Examples: Client exchanging files with the server

Example of client and server applications using methods of the com.HttpPart class to send and receive files in multipart.

This example consists of two applications: a client and server exchanging an XML document in multipart with an image as an attachment.

IMPORT com
IMPORT xml

CONSTANT SERVER_URL = "http://localhost:8090/MultipartMixed/Sample"                   

MAIN
 
  DEFINE req      com.HttpRequest
  DEFINE resp     com.HttpResponse
  DEFINE doc      xml.DomDocument
  DEFINE p        com.HttpPart
  DEFINE type     STRING
  DEFINE ind      INTEGER
  
  LET req = com.HttpRequest.Create(SERVER_URL)
  CALL req.setMethod("POST")
  CALL req.setHeader("MyClientHeader","Hello")
  TRY
    # Set multipart type
    CALL req.setMultipartType("mixed",NULL,NULL)
    # Add filename as part
    LET p = com.HttpPart.CreateAttachment("my_picture.png")
    # Set attachment Content-Type 
    CALL p.setHeader("Content-Type","image/png")
    # Add part to the request
    CALL req.addPart(p)
    # Perform XML request              
    LET doc = xml.DomDocument.CreateDocument("MyXmlDocument")
    CALL req.doXmlRequest(doc)
    # Check response
    LET resp=req.getResponse()
    IF resp.getStatusCode() != 200 THEN
      DISPLAY  "HTTP Error ("||resp.getStatusCode()||") ",
        resp.getStatusDescription()
      EXIT PROGRAM (-1)
    END IF
    IF resp.getStatusDescription() != "OK" THEN
      DISPLAY  "HTTP Error ("||resp.getStatusCode()||") ",
        resp.getStatusDescription()
      EXIT PROGRAM (-1)
    END IF
    # Check whether multipart response or not
    LET type = resp.getMultipartType()
    IF type IS NULL THEN
      DISPLAY  "Failed : Expected multipart in response"
      EXIT PROGRAM (-1)
    ELSE
      DISPLAY "Response is multipart of :",type
    END IF
    # Check response
    LET doc = resp.getXmlResponse()
    IF doc IS NULL THEN
      DISPLAY  "Expected XML document as response"
      EXIT PROGRAM (-1)
    ELSE
      DISPLAY "Response is : ",doc.saveToString()
    END IF  
    # Process additional parts
    FOR ind = 1 TO resp.getPartCount()
      LET p = resp.getPart(ind)
      IF p.getAttachment() IS NOT NULL THEN
        DISPLAY "Attached file at :",p.getAttachment()
      ELSE
        DISPLAY "Attached part is :",p.getContentAsString()
      END IF
    END FOR
  CATCH
    DISPLAY "unexpected exception :",status," ("||sqlca.sqlerrm||")"          
    EXIT PROGRAM (-1)
  END TRY
END MAIN

IMPORT com
IMPORT xml

MAIN

  DEFINE req        com.HttpServiceRequest
  DEFINE url        STRING
  DEFINE method     STRING
  DEFINE doc        xml.DomDocument
  DEFINE type       STRING
  DEFINE ind        INTEGER
  DEFINE p          com.HttpPart
  
  CALL com.WebServiceEngine.Start()
  
  LET req = com.WebServiceEngine.GetHTTPServiceRequest(-1)
  LET url = req.getUrl()
  IF url IS NULL  THEN
    DISPLAY "Failed: url should not be null"
    EXIT PROGRAM (-1)    
  END IF
  LET method = req.getMethod()
  IF method IS NULL OR method != "POST" THEN
    DISPLAY "Failed: method should be POST"
    EXIT PROGRAM (-1)    
  END IF
  # Check multipart type
  LET type = req.getRequestMultipartType()
  IF type IS NULL THEN
    DISPLAY "Failed: expected multipart in request"
    EXIT PROGRAM (-1)    
  END IF
  TRY
    LET doc = req.readXMLRequest()
    DISPLAY "Request is :", doc.saveToString()
  CATCH
    DISPLAY "Failed: unexpected error :", status
    EXIT PROGRAM (-1)    
  END TRY
  # Process additional parts
  FOR ind = 1 TO req.getRequestPartCount()
    LET p = req.getRequestPart(ind)
    IF p.getAttachment() IS NOT NULL THEN
      DISPLAY "Attached file at :",p.getAttachment()
    ELSE
      DISPLAY "Attached part is :",p.getContentAsString()
    END IF
  END FOR
  # Set multipart response type
  CALL req.setResponseMultipartType("mixed",NULL,NULL)
  # Add XML Part
  LET p = com.HttpPart.CreateAttachment("my_other_picture.jpg")
  CALL p.setHeader("Content-Type","image/jpg")
  CALL req.addResponsePart(p)
  LET doc = xml.DomDocument.CreateDocument("MyResponse")
  CALL req.sendXmlResponse(200,NULL,doc)
END MAIN