I need to provide an RESTful api to be developed in ruby on rails with CRUD features for an android app. I haven't worked with mobile phone OS(android/iphone) integration with RoR earlier. So, please help me getting started.
Thanks in advance.
you can send the data as Json packets to the device and in device parse the json packets and access the data. your calls to webservice should be a http call eg this is for the client.
http:\server\metnod\get_somedata?name=something
and the server should query the database for this parameter and send you the reponse as Json. parse json and get your details.
String url = "http:\\example.com\mycontroller\get_employee?id=2"
HttpPost httpPostRequest = new HttpPost(url);
StringEntity se;
se = new StringEntity(jsonObjSend.toString());
httpPostRequest.setEntity(se);
httpPostRequest.setHeader("Authorization", usercredential);
httpPostRequest.setHeader("Accept", "application/json");
httpPostRequest.setHeader("Content-type", "application/json");
long t = System.currentTimeMillis();
response = (HttpResponse) httpclient.execute(httpPostRequest);
Log.i(TAG, "HTTPResponse received in [" + (System.currentTimeMillis()-t) + "ms]");
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
Header contentEncoding = response.getFirstHeader("Content-Encoding");
if (contentEncoding != null && contentEncoding.getValue().equalsIgnoreCase("gzip")) {
instream = new GZIPInputStream(instream);
}
// convert content stream to a String
String resultString= convertStreamToString(instream);
Log.v(null, "resultString "+resultString);
instream.close();
// Transform the String into a JSONObject
if(resultString!=null){
jsonObjRecv = new JSONObject(resultString);
}
// Raw DEBUG output of our received JSON object:
Log.i(TAG,"<jsonobject>\n"+jsonObjRecv.toString()+"\n</jsonobject>");
return jsonObjRecv;
In the server side you should have a get_employee method in a controller called mycontroller. in the method you can process the request as a normal http request and send the response as json eg
employee = Employee.find_by_id(params[:id])
#js_response = ActiveSupport::JSON.encode(employee)
respond_to do |format|
format.json { render :json => #js_response}
format.html
end
for CRUD you need to create different methods with appropriate parameters like delete_employee, update_employee etc. refer json.org to create/parse json in android
Related
Scenario:
REST API: PHP Slim Framework
Android HTTP client library: loopj
I am storing an ITEM as json string in sqlite.
I want to POST this JSON on server. Each item is a record in my SQLite database.
What I am currently doing?
I have JSON with list of objects. I want to POST it to my PHP based REST API.
Here is the code
if (cursor != null && cursor.getCount() > 0) {
if (cursor.moveToFirst()) {
do {
Item item = new Item();
try {
item.setOfflineId(Long.parseLong(cursor.getString(0)));
item.setName(cursor.getString(1));
item.setImageLocalPath(itemPayload.getImageLocalPath());
item.setToUpdate(Boolean.parseBoolean(cursor.getString(3).toString()));
item.setDeviceID(cursor.getString(4));
item.setCreatedDate(cursor.getString(5));
//item.setImageBlob(cursor.getBlob(5));
String imageURL = itemPayload.getImageLocalPath();
File imageFile = new File(imageURL);
} catch (Exception e) {
Log.d("Ex", e.getMessage().toString());
}
itemList.add(item);
} while (cursor.moveToNext());
}
}
}catch(SQLException ex){
Log.d("DB", ex.getMessage().toString());
}
The challenge?
When I put the params for post, I also set one Param to File as I want to upload an image file as well. I know how to send one object as JSON. I want to POST the list of items (items having image Files). How to achieve this?
One way is that I do an API POST for each object in the list. Not sure if it is a good way to do it.
Looking for advice.
You can post json using this way
JSONObject json = new JSONObject();
json.put("obj", "obj value");
StringEntity entity = new StringEntity(json.toString());
client.post(context, url, entity, "application/json",
responseHandler);
Use this code to send Json data
try{
JSONObject jsonObject = new JSONObject();
jsonObject.accumulate("projectid","1");
jsonObject.accumulate("cnumber", "8983899383");
jsonObject.accumulate("address","IN");
jsonObject.accumulate("companyid","5");
jsonObject.accumulate("uploadimage","");
jsonObject.accumulate("id","9")
data = jsonObject.toString();
Log.d("json data",data);
// 1. create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// 2. make POST request to the given URL
HttpPost httpPost = new HttpPost(CHECK_WEBSERVICE_URL);
StringEntity se = new StringEntity(data);
// 6. set httpPost Entity
httpPost.setEntity(se);
// 7. Set some headers to inform server about the type of the content
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json");
// 8. Execute POST request to the given URL
HttpResponse httpResponse = httpclient.execute(httpPost);
// 9. receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
I am trying to get an android app to interact with a server in Django.
The app is trying to POST "json" data to Django. However, I am unable to receive the object on the Django end.
The value of request.POST is <QueryDict: {}> although the data sent isn't blank. Following is the code snippet for POST request from android.
public static String POST(String url,JSONObject obj){
InputStream inputStream = null;
String result = "";
try{
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
String json = obj.toString();
StringEntity se = new StringEntity(json);
httpPost.setEntity(se);
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type","application/json");
HttpResponse httpResponse = httpClient.execute((HttpUriRequest)httpPost);
inputStream = httpResponse.getEntity().getContent();
if(inputStream!=null){
result = convertInputStreamToString(inputStream);
}else{
result = "Did not work!";
}
}catch(Exception e){
}
return result;
}
EDIT:
Earlier, I was getting CSRF error and handled it this way (I haven't worked with Django enough to know if this is correct way to handle CSRF error)
#csrf_exempt
def search(request):
logger.debug(request.POST)
"""Code for JSON object processing"""
Any help with rectifying the problem would be highly appreciated.
OK I'm not very fluent in java but it seems to me that your request is well formed.
I think the issue is that you are sending the data as a json string instead of as if it was a raw form. When you do it this way, the data is not displayed in request.POST but in request.body as what it is: a json string, not form-like data.
So I think you have to take one of these ways:
send the data from the Android app as a form (not json-like). This way you'll see it in request.POST or
translate request.body into a dict and work with it instead of request.POST
Hope this helps! :)
It has been a while since I programmed for Android and I have lost all my previous work which had the code in it I am having problems with. I am developing an app for both Android and iPhone which connect to the same server to download data. All is well in the iPhone version but on Android when I hit the server with the post data containing the method name I would like to to run on the server it seems that the data is not added to the request.
Why is the POST not working in this request for Android but does for the iPhone version of the app?
Here is the code I am using:
public static void makeRequest() throws Exception {
Thread t = new Thread() {
public void run() {
Looper.prepare(); //For Preparing Message Pool for the child Thread
HttpClient client = new DefaultHttpClient();
HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000);
HttpResponse response;
HttpEntity entity;
JSONObject json = new JSONObject();
try {
HttpPost post = new HttpPost("http://divisi.co.uk/rest/requesthandler.php");
json.put("method", "getEventListData");
StringEntity se = new StringEntity(json.toString());
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post.setEntity(se);
response = client.execute(post);
entity = response.getEntity();
String retSrc = EntityUtils.toString(entity);
JSONObject result = new JSONObject(retSrc); //Convert String to JSON Object
if(result.getString("SC") == "200"){
JSONArray data = result.getJSONArray("data");
}
else{
}
} catch(Exception e) {
e.printStackTrace();
}
Looper.loop(); //Loop in the message queue
}
};
t.start();
}
The response I get mack from the server is:
{"data":{"scalar":""},"SC":405,"timestamp":1363788265}
Meaning the method name was not found, i.e. not posted in my request to the server.
heres an example of how i do things like this:
HttpClient httpClient = new DefaultHttpClient();
HttpPost postRequest = new HttpPost("http://divisi.co.uk/rest/requesthandler.php");
MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
reqEntity.addPart(new FormBodyPart("method", new StringBody("getEventListData")));
reqEntity.addPart(new FormBodyPart("NEED_A_KEY_HERE", new StringBody("" + json.toString())));
postRequest.setEntity(reqEntity);
HttpResponse response = httpClient.execute(postRequest);
JSONObject responseDict = new JSONObject(EntityUtils.toString(response.getEntity()));
allow this is your "http://divisi.co.uk/rest/requesthandler.php" page code, then in android you can use this... you don't allow post in your URL,
use fiddler on your sever side. see if the http message is correct. it seems your sever side problem, can you show us your sever side code which receive and parse json.
If the server can't read your request try to remove:
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
It will use the mime type defaults HTTP.PLAIN_TEXT_TYPE i.e. "text/plain".
I don't see any other possibility, if your code is the one you posted and not a more complicated input JSON object.
Your code to set the POST body may be just fine. I think the problem may be with your web service. Try using something like Rested or curl to manually make the call to your server. I made exactly the same request you are making, including with and without the POST body, and I got the same response from your server:
{"data":{"scalar":""},"SC":405,"timestamp":1365704082}
Some things that may be tripping you up:
JSONObject result = new JSONObject(retSrc); //Convert String to JSON Object
if(result.getString("SC") == "200"){
JSONArray data = result.getJSONArray("data");
}
Here, you are comparing the string "405" to "200" using ==, when you should first do a null check and then use .equals("200") instead. Or, use result.getInt("SC") == 200 since this is an integer type in your response JSON.
Also, the "data" entity from your server response is not actually coming back as a JSON array. You should use getJSONObject("data") instead.
Additionally, it's always a good idea to externalize your strings.
Here's how the code should look:
public static final String JSON_KEY_SC = "SC";
public static final String JSON_KEY_DATA = "data";
...
JSONObject result = new JSONObject(retSrc); //Convert String to JSON Object
String sc = result.getString(JSON_KEY_SC);
if (sc != null && sc.equals("200")) {
JSONObject data = result.getJSONObject(JSON_KEY_DATA);
}
else {
...
}
I'm working on a Android application and I'm trying to get a JSON response from a server which is configured to return a json object (".../current_user.json") when receives a GET message, but the answer I get is in HTML format and not in JSON format as expected.
I don't understand why is this happening because I did the same requests on the browser and with the program RESTClient and got the right answer in JSON format.
Here is the code I'm using.
JSONObject json = new JSONObject();
HttpParams params = new BasicHttpParams();
HttpConnectionParams.setSoTimeout(params, 10000);
HttpClient httpClient = new DefaultHttpClient(params);
HttpGet get = new HttpGet(url_getiduser);
HttpResponse response = httpClient.execute(get);
String sresponse = "error";
Log.d("url get", url_getiduser);
Log.d("pedido get", get.getMethod());
if(response != null)
{
InputStream in = response.getEntity().getContent();
sresponse = convertStreamToString(in);
Log.d("resposta http", sresponse);
if(!sresponse.equals("error"))
{
JSONObject object = new JSONObject(sresponse);
id_user = (String) object.get("id");
json = object;
Log.d("objecto json", object.toString());
}
else Log.d("Error on json parser", sresponse);
There are few cases where you get HTML text
You might have called a wrong function which gives a 404 page.
Might be a database error on server side where you will get database error message
Server might be sending a styled data which has HTML tags
But you better Log the response and paste it here.
I am trying to build a small application in which the application will communicate with a php script with the help of JSON objects. I successfully implemented the GET Request test application but using JSON with post is creating problems. The code generates no error but my php script reply with no nothing except an empty Array() which implies that nothing was sent over the connection with code:
<?php print_r($_REQUEST); ?>
and trying with
<?php print($_REQUEST['json']); ?>
throws HTML back to the application with json variable not found error.
I have already tried a few solutions mentioned here including: How to send a JSON object over Request with Android? and How to send a json object over httpclient request with android so it would be great if you can point out my mistake and can briefly describe what exactly I was doing wrong. Thanks.
Here is the code snippet for from where the JSON Object is converted into string and then attached to a Post variable.
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpPost httppostreq = new HttpPost(wurl);
StringEntity se = new StringEntity(jsonobj.toString());
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
httppostreq.setEntity(se);
//httppostreq.setHeader("Accept", "application/json");
//httppostreq.setHeader("Content-type", "application/json");
//httppostreq.setHeader("User-Agent", "android");
HttpResponse httpresponse = httpclient.execute(httppostreq);
HttpEntity resultentity = httpresponse.getEntity();
Here is TCP Stream Dump collected through wireshark if it can help:
POST /testmysql.php?test=true HTTP/1.1
Content-Length: 130
Content-Type: application/json;charset=UTF-8
Content-Type: application/json;charset=UTF-8
Host: 192.168.100.4
Connection: Keep-Alive
User-Agent: Apache-HttpClient/UNAVAILABLE (java 1.4)
{"weburl":"hashincludetechnology.com","header":{"devicemodel":"GT-I9100","deviceVersion":"2.3.6","language":"eng"},"key":"value"}HTTP/1.1 200 OK
Date: Mon, 30 Apr 2012 22:43:10 GMT
Server: Apache/2.2.17 (Win32)
Content-Length: 34
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html
Array
(
[test] => true
)
Test // echo statement left intentionally.
you are using PHP on the server side, so your HTTP entity must be a multipart encoded one. See this link. You are using a string entity, but this is not correct. It must be a MultipartEntity, which emulates what the browser does when you submit a form in a web page. MultipartEntity should be in httpmime jar.
Once you have your multipart entity, simply add a Part named "json", and set its contents to the string representation of your json-encoded object.
Note that this answer is because you use PHP on the server side, so you must use its "protocol" to read variables via $_REQUEST. If you used your own request parser oh the server side, even a StringEntity could be ok. See HTTP_RAW_POST_DATA
The below should work. Make sure to set the appropriate keys for what your form post is expecting at the top. Also I included how to send an image as well as other various json data, just delete those lines if that is not necessary.
static private String postToServerHelper(
String action,
JSONObject jsonData,
byte[] imageData){
// keys for sending to server
/** The key for the data to post to server */
final String KEY_DATA = "data";
/** The key for the action to take on server */
final String KEY_ACTION = "action";
/** The return code for a successful sync with server */
final int GOOD_RETURN_CODE = 200;
/** The key for posting the image data */
final String KEY_IMAGE = "imageData";
/** The image type */
final String FILE_TYPE = "image/jpeg";
/** The encoding type of form data */
final Charset ENCODING_TYPE = Charset.forName("UTF-8");
// the file "name"
String fileName = "yourFileNameHere";
// initialize result string
String result = "";
// initialize http client and post to correct page
HttpClient client = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://www.yourdomain.com/yourpage.php");
// set to not open tcp connection
httpPost.getParams().setBooleanParameter(CoreProtocolPNames.USE_EXPECT_CONTINUE, false);
// build the values to post, the action and the form data, and file data (if any)
MultipartEntity multipartEntity = new MultipartEntity(
HttpMultipartMode.BROWSER_COMPATIBLE);
try{
multipartEntity.addPart(KEY_ACTION, new StringBody(action, ENCODING_TYPE));
multipartEntity.addPart(KEY_DATA, new StringBody(jsonData.toString(), ENCODING_TYPE));
if (imageData != null){
multipartEntity.addPart(KEY_IMAGE, new ByteArrayBody(imageData, FILE_TYPE, fileName));
}
}catch (Exception e){
return e.getMessage();
}
// set the values to the post
httpPost.setEntity(multipartEntity);
int statusCode= -1;
// send post
try {
// actual send
HttpResponse response = client.execute(httpPost);
// check what kind of return
StatusLine statusLine = response.getStatusLine();
statusCode = statusLine.getStatusCode();
// good return
if (statusCode == GOOD_RETURN_CODE) {
// read return
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line + "\n");
}
content.close();
result = builder.toString();
// bad return
} else {
return String.parse(statusCode);
}
// different failures
} catch (ClientProtocolException e) {
return e.getMessage();
} catch (IOException e) {
return e.getMessage();
}
// return the result
return result;
}
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
JSONObject clientList = new JSONObject ();
clientList.put("name","");
clientList.put("email","");
clientList.put("status","");
clientList.put("page","");
JSONObject listclient = new JSONObject ();
listclient.put("mydetail", clientList);
//--List nameValuePairs = new ArrayList(1);
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("token", tokenid));
nameValuePairs.add(new BasicNameValuePair("json_data", listclient.toString()));
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
Log.d("JSON",nameValuePairs.toString());
//-- Storing Response
HttpResponse httpResponse = httpClient.execute(httpPost);