Anita Singh

Thanks a lot

Congratulation
Perfect Score

Thanks

Hello,

I passed SCJP 5 with 100%.

Congrats Anil

Nice Score

Thanks Rahul
I got it.

Hi,
I have saved the password in database in Encrypted form successfully.But it shows me "javax.crypto.BadPaddingException: Data must start with zero" Exception while Decryption.I m posting here both the Encryption & Decryption code.Please Help Me.

//Code For Encryption package PracticeApplication1; import java.util.Date; import java.util.*; import java.security.*; import javax.crypto.*; import org.bouncycastle.jce.provider.BouncyCastleProvider; import java.sql.*; public class RSAPasswordEncryption { public static void main(String args[]) { String uname="AnitaSingh"; String password="AnitaSingh"; try{ //Security for password encryption Security.addProvider(new BouncyCastleProvider()); KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA"); SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN"); keyGen.initialize(1024, random); KeyPair pair = keyGen.generateKeyPair(); PrivateKey priv = pair.getPrivate(); PublicKey pub = pair.getPublic(); /* Create the cipher */ Cipher rsaCipher = Cipher.getInstance("RSA/ECB/PKCS1Padding"); // Initialize the cipher for encryption rsaCipher.init(Cipher.ENCRYPT_MODE, pub); // Cleartext byte[] cleartext = null; cleartext = password.getBytes(); String theString = new String(cleartext); System.out.println("Original String:"+theString); // Encrypt the cleartext byte[] ciphertext = null; ciphertext = rsaCipher.doFinal(cleartext); System.out.println("the encrypted text is: " + ciphertext.toString()); Class.forName("org.gjt.mm.mysql.Driver"); Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/anita","root","root"); PreparedStatement pstmt=con.prepareStatement("insert into upassword values(?,?)"); pstmt.setString(1,uname); System.out.println(ciphertext); pstmt.setString(2,ciphertext.toString()); pstmt.execute(); System.out.println("Hello from backing .. 2"); System.out.println(uname); rsaCipher.init(Cipher.DECRYPT_MODE, priv); } catch(Exception e){System.out.println(e);} } }
/*Encryption program is working fine*/
************************************************************************

//CODE For Decryption package PracticeApplication1; import java.util.Date; import java.util.*; import java.security.*; import javax.crypto.*; import org.bouncycastle.jce.provider.BouncyCastleProvider; import java.sql.*; import org.bouncycastle.util.encoders.Base64Encoder; public class RSAPasswordDecryption { public static void main(String args[]) { String uname="AnitaSingh"; try { System.out.println("Inside Try"); Class.forName("org.gjt.mm.mysql.Driver"); Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/anita","root","root"); PreparedStatement pstmt=con.prepareStatement("select * from upassword where uname=?"); pstmt.setString(1,uname); ResultSet rs= pstmt.executeQuery(); System.out.println("After Query Execution"); while(rs.next()) { System.out.println("Inside rs.next()"); System.out.println(rs.getString("password")); byte[] password1=rs.getBytes("password"); System.out.println(password1); Security.addProvider(new BouncyCastleProvider()); KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA"); SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN"); keyGen.initialize(1024, random); KeyPair pair = keyGen.generateKeyPair(); PrivateKey priv = pair.getPrivate(); PublicKey pub = pair.getPublic(); /* Create the cipher */ Cipher rsaCipher = Cipher.getInstance("RSA/ECB/PKCS1Padding"); // Initialize the same cipher for decryption rsaCipher.init(Cipher.DECRYPT_MODE, priv); // Decrypt the ciphertext byte[] cleartext1 = rsaCipher.doFinal(password1); System.out.println("After dofinal"); String theString1 = new String(cleartext1); System.out.println("the final cleartext is: " + theString1); } } catch(Exception e){System.out.println(e); } } }

Please help me
Thanks in Advance

Congrats Abdul
Good score

Hi Rajesh,
You can not access private constructor from outside the class,
If you want to access the constructor from outside class,you have to make this constructor as "public".

class drinks
{
public drinks()//public constructor
{
System.out.println("i am abstarct constructor");
}
}
class PracticeTest
{
public static void main(String[] args)
{
drinks d=new drinks();
}
}

Thanks

Hi Chandra
Congrats
very good score

Hi,
NullPointerException is thrown here,but you are printing that exception.
make some change in your code:

public class PracticeTest {
public static int[ ] getArray() { return null; }
public static void main(String[] args)
{
int index = 1;
try
{
getArray() [index=2]++;
} catch (Exception e)
{
System.out.println(e);//change
}
System.out.println("index = " + index);
}
}
Now you will see that your program is throwing NullPointerException.

public static void main(String args[]){
float a=8;
float b=3;
float f;
f=(float)(a++/b--);
System.out.println(f);
}

if You do in this way then it gives you 2.6.
Because in your case a and b are int,and the result is based upon int division,thats why answer is 2.0 not 2.6

Hi
Here you are comparing String literal to array of String Object,by using ==,it is not possible.
If you want to do this,then write
if(s1.equals(args[0])
{
System.out.println("equal");
}

Thanks & Regards

Hi,
You are telling that B.java is also in test package,but You are not using package statement there.

use package test;
in B.java also.
& remove import statement from there.

Then compile both the java file using below comand:-
javac -d . A.java
javac -d . B.java
it crete the folder test & put your class file there &
for running B.java write:-
java test.B

Anita Singh

The wait(),notify(), and notifyAll() methods are used to provide an efficient way for threads to communicate each other.
wait():-Causes current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object.
notify():-Wakes up a single thread that is waiting on this object's monitor.
notifyAll():-Wakes up all threads that are waiting on this object's monitor.

Anita Singh