I am new to JSP and I am having trouble finding a simple concrete example to make a request to a server that returns a JSON object.
What I am trying to do is something like:
myjson_object = getJSONfrom("my.webserver.com/get/json")
I basically want to add such a line to an existing JSP page so that I can have the JSON object available. I would like to avoid using AJAX or JQuery. I have found several examples like this one, but for some reason they do not work in my case.
Probably trying to do that operation into JSP is not a good idea, since you'd need to use scriptlets and I understand scriptlets are now considered not a good practice (see this)... You'd better do it into a servlet (see this)...
Anyway the code would be similar. You first need to make the request and then parse the JSON response...
In order to make the request you can use HttpURLConnection class. See this question.
Once you have the server response into a BufferedReader, you can parse the JSON using some library, such as Gson. You can find lots of examples of JSON deserializing using Gson in SO, like this or this.
Related
I am new to wso2 API Manager, trying to set it up expose my plain HTTP POST back end calls as a REST API. I am sure this is not a new pattern that I am trying to achieve here. The requirement is to convert the JSON data coming in (has array structures) into the HTTP URL query string parameters.
After some research through the documentation and other posts on this forum, decided to go with the script mediator that would parse the JSON data and convert it to a string that can be appended to the endpoint URL. Some how I am not able to achieve this.
I have followed the following post that seems to be very straight forward. As the original poster suggested, I am also not able to use getPayloadJSON() method. Even have trouble using the work around suggested there due to JSON.parse() not working.
Link
Also, this approach of editing the service bus configuration from source view does not sound like the correct option. Is there another elegant solution to achieve this? Thanks for the help in advance.
I was able to get both methods working by using an external script instead of the inline java script. Thanks
I'm brand new to Pentaho and I'm trying to do the following workflow:
read a bunch of lines out of a DB
do some transformations
POST them to a REST web service in JSON
I've got the first two figured out using an input step and the Json Output step.
However I have two problems doing the final step:
1) I can't get the JSON formatted how I want. It insists on doing {""=[{...}]} when I just want {...}. This isn't a big deal - I can work around this since I have control over the web service and I could relax the input requirements a bit. (Note: this page http://wiki.pentaho.com/display/EAI/JSON+output gives an example for the output I want by setting no. rows in a block=1 and an empty JSON block name, but it doesn't work as advertised.)
2) This is the critical one. I can't get the data to POST as JSON. It posts as key=value, where the key is the name I specify in the HTTP Post field name (on the 'Fields' tab) and the value is the encoded JSON. I just want to post the JSON as the request body. I've tried googling on this but can't find anyone else doing it, leading me to believe that I'm just approaching this wrong. Any pointers in the right direction?
Edit: I'm comfortable scripting (in Javascript or another language) but when I tried to use XmlHttpRequest in a custom javascript snippet I got an error that XmlHttpRequest is not defined.
Thanks!
This was trivial...just needed to use the REST Client (http://wiki.pentaho.com/display/EAI/Rest+Client) instead of the HTTP Post task. Somehow all my googling didn't discover that, so I'll leave this answer here in case someone else has the same problem as me.
You need to parse the JSON using a Modified JavaScript step. e.g. if the Output Value from the JSON Output is called result and its contents are {"data"=[{...}]}, you should call var plainJSON = JSON.stringify(JSON.parse(result).data[0]) to get the JSON.
In the HTTP Post step, the Request entity field should be plainJSON. Also, don't forget to add a header for Content-Type as application/json (you might have to add that as a constant)
I'm horribly sorry if there is a post for this, I tried to search but didn't find a answer.
Problem:
I'm calling a web service and receiving not so well formed JSON data from a Dynamics Nav service:
JSON:
"[{\"type\":\"2\",\"number\":\"VHT3866\",\"location\":\"Delta\",\"destinationNo\":\"\",\"contactName\":\"Jesus\",\"shipToName\":\"Lord jesus\",\"highPriority\":\"false\",\"hasComment\":\"true\",\"assignedTo\":\"\",\"source\":\"\"},{\"type\":\"2\",\"number\":\"VHT3866\",\"location\":\"Delta\",\"destinationNo\":\"\",\"contactName\":\"Jesus\",\"shipToName\":\"Lord jesus\",\"highPriority\":\"false\",\"hasComment\":\"true\",\"assignedTo\":\"\",\"source\":\"\"}]"
I then take this JSON and use angular.fromJson(json) to get it properly.
It doesn't seem to change into an array of javascript objects, but just plain text.
However if I take the same JSON and just put it manually in like this:
var json = angular.fromJson(stringfromserver);
It turns into a proper javascript object and ng-repeat throws no error.
I found an answer on Quora:
--- Le Batoure,
Angular from json is now strict so assuming that this string is from a trusted source you would have to use "eval()" plus surround the call in parenthesis for it to work
var hatsData = angular.fromJson(eval("(" + hats + ")"))
If you bring your JSON from http request for example you don't need to use the fromJson method.
The JSON is automatically parsed by Angular and you can use it directly.
I am trying to achieve something like which is mentioned in this link
but i don't know whereto write the parsing code. I tried to write it in new method and added the method in "my adapter.xml" but nothing happens. I even don't know how to log in IBM WorkLight. I used WL.logger(some) but its throwing error that "Logger can not be called on an object".
Any help would be appreciated. Thanks in advance.!
In most cases you don't need to manually parse responses because WL adapter framework will do this for you. Anything you retrieve via WL.Server.invokeHttp API will be parsed to JSON automatically unless you specify returnedContentType:"plain". In case you DO need to manually parse JSON you can use JSON.parse() and JSON.stringify() APIs.
Server side logging is achieved via WL.Logger.debug/error/info etc. You can get more info about it here
You don't have to parse JSON data, there are libraries in Javascript to do that. Try JSON.parse(). You should learning how to write adapters and invoking them from clients. The Getting Started modules are a good place to start, specifically Module 4 in your case.
I have a Restlet application already working that accepts JSON and returns JSON entity as response.
I'm trying to understand how I can compress the JSON entity that is returned in the response.
I did not find any clear example on how to achieve it.
I think I have to put somewhere on the router chain the Encoder/EncoderService classes, but I really don't understand where and how to use them.
Could anybody help me?
After some testing, I got the answer.
Creating a new filter like this
Filter encoder = new Encoder(getContext(), false, true, new EncoderService(true));
inside the createInboundRoot() method of my own Application class did the trick, the client requests were already containing the gzip header needed.