-
Why we cannot define constructor of super class in a sub class ?
sampra
- Feb 15th, 2008
We cannot define constructor of super class in subclass because the order of execution of constructors will be from super class to current class. So there is no need of defining the super class constructor in subclass.
-
How to check infinity value? when we passed too large number in String and cast in to float value it will be give infinity. how to catch it?
jay
- Sep 23rd, 2006
Why not just treat infinty like any other String->float conversion error ? :float myfloat;try { myfloat = Float.parseFloat(floatAsString);} catch (Exception e) { // o-o the format of floatAsString is not quite compatible with java float}
Thakkar Nirav
- Apr 29th, 2006
Hi ,Finally i got the answer, but thank u all to give me prompt reply.i am using jdk1.4 . thats why i cant use Float.isInfinity() but i'll remember so in future i can use.thank u again.
-
How to writer String Reverse program without using any string libraries even length(), strrev().
Y_NOT_
- Feb 6th, 2007
public class ReverseString{ public ReverseString() { String str = "Hello World"; StringBuffer buff = new StringBuffer( str ); buff.reverse(); System.out.println( "Reversed String: " + buff.toString() ); } public static void main( String[] args ) { new ReverseString(); }}
subramanian_ram
- Jan 3rd, 2007
public static void main(String args[]){String s1=" Mera Bharat Mahan";String s2="";int lenght = 0;for(int i=0;s1.charAt(i) != null;i++) length++;for(j=length; j<0;j++){ s2=s2+s1.charAt(j);}System.out.println("the reverse string is"+ s2);}}
-
Marker interface having no methods right.. then what is the use of marker interface? for what purpose we use marker interface?
One of the "clean" features of the Java programming language is that it mandates a separation between interfaces (pure behavior) and classes (state and behavior). Interfaces are used in Java to specify the behavior of derived classes. Often you will come across interfaces in Java that have no behavior. In other words, they are just empty interface definitions. These are known as marker interfaces....
-
When does the String Literal pool gets cleared?
In one java class I have created this string String s1 = "abc";Now if I again use this same statement in a different java class, ie;String s2 = "abc";Will I get the same reference for "abc" in both the classes.
adarsh
- Jul 30th, 2012
"c public class stringreferencetest { public static void main(String[] args) { String s1 = "abc"; class AnotherClassString { String s2=""; public AnotherClassString() {...
-
How we can create marker interface in java?
trinadh
- Mar 19th, 2008
We can create it by having no method defenitions on out own interface .u first extend Serializable interface to ur Apple interface and after that what ever class implements ur Apple interface will be Serializable OK
sampra
- Mar 11th, 2008
To inform to JVM that the objectedt created for particular class will be follw this property
-
How would you declare a SingleThreaded servlet
mayur
- Aug 15th, 2007
We can put the code in the servlet in a synchronized block with a static member as a monitor.
-
How does garbage collection work
-
Is it advisable to depend on finalize for all cleanups
archikinu
- Oct 2nd, 2007
No it is not advisable to depend on finalize, because we cannot know when -- or even if -- finalize will be executed.
-
How can we take various inputs from user as int,char,string,float etc ?
dinesh
- Oct 12th, 2011
Example we get input for integer,
Scanner scan = new Scanner(System.in);
int variable_name = scan.nextInt();geeksterrahul
- Jul 25th, 2009
Firstly take the User input as String using the BufferedReader API.Call br.readLine();Once you get the input Use .ValueOf method for conversion. Eg: String MyString; Buffere...
-
Please give me answer why we use Interface though it contain only blank implementation.
muralidhar.9e
- Sep 20th, 2010
An Interface may Contain implementation or not. Sometimes these type of interfaces (blank interfaces) which are not implemented are called as "marker interfaces".
nikhil_52001
- Sep 19th, 2010
The purpose of Marker interface is to just let the compiler know that the clas which implements the Marker Interface will be serialized or cloned. Ther is not any other use of Marker Interface. E.g If...
-
What is daemon threads?
Srinivas Kallumadi
- Nov 4th, 2005
Any Java thread can be a daemon thread. Daemon threads are service providers for other threads running in the same process as the daemon thread. For example, the HotJava browser uses up to four daemon...
-
-
If we have two public classes in a single java file ,how i have to give the name of the particular java file and how i can compile it?
-
Which is superclass of Exception?many people think that object,no there is particular class which is superclass of all exception it starts with letter B,plz tell me
nv_krishna
- May 19th, 2008
The super class of all Exceptions in java is Throwable. It has two sub-classes :: Exception and ErrorException forms the base class for Exceptions like ArrayIndexOutofBounds etc..Error is another sub-class, these are catastrophic in nature and not caught by normal java program..
-
What happens if we execute the program?class Return{ int display(){ try{ return 1; } finally{ return 2; }}public static void main(String args[]){ Return r=new Return(); r.display();}}when i executed i got the compile time error when i executed on jdk 1.4?but in khalid moghal book its executed and result is printed.
Pallu
- Sep 5th, 2006
You are right Sandeep.But I guess, Sadashivrao did not set a classpath if he is executing this program on command prompt.You can set classpath by:(if u saved Return.java in temp folder)C:Documents and Settingsx.yDesktoptemp>set classpath=%classpath%;C:Documents and Settingsx.yDesktoptemp
-
Hi, can we declare non static variables in static methods?if so plz explain by an example?
vinaymudgil007
- Jun 12th, 2008
yes, we can declare and they would be local to the block.Here is an example.....class Test { public static void main(String[] args) { ...
Seema
- Feb 2nd, 2007
Declaration of i is outside static method, so it is giving error "can not make static reference to non static field" if it is declared inside then it will print 10.
-
Abstract class is a partially implemented class so, How can we call an abstract method without creating a subclass.
navneetgoyal2000
- Jan 6th, 2011
I am not sure, but if ABS class can have a static member function (I am not sure either about if ABS class can have static member function), then without instantiating an OBJ of ABS class, the class function can be invoked.Guys, please check it, and update here...It will be helpful for others too.
sayoke
- Dec 12th, 2006
Another useful method is to use reflextion api. But this is not recommended. It will also ask users knoledge to a very lower level.
-
-
Java Connection Pooling Questions
1.What is save point?2.Which among the four drivers is pure Java driver?3.What is Connection Pooling ?4.How differ servlet from its peer Technology?5.What are the parameters used in Connection pooling?6.What are the Normalization Rules? Define the Normalization?9.What are batch updates.10.How many JDBC drivers are there ?
nuttyvarun
- Feb 21st, 2008
Connection pooling is a technique of creating and managing a pool of connections that are ready for use by any thread that needs them, and generally leads to more predictable resource usage under load...
Core Java Interview Questions
Ans