Whats the difference between these two?

[arnab321]

****1st case:

InputStream in;
DataInputStream stin;
HttpConnection hcon = (HttpConnection)Connector.open("http://example.com");

in = hcon.openInputStream();
stin = new DataInputStream(in);
//read data from stin


*****2nd case:

InputStream in;
DataInputStream stin;
HttpConnection hcon = (HttpConnection)Connector.open("http://example.com");

in = hcon.openInputStream();
//read data from in



well, im new to these terms.

[Eranga]

Only the difference is the following line of code.

stin = new DataInputStream(in);

So did you read about DataInputStream on Java doc?

[arnab321]

I meant whats the difference between execution of the two codes. Whats the purpose of opening a datainputstream on an inputstream? What advattage or disadvantage does it provide?
I read about datainputstream in the doc but understood nothing except the number of functions it provides

[masijade]

Read the API docs for DataInputStream and InputStream and maybe you'll find out.

[Eranga]

Read the API docs for DataInputStream and InputStream and maybe you'll find out.

Yep, that's what I told too my friend. But seems to me, he's not clearly read the API. Or else, he cannot understand what Java doc says.

Simple extraction from the API.

public abstract class InputStream
extends Object

This abstract class is the superclass of all classes representing an input stream of bytes

public class DataInputStream
extends FilterInputStream
implements DataInput

A data input stream lets an application read primitive Java data types from an underlying input stream in a machine-independent way. An application uses a data output stream to write data that can later be read by a data input stream