以前写过一篇介绍NSInvocationOperation的文章：多线程之NSInvocationOperation，这篇文章是基于此的一个例子。

RootViewController.h

#import <UIKit/UIKit.h>

@interface RootViewController : UITableViewController {
	NSMutableArray *array;
}

@property (nonatomic, retain) NSMutableArray *array;

@end

RootViewController.m

#import "RootViewController.h"

@implementation RootViewController
@synthesize array;

- (void)viewDidLoad {
    [super viewDidLoad];
    
	self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Load" 
                                                                              style:UIBarButtonItemStyleDone 
                                                                             target:self 
                                                                             action:@selector(loadData)];
	
	NSMutableArray *_array = [[NSMutableArray alloc] initWithCapacity:10000];
	self.array = _array;
	[_array release];	
}

- (void) loadData {	
	NSOperationQueue *queue = [NSOperationQueue new];
	NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self 
                                                                            selector:@selector(loadDataWithOperation) object:nil];
	[queue addOperation:operation];
	[operation release];
}

- (void) loadDataWithOperation {
	NSURL *dataURL = [NSURL URLWithString:@"http://icodeblog.com/samples/nsoperation/data.plist"];
	
	NSArray *tmp_array = [NSArray arrayWithContentsOfURL:dataURL];
	
	for(NSString *str in tmp_array) {
		[self.array addObject:str];
	}
	
	[self.tableView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:YES];
}

#pragma mark Table view methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [self.array count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"Cell";
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }
    
	[cell.textLabel setText:[self.array objectAtIndex:indexPath.row]];
	
    return cell;
}

- (void)dealloc {
    [super dealloc];
	[array release];
}

@end

MQTT的官方推荐网站：

http://mqtt.org/software

使用IBM 的MQTT协议实现push消息
地址：

http://tokudu.com/2010/how-to-implement-push-notifications-for-android/

 google code 下载MQTT moquette Broker 地址：
    http://code.google.com/p/moquette-mqtt/
    
GIT 下载MQTT moquette client 地址：
  https://github.com/fusesource/mqtt-client

参考链接

http://stackoverflow.com/questions/1243066/does-android-support-near-real-time-push-notification

http://stackoverflow.com/questions/1378671/push-notifications-in-android-platform

http://blog.boxedice.com/2010/10/07/android-push-notifications-tutorial/

http://dalelane.co.uk/blog/?p=1599

http://tokudu.com/2010/how-to-implement-push-notifications-for-android/

http://blog.isidorey.com/2011/05/cloud-to-device-and-back-with-android.html

http://www.hardill.me.uk/wordpress/?p=207

http://tokudu.com/demo/android-push/

附加一个好玩的链接

http://www.hardill.me.uk/wordpress/?p=204

http://mosquitto.org/