All about Ramakrishna Konanki

login.LoginException

Dear Friend,
i hope this is related to Filenet.

this type of error will occur
1) when user/password is incorrect.
2) getting filenet objects in to java based web application.

for 2 part you required some more configurations.

12 years ago

WebSphere

scjp certificate not recieved

Hi ,
i have completed scjp certification on dec 1,2010.
till now i did not recieved the certificate.
whom i have to contact.
please reply as early as possible

thanks and regards
Rama

12 years ago

Programmer Certification (OCPJP)

Difference between instanceof and instanceOf

// : c10:FamilyVsExactType.java
// The difference between instanceof and class
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
class Base {
}
class Derived extends Base {
}
public class FamilyVsExactType {
static void test(Object x) {
System.out.println("Testing x of type " + x.getClass());
System.out.println("x instanceof Base " + (x instanceof Base));
System.out.println("x instanceof Derived " + (x instanceof Derived));
System.out.println("Base.isInstance(x) " + Base.class.isInstance(x));
System.out.println("Derived.isInstance(x) "
+ Derived.class.isInstance(x));
System.out.println("x.getClass() == Base.class "
+ (x.getClass() == Base.class));
System.out.println("x.getClass() == Derived.class "
+ (x.getClass() == Derived.class));
System.out.println("x.getClass().equals(Base.class)) "
+ (x.getClass().equals(Base.class)));
System.out.println("x.getClass().equals(Derived.class)) "
+ (x.getClass().equals(Derived.class)));
}
public static void main(String[] args) {
test(new Base());
test(new Derived());
}
}

12 years ago

Programmer Certification (OCPJP)

taglib uri error

<%-- use the 'taglib' directive to make the JSTL 1.0 core tags available; use the uri
"http://java.sun.com/jsp/jstl/core" for JSTL 1.1 --%>
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>

<%-- use the 'jsp:useBean' standard action to create the Date object; the object is set
as an attribute in page scope
--%>
<jsp:useBean id="date" class="java.util.Date" />

<html>
<head><title>First JSP</title></head>
<body>
<h2>Here is today's date</h2>

<c:out value="${date}" />

</body>
</html>

i am executing this jsp page in eclipse.......geting error at <%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>
i.e uri not found....so how to get this...

12 years ago

JSP

request for creation of util class for jdbc

Hi Good Morning.

i want to write util package like class for my JDBC connection....

could any one give me the sample code please...

12 years ago

Java in General

can constructor throw exceptions?

the above program works fine......but my question is
1)as i studied in a book,a constructor can not handle exception----------above code throwing exception
2)a constructor can not call method(even in the same class),
except super class constructor, but it should be the first line(super()).............How it works with new IllegalArgmentException
3) a constructor cannot return values......

in the above code........how constructor handled exception.....
i required the flow of execution.........

12 years ago

Beginning Java

object Comparision wtih equals

class Value {
int i ;
}
public class Equalscomp {
public static void main(String []args) {
Value vl = new Value();
Value v2 = new Value();
vl.i = 100;
v2.i = 100;
System.out.println(vl.equals("v2"));
}
}

here i am geting result as false...
why......................

previous i have studied == is comparing references.
.equals() compares values.....
so what abt the above code..

please explain

13 years ago

Beginning Java

boolean comparision

thanq

Sudhakar Sharma wrote:Hi Ram,

If you construct a Boolean object other then with the "true" string, it evaluate it as false
Boolean b1 = new Boolean("yes"); Boolean b2 = new Boolean("no");

Both evaluates false, and due to overriding equals() method it checks meaningfully equals which returns true.

welcome,

13 years ago

Beginning Java

srting doubt on ==

sorry for voilating rules.
could you please explain the naming policy rules....

Campbell Ritchie wrote:"Ramakrishna" it is not possible to send you a private message to warn you about the naming policy, but you are still in violation of it.
Correct your displayed name to match the policy, or we shall withdraw your privilege of using this website.

13 years ago

Beginning Java

boolean comparision

Boolean b1 = new Boolean(“yes”);
Boolean b2 = new Boolean("no");
System.out.println(b1.equals(b2));

i'm geting result : true...

tha value in b1 is yes and b2 is no...

how it is possible to get true....

could you state the reason please...

13 years ago

Beginning Java

srting doubt on ==

What does the == operator do?
== operator compares two references of a string.

What is a String? Where in memory does it live?
String is a set/combinations of characters.

String s; s="ab"; //this will store in stack
String s= new String("ab"); //this will store in heap
.............
this is my expectation
.................

What do you want to do with the two Strings?
just i want to compare two strings.

Is what you want to do the same thing the == operator does?
String s4 = "change me";
String s5 = "change "+"me";

s4==s5
the result is true..

my doubt is
String s6 = "change ";
String s7 = s6+"me";
s4==s7
should be true....
but it is getting false....what would be the reason.......

13 years ago

Beginning Java

srting doubt on ==

class StringTest
{
public static void main(String[] args)
{
String s1 = new String("change me");
String s2 = new String("change me");
System.out.println(s1==s2);
String s3 = "change me";
System.out.println(s1==s3);
String s4 = "change me";
System.out.println(s3==s4);
String s5 = "change "+"me";
System.out.println(s4==s5);
String s6 = "change ";
String s7 = s6 + "me";
System.out.println(s4==s7);
final String s8 = "change ";
String s9 = s8 + "me";
System.out.println(s4==s9);
}
}

output
-------
false
false
true
true
false
true

here s7=s6+"me";
s4 and s7 are equal but it is showing false...why...

one of my friend told s7 stores in heap.....
my doubt is s7 is normal variable....how it is going to store in heap

13 years ago

thank q very much

13 years ago

an object can call static method.

in the site mock example i have seen code
like
an object can call static method.

as i've studied static members should be called with class name.

please justify the solution

13 years ago

Beginning Java

Ramakrishna Konanki

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