Submit HTTP GET and HTTP POST requests using the Android client to the WEB application built on the Ruby on Rails

Recently wanted to get an Android app that has access to the Internet, because it's fast so it uses Ruby on Rails to provide HTTP resources. This information is still relatively small, so the attempt to record the process.

1 building Web application with Ruby on Rails

1.1 New Web Application

CD Test

1.2 Generate product

Rails Generate Scaffold Product reference:string quantity:decimal
Rake Db:migrate

Start the service

Rails Server

Open Http://localhost:3000/products

You should see the following information (this is the result of get, but it is not yet recorded):

Add a record to the Web page, click "New Product", go to "http://localhost:3000/products/new", fill in the information and click "Greate Product" (this commits a post):

In other words, both get and POST on the web side can be executed.

1.3 Using JSON format to transfer data first try GET JSON format data

Open: Http://localhost:3000/products/1.json

As you can see, using Ruby on Rails is a straightforward means of getting Json data, which is why?

To figure out how the Json data came in, check out the routes

Rake routes

The following results are displayed:

So the input http://localhost:3000/products/1.json corresponding to the Controller inside the show, in the code to find show (test/app/controllers/products_ CONTROLLER.RB):

Hey! What's the situation? Can you support Json directly without writing anything? That's too cool.

Try the Post Json-formatted data again

As already known, with the Web page can submit a post, first trace the next post, using the Developer tool to view the Web page submitted when the submission of a post:

This POST is based on the previous Routes should be given to the controller in create.

So it is @product = Product.new (product_params) to create the object @product. Save Object. So, how did Product_params get here?

All right, here's the thing.

Well.. Still did not solve I want the Json transfer method, and then search for the big god ...

Add the following code to the TEST/APP/CONTROLLERS/PRODUCTS_CONTROLLER.RB to accept the Json data submitted by the Android app.

  def Create_from_app      Data_json=json.parse request.body.read      = product.new (data_json)      @product. Save  End

1.4 Test if GET and POST are normal

The test uses Firefox's Poster tool.

Test GET

Test POST

Make up an episode: There was an error when submitting the POST directly:

Paste the contents of the error into HTML and find the error:

Baidu asks the big God to get this answer:

This is a new feature, starting with Rails 2.0, designed to prevent CSRF (Cross-site Request forgery) from attacking

There are several ways to solve this problem

Please forgive me for being directly violent. Choose the way to disable CSRF, find test/app/controllers/products_controller.rb, insert code

  Protect_from_forgery:except = : Index      #  can disable CSRF protection on Controller-by-controller basis:    Skip_before_filter:verify_authenticity_token  

Restart Rails Server

Problem resolution, submit the POST again:

This means that the Android client can only send HTTP requests in the format above.

2 using an Android client to access HTTP resources

2.1 Getting permission to access the network

Add the following line to the Androidmanifest.xml file

<android:name= "Android.permission.INTERNET"/>

2.2 Submitting a GET request using the Android client

        Try {            FinalString url = "http://192.168.0.138:3000/products/" +message+ ". JSON"; Thread Thread=NewThread (NewRunnable () {@Override Public voidrun () {Try{httpget HttpGet=Newhttpget (URL); HttpResponse HttpResponse=Newdefaulthttpclient (). Execute (httpget); if(Httpresponse.getstatusline (). Getstatuscode () = = 200) {result=entityutils.tostring (HttpResponse. getentity ()); }                    } Catch(Exception e) {e.printstacktrace ();            }                }            });            Thread.Start ();        Thread.Join (); } Catch(interruptedexception e) {e.printstacktrace (); }

2.3 Submitting a POST request using an Android client

Try{Thread Threadpost=NewThread (NewRunnable () {@Override Public voidrun () {Try {                    FinalString url = "Http://192.168.0.138:3000/products"; HttpPost HttpPost=Newhttppost (URL); Jsonobject JSON=NewJsonobject (); Json.accumulate ("Reference", "888"); Json.accumulate ("Quantity", "8"); Jsonobject Response=NULL; stringentity s=Newstringentity (json.tostring ()); S.setcontentencoding ("UTF-8"); S.setcontenttype ("Application/json");                                        Httppost.setentity (s); HttpResponse HttpResponse=Newdefaulthttpclient (). Execute (httppost); if(Httpresponse.getstatusline (). Getstatuscode () = = 200) {result=entityutils.tostring (Httpresponse.getentity ()); }                } Catch(Exception e) {e.printstacktrace ();        }            }        });        Threadpost.start ();        Threadpost.join (); } Catch(Exception e) {e.printstacktrace (); }