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Can a lock be acquired on a class
Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object.
jimmy514in
- May 18th, 2010
You can acquire a lock on the class usingsynchronized keyword on the static method.ex:public static synchronized void myfunction(){//function body}
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Why there are some null interface in java. What does it mean. Give me some null interfaces in JAVA
jimmy514in
- May 18th, 2010
Null Interfaces are markable interfaces. Ex: Cloneable Runnable Serializable Externalizable. SingleThreadModel, Event listener
reddybajjuri
- Mar 27th, 2007
Null Interfaces also know as Marker Interfaces are simply marking the class that implements them.Now when the JVM looks at such a class it allows it to call certain methods.e.g There is a method clone...
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How do you invoke a Servelt. What is the difference in between doPost and doGet methods
jimmy514in
- May 18th, 2010
doGet():the parameters that are passed appear in teh address bar.There can be security violations since the parameters can be changed.The doGet() functionality is idempotent.The doGet() allows payload...
arshiya
- Nov 7th, 2007
DoGet1.allows only 2k data2.url in the form of name=value pairs (www.getHelp.com?name1=value1&name2=value2doPost1.no limit on data siza2.no name value pairs in the url
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What is meant by cookies. Explain
jimmy514in
- May 18th, 2010
Cookies cache useful information about the page / website being visited Cookies is a object in Java. HttpServlet returns a Cookies [] cookies= request.getCookies().
saravanan_msit
- Oct 26th, 2005
Cookies is linking one page to another page in web pages.
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Try Catch
Which design pattern is used in try catch?
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What is the purpose of the Runtime class
The purpose of the Runtime class is to provide access to the Java runtime system.
jimmy514in
- Jul 5th, 2010
I think we can use the runtime to get the properties of the class and also to load a specific .exe file from a particular location.Please let me know if I am mistaken. Thank you.
Suresh
- Mar 30th, 2006
Which returns the runtime information like memory availablilityRuntime.freeMemory() --> Returns JVM Free MemoryRuntime.maxMemory() --> Returns the maximum amount of memory that the JVM will attempt to use.also helps to run the garbage collectorRuntime.gc()
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How are commas used in the intialization and iteration parts of a for statement
Commas are used to separate multiple statements within the initialization and iterationparts of a for statement.
jimmy514in
- Jul 5th, 2010
For initialization of x and y integersfor(int x=10,y=20;x<100;x++,y--){//the loop to be executed}
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What is the purpose of the wait(), notify(), and notifyAll() methods
The wait(),notify(), and notifyAll() methods are used to provide an efficient way forthreads to wait for a shared resource. When a thread executes an object's wait() method, itenters the waiting state. It only enters the ready state after another thread invokes theobject's notify() or notifyAll() methods..
jimmy514in
- Jul 5th, 2010
this is how signalling between threads works using 'wait and notify':We can call the wait() method of any Java object, which suspends the current thread. The thread is said to be &qu...
saranath
- Mar 23rd, 2008
wait() will move the thread to sleep state allowing for the other thread to execute. notify() will trigger back the wait() thread to ready state and to execute further. notifyAll() will trigger all wa...
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Name three subclasses of the Component class.Box.Filler, Button, Canvas, Checkbox, Choice, Container, Label, List, Scrollbar, orTextComponent
jimmy514in
- Jul 5th, 2010
Directly known subclasses of component: Button Canvas Checkbox Choice Container Label List Scrollbar TextComponent
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How are Observer and Observable used
Objects that subclass the Observable class maintain a list of observers. When anObservable object is updated it invokes the update() method of each of its observers tonotify the observers that it has changed state. The Observer interface is implemented byobjects that observe Observable objects.
jimmy514in
- Jul 4th, 2010
An observable object can have one or more observers. An observer may be any object that implements interface Observer. After an observable instance changes, an application calling theObservable's noti...
jimmy514in
- Jul 4th, 2010
observer pattern (a subset of the publish/subscribe pattern) is a software design pattern in which an object, called the subject, maintains a list of its dependants, called observers, and notifies the...
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What is the difference between function synchronization and object synchronization
jimmy514in
- Jul 5th, 2010
Not to sure what he meant by function synchronization, but i think that if you synchronize a function, the object is synchronized.The word synchronized before function_name locks the object for t...
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What is the difference between applet and swing
jimmy514in
- Jul 5th, 2010
Component Swing: Swing is light weght Component Applet: Applet is heavy weight Components Look and feelSwing: Using UIManager swing have look and feel according to user view You can change look and fe...
Prasanna kanth
- Sep 13th, 2005
I also have the same doubt, but still i not getting a clear idea
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In an HTML form I have a Button which makes us to open another page in 15 seconds. How will do you that
jimmy514in
- Jul 5th, 2010
How about if we create a javascript function which delays the onlick event for 15 seconds and then a window.open method is called to open another window using the delay logic of the javascript..??That wuld work won't it..Please clarify on the same,
vinodkrmenaria
- Feb 28th, 2009
On the on-click of the button create a thread and make it sleep for 5 second and then the action (jsp) file will be called.
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How will you perform transaction using JDBC
jimmy514in
- Jul 5th, 2010
Create the connectionSet the autocommit property to be falseExecute the queries neededCommit the transaction by calling the commit() on the connection.Set the transaction autocommit property to be trueClose the connection.
Taranjeet
- Aug 25th, 2005
Using the autocommit method provided by the connection object.
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What is encapsulation?
sarabjit
- Jul 8th, 2010
Encapsulation means wrapping data n associated funtion into a single unit .The data is accessible to only those functions which are wrapped in the class
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What is the difference between interface and abstract class
ashokhullur
- Jul 22nd, 2010
Abstract classes can have only non abstract methods. Its not mandatory that it must have atleaset one abstract method. Declaring class using keyword abstract is enough to make class as abstract.
anooshay
- May 16th, 2008
Interface: In interface just signature of the methods are defined(means abstract meathod). there is?no a single method which has body.e.g. void add();Abstract class: In a abstract class some method a...
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JDBC Form Data
Can we represent data in the form of objects in JDBC? Explain
rohitrichhariya
- Jul 23rd, 2010
Yes we can.For example you have a table customer make a class Customer and fire query in DB and initialize data member of Customer class with the result of query witch fetch the customer info from db and use Customer class likeString name=Customer.name;
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Mention 5 basic difference between Array List and Vector in Java Colletion FrameWork.
Vector is unsynchronized wheras ArrayList is synchronized.
nextcome
- Jul 31st, 2010
ArrayList vs Vector1. Not thread-safe - Thread-safe2. Default size 0 - Default size is 103. Faster - Slower4. Belongs to legacy classes - Belongs to Collection framework5. User Iterator (fail-safe) - Enumator (no guarantee)Thanks
jyoti.bhandari
- Jun 11th, 2009
1. default arraylist size is 0 at initialization and vector is 102. vector is synchronized arraylist not3. vector increase its size double and arraylist half its initial size4. vector comes with legency classes but arraylist not5. vector cms with jdk 1.4 arraylist not
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Explain RMI Architecture
ashok16
- Aug 10th, 2010
RMI architecture consists of four layers and each layer performs specific functions: 1. Application Layer: Contains the actual object definition. 2. Proxy Layer: Consists of stub and skeleton. 3....
Pattukkottai Arun
- Jul 22nd, 2005
Java Remote Method Invocation (Java RMI) enables the programmer to create distributed Java technology-based to Java technology-based applications, in which the methods of remote Java objects can be in...
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What is meant by class loader. How many types are there. When will we use them
ankita surendra bimal
- Aug 10th, 2010
Class loader is a ways to load the class in the memory. The class loader is of two type. 1) Static Loading. 2) Dynamic Loading. Dynamic way is done by the help of class.forName(); Static loadi...
rsenthil
- Aug 9th, 2010
Class Loader is a part of JVM used to load the classes dynamically. It will load the classes based on demand. Diffrent types of class loaders are extension class loader, system class loader and bootst...
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