Establish socket connection in Objective-C

//************************************************************************

// ClassName     : Communicator.h

// Created On    : 10/13/12.

// Created By    : Jayprakash Dubey

// Purpose       : Socket connection

//************************************************************************

#import <Foundation/Foundation.h>

#define REQUEST_DETAILS @"search^10|5|2|1^diab mel^abcdefrgh\r\n\r\n"

@interface Communicator : NSObject <NSStreamDelegate> {

@public

NSString *host;

int port;

    

    NSInputStream *inputStream;

    NSOutputStream *outputStream;       

}

- (void)setup;

- (void)open;

- (void)close;

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)event;

@property (strong) NSInputStream *inputStream;

@property (strong) NSOutputStream *outputStream;

@end

=================================================

//************************************************************************

// ClassName     : Communicator.m

// Created On    : 10/13/12.

// Created By    : Jayprakash Dubey

// Purpose       : Socket connection

//************************************************************************

#import "Communicator.h"

CFReadStreamRef readStream;

CFWriteStreamRef writeStream;

@implementation Communicator

@synthesize inputStream,outputStream;

//////////////////////////////////////////////////////////////////

// Method : setup

// Params :nil

// Description : Establishes a connection for socket

//////////////////////////////////////////////////////////////////

#pragma mark - Connection handlers

- (void)setup {

NSURL *url = [NSURL URLWithString:host];

NSLog(@"Setting up connection to %@ : %i", [url absoluteString], port);

CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, (CFStringRef)CFBridgingRetain([url host]), port, &readStream, &writeStream);

if(!CFWriteStreamOpen(writeStream)) {

NSLog(@"Error, writeStream not open");

return;

}

    

[self open];

NSLog(@"Status of outputStream: %i", [outputStream streamStatus]);

return;

}

- (void)open {

NSLog(@"Opening streams.");

    inputStream = (NSInputStream *)CFBridgingRelease(readStream);

    outputStream = (NSOutputStream *)CFBridgingRelease(writeStream);

    

[inputStream setDelegate:self];

[outputStream setDelegate:self];

[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

[inputStream open];

[outputStream open];

}

- (void)close {

NSLog(@"Closing streams.");

[inputStream close];

[outputStream close];

[inputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

[outputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

[inputStream setDelegate:nil];

[outputStream setDelegate:nil];

inputStream = nil;

outputStream = nil;

}

//////////////////////////////////////////////////////////////////

// Method : handleEvent

// Params :event

// Description : Handles events of NSStream

//////////////////////////////////////////////////////////////////

#pragma mark - NSStreamEvent delegates

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)event {

NSLog(@"Stream triggered.");

    NSMutableString *strServerResponse = [[NSMutableString alloc] init];

    

switch(event) {

            

case NSStreamEventHasSpaceAvailable: {

if(stream == outputStream) {

NSLog(@"outputStream is ready.");

                

                NSString *response  = @"search^10|5|2|1^diab mel^abdefghjik\r\n\r\n";

                NSData *data = [[NSData alloc] initWithData:[response dataUsingEncoding:NSASCIIStringEncoding]];

                

                [outputStream write:[data bytes] maxLength:[data length]];

                [outputStream close];

            }

break;

}

case NSStreamEventHasBytesAvailable: {

         

            NSLog(@"NSStreamEventHasBytesAvailable");

            

            if (stream == inputStream) {

                NSLog(@"inputStream is ready.");

                uint8_t buffer[1024];

                int len;

                

                while ([inputStream hasBytesAvailable]) {

                    len = [inputStream read:buffer maxLength:sizeof(buffer)];

                    if (len > 0) {

                        

                        NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];

                        

                        if (nil != output) {

                            

                            NSLog(@"server said: %@", output);

                            [strServerResponse appendString:output];

                        }

                    }

                }

            }

            

break;

}

        case NSStreamEventErrorOccurred: {

            NSLog(@"Can not connect to the host!");

            

            break;

        }

case NSStreamEventEndEncountered: {

NSLog(@"Event end occured");

break;

}

default: {

NSLog(@"Stream is sending an Event: %i", event);

break;

}

}      

}

@end

=================================

Invoke socket connection :

Communicator *c = [[Communicator alloc] init];

c->host = @"http://your URL here";

c->port = port number;

[c setup];

[c open];