Writing and reading JSON in RPGLE

[Henrik Rutzou]

Hi, I have written a little article on how to write and read JSON in RPGLE

It can be found here:

http://powerext.com/JSON_RPGLE.pdf

[jamief]

Re: Writing and reading JSON in RPGLE

Nice work.....

[dhanuxp]

Re: Writing and reading JSON in RPGLE

Great Work Henrik!

Never tried to pass the JSON in RPGLE and just finished the project with java,
One more thing, does powerEXT support Base64 - encode and decode ?

Thanks
Dhanuxp

[GLS400]

Re: Writing and reading JSON in RPGLE

Hi dhanuxp:

One more thing, does powerEXT support Base64 - encode and decode ?

If it doesn't it's built into the powerx box:

http://www.iprodeveloper.com/article/application-development/base64-is-built-in-to-ibm-i-63967

or Scott Klement wrote his own:

http://www.scottklement.com/base64/

Best of Luck
GLS

[Henrik Rutzou]

Re: Writing and reading JSON in RPGLE

Hi,

no I haven't build in Base64 support but either use the system API or Scott's Base64 subprocedures.

Regards
Henrik

[Henrik Rutzou]

Re: Writing and reading JSON in RPGLE

This is a little tricky because powerEXT runs EBCDIC internally so if you have to include base64 in a XML document that typical are translated from EBCDIC to ASCII/UTF-8 when saved or send to a client you will have to convert back and forth.

However it can be done and here is a proposal:

Create a new store (similar to a user space) and import a file into the store like this:

setContent(?text/xml?); // tells Apache to do EBCDIC conversion
myBinStore = storeNew();
storeInz(myBinStore);
storeFromStmf64(myBinStore:?/mytifffile.tif?); // This new procedure I have to build

The store now holds mytifffile.tif in Base64 ASCII

convCCS(storeAddr(myBinStore):storeSize(myBinStore ):819:0);

The store now holds mytifffile.tif in base64 EBCDIC

xmlNode(?MYTIFF?);
storeAppend(0: storeAddr(myBinStore):storeSize(myBinStore));
storeFree(myBinStore);
xmlEndNode();
echoToClient();

The buffer now has an XML element MYTIFF but it is all in EBCDIC

But when send/saved it will be converted back into ASCII or UTF-8 that in a Base64 perspective are exactly the same since UTF-8 shares x?00? > x?7F? with ASCII and Base64 always will be in that range.

Sending a file RAW in Base64 could be like

setContent(?application/xml?); // tells Apache NOT to do EBCDIC conversion
myBinStore = storeNew();
storeInz(myBinStore);
storeFromStmf64(myBinStore:?/mytifffile.tif?); // This new procedure I have to build

The store now holds mytifffile.tif in Base64 ASCII

storeAppend(0: storeAddr(myBinStore):storeSize(myBinStore));
storeFree(myBinStore);
echoToClient();


Getting the base64 code back from an XML element is also a little tricky because it is processed in EBCDIC

xmlFromStmf(?/mytiffxml.xml?);
xmlReaderInz(xmlAddr():xmlSize());
dow xmlReader = 0;
select;
when xmlGetNode = ?/MYTIFF?;
myBinStore = storeNew();
storeInz(myBinStore);
storeAppend(myBinStore:xmlInnerAddr():xmlInnerSize ());
convCCS(storeAddr(myBinStore):storeSize(myBinStore ):0:819);
storeToStmf64(myBinStore:?/mynewtiff.tif?:819); // This new procedure I have to build
endsl;
enddo;

[dhanuxp]

Re: Writing and reading JSON in RPGLE

Thanks Henrik/ GLS

Sorry for my poor knowledge. Since Im not a Java programmer, this powerEXT impress me so much
What I need to do is send a Image using RPG-JSON
This is how I did it using java
(ofcasue this is client side program, donot think about it)

			JSONObject jImage = new JSONObject();
			Bitmap bm = setImageToImageView("/mnt/sdcard/IMG001.JPG");			
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			bm.compress(Bitmap.CompressFormat.JPEG, 100, baos);  
																// bitmap object
			byte[] byteArrayImage = baos.toByteArray();

			String encodedImage = Base64.encodeToString(byteArrayImage,Base64.DEFAULT);
					
			jImage.put("ImageID", "IMG0001");			
			jImage.put("Image", encodedImage);

I'm going to check the System Api and Scott Base64 in details soon. Say anyhow I encoded the image to String but
What make me confuse is, If encoded string is bigger than variable length 65535, how can i handle it in RPG-JSON?

Thanks
Dhanuxp