Shelly Biswal

Thanks Campbell, your post helped me

Hi,

I have the following

1) a list of strings. These strings are related to each other as parent and children.
For e.g, if my list contains a,b,c,d, then a is parent of c and b, c is parent of d.
each child can have only one parent.

I need to write logic to pass this list in an iterator and keep finding the parents till the root(in e.g. it is a) and in each iteration i need to check for an attribute of the parent(by passing parent in some xyz method).

Please let me know how i could implement this logic.

Hoping for a response soon.

Regards,
Shelly

Hi All,

i need to split the following string : "//name['firstname = shelly']"
and get output as : firstname
shelly
and then i need to put them in string variables like
nameCategory = firstname and
myName =shelly
how do i do it?
do i need to use multiple split statements?

I wrote the code everyting wrks fine except line /*1*/ - the output is always null dont know why.. pls explain

import java.util.Arrays; import java.lang.StringBuffer; import java.io.IOException; import java.util.HashMap; public class ReverseAndEncrypt { String s1; public ReverseAndEncrypt(String str) { s1 = str; } public String reverse () { int length = 0; StringBuffer s2 = new StringBuffer(); System.out.println(" String: "+s1); System.out.println(" String length: "+s1.length()); length = s1.length(); s1 = s1.toUpperCase(); for (int i = length-1;i>=0;i--){ s1.charAt(i); s2.append(s1.charAt(i)); System.out.println(" String: "+s2.length()); } return s2.toString(); } public String encrypt() throws IOException{ ReadCharacterMapping readEncryptMap = new ReadCharacterMapping(); HashMap h1 = readEncryptMap.processMyFile(); int length = 0; length = s1.length(); s1 = s1.toUpperCase(); StringBuffer s2 = new StringBuffer(); System.out.println("Your String" +s1); for (int i = length-1;i>=0;i--){ System.out.println("Your String characters" +s1.charAt(i) ); System.out.println(h1.get(s1.charAt(i))); /*1*/ s2.append(h1.get(s1.charAt(i))); } return s2.toString(); } }

ReadCharacterMapping.java

import java.io.FileReader; import java.io.FileWriter; import java.io.BufferedReader; import java.io.PrintWriter; import java.io.IOException; import java.util.StringTokenizer; import java.util.HashMap; public class ReadCharacterMapping{ public HashMap processMyFile() throws IOException { BufferedReader inputStream = null; try { inputStream = new BufferedReader(new FileReader("xanadu.txt")); String l = null; String key = null; StringTokenizer st = null; String value = null; HashMap hEncryptData = new HashMap(); while ((l = inputStream.readLine()) != null) { st = new StringTokenizer(l); key = st.nextToken().trim(); value = st.nextToken().trim(); //System.out.println(key +" KEY VALUE "+value); hEncryptData.put(key,value); } return hEncryptData; } finally { if (inputStream != null) { inputStream.close(); } } } }

Hi all,
i urgently need help....

i need to write a program which will encrypt a string using a character mapping provided in a file.
The input to your program will be a file which contains mapping for characters.
For E.g. A D
B R
S H
with this mapping if the string has an 'A' then it should be replaced by 'D' etc...
I have to use java exception handling to handle any exceptions like "File not found","File format not correct", "No mapping Present" etc....

Thanks guys n thanks to david.
my problem is solved.
i guess thats what interfaces are for !

The only possibility i can see in your problem is that..

you want to pass x instance to both abc(A a) and xyz(B b), Just tell me How two different reference type (a and b) can accept X Object..The only one possible way is they must have to be in same hirerachy...!! so as per my knowledge the only solution is let B inherits A..and X inherits B..!!!

The problem above is my methods are in different frameworks, as in, not in the same heirarchy.They are two different classes from any location but they are not aware of each other.
If B inherits from A then B compulsorily will have all the methods from A which is not desired here.

Hi All,

My question is how to use polymorphism to solve the problem described.

I have two Frameworkd Fr1 and Fr2.

Fr1 has a class with method abc(A a) which takes an instance of some class A
Fr2 has a class with method xyz(B b) which takes an instance of some class B

I have a Class where i am instantiating an instance of Some Class X.
X x = new X();
now i want to pass the above instance x to both the methods abc() and xyz() in two different framewroks.
how would i do that using polymorphism?
I understand that i can make Class X extend from A or B and pass x instance but we cant extend from more than one class.
So how do i solve the above?

Yes there was another class named Animal in another java class called o.java.
i dnt understnd why that should affect my class animal in another java class.
cant i ve same class names in two different java files???

I have a java class called TestHippo.
While compiling i get the following error:
D:\shell\Personal\Tech\Java\TestHippo.java:1: duplicate class: Animal
class Animal {
^
1 error

Following is the code:

[B][B]class Animal { public Animal() { System.out.println("Making an Animal"); } } class Hippo extends Animal { public Hippo() { System.out.println("Making an Hippo"); } } public class TestHippo { public static void main (String args[]) { System.out.println("Starting..."); Hippo h = new Hippo(); } }[/B][/B]

Hi all,

i compiled the following code and it compiled but gave me a run time exception followed by the code

class Animal { public void add() { System.out.println("Add Animal"); } public void added() { System.out.println("Added Animal"); } } class Dog { public void dog() { System.out.println("I am a Dog"); } } class o extends Dog{ public static void main(String [] args) { o O = new o(); O.call(); Dog dog = new Dog(); dog.dog(); Animal an = new Animal(); an.add(); an.added(); O = (o)dog; System.out.println("Calling O.call() method again"); O.call(); O.dog(); if(O==dog) { System.out.println("O == dog"); } else if(O.equals(dog)) { System.out.println("O equals dog"); } else { System.out.println("O doesnt equal or == dog"); } } public void call() { System.out.println("Inside O"); } }

ERROR

Inside O
I am a Dog
Add Animal
Added Animal
Exception in thread "main" java.lang.ClassCastException
at o.main(o.java:29)

Questions
1) Why did it compile in the first place?
2) At runtime why Cast Exception, i am extending from Dog and casting o to it
3) if i change O = (o)dog to O = dog , it throws compile time error as follows :
found : Dog
required: o
O = dog;
^
1 error
Why so???

hi was just wondering what does java -cp exactly do and what parameters does it take???

hi was just wondering what does java -cp exactly do and what parameters does it take???

Yup Got it guys

Thanks a lot Dharmendra and Prahald...
excuse my silly mistake am just starting out!!!