[ckan-dev] [ckan-global-user-group] CKAN java library
Matthew Fullerton
matt.fullerton at gmail.com
Mon Jun 22 11:35:10 UTC 2015
Me again. To answer your more specific issue with the Bad Request error:
you need to send what you are sending as get parameters as keys within a
JSON body. That is a POST request where the body is in JSON. You can play
with the API using an extension like Postman in Chrome where you can set
body type JSON and use the API docs as guidance. Whether httpget has a way
to make post requests with JSON bodies, I don't know, but the code I sent
can do it (append .post after the .header segment in the code:
http://docs.oracle.com/javaee/7/api/javax/ws/rs/client/SyncInvoker.html#post(javax.ws.rs.client.Entity)
)
--
Matthew Fullerton
Freelance Software Developer und EXIST Stipend holder with the start up
project "Tapestry" - http://www.smartlane.de/
On 22 June 2015 at 13:26, Matthew Fullerton <matt.fullerton at gmail.com>
wrote:
> ckan-dev in cc.
>
> Hmm, it might be simpler to just write a Java wrapper around
> https://github.com/ckan/ckanapi using Jython (http://www.jython.org/)
>
> However, if you want to start from scratch, I can maybe give you a little
> help to get started; this is how we access the API for the few things we
> need from inside Java (url is the API endpoint, you can include url
> arguments; apiKey is your API key, needed if the dataset is private):
>
> package package.name;
>
> import javax.ws.rs.client.Client;
> import javax.ws.rs.client.ClientBuilder;
> import javax.ws.rs.client.WebTarget;
> import javax.ws.rs.core.MediaType;
> import javax.ws.rs.core.Response;
>
> import org.json.JSONException;
> import org.json.JSONObject;
>
> public class CkanApiClient {
> private JSONObject getJsonResultForResource(String url, String apiKey)
> throws JSONException {
> JSONObject resourceProperties = null;
> Client client = ClientBuilder.newClient();
> WebTarget resourceTarget = client.target(url);
> //Set API key
> Response response =
> resourceTarget.request(MediaType.APPLICATION_JSON).header("X-CKAN-API-Key",
> apiKey).get();
> String responseString = response.readEntity(String.class);
> resourceProperties = new JSONObject(responseString);
> return resourceProperties;
> }
> }
>
> What's not in there is sending a JSON body which you will need for e.g.
> creating datasets.
>
> Best,
> Matt
>
> --
> Matthew Fullerton
> Freelance Software Developer und EXIST Stipend holder with the start up
> project "Tapestry" - http://www.smartlane.de/
>
>
> On 19 June 2015 at 23:33, Skaros Ilias <skaros.ilias at gmail.com> wrote:
>
>> Hi all,
>> I am trying to create a java application that would eventually get use of
>> the API and mainly upload files(csv and zip) to a ckan
>> installation(currently a local installation under a VM).
>> The problem is that i cant find any libraries that would help me do this.
>> I tried to do it manually, using json and http commands but i hit a wall
>> (more than once)
>> I have found some that claim to be java libs, but either i cant get them
>> to work, or they are not what they say they are.
>>
>> Mostly i think ckan clients are written in Python, the problem is that i
>> dont know python. I would really love if there was a library that i could
>> just use and do all the hard work for me.
>>
>> In case someone might be able to help this is the code I did in java
>>
>> static String myApiKey="fa0499d1-ffda-4590-82b3-4afdb9c91576";
>> static String uploadFileName="/home/ilias/2013/05/csv/2013_05_15.csv"; public static void uploadFile()
>>
>> { HttpClient httpclient = new DefaultHttpClient();
>>
>> Date now=new Date();
>> File file = new File(uploadFileName);
>> httpclient = new DefaultHttpClient();
>> try {
>>
>> SimpleDateFormat dateFormatGmt = new SimpleDateFormat("yyyyMMMddHHmmss");
>> dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));
>> String date=dateFormatGmt.format(new Date());
>> /* First we specify the data */
>> HttpEntity reqEntity = MultipartEntityBuilder.create()
>> .addTextBody("package_id","test2")
>> .addTextBody("url",page)
>> .setCharset(Charset.forName("utf-8"))
>> .addTextBody("file", date +"/"+uploadFileName)
>> .build();
>> /* Set up the headers */
>> HttpPost postRequest = new HttpPost(page+"/api/action/resource_create/");
>> postRequest.setEntity(reqEntity);
>> postRequest.setHeader("X-CKAN-API-Key", myApiKey);
>> /* execute */
>>
>> System.out.println("request2: "+postRequest.toString()+"\n"+postRequest.getRequestLine().toString());
>>
>> Header[]a=postRequest.getAllHeaders();
>> HttpResponse response = httpclient.execute(postRequest);/* get respond */
>> int statusCode = response.getStatusLine().getStatusCode();
>> BufferedReader br = new BufferedReader(
>> new InputStreamReader((response.getEntity().getContent())));
>>
>> String line;
>> while ((line = br.readLine()) != null) {
>> System.out.println("__"+line);}if(statusCode!=200){
>> System.out.println("statusCode ==" +statusCode);}}catch (IOException ioe) {System.out.println(ioe);
>> } finally {
>> httpclient.getConnectionManager().shutdown();}
>> /*Upload the file */
>> file = new File(uploadFileName);
>> httpclient = new DefaultHttpClient();try {
>> FileBody bin = new FileBody(file,ContentType.TEXT_PLAIN,now.toString()+file.getName());
>> /* add the data */
>> HttpEntity reqEntity = MultipartEntityBuilder.create()
>> .addPart("file", bin)
>> .addTextBody("key", now.toString()+file.getName())
>> .build();
>>
>> HttpPost postRequest = new HttpPost(page+"/api/action/resource_create/");
>> postRequest.setEntity(reqEntity);
>> postRequest.setHeader("X-CKAN-API-Key", myApiKey);
>> HttpResponse response = httpclient.execute(postRequest);
>> int statusCode = response.getStatusLine().getStatusCode();
>> BufferedReader br = new BufferedReader(
>> new InputStreamReader((response.getEntity().getContent())));
>>
>> String line;
>> while ((line = br.readLine()) != null) {
>> System.out.println("+"+line);
>> }
>> if(statusCode!=200){
>> System.out.println("statusCode =!=" +statusCode);
>> }}catch (IOException ioe) {System.out.println(ioe);} finally {
>> httpclient.getConnectionManager().shutdown();}}
>>
>>
>> And the error i was getting is a 301 Error
>>
>> I also tried this, using httpGet
>> URIBuilder builder = new URIBuilder();
>> builder.setScheme("http").setHost("192.168.1.1:5000").setPath("/api/action/resource_create/")
>> .setCharset(Charset.forName("utf-8"))
>> .setParameter("package_id", "test2")
>> .setParameter("url", "http://www.example.com");
>>
>> URI uri = builder.build();HttpGet postRequest = new HttpGet(uri);
>> postRequest.setHeader("X-CKAN-API-Key", myApiKey);
>>
>> Which returned a more understandable error of
>>
>> "Bad request - JSON Error: No request body data"
>>>
>> Any help/guideline is appreciated
>>
>>
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>
>
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