Retrofit2 Simple to use

RETROFIT2 official release has a period of time, the official also just out of 2.0beta version of the time to replace the official website, so use retrofit, we also do not tangle it with the previous version of the difference, from the 2.0 version of the beginning of it.

Introduced

Using the Android Studio development tool, introduce the following:

    ‘com.squareup.retrofit2:retrofit:2.0.2‘    ‘com.squareup.okhttp3:okhttp:3.2.0‘    ‘com.squareup.retrofit2:converter-gson:2.0.2‘

Retrofit supports Rxjava, so I'm going to write another example of Rxjava, which is a comparison with normal use. So go into these libraries (don't introduce the following three libraries if you don't know Rxjava):

    ‘io.reactivex:rxjava:1.1.3‘    ‘io.reactivex:rxandroid:1.1.0‘    ‘com.squareup.retrofit2:adapter-rxjava:2.0.2‘

Interface class

First look at a simple effect, enter the ID number, determine the validity of the ID card number, the output of the person's birthday:

function is very simple, interface I use the aggregated data provided by the identity query API, the main implementation of the following methods.

Let's start by showing this URL:

http://apis.juhe.cn/idcard/index?key=您申请的KEY&cardno=330326198903081211

First, an interface (interface) is required to encapsulate this URL:

publicinterface PersonApi {    @GET("index")    Call<PersonPojo> getPersonCardNum(@Query("key"@Query("cardno") String num);}

For friends who have not contacted retrofit, here are some explanations:

@GET ("index")

The delegate uses the Get method request, and index is part of the question mark in the above URL, followed by the previous section.

@Query

Represents access to this URL parameter, which means that access to this URL requires two parameters, one is the access to use the secret key, one is the ID number.

Call<PersonPojo>

This is the return value that has parsed the JSON into an entity.

Network Engine class

Then you need a network engine class, which puts the access to the data, first of all the construction method is written inside:

public  class  Net { Span class= "Hljs-keyword" >private static  personapi Personapi; private  static  Okhttpclient okhttpclient = new  okhttpclient (); private  static  Converter.factory gsonconverterfactory = Gsonconverterfactory.create (); public  net  () {Retrofit Retrofit = new  retrofit.builder (). Client (Okhttpclien T). BASEURL ( "http://apis.juhe.cn/idcard/" ). Addconverterfac Tory (Gsonconverterfactory). build (); Personapi = Retrofit.create (Personapi.class); }

Okhttpclient is the underlying network access tool, Gsonconverterfactory.create () means an instance of the internal JSON parsing tool Gson. In BaseURL, the first half of the URL above is actually the URL of the host we use.
Then there is the way to write the data:

 Public void Getpseroncardnum(String num,FinalOncheckcardlistener Oncheckcardlistener) {call<personpojo> call = Personapi.getpersoncardnum ("Fe15ed66cfb72823024958f4b1dc50e7", num); Call.enqueue (NewCallback<personpojo> () {@Override             Public void Onresponse(call<personpojo> call, response<personpojo> Response)            {oncheckcardlistener.onsuccess (Response.body ()); }@Override             Public void onfailure(call<personpojo> call, Throwable t) {Oncheckcardlistener.onerror ("Error"); System.out.println ("Err");    }        }); }

Oncheckcardlistener is a callback interface for activity. If it succeeds, the parsed entity is passed out, and if it fails, the string "error" is simple and straightforward.
Then look at the activity:

 Public  class mainactivity extends appcompatactivity  implements  Oncheckcardlistener{TextView Card,result;    Button check; NET net;@Override    protected void onCreate(Bundle savedinstancestate) {Super. OnCreate (Savedinstancestate);        Setcontentview (R.layout.activity_main); NET =NewNet ();        Card = (TextView) Findviewbyid (R.id.tv_card);        result = (TextView) Findviewbyid (R.id.tv_result);        Check = (Button) Findviewbyid (R.id.btn_check); Check.setonclicklistener (NewView.onclicklistener () {@Override             Public void OnClick(View v) {Net.getpseroncardnum (Card.gettext (). toString (), mainactivity. This);    }        }); }@Override     Public void onsuccess(Personpojo Personpojo) {if(Personpojo.getresultcode (). Equals (" the") {Result.settext (Personpojo.getresult (). Getbirthday ()); }Else{Result.settext (Personpojo.getresultcode ()); }    }@Override     Public void OnError(String msg)    {Result.settext (msg); }}

This is the use of Retrofit2 do simple function, just for the sake of getting started, in fact, there are many functions retrofit, in terms of parameters, such as access to the RESTful URL when the use of @path, as well as the entity as the parameters used to @body and so on.

Returning entities that support Rxjava

The following section is for the above function with Rxjava implementation, the function has not changed, so paste the code directly.

publicinterface PersonApi {    @GET("index")    Call<PersonPojo> getPersonCardNum(@Query("key"@Query("cardno") String num);    @GET("index")    Observable<PersonPojo> getPersonCardNum2(@Query("key"@Query("cardno") String num);}

Network Engine class, Net.java:

 Public  class Net {    Private StaticPersonapi Personapi;Private StaticOkhttpclient okhttpclient =NewOkhttpclient ();Private StaticConverter.factory gsonconverterfactory = Gsonconverterfactory.create ();Private StaticCalladapter.factory rxjavacalladapterfactory = Rxjavacalladapterfactory.create (); Public Net() {Retrofit Retrofit =NewRetrofit.builder (). Client (okhttpclient). BASEURL ("http://apis.juhe.cn/idcard/"). Addconverterfactory (Gsonconverterfactory). Addcalladapterfactory (rxjavacalladapterfactory        ). build ();    Personapi = Retrofit.create (Personapi.class); } Public void Getpseroncardnum(String num,FinalOncheckcardlistener Oncheckcardlistener) {call<personpojo> call = Personapi.getpersoncardnum ("Fe15ed66cfb72823024958f4b1dc50e7", num); Call.enqueue (NewCallback<personpojo> () {@Override             Public void Onresponse(call<personpojo> call, response<personpojo> Response)            {oncheckcardlistener.onsuccess (Response.body ()); }@Override             Public void onfailure(call<personpojo> call, Throwable t) {Oncheckcardlistener.onerror ("Error"); System.out.println ("Err");    }        }); } Public  void getPseronCardNum2(String num,FinalOncheckcardlistener oncheckcardlistener) {observable<personpojo> Observable = personapi.getpersoncardnum2 ("Fe15ed66cfb72823024958f4b1dc50e7", num); Observable.subscribeon (Schedulers.io ()). Observeon (Androidschedulers.mainthread ()). Subscribe (NewSubscriber<personpojo> () {@Override             Public void oncompleted() {System.out.println ("Complete"); }@Override             Public void OnError(Throwable e) {Oncheckcardlistener.onerror ("Error"); System.out.println ("Err"); }@Override             Public void OnNext(Personpojo Personpojo)            {oncheckcardlistener.onsuccess (Personpojo);    }        }); }}

The others are the same, and there are projects above that can be downloaded.
Download point here

Retrofit2 Simple to use