Progress 文档在 SOAP 上泼了很多墨，但我很难找到带有 Progress ABL 的简单 HTTP GET/POST 示例。
如何从 URL 获取和发布字符串？
网址可以是 https:// 吗？
Progress 能否提供 HTTP Basic 或 HTTP Digest 身份验证？
【问题讨论】：
标签： progress-4gl openedge
对于这个问题的未来旁观者：
Openedge 现在（我相信是从 11.5.1 开始）内置了对调用基于 REST 的 Web 服务的支持。它们包含在提供的 .pl 存档中，默认情况下该存档不在您的 PROPATH 中，因此需要首先处理（或者存档可以移动到“更好的位置”）。
propath 可以通过多种方式设置，init 文件、注册表、以编程方式等。这就是在 ABL 中可以完成的方式（如果以这种方式完成，则必须为每个新会话重复）。
PROPATH = PROPATH + ",c:\pathtoprogress\OpenEdge\gui\OpenEdge.Net.pl".
“tty”目录中还有一个版本，“src”目录中还有一个包含源代码的存档。
这是一个非常基本的例子：
USING OpenEdge.Net.HTTP.IHttpRequest.
USING OpenEdge.Net.HTTP.IHttpResponse.
USING OpenEdge.Net.HTTP.ClientBuilder.
USING OpenEdge.Net.HTTP.RequestBuilder.
DEFINE VARIABLE oRequest AS IHttpRequest NO-UNDO.
DEFINE VARIABLE oResponse AS IHttpResponse NO-UNDO.
oRequest = RequestBuilder:Get('http://stackoverflow.com/'):Request.
oResponse = ClientBuilder:Build():Client:Execute(oRequest).
MESSAGE
oResponse:StatusCode SKIP
oResponse:StatusReason SKIP
VIEW-AS ALERT-BOX.
【讨论】：
Openedge 内置了用于处理 SOAP 服务的语句，但没有用于 GET/POST 的简单语句。然而，它所拥有的是一种读取/写入特定套接字的机制。因此，您可以使用它来构建 HTTP post 例程，或者就此而言，构建一个例程来处理任何其他基于套接字的协议。
有一个例程 - http.p - 将为您执行 GET。如果不出意外，会让你看看套接字编程是如何工作的。您应该能够很容易地对其进行修改以进行简单的 POST，但是使用 SSL 或进入身份验证可能需要相当多的工作。在这种情况下，退出 CURL 可能会更容易。
http.p 以前可以从 freeframework.org 获得，但我刚刚检查过该域已过期，所以我在下面发布了代码。
/*-----------------------------------------------------------------------*
File........: http.p
Version.....: 1.1
Description : Makes a "Get" request from an HTTP server
Input Param : pHost = host name (without the "http://")
pPort = port number (usually 80)
pURL = begin with the first slash after the domain name.
Output Param: pResult = 0 or 1 (character)
pResponse = http headers returned
pContent = the document returned.
Author......: S.E. Southwell, Mario Paranhos - United Systems, Inc. (770) 449-9696
Created.....: 12/13/2000
Notes.......: Will not work with HTTPS.
Usage:
define var v-result as char no-undo.
define var v-response as char no-undo.
define var v-content as char no-undo.
{&out} "Hello" skip.
put stream webstream control null(0).
run proc/http.p("www.whosplayin.com","80","/",output v-result,output v-response,output v-content).
{&out} v-result "<hr>" skip
html-encode(v-response) "<hr>" skip
html-encode(v-content) "<hr>" skip
.
Last Modified: 10/20/01 - SES - Fixed to work in batch mode, or within a UDF.
--------------------------------------------------------------------------*/
&SCOPED-DEFINE HTTP-NEWLINE CHR(13) + CHR(10)
&SCOPED-DEFINE RESPONSE-TIMEOUT 45
DEFINE INPUT PARAMETER pHOST AS CHAR NO-UNDO.
DEFINE INPUT PARAMETER pPORT AS CHAR NO-UNDO.
DEFINE INPUT PARAMETER pURL AS CHAR NO-UNDO.
DEFINE OUTPUT PARAMETER pRESULT AS CHAR NO-UNDO.
DEFINE OUTPUT PARAMETER pRESPONSE AS CHAR NO-UNDO.
DEFINE OUTPUT PARAMETER pContent AS CHAR NO-UNDO.
DEFINE VARIABLE requestString AS CHAR NO-UNDO.
DEFINE VARIABLE vSocket AS HANDLE NO-UNDO.
DEFINE VARIABLE vBuffer AS MEMPTR NO-UNDO.
DEFINE VARIABLE vloop AS LOGICAL NO-UNDO.
DEFINE VARIABLE vPackets AS INTEGER NO-UNDO.
DEFINE VARIABLE wStatus AS LOGICAL NO-UNDO.
ASSIGN requestString = "GET " + pURL + " HTTP/1.0" + {&HTTP-NEWLINE} +
"Accept: */*" + {&HTTP-NEWLINE} +
"Host: " + phost + {&HTTP-NEWLINE} +
/*"Connection: Keep-Alive" + {&HTTP-NEWLINE} + */
{&HTTP-NEWLINE}.
/*OPEN THE SOCKET*/
CREATE SOCKET vSocket.
vSocket:SET-READ-RESPONSE-PROCEDURE ("readHandler",THIS-PROCEDURE).
ASSIGN wstatus = vSocket:CONNECT("-H " + phost + " -S " + pport) NO-ERROR.
/*Now make sure the socket is open*/
IF wstatus = NO THEN DO:
pResult = "0:No Socket".
DELETE OBJECT vSocket.
RETURN.
END.
/*Got socket - Now make HTTP request*/
SET-SIZE(vBuffer) = LENGTH(requestString) + 1.
PUT-STRING(vBuffer,1) = requestString.
vSocket:WRITE(vBuffer, 1, LENGTH(requestString)).
SET-SIZE(vBuffer) = 0.
/*Wait for a response*/
ASSIGN vloop = TRUE. /*Turns off automatically when request is done*/
DEFINE VAR vstarttime AS INTEGER.
ASSIGN vstarttime = etime.
WAITLOOP: DO WHILE vloop:
PROCESS EVENTS.
PAUSE 1.
/* Build in timer in case sending is never set to NO
this will terminate the program after 60 seconds
start-Etime will be reset by WriteData each time there
is activity on the socket to allow for long transmissions */
IF vstarttime + ({&RESPONSE-TIMEOUT} * 1000) < ETIME
THEN DO:
MESSAGE "timed out at " + string(etime - vstarttime) + " msec".
vSocket:DISCONNECT().
ASSIGN pResult = "0:Failure".
RETURN.
END. /*No Response, or timed out*/
END.
/*At this point, pResponse should be populated with the result (up to 32K)*/
vSocket:DISCONNECT().
DELETE OBJECT vSocket.
/*All Done!*/
ASSIGN pResult = "1:Success".
ASSIGN
pContent = SUBSTRING(pResponse,INDEX(pResponse,{&HTTP-NEWLINE} + {&HTTP-NEWLINE}),-1)
.
ASSIGN
pResponse = SUBSTRING(pResponse,1,INDEX(pResponse,{&HTTP-NEWLINE} + {&HTTP-NEWLINE}))
.
RETURN.
/*Handle the response from the webserver*/
PROCEDURE readHandler:
DEFINE VARIABLE bytesAvail AS INTEGER NO-UNDO.
DEFINE VARIABLE b AS MEMPTR NO-UNDO.
DEFINE VARIABLE lastBytes AS INTEGER NO-UNDO.
IF vSocket:connected() THEN ASSIGN bytesAvail = vSocket:GET-BYTES-AVAILABLE().
IF bytesAvail = 0 THEN DO: /*All Done*/
ASSIGN vloop = FALSE.
RETURN.
END.
/*OK, there's something on the wire... Read it in*/
SET-SIZE(b) = bytesAvail + 1.
vSocket:READ(b, 1, bytesAvail, 1).
ASSIGN pResponse = pResponse + GET-STRING(b,1).
SET-SIZE(b) = 0.
END PROCEDURE. /*readHandler*/
【讨论】：
Progress Kbase ID：20011：“使用 4GL 套接字通过 HTTP 访问网站的示例代码”也是一个不错的通用示例。
【讨论】：
我建议使用上面 Gordon Roberertson 的代码示例，因为 Progress KB 文章的“WAIT-FOR”被替换为循环。因此，如果出现任何问题，程序将在超时期限后终止。
请注意，更改 requestString 中的任何内容都可能导致超时。但是，如果您需要登录您的网络服务器，则可以添加用户代理：
ASSIGN requestString = "GET " + Path + " HTTP/1.0" + {&HTTP-NEWLINE}
+ "Accept: */*" + {&HTTP-NEWLINE}
+ "User-Agent: " + "User Agent String" + {&HTTP-NEWLINE}
+ "Host: " + Host + {&HTTP-NEWLINE}
+ {&HTTP-NEWLINE}.
感谢 Gordon 提供的代码示例。
【讨论】：