I am not sure if you are using the right way . you may check the J2EE
templates for one or other ways that you may do that more effective.

As a short term solution you can encrypt the parameter values using a
server encryption key on the provider and decrypt it on the consumer
side.
In order to Encipher, decipher the strings you have different
alternatives. From simple own written classes that "Xors" the bytes to
deploying Public key cryptography algorithms using a JCA/JCE provider.

Xor way :

original-byte xor key = transmission-byte
transmission-byte xor key = original-byte

JCA/JCE Way:

read and get yourself informed about the java  security architecture. the
class you will use ( assuming you have a security provider
implementation deployed in your server framework) is
java.sun.com/.../Cipher.html

There is different way of passing information from
front end application(Applet and application)to the
middlewares( such as servlet and jsp).
you can use a javabean as a data container and fill
your information in it and write it to stream by using
diiferent method such "writeobject" and in the other
side use"Readobject" and get the pointer to the
object .The following code  will help  you.

Client side:

try
{
URL url=new URL(urlStr);
URLConnection con=url.openConnection();
con.setUseCaches(false);
con.setDoInput(true);
con.setDoOutput(true);
OutputStream out = con.getOutputStream();
ObjectOutputStream outStream = new
ObjectOutputStream(out);
outStream.writeObject(item);
outStream.close();
out.close();
InputStream in=con.getInputStream();
DataInputStream textStream=new DataInputStream(in);
textStream.close();
in.close();
}catch(Exception ex){
ex.printStackTrace() ;
}


server Side:

try{
InputStream in = request.getInputStream();
ObjectInputStream objStream;
objStream = new ObjectInputStream(in);
RequesterItem item= new RequesterItem();
item =(RequesterItem) objStream.readObject();
objStream.close();
in.close();

You may try encrypting your pwd by an MD5 method:

  import java.security.*;
  ...
  public  String getMD5(String givenStr) {
        String result = null;
        try {
            byte[] data1 = givenStr.getBytes();
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            byte[] bytes = md5.digest(data1);
            result = new String(md5.digest(data1));
        } catch(Exception e){
            //do something
        }
        return result;
  }