android应用开发：android网络通信

浏览数：38 / 时间：2015年06月11日

众所周知，Android与服务器通信通常采用HTTP通信方式和Socket通信方式，而HTTP通信方式又分get和post两种方式。

HTTP协议简介：

HTTP (Hypertext Transfer Protocol )，是Web联网的基础，也是手机联网常用的协议之一，HTTP协议是建立在TCP协议之上的一种协议。

HTTP连接最显著的特点是客户端发送的每次请求都需要服务器回送响应，在请求结束后，会主动释放连接。从建立连接到关闭连接的过程称为“一次连接”。在HTTP 1.0中，客户端的每次请求都要求建立一次单独的连接，在处理完本次请求后，就自动释放连接。在HTTP 1.1中则可以在一次连接中处理多个请求，并且多个请求可以重叠进行，不需要等待一个请求结束后再发送下一个请求。

由于HTTP在每次请求结束后都会主动释放连接，因此HTTP连接是一种“短连接”、“无状态”，要保持客户端程序的在线状态，需要不断地向服务器发起连接请求。通常的做法是即使不需要获得任何数据，客户端也保持每隔一段固定的时间向服务器发送一次“保持连接”的请求，服务器在收到该请求后对客户端进行回复，表明知道客户端“在线”。若服务器长时间无法收到客户端的请求，则认为客户端“下线”，若客户端长时间无法收到服务器的回复，则认为网络已经断开。

基于HTTP1.0协议的客户端在每次向服务器发出请求后，服务器就会向客户端返回响应消息，在确认客户端已经收到响应消息后，服务端就会关闭网络连接。在这个数据传输过程中，并不保存任何历史信息和状态信息，因此，HTTP协议也被认为是无状态的协议。

HTTP1.1和HTTP1.0相比较而言，最大的区别就是增加了持久连接支持。当客户端使用HTTP1.1协议连接到服务器后，服务器就将关闭客户端连接的主动权交还给客户端；也就是说，只要不调用Socket类的close方法关闭网络连接，就可以继续向服务器发送HTTP请求。

HTTP连接使用的是“请求—响应”的方式（2次握手），不仅在请求时需要先建立连接，而且需要客户端向服务器发出请求后，服务器端才能回复数据。而Socket连接在双方建立起连接后就可以直接进行数据的传输

HTTP协议的特点：支持B/S及C/S模式；

简单快速：客户向服务器请求服务时，只需传送请求方法和路径。请求方法常用的有GET、HEAD、POST。

灵活：HTTP 允许传输任意类型的数据对象。正在传输的类型由Content-Type 加以标记；

无状态：HTTP 协议是无状态协议。无状态是指协议对于事务处理没有记忆能力。缺少状态意味着如果后续处理需要前面的信息，则它必须重传，这样可能导致每次连接传送的数据量增大。

HTTP协议请求方法：

请求行中包括了请求方法，解释如下：

GET 请求获取Request-URI 所标识的资源；

POST 在Request-URI 所标识的资源后附加新的数据；

HEAD 请求获取由Request-URI 所标识的资源的响应消息报头

PUT 请求服务器存储一个资源，并用Request-URI 作为其标识

DELETE 请求服务器删除Request-URI 所标识的资源；

TRACE 请求服务器回送收到的请求信息，主要用于测试或诊断

CONNECT 保留将来使用

OPTIONS 请求查询服务器的性能，或者查询与资源相关的选项和需求

Get与Post请求区别：

Post请求可以向服务器传送数据，而且数据放在HTML HEADER内一起传送到服务端URL地址，数据对用户不可见。而get是把参数数据队列加到提交的URL中，值和表单内各个字段一一对应，例如

http://c.tieba.baidu.com/p/3377964103
http://c.tieba.baidu.com/p/3378005804
http://c.tieba.baidu.com/p/3378009365
http://c.tieba.baidu.com/p/3378012438
http://c.tieba.baidu.com/p/3378016459
http://c.tieba.baidu.com/p/3378016610
http://c.tieba.baidu.com/p/3378019503
http://c.tieba.baidu.com/p/3378019830
http://c.tieba.baidu.com/p/3378021984
http://c.tieba.baidu.com/p/3378022788
http://c.tieba.baidu.com/p/3378035226
http://c.tieba.baidu.com/p/3378036943
http://c.tieba.baidu.com/p/3378037887
http://c.tieba.baidu.com/p/3378040680
http://c.tieba.baidu.com/p/3378044481
http://c.tieba.baidu.com/p/3378045262
http://c.tieba.baidu.com/p/3378047815
http://c.tieba.baidu.com/p/3378049138
http://c.tieba.baidu.com/p/3378050716
http://c.tieba.baidu.com/p/3378051436
http://c.tieba.baidu.com/p/3378054281
http://c.tieba.baidu.com/p/3378064684
http://c.tieba.baidu.com/p/3378065265
http://c.tieba.baidu.com/p/3378067482
http://c.tieba.baidu.com/p/3378067923
http://c.tieba.baidu.com/p/3378069730
http://c.tieba.baidu.com/p/3378070378
http://c.tieba.baidu.com/p/3378057285
http://c.tieba.baidu.com/p/3378071134
http://c.tieba.baidu.com/p/3378071751
http://c.tieba.baidu.com/p/3378072446
http://c.tieba.baidu.com/p/3378073739
http://c.tieba.baidu.com/p/3378074211
http://c.tieba.baidu.com/p/3378074998
http://c.tieba.baidu.com/p/3378076189
http://c.tieba.baidu.com/p/3378076255
http://c.tieba.baidu.com/p/3378077285
http://c.tieba.baidu.com/p/3378077446
http://c.tieba.baidu.com/p/3378078582
http://c.tieba.baidu.com/p/3378079467
http://c.tieba.baidu.com/p/3378079774
http://c.tieba.baidu.com/p/3378080709
http://c.tieba.baidu.com/p/3378080912
http://c.tieba.baidu.com/p/3378081949
http://c.tieba.baidu.com/p/3378082221
http://c.tieba.baidu.com/p/3378082974
http://c.tieba.baidu.com/p/3378084014
http://c.tieba.baidu.com/p/3378084930
http://c.tieba.baidu.com/p/3378085804
http://c.tieba.baidu.com/p/3378086708
http://c.tieba.baidu.com/p/3378087595
http://c.tieba.baidu.com/p/3378088404
http://c.tieba.baidu.com/p/3378089243
http://c.tieba.baidu.com/p/3378090829
http://c.tieba.baidu.com/p/3378091595
http://c.tieba.baidu.com/p/3378092332
http://c.tieba.baidu.com/p/3378093041
http://c.tieba.baidu.com/p/3378093707
http://c.tieba.baidu.com/p/3378094380
http://c.tieba.baidu.com/p/3378095068
http://c.tieba.baidu.com/p/3378095692
http://c.tieba.baidu.com/p/3378096379
http://c.tieba.baidu.com/p/3378096999
http://c.tieba.baidu.com/p/3378097660
http://c.tieba.baidu.com/p/3378098251
http://c.tieba.baidu.com/p/3378098860
http://c.tieba.baidu.com/p/3378099478
http://c.tieba.baidu.com/p/3378100110
http://c.tieba.baidu.com/p/3378100746
http://c.tieba.baidu.com/p/3378101356
http://c.tieba.baidu.com/p/3378101940
http://c.tieba.baidu.com/p/3378103574
http://c.tieba.baidu.com/p/3378104124
http://c.tieba.baidu.com/p/3378104670
http://c.tieba.baidu.com/p/3378105199
http://c.tieba.baidu.com/p/3378105692
http://c.tieba.baidu.com/p/3378106169
http://c.tieba.baidu.com/p/3378106713
http://c.tieba.baidu.com/p/3378107195
http://c.tieba.baidu.com/p/3378107692
http://c.tieba.baidu.com/p/3378108127
http://c.tieba.baidu.com/p/3378108595
http://c.tieba.baidu.com/p/3378109024
http://c.tieba.baidu.com/p/3378109421
http://c.tieba.baidu.com/p/3378109842
http://c.tieba.baidu.com/p/3378110259
http://c.tieba.baidu.com/p/3378110693
http://c.tieba.baidu.com/p/3378111135
http://c.tieba.baidu.com/p/3378111530
http://c.tieba.baidu.com/p/3378111917
http://c.tieba.baidu.com/p/3378103028
http://c.tieba.baidu.com/p/3378112307
http://c.tieba.baidu.com/p/3378112702
http://c.tieba.baidu.com/p/3378112702
http://c.tieba.baidu.com/p/3378113492
http://c.tieba.baidu.com/p/3378113894
http://c.tieba.baidu.com/p/3378114317
http://c.tieba.baidu.com/p/3378114674
http://c.tieba.baidu.com/p/3378102481
http://c.tieba.baidu.com/p/3378115036
http://c.tieba.baidu.com/p/3378115397
http://c.tieba.baidu.com/p/3378115758
http://c.tieba.baidu.com/p/3378116127
http://c.tieba.baidu.com/p/3378116540
http://c.tieba.baidu.com/p/3378116929
http://c.tieba.baidu.com/p/3378117277
http://c.tieba.baidu.com/p/3378116929
http://c.tieba.baidu.com/p/3378117631
http://c.tieba.baidu.com/p/3378118023
http://c.tieba.baidu.com/p/3378118423
http://c.tieba.baidu.com/p/3378118788
http://c.tieba.baidu.com/p/3378119164
http://c.tieba.baidu.com/p/3378119578
http://c.tieba.baidu.com/p/3378120029
http://c.tieba.baidu.com/p/3378120487
http://c.tieba.baidu.com/p/3378120897
http://c.tieba.baidu.com/p/3378121295
http://c.tieba.baidu.com/p/3378121737
http://c.tieba.baidu.com/p/3378122175
http://c.tieba.baidu.com/p/3378122609
http://c.tieba.baidu.com/p/3378123095
http://c.tieba.baidu.com/p/3378798630
http://c.tieba.baidu.com/p/3378804120
http://c.tieba.baidu.com/p/3378807890
http://c.tieba.baidu.com/p/3378812662
http://c.tieba.baidu.com/p/3378820014
http://c.tieba.baidu.com/p/3378824084
http://c.tieba.baidu.com/p/3378832928
http://c.tieba.baidu.com/p/3378842937
http://c.tieba.baidu.com/p/3378850215
http://c.tieba.baidu.com/p/3378855876
http://c.tieba.baidu.com/p/3378861160
http://c.tieba.baidu.com/p/3378865053
http://c.tieba.baidu.com/p/3378873772
http://c.tieba.baidu.com/p/3378880510
http://c.tieba.baidu.com/p/3378886573
http://c.tieba.baidu.com/p/3378890024
http://c.tieba.baidu.com/p/3378900813
http://c.tieba.baidu.com/p/3378904442
http://c.tieba.baidu.com/p/3378910860
http://c.tieba.baidu.com/p/3378919463
http://c.tieba.baidu.com/p/3378924191
http://c.tieba.baidu.com/p/3378928733
http://c.tieba.baidu.com/p/3378933474
http://c.tieba.baidu.com/p/3378938277
http://c.tieba.baidu.com/p/3378977259
http://c.tieba.baidu.com/p/3378987464
http://c.tieba.baidu.com/p/3378997405
http://c.tieba.baidu.com/p/3379001265
http://c.tieba.baidu.com/p/3379005827
http://c.tieba.baidu.com/p/3379013947
http://c.tieba.baidu.com/p/3379027672
http://c.tieba.baidu.com/p/3379028124
http://c.tieba.baidu.com/p/3379040717
http://c.tieba.baidu.com/p/3379044326
http://c.tieba.baidu.com/p/3379053998
http://c.tieba.baidu.com/p/3379061330
http://c.tieba.baidu.com/p/3379066850
http://c.tieba.baidu.com/p/3379071395
http://c.tieba.baidu.com/p/3379078552
http://c.tieba.baidu.com/p/3379087386
http://c.tieba.baidu.com/p/3379104849
http://c.tieba.baidu.com/p/3379120475
http://c.tieba.baidu.com/p/3379127041
http://c.tieba.baidu.com/p/3379130751
http://c.tieba.baidu.com/p/3379136990
http://c.tieba.baidu.com/p/3379143814
http://c.tieba.baidu.com/p/3379150653
http://c.tieba.baidu.com/p/3379157738
http://c.tieba.baidu.com/p/3379164716
http://c.tieba.baidu.com/p/3379168415
http://c.tieba.baidu.com/p/3379197784
http://c.tieba.baidu.com/p/3379202187
http://c.tieba.baidu.com/p/3379207322
http://c.tieba.baidu.com/p/3379398670
http://c.tieba.baidu.com/p/3379411106
http://c.tieba.baidu.com/p/3379424106
http://c.tieba.baidu.com/p/3379435926
http://c.tieba.baidu.com/p/3379442149
http://c.tieba.baidu.com/p/3379447860
http://c.tieba.baidu.com/p/3379451787
http://c.tieba.baidu.com/p/3379457907
http://c.tieba.baidu.com/p/3379463892
http://c.tieba.baidu.com/p/3379470556
http://c.tieba.baidu.com/p/3379475874
http://c.tieba.baidu.com/p/3379481202
http://c.tieba.baidu.com/p/3379486512
http://c.tieba.baidu.com/p/3379491857
http://c.tieba.baidu.com/p/3379507300
http://c.tieba.baidu.com/p/3379513254
http://c.tieba.baidu.com/p/3379518782
http://c.tieba.baidu.com/p/3379523805
http://c.tieba.baidu.com/p/3379618567
http://c.tieba.baidu.com/p/3379622898
http://c.tieba.baidu.com/p/3379649500
http://c.tieba.baidu.com/p/3379655168
http://c.tieba.baidu.com/p/3379674479
http://c.tieba.baidu.com/p/3379680086
http://c.tieba.baidu.com/p/3379686005
http://c.tieba.baidu.com/p/3379691944
http://c.tieba.baidu.com/p/3379697946
http://c.tieba.baidu.com/p/3379703907
http://c.tieba.baidu.com/p/3379709893
http://c.tieba.baidu.com/p/3379715841
http://c.tieba.baidu.com/p/3379721783
http://c.tieba.baidu.com/p/3379727566
http://c.tieba.baidu.com/p/3379733382
http://c.tieba.baidu.com/p/3379737574
http://c.tieba.baidu.com/p/3379738993
http://c.tieba.baidu.com/p/3379744780
http://c.tieba.baidu.com/p/3379746437
http://c.tieba.baidu.com/p/3379750440
http://c.tieba.baidu.com/p/3379754764
http://c.tieba.baidu.com/p/3379756122
http://c.tieba.baidu.com/p/3379761769
http://c.tieba.baidu.com/p/3379761886
http://c.tieba.baidu.com/p/3379767622
http://c.tieba.baidu.com/p/3379773214
http://c.tieba.baidu.com/p/3379775595
http://c.tieba.baidu.com/p/3379778839
http://c.tieba.baidu.com/p/3379784070
http://c.tieba.baidu.com/p/3379788547
http://c.tieba.baidu.com/p/3379789495
http://c.tieba.baidu.com/p/3379794777
http://c.tieba.baidu.com/p/3379800020
http://c.tieba.baidu.com/p/3379805383
http://c.tieba.baidu.com/p/3379806346
http://c.tieba.baidu.com/p/3379810607
http://c.tieba.baidu.com/p/3379814428
http://c.tieba.baidu.com/p/3379815631
http://c.tieba.baidu.com/p/3379818302
http://c.tieba.baidu.com/p/3379820549
http://c.tieba.baidu.com/p/3379825459
http://c.tieba.baidu.com/p/3379828936
http://c.tieba.baidu.com/p/3379830324
http://c.tieba.baidu.com/p/3379835035
http://c.tieba.baidu.com/p/3379836800
http://c.tieba.baidu.com/p/3379839668
http://c.tieba.baidu.com/p/3379839668
http://c.tieba.baidu.com/p/3379844219
http://c.tieba.baidu.com/p/3379851995
http://c.tieba.baidu.com/p/3379857209
http://c.tieba.baidu.com/p/3379857691
http://c.tieba.baidu.com/p/3379862291
http://c.tieba.baidu.com/p/3379862665
http://c.tieba.baidu.com/p/3379867248
http://c.tieba.baidu.com/p/3379869439
http://c.tieba.baidu.com/p/3379871737
http://c.tieba.baidu.com/p/3379873954
http://c.tieba.baidu.com/p/3379875930
http://c.tieba.baidu.com/p/3379880033
http://c.tieba.baidu.com/p/3379880441
http://c.tieba.baidu.com/p/3379884050
http://c.tieba.baidu.com/p/3379887193
http://c.tieba.baidu.com/p/3379887876
http://c.tieba.baidu.com/p/3379891568
http://c.tieba.baidu.com/p/3379895149
http://c.tieba.baidu.com/p/3379897354
http://c.tieba.baidu.com/p/3379898661
http://c.tieba.baidu.com/p/3379900071
http://c.tieba.baidu.com/p/3379901971
http://c.tieba.baidu.com/p/3379905277
http://c.tieba.baidu.com/p/3379906939
http://c.tieba.baidu.com/p/3379908508
http://c.tieba.baidu.com/p/3379911512
http://c.tieba.baidu.com/p/3379911521
http://c.tieba.baidu.com/p/3379913696
http://c.tieba.baidu.com/p/3379914416
http://c.tieba.baidu.com/p/3379917089
http://c.tieba.baidu.com/p/3379919751
http://c.tieba.baidu.com/p/3379920356
http://c.tieba.baidu.com/p/3379922427
http://c.tieba.baidu.com/p/3379923497
http://c.tieba.baidu.com/p/3379924940
http://c.tieba.baidu.com/p/3379927196
http://c.tieba.baidu.com/p/3379926347
http://c.tieba.baidu.com/p/3379937545
http://c.tieba.baidu.com/p/3379940750
http://c.tieba.baidu.com/p/3379943364
http://c.tieba.baidu.com/p/3379975539
http://c.tieba.baidu.com/p/3379976909
http://c.tieba.baidu.com/p/3379977884
http://c.tieba.baidu.com/p/3379978817
http://c.tieba.baidu.com/p/3379980461
http://c.tieba.baidu.com/p/3379981524
http://c.tieba.baidu.com/p/3379982529
http://c.tieba.baidu.com/p/3379983460
http://c.tieba.baidu.com/p/3379984504
http://c.tieba.baidu.com/p/3379985441
http://c.tieba.baidu.com/p/3379986132
http://c.tieba.baidu.com/p/3379987257
http://c.tieba.baidu.com/p/3379988702
http://c.tieba.baidu.com/p/3379989470
http://c.tieba.baidu.com/p/3379989937
http://c.tieba.baidu.com/p/3379990662
http://c.tieba.baidu.com/p/3379991227
http://c.tieba.baidu.com/p/3379991770
http://c.tieba.baidu.com/p/3379992308