I am somewhat new to HTTP REST operations on Android, and a server I am working with uses PUT commands to process updates. I am having a difficult time using Spring (for Android) with Jackson2. The server doesn't seem to work with application/json
put requests (though it will reply with them), and only seem to work with application/x-www-form-urlencoded
versions (tested with python and curl. On python, if I set the header type to application/json
, it fails.
I am using the latest versions of Spring and Jackson2, and I know everything is setup properly because my get request on the same URL gets me all the correct information.
I am using Robospice, but I don't really think that is relevant. Here is my request code.
@Override
public GPIO loadDataFromNetwork() throws Exception {
String url = String.format("http://%s/api/control/gpio", ip);
RestTemplate rt = getRestTemplate();
DefaultHttpClient client = new DefaultHttpClient();
Credentials defaultcreds = new UsernamePasswordCredentials("admin",
password);
client.getCredentialsProvider().setCredentials(
new AuthScope(routerip, 80, AuthScope.ANY_REALM), defaultcreds);
// Makes authentication work.
rt.setRequestFactory(new HttpComponentsClientHttpRequestFactory(client));
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
HttpEntity request = new HttpEntity(data, requestHeaders);
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
MappingJackson2HttpMessageConverter map = new MappingJackson2HttpMessageConverter();
messageConverters.add(map);
messageConverters.add(new FormHttpMessageConverter());
rt.setMessageConverters(messageConverters);
ResponseEntity<GPIO> r = rt.exchange(url, HttpMethod.PUT, request, GPIO.class);
return r.getBody();
}
I am getting the exception stating it cannot find a way to convert:
02-01 10:59:29.466: E//DefaultRequestRunner.java:138(30086):
10:59:29.474 Thread-11651 An exception occurred during request network
execution :Could not write request: no suitable HttpMessageConverter
found for request type [com.xxxxx.control.gpio.GPIO] and content
type [application/x-www-form-urlencoded]
GPIO is my POJO object. I want to 'put' that to the server, as in serialize and put it.
I have looked at the following question that seems fairly relevant:
However, I need the result of my put command, and that requires me to use exchange()
because Spring's put()
returns nothing.
I have tried several different items (such as removing GPIO references, setting specific headres...) and none seem to work. I have a feeling this is probably an easy solution that I don't know how to fix. If anyone can help me that would be great.
TLDR: I'm using Spring for Android with Jackson2. I want to serialize my object (in this example, GPIO) so I can do a PUT request with the content type application/x-www-form-urlencoded. However I cannot get jackson to convert to that type, only to application/json, which does not work for me. I am not sure how to fix this, and I have run out of ideas. If I can't find a solution I'll probably have to dumb robospice. (or jackson, not sure which yet.)
Solution
Spring for Android doesn't seem to simplify things, so I dumped it and used the apache client directly in my loadDataFromNetwork() method. Robospice handles it pretty well and I can get the responses I need. If you are new to HTTP like I was take the time and learn the apache client, it's far easier in my opinion. Tweaking the ObjectMapper (like making a JsonTree and parsing that) made it much easier to get the data I needed without having to do as much work with POJO objects.