大家好,又见面了,我是全栈君,祝每个程序员都可以多学几门语言。
使用WinINet和WinHTTP实现Http訪问
飘飘白云 l_zhaohui@163.com
2007-11-30
Http訪问有两种方式,GET和POST,就编程来说GET方式相对简单点,它不用向server提交数据,在这个例程中我使用POST方式,提交数据value1与value2,并从server得到他们的和(value1 + value2)。
为实现Http訪问,微软提供了二套API:WinINet, WinHTTP。WinHTTP比WinINet更加安全和健壮,能够这么觉得WinHTTP是WinINet的升级版本号。这两套API包括了非常多类似的函数与宏定义,呵呵,具体对照请查阅msdn中的文章“Porting WinINet Applications to WinHTTP”,在线MSDN连接:http://msdn2.microsoft.com/en-us/library/aa384068.aspx。在这个例程中,通过一个宏的设置来决定是使用WinHttp还是WinINet。代码例如以下:
#define USE_WINHTTP //Comment this line to user wininet.
以下来说说实现Http訪问的流程(两套API都一样的流程):
1, 首先我们打开一个Session获得一个HINTERNET session句柄;
2, 然后我们使用这个session句柄与server连接得到一个HINTERNET connect句柄;
3, 然后我们使用这个connect句柄来打开Http 请求得到一个HINTERNET request句柄;
4, 这时我们就能够使用这个request句柄来发送数据与读取从server返回的数据;
5, 最后依次关闭request,connect,session句柄。
在这个例程中以上各个流程都进行了简单封装,以便对照两套API函数的些许差异。以下让源码说话,原project是一个windows控制台project,你能够非常easy通过拷贝代码重建project。
另:假设你从server得到的返回数据是utf8格式的文本数据,你将须要对返回的数据进行转换才干正确显示中文,日文等。仅供參考,转换为ATL CStringW的函数见下:
CStringW GetStringWFromUtf8(
const
std::string
&
str)
{
int len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), int(str.length()), 0, 0);
CStringW buf;
WCHAR* dd = buf.GetBuffer(len);
len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), int(str.length()), dd, len);
buf.ReleaseBuffer(len);
return buf;
}
完整代码例如以下:
//
HttpPost.cpp written by l_zhaohui@163.com
2
//
2007/11/30
3
#include
“
stdafx.h
“
4
#include
<
windows.h
>
5
#include
<
stdio.h
>
6
#include
<
stdlib.h
>
7
8
#define _ATL_CSTRING_EXPLICIT_CONSTRUCTORS
9
#include
<
atlbase.h
>
10
#include
<
atlstr.h
>
11
12
#define USE_WINHTTP
//
Comment this line to user wininet.
13
#ifdef USE_WINHTTP
14
#include
<
winhttp.h
>
15
#pragma comment(lib,
“
winhttp.lib
“
)
16
#
else
17
#include
<
wininet.h
>
18
#pragma comment(lib,
“
wininet.lib
“
)
19
#endif
20
#define BUF_SIZE (
1024
)
21
22
//
CrackedUrl
23
class
CrackedUrl
{
24 int m_scheme;
25 CStringW m_host;
26 int m_port;
27 CStringW m_path;
28public:
29 CrackedUrl(LPCWSTR url)
30 {
31 URL_COMPONENTS uc = { 0};
32 uc.dwStructSize = sizeof(uc);
33
34 const DWORD BUF_LEN = 256;
35
36 WCHAR host[BUF_LEN];
37 uc.lpszHostName = host;
38 uc.dwHostNameLength = BUF_LEN;
39
40 WCHAR path[BUF_LEN];
41 uc.lpszUrlPath = path;
42 uc.dwUrlPathLength = BUF_LEN;
43
44 WCHAR extra[BUF_LEN];
45 uc.lpszExtraInfo = extra;
46 uc.dwExtraInfoLength = BUF_LEN;
47
48#ifdef USE_WINHTTP
49 if (!WinHttpCrackUrl(url, 0, ICU_ESCAPE, &uc)) {
50 printf(“Error:WinHttpCrackUrl failed!/n“);
51 }
52
53#else
54 if (!InternetCrackUrl(url, 0, ICU_ESCAPE, &uc)) {
55 printf(“Error:InternetCrackUrl failed!/n“);
56 }
57#endif
58 m_scheme = uc.nScheme;
59 m_host = host;
60 m_port = uc.nPort;
61 m_path = path;
62 }
63
64 int GetScheme() const
65 {
66 return m_scheme;
67 }
68
69 LPCWSTR GetHostName() const
70 {
71 return m_host;
72 }
73
74 int GetPort() const
75 {
76 return m_port;
77 }
78
79 LPCWSTR GetPath() const
80 {
81 return m_path;
82 }
83
84 static CStringA UrlEncode(const char* p)
85 {
86 if (p == 0) {
87 return CStringA();
88 }
89
90 CStringA buf;
91
92 for (;;) {
93 int ch = (BYTE) (*(p++));
94 if (ch == ‘/0‘) {
95 break;
96 }
97
98 if (isalnum(ch) || ch == ‘_‘ || ch == ‘–‘ || ch == ‘.‘) {
99 buf += (char)ch;
100 }
101 else if (ch == ‘ ‘) {
102 buf += ‘+‘;
103 }
104 else {
105 char c[16];
106 wsprintfA(c, “%%%02X“, ch);
107 buf += c;
108 }
109 }
110
111 return buf;
112 }
113}
;
114
115
//
CrackedUrl
116
HINTERNET OpenSession(LPCWSTR userAgent
=
0
)
117
{
118#ifdef USE_WINHTTP
119 return WinHttpOpen(userAgent, NULL, NULL, NULL, NULL);;
120#else
121 return InternetOpen(userAgent, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
122#endif
123}
124
125
HINTERNET Connect(HINTERNET hSession, LPCWSTR serverAddr,
int
portNo)
126
{
127#ifdef USE_WINHTTP
128 return WinHttpConnect(hSession, serverAddr, (INTERNET_PORT) portNo, 0);
129#else
130 return InternetConnect(hSession, serverAddr, portNo, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
131#endif
132}
133
134
HINTERNET OpenRequest(HINTERNET hConnect, LPCWSTR verb, LPCWSTR objectName,
int
scheme)
135
{
136 DWORD flags = 0;
137#ifdef USE_WINHTTP
138 if (scheme == INTERNET_SCHEME_HTTPS) {
139 flags |= WINHTTP_FLAG_SECURE;
140 }
141
142 return WinHttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags);
143
144#else
145 if (scheme == INTERNET_SCHEME_HTTPS) {
146 flags |= INTERNET_FLAG_SECURE;
147 }
148
149 return HttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags, 0);
150#endif
151}
152
153
BOOL AddRequestHeaders(HINTERNET hRequest, LPCWSTR header)
154
{
155 SIZE_T len = lstrlenW(header);
156#ifdef USE_WINHTTP
157 return WinHttpAddRequestHeaders(hRequest, header, DWORD(len), WINHTTP_ADDREQ_FLAG_ADD);
158#else
159 return HttpAddRequestHeaders(hRequest, header, DWORD(len), HTTP_ADDREQ_FLAG_ADD);
160#endif
161}
162
163
BOOL SendRequest(HINTERNET hRequest,
const
void
*
body, DWORD size)
164
{
165#ifdef USE_WINHTTP
166 return WinHttpSendRequest(hRequest, 0, 0, const_cast<void*>(body), size, size, 0);
167#else
168 return HttpSendRequest(hRequest, 0, 0, const_cast<void*>(body), size);
169#endif
170}
171
172
BOOL EndRequest(HINTERNET hRequest)
173
{
174#ifdef USE_WINHTTP
175 return WinHttpReceiveResponse(hRequest, 0);
176#else
177 // if you use HttpSendRequestEx to send request then use HttpEndRequest in here!
178 return TRUE;
179#endif
180}
181
182
BOOL QueryInfo(HINTERNET hRequest,
int
queryId,
char
*
szBuf, DWORD
*
pdwSize)
183
{
184#ifdef USE_WINHTTP
185 return WinHttpQueryHeaders(hRequest, (DWORD) queryId, 0, szBuf, pdwSize, 0);
186#else
187 return HttpQueryInfo(hRequest, queryId, szBuf, pdwSize, 0);
188#endif
189}
190
191
BOOL ReadData(HINTERNET hRequest,
void
*
buffer, DWORD length, DWORD
*
cbRead)
192
{
193#ifdef USE_WINHTTP
194 return WinHttpReadData(hRequest, buffer, length, cbRead);
195#else
196 return InternetReadFile(hRequest, buffer, length, cbRead);
197#endif
198}
199
200
void
CloseInternetHandle(HINTERNET hInternet)
201
{
202 if (hInternet)
203 {
204#ifdef USE_WINHTTP
205 WinHttpCloseHandle(hInternet);
206#else
207 InternetCloseHandle(hInternet);
208#endif
209 }
210}
211
212
int
_tmain(
int
argc, _TCHAR
*
argv[])
213
{
214 HINTERNET hSession = 0;
215 HINTERNET hConnect = 0;
216 HINTERNET hRequest = 0;
217 CStringW strHeader(L“Content-type: application/x-www-form-urlencoded/r/n“);
218
219 // Test data
220 CrackedUrl crackedUrl(L“http://www.easy-creator.net/test2/add.asp“);
221 CStringA strPostData(“value1=10&value2=14“);
222
223 // Open session.
224 hSession = OpenSession(L“HttpPost by l_zhaohui@163.com“);
225 if (hSession == NULL) {
226 printf(“Error:Open session!/n“);
227 return –1;
228 }
229
230 // Connect.
231 hConnect = Connect(hSession, crackedUrl.GetHostName(), crackedUrl.GetPort());
232 if (hConnect == NULL) {
233 printf(“Error:Connect failed!/n“);
234 return –1;
235 }
236
237 // Open request.
238 hRequest = OpenRequest(hConnect, L“POST“, crackedUrl.GetPath(), crackedUrl.GetScheme());
239 if (hRequest == NULL) {
240 printf(“Error:OpenRequest failed!/n“);
241 return –1;
242 }
243
244 // Add request header.
245 if (!AddRequestHeaders(hRequest, strHeader)) {
246 printf(“Error:AddRequestHeaders failed!/n“);
247 return –1;
248 }
249
250 // Send post data.
251 if (!SendRequest(hRequest, (const char*)strPostData, strPostData.GetLength())) {
252 printf(“Error:SendRequest failed!/n“);
253 return –1;
254 }
255
256 // End request
257 if (!EndRequest(hRequest)) {
258 printf(“Error:EndRequest failed!/n“);
259 return –1;
260 }
261
262 char szBuf[BUF_SIZE];
263 DWORD dwSize = 0;
264 szBuf[0] = 0;
265
266 // Query header info.
267#ifdef USE_WINHTTP
268 int contextLengthId = WINHTTP_QUERY_CONTENT_LENGTH;
269 int statusCodeId = WINHTTP_QUERY_STATUS_CODE;
270 int statusTextId = WINHTTP_QUERY_STATUS_TEXT;
271#else
272 int contextLengthId = HTTP_QUERY_CONTENT_LENGTH;
273 int statusCodeId = HTTP_QUERY_STATUS_CODE;
274 int statusTextId = HTTP_QUERY_STATUS_TEXT;
275#endif
276 dwSize = BUF_SIZE;
277 if (QueryInfo(hRequest, contextLengthId, szBuf, &dwSize)) {
278 szBuf[dwSize] = 0;
279 printf(“Content length:[%s]/n“, szBuf);
280 }
281
282 dwSize = BUF_SIZE;
283 if (QueryInfo(hRequest, statusCodeId, szBuf, &dwSize)) {
284 szBuf[dwSize] = 0;
285 printf(“Status code:[%s]/n“, szBuf);
286 }
287
288 dwSize = BUF_SIZE;
289 if (QueryInfo(hRequest, statusTextId, szBuf, &dwSize)) {
290 szBuf[dwSize] = 0;
291 printf(“Status text:[%s]/n“, szBuf);
292 }
293
294 // read data.
295 for (;;) {
296 dwSize = BUF_SIZE;
297 if (ReadData(hRequest, szBuf, dwSize, &dwSize) == FALSE) {
298 break;
299 }
300
301 if (dwSize <= 0) {
302 break;
303 }
304
305 szBuf[dwSize] = 0;
306 printf(“%s/n“, szBuf); //Output value = value1 + value2
307 }
308
309 CloseInternetHandle(hRequest);
310 CloseInternetHandle(hConnect);
311 CloseInternetHandle(hSession);
312
313 return 0;
314}
315
发布者:全栈程序员-用户IM,转载请注明出处:https://javaforall.cn/118186.html原文链接:https://javaforall.cn
【正版授权,激活自己账号】: Jetbrains全家桶Ide使用,1年售后保障,每天仅需1毛
【官方授权 正版激活】: 官方授权 正版激活 支持Jetbrains家族下所有IDE 使用个人JB账号...