Rotrofit的简单使用

加入Rotrofit类库
compile ‘com.android.support:appcompat-v7:25.1.0’
compile ‘com.squareup.retrofit2:retrofit:2.0.1’
compile ‘com.squareup.retrofit2:converter-gson:2.2.0’//json转换器
compile ‘com.squareup.picasso:picasso:2.5.2’//加载图片
compile ‘com.squareup.retrofit2:adapter-rxjava2:2.2.0’//支持Rxjava调用
compile ‘io.reactivex.rxjava2:rxandroid:2.0.1’//Rxjava增加对android支持
compile ‘io.reactivex.rxjava2:rxjava:2.0.7’//Rxjava异步请求库

定义一个接口
public interface Isenond {

 //  @POST("")
//  @FormUrlEncoded//post请求需要加上这句@Field提交注解参数
//  Call<ResuteBean> getList(@Path("categroe") String categroe, 
@Field("id") int id,@Field("name") int name, @Field("row") int row);
暂时只用了get请求 @Query传递查询参数注解
@GET("/api/{categroe}/list")//get请求拼接baseurl的url {categroe}是可以动态替换的url参数
Call<ResuteBean> getList(@Path("categroe") String categroe,
 @Query("id") int id,  @Query("name") int name, @Query("row") int row);
}
public class seconActivity extends AppCompatActivity {
private ListView listView;
private List<ResuteBean.TngouBean>list1=new ArrayList<ResuteBean.TngouBean>();
private ThreeAdapter adapter;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.seconlayout);
       listView= (ListView) findViewById(R.id.listview);
    adapter = new ThreeAdapter(list1,this);
    listView.setAdapter(adapter);
    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl("http://www.tngou.net")
            .addConverterFactory(GsonConverterFactory.create())//加入json自动转换工厂
            .build();
    Isenond isenond = retrofit.create(Isenond.class);//拿到接口代理实现类
    Call<ResuteBean> list = isenond.getList("cook",0, 1, 20);//拿到call接口对象
    //Call<ResuteBean> list = isenond.getList("top",0, 1, 20);
          //Response<ResuteBean> execute = list.execute();//同步请求 在子线程中请求最好
    list.enqueue(new Callback<ResuteBean>() {//加入异步队列
        @Override
        public void onResponse(Call<ResuteBean> call, Response<ResuteBean> response) { //String string = response.errorBody().string();//即使错误也可以获取到返回的内容
            List<ResuteBean.TngouBean> tngou = response.body().getTngou();
            adapter.addlist(tngou);
        }

        @Override
        public void onFailure(Call<ResuteBean> call, Throwable t) {
            Toast.makeText(seconActivity.this, "加载数据失败",    Toast.LENGTH_SHORT).show();
        }
    });

}
}
//如果对获取的数据再次进行处理的话可以配合Rxjava使用
将接口文件增加返回类型为Observable
public interface IsFour {
@GET("/api/{categroe}/list")
Observable<ResuteBean> getList(@Path("categroe") String categroe, 
@Query("id") int id, @Query("name") int name, @Query("row") int row);
 }
//第二步
 Retrofit retrofit = new Retrofit.Builder()
            .baseUrl("http://www.tngou.net")
            .addConverterFactory(GsonConverterFactory.create())
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            //为RxJava准备的CallAdapter，它将作为Observable返回。
            .build();
    IsFour four = retrofit.create(IsFour.class);
    four.getList("cook", 0, 1, 20)
            .observeOn(AndroidSchedulers.mainThread())
            //.map()可以再次处理数据
            .subscribe(new Observer<ResuteBean>() {
                @Override
                public void onSubscribe(Disposable d) {

                }

                @Override
                public void onNext(ResuteBean resuteBean) {
                    adapter.addlist(resuteBean.getTngou());//拿到处理的数据显示
                }

                @Override
                public void onError(Throwable e) {

                }

                @Override
                public void onComplete() {

                }
            });

}