ios中的http：get，post，同步，異步

1、服務端

　　一、主要結構：

　　　　

　　二、主要代碼：

　　　　1）web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
      <servlet-name>LoginServlet</servlet-name><!--lsdkalskdfjasdkfj-->
      <servlet-class>com.wiscom.servlet.LoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
      <servlet-name>LoginServlet</servlet-name>
      <url-pattern>/LoginServlet</url-pattern>
  </servlet-mapping>
</web-app>

　　　　2）LoginServlet.java

package com.wiscom.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginServlet extends HttpServlet {

  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    response.setContentType("text/html;charset=utf-8");
    
    request.setCharacterEncoding("utf-8");//設置參數解碼類型，必須和頁面中一致
    String sName=request.getParameter("name");
    String sPassword=request.getParameter("psw");
    
    PrintWriter out = response.getWriter();
    if(sName.equals("admin")&&sPassword.equals("admin")){
                out.print(sName+",您已成功登錄！！");
    }else{
            out.print(sName+",用戶名密碼有誤！！");
    }
   }
  
  public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
      this.doGet(request, response);
  }
}

2、客戶端

　　一、頭文件：NetCenter.h

#import <Foundation/Foundation.h>

@interface NetCenter : NSObject

@property(nonatomic,retain) NSMutableData *receiveData;

@property(nonatomic,assign)int dataPackSerialNo;

- (void)httpGetSyn;

- (void)httpPostSyn;

- (void)httpGetNoSyn;

- (void)httpPostNoSyn;

@end

　　二、實現文件：NetCenter.m

#import "NetCenter.h"

@implementation NetCenter

@synthesize receiveData=_receiveData;
@synthesize dataPackSerialNo=_dataPackSerialNo;

- (void)httpGetSyn
{
    NSLog(@"httpGetSyn...");
    
    /*
    NSString *urlString =url;
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:urlString]];
    [request setHTTPMethod:@"GET"];
    NSHTTPURLResponse* urlResponse = nil;
    NSError *error = [[NSError alloc] init];
    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&error];
    NSMutableString *result = [[NSMutableString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
    NSLog(@"The result string is :%@",result);
    */
    //第一步，建立URL
    NSURL *url = [NSURL URLWithString:@"http://10.0.0.96:8080/app_server/LoginServlet?name=admin&psw=admin"];
    
    //第二步，經過URL建立網絡請求
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
    //NSURLRequest初始化方法第一個參數：請求訪問路徑，第二個參數：緩存協議，第三個參數：網絡請求超時時間（秒）
    /*
    其中緩存協議是個枚舉類型包含：
    NSURLRequestUseProtocolCachePolicy（基礎策略）
    NSURLRequestReloadIgnoringLocalCacheData（忽略本地緩存）
    NSURLRequestReturnCacheDataElseLoad（首先使用緩存，若是沒有本地緩存，才從原地址下載）
    NSURLRequestReturnCacheDataDontLoad（使用本地緩存，從不下載，若是本地沒有緩存，則請求失敗，此策略多用於離線操做）
    NSURLRequestReloadIgnoringLocalAndRemoteCacheData（無視任何緩存策略，不管是本地的仍是遠程的，老是從原地址從新下載）
    NSURLRequestReloadRevalidatingCacheData（若是本地緩存是有效的則不下載，其餘任何狀況都從原地址從新下載）
    */
    //第三步，鏈接服務器
    NSData *received = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSString *str = [[NSString alloc]initWithData:received encoding:NSUTF8StringEncoding];
    
    NSLog(@"%@",str);

}

- (void)httpPostSyn
{
    NSLog(@"httpPostSyn...");
    
    //第一步，建立URL
    NSURL *url = [NSURL URLWithString:@"http://10.0.0.96:8080/app_server/LoginServlet"];
    
    //第二步，建立請求
    NSString *postStr = [[NSString alloc] initWithFormat:@"name=%@&psw=%@",@"admin",@"admin"];
    NSData *postData = [postStr dataUsingEncoding:NSUTF8StringEncoding];
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
    [request setHTTPMethod:@"POST"];//設置請求方式爲POST，默認爲GET
    [request setHTTPBody:postData];//設置參數
    
    //第三步，鏈接服務器
    NSData *received = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSString *backStr = [[NSString alloc]initWithData:received encoding:NSUTF8StringEncoding];
    
    NSLog(@"%@",backStr);
}

- (void)httpGetNoSyn
{
    NSLog(@"httpGetNoSyn...");
    
    //第一步，建立url
    NSURL *url = [NSURL URLWithString:@"http://10.0.0.96:8080/app_server/LoginServlet?name=admin&psw=admin"];
    
    //第二步，建立請求
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
    
    //第三步，鏈接服務器
    NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
    
}

- (void)httpPostNoSyn
{
    NSLog(@"httpPostNoSyn...");
    
    //第一步，建立url
    NSURL *url = [NSURL URLWithString:@"http://10.0.0.96:8080/app_server/LoginServlet"];
    
    //第二步，建立請求
    NSString *postStr = [[NSString alloc] initWithFormat:@"name=%@&psw=%@",@"admin",@"admin"];
    NSData *postData = [postStr dataUsingEncoding:NSUTF8StringEncoding];
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
    [request setHTTPMethod:@"POST"];
    [request setHTTPBody:postData];
    
    //第三步，鏈接服務器
    NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
}

/*************五、異步請求的代理方法[start]****************/

//接收到服務器迴應的時候調用此方法
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    NSHTTPURLResponse *res = (NSHTTPURLResponse *)response;
    NSLog(@"%@",[res allHeaderFields]);
    self.receiveData = [NSMutableData data];//數據存儲對象的的初始化
    self.dataPackSerialNo=0;
    NSLog(@"收到服務器迴應。。。");
}

//接收到服務器傳輸數據的時候調用，此方法根據數據大小執行若干次
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    NSLog(@"收到服務器傳回的數據包,數據包序號：%d",self.dataPackSerialNo);
    [self.receiveData appendData:data];
    self.dataPackSerialNo+=1;
}

//數據傳完以後調用此方法
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"數據傳輸完成，輸出全部數據結果。。。");
    NSString *receiveStr = [[NSString alloc]initWithData:self.receiveData encoding:NSUTF8StringEncoding];
    NSLog(@"%@",receiveStr);
}

//網絡請求過程當中，出現任何錯誤（斷網，鏈接超時等）會進入此方法
-(void)connection:(NSURLConnection *)connection
 didFailWithError:(NSError *)error
{
    NSLog(@"網絡請求出錯：%@",[error localizedDescription]);
}

/*************五、異步請求的代理方法[end]****************/

@end

　　三、調用

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    
    NetCenter *netCenter=[[NetCenter alloc]init];
    
    
    /*****************同步請求****************/
    //[netCenter httpGetSyn];
    //[netCenter httpPostSyn];
    
    /*****************異步請求****************/
    //[netCenter httpGetNoSyn];
    [netCenter httpPostNoSyn];
    
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}　　

3、測試

　　一、同步get

　　

　　二、同步post

　　

　　三、異步get

　　

　　四、異步post

　　

3、擴展

　　一、http和https

　　　　http://www.cnblogs.com/stan0714/archive/2012/03/21/2409872.html

　　二、ios網絡編程理論與實例

　　　　http://blog.csdn.net/hgy2011/article/details/8676084