shortcuts

1. CTRL+TAB (Move forward through the tabs)
2. CTRL+SHIFT+TAB (Move backward through the tabs)
3. TAB (Move forward through the options)
4. SHIFT+TAB (Move backward through the options)
5. ALT+Underlined letter (Perform the corresponding command or select the corresponding option)
6. ENTER (Perform the command for the active option or button)
7. SPACEBAR (Select or clear the check box if the active option is a check box)
8. Arrow keys (Select a button if the active option is a group of option buttons)
9. F1 key (Display Help)
10. F4 key (Display the items in the active list)
11. BACKSPACE (Open a folder one level up if a folder is selected in the Save As or Open dialog box)

Microsoft Natural Keyboard Shortcuts
1. Windows Logo (Display or hide the Start menu)
2. Windows Logo+BREAK (Display the System Properties dialog box)
3. Windows Logo+D (Display the desktop)
4. Windows Logo+M (Minimize all of the windows)
5. Windows Logo+SHIFT+M (Restorethe minimized windows)
6. Windows Logo+E (Open My Computer)
7. Windows Logo+F (Search for a file or a folder)
8. CTRL+Windows Logo+F (Search for computers)
9. Windows Logo+F1 (Display Windows Help)
10. Windows Logo+ L (Lock the keyboard)
11. Windows Logo+R (Open the Run dialog box)
12. Windows Logo+U (Open Utility Manager)
13. Accessibility Keyboard Shortcuts
14. Right SHIFT for eight seconds (Switch FilterKeys either on or off)
15. Left ALT+left SHIFT+PRINT SCREEN (Switch High Contrast either on or off)
16. Left ALT+left SHIFT+NUM LOCK (Switch the MouseKeys either on or off)
17. SHIFT five times (Switch the StickyKeys either on or off)
18. NUM LOCK for five seconds (Switch the ToggleKeys either on or off)
19. Windows Logo +U (Open Utility Manager)
20. Windows Explorer Keyboard Shortcuts
21. END (Display the bottom of the active window)
22. HOME (Display the top of the active window)
23. NUM LOCK+Asterisk sign (*) (Display all of the subfolders that are under the selected folder)
24. NUM LOCK+Plus sign (+) (Display the contents of the selected folder)

MMC COnsole Windows Shortcut keys
1. SHIFT+F10 (Display the Action shortcut menu for the selected item)
2. F1 key (Open the Help topic, if any, for the selected item)
3. F5 key (Update the content of all console windows)
4. CTRL+F10 (Maximize the active console window)
5. CTRL+F5 (Restore the active console window)
6. ALT+ENTER (Display the Properties dialog box, if any, for theselected item)
7. F2 key (Rename the selected item)
8. CTRL+F4 (Close the active console window. When a console has only one console window, this shortcut closes the console)

Remote Desktop Connection Navigation
1. CTRL+ALT+END (Open the Microsoft Windows NT Security dialog box)
2. ALT+PAGE UP (Switch between programs from left to right)
3. ALT+PAGE DOWN (Switch between programs from right to left) 4. ALT+INSERT (Cycle through the programs in most recently used order)
5. ALT+HOME (Display the Start menu)
6. CTRL+ALT+BREAK (Switch the client computer between a window and a full screen)
7. ALT+DELETE (Display the Windows menu)
8. CTRL+ALT+Minus sign (-) (Place a snapshot of the active window in the client on the Terminal server clipboard and provide the same functionality as pressing PRINT SCREEN on a local computer.)
9. CTRL+ALT+Plus sign (+) (Place asnapshot of the entire client window area on the Terminal server clipboardand provide the same functionality aspressing ALT+PRINT SCREEN on a local computer.)

Microsoft Internet Explorer Keyboard Shortcuts
1. CTRL+B (Open the Organize Favorites dialog box)
2. CTRL+E (Open the Search bar)
3. CTRL+F (Start the Find utility)
4. CTRL+H (Open the History bar)
5. CTRL+I (Open the Favorites bar)
6. CTRL+L (Open the Open dialog box)
7. CTRL+N (Start another instance of the browser with the same Web address)
8. CTRL+O (Open the Open dialog box,the same as CTRL+L)
9. CTRL+P (Open the Print dialog box)
10. CTRL+R (Update the current Web )

Injectable Singleton - APIDesign

Using Service Loader along with Singleton Design is really not possible.
Because Service Loader always going to return new object after loading.

To overcome this following is the useful approach to design such requirement.

This is about looking for :

• Always getting Single Object 
• Using Service Loader

Refer:
Injectable Singleton - APIDesign

Using VIRTUAL Column in JPA Entity

While working with Java Persistence using ORM Layer, new feature from Oralce 11g can be useful.
E.g. Virtual Column.
 
Whenever want to use Virtual Column in JPA Entity, it should follow:

• Field should not be Updatable.
• Field should not be populated while creating the entity.

For such scenario, one has to use below annotation on field:

@Column(insertable=false, updatable=false)

Below is Detailed Example JPA Entity with Virtual Column usage:

Virtual Column Should be added like:

alter table cosnumers add(      IS_ADMIN GENERATED ALWAYS AS ( CASE WHEN CONSUMER_ID IS NOT NULL THEN 1 ELSE 0 END) );

JPA Entity Should define field for Virtual Column as shown below:

Package com.acp.jpa; import javax.persistence.Column; import javax.persistence.Entity; @Entity public class Consumer {        private Long consumerID;        @Column(insertable=false, updatable=false)        private boolean isAdmin;               /**        * @return the consumerID        */        public Long getConsumerID() {               return consumerID;        }        /**        * @param consumerID the consumerID to set        */        public void setConsumerID(Long consumerID) {               this.consumerID = consumerID;        }        //--- For Virtual Column - Provide only Getters.        /**        * @return the isAdmin        */        public boolean isAdmin() {               return isAdmin;        } }

--

III  Cheers!

Using Oracle SQL Developer as MySQL IDE

Need to follow below steps:

- Download desired MySQL connector, unzip and place to desired directory.

- From SQLDeveloper -> Tools -> Preferences -> Databases -> Third party JDBC driver.

  "Add Entry" for desired MySQL connector.

That's It!!!

Now you can observe MySQL tab in the DB Connections SQLDeveloper window.

References:

http://www.techrepublic.com/blog/programming-and-development/configuring-sql-developer-for-mysql/564

Cheers!

Eclipse Performance Enhancement!

Hi,

Most of the time we suffer from Eclipse responsiveness or performance.

Below is the link for changing Eclipse Memory settings in "eclipse.ini" file:

https://gist.github.com/justingarrick/2588828