Android Retrofit的使用--基础篇

简介：

Retrofit与Okhttp共同出自于Square公司，retrofit就是对Okhttp做了一层封装。把网络请求都交给给了Okhttp，我们只需要通过简单的配置就能使用Retrofit来进行网络请求了。下面是关于Retrofit学习的一个小Demo：<get请求>

1. 导包：

compile 'com.squareup.retrofit2:retrofit:2.3.0'compile 'com.squareup.retrofit2:converter-gson:2.3.0'compile 'com.squareup.retrofit2:adapter-rxjava:2.3.0'

2. 定义我们的api：（在这感谢gank.io）

http://gank.io/api/data/福利/50/1

2. 代码：

1>定义接口GankApiService.java

package com.example.myretrofitdemo_01;import retrofit2.Call;import retrofit2.http.GET;import retrofit2.http.Path;public interface GankApiService {    /**     * 根据category获取Android、iOS等干货数据     * @param category  类别     * @param count     条目数目     * @param page      页数     */    @GET("data/{category}/{count}/{page}")    Call<GankFuliDataResponse> getCategoryData(@Path("category")String category,                                               @Path("count")int count,                                               @Path("page")int page);}

2>新建请求实体类GankFuliDataResponse .java：

package com.example.myretrofitdemo_01;import java.util.List;

public class GankFuliDataResponse {    /**     * error : false     * results : [{"_id":"591a4a02421aa92c794632c8","createdAt":"2017-05-16T08:38:26.35Z","desc":"5-16","publishedAt":"2017-05-16T12:10:38.580Z","source":"chrome","type":"福利","url":"http://ww1.sinaimg.cn/large/610dc034ly1ffmwnrkv1hj20ku0q1wfu.jpg","used":true,"who":"daimajai"},{"_id":"59187082421aa91c8da340d1","createdAt":"2017-05-14T22:58:10.836Z","desc":"5-14","publishedAt":"2017-05-15T12:03:44.165Z","source":"chrome","type":"福利","url":"https://ws1.sinaimg.cn/large/610dc034ly1ffla9ostxuj20ku0q2abt.jpg","used":true,"who":"带马甲"},{"_id":"59154ae7421aa90c7a8b2b0d","createdAt":"2017-05-12T13:40:55.505Z","desc":"5-13","publishedAt":"2017-05-12T13:44:54.673Z","source":"chrome","type":"福利","url":"http://7xi8d6.com1.z0.glb.clouddn.com/2017-05-12-18380140_455327614813449_854681840315793408_n.jpg","used":true,"who":"daimajia"},{"_id":"5913d09d421aa90c7fefdd8e","createdAt":"2017-05-11T10:46:53.608Z","desc":"5-11","publishedAt":"2017-05-11T12:03:09.581Z","source":"chrome","type":"福利","url":"http://7xi8d6.com1.z0.glb.clouddn.com/2017-05-11-18380166_305443499890139_8426655762360565760_n.jpg","used":true,"who":"代码家"},{"_id":"591264ce421aa90c7a8b2aec","createdAt":"2017-05-10T08:54:38.531Z","desc":"5-10","publishedAt":"2017-05-10T11:56:10.18Z","source":"chrome","type":"福利","url":"http://7xi8d6.com1.z0.glb.clouddn.com/2017-05-10-18382517_1955528334668679_3605707761767153664_n.jpg","used":true,"who":"带马甲"}]     */    private boolean error;    private List<ResultsBean> results;    public boolean isError() {        return error;    }    public void setError(boolean error) {        this.error = error;    }    public List<ResultsBean> getResults() {        return results;    }    public void setResults(List<ResultsBean> results) {        this.results = results;    }    public static class ResultsBean {        /**         * _id : 591a4a02421aa92c794632c8         * createdAt : 2017-05-16T08:38:26.35Z         * desc : 5-16         * publishedAt : 2017-05-16T12:10:38.580Z         * source : chrome         * type : 福利         * url : http://ww1.sinaimg.cn/large/610dc034ly1ffmwnrkv1hj20ku0q1wfu.jpg         * used : true         * who : daimajai         */        private String _id;        private String createdAt;        private String desc;        private String publishedAt;        private String source;        private String type;        private String url;        private boolean used;        private String who;        public String get_id() {            return _id;        }        public void set_id(String _id) {            this._id = _id;        }        public String getCreatedAt() {            return createdAt;        }        public void setCreatedAt(String createdAt) {            this.createdAt = createdAt;        }        public String getDesc() {            return desc;        }        public void setDesc(String desc) {            this.desc = desc;        }        public String getPublishedAt() {            return publishedAt;        }        public void setPublishedAt(String publishedAt) {            this.publishedAt = publishedAt;        }        public String getSource() {            return source;        }        public void setSource(String source) {            this.source = source;        }        public String getType() {            return type;        }        public void setType(String type) {            this.type = type;        }        public String getUrl() {            return url;        }        public void setUrl(String url) {            this.url = url;        }        public boolean isUsed() {            return used;        }        public void setUsed(boolean used) {            this.used = used;        }        public String getWho() {            return who;        }        public void setWho(String who) {            this.who = who;        }    }}

3>主MainActivity.java

public class MainActivity extends AppCompatActivity {    private Call<GankFuliDataResponse> gankFuliDataResponse;    private FloatingActionButton fabButton;    private ImageView imageView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        fabButton = (FloatingActionButton) findViewById(R.id.fab);        imageView = (ImageView) findViewById(R.id.image);        Retrofit retrofit = new Retrofit.Builder()                .baseUrl("http://gank.io/api/")                .addConverterFactory(GsonConverterFactory.create())                .build();        GankApiService gankApiService = retrofit.create(GankApiService.class);        gankFuliDataResponse = gankApiService.getCategoryData("福利", 50, 1);//50代表有50条数据        gankFuliDataResponse.enqueue(new Callback<GankFuliDataResponse>() {            @Override            public void onResponse(Call<GankFuliDataResponse> call,                                   final Response<GankFuliDataResponse> response) {                String imgageurl = response.body().getResults().get(0).getUrl();                Glide.with(MainActivity.this).load(imgageurl).into(imageView);                fabButton.setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View v) {                        Random random = new Random();                        int i = random.nextInt(50);                        Log.i("jkl","随机数"+i);                        String imgageurl = response.body().getResults().get(i).getUrl();                        Glide.with(MainActivity.this)                                .load(imgageurl)                                .into(imageView);                    }                });            }            @Override            public void onFailure(Call<GankFuliDataResponse> call, Throwable t) {                Toast.makeText(MainActivity.this,"获取图片失败",Toast.LENGTH_SHORT).show();            }        });    }}

4>activity_main.xml

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.myretrofitdemo_01.MainActivity">    <ImageView        android:id="@+id/image"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_gravity="center"        android:src="@mipmap/ic_launcher" />    <android.support.design.widget.FloatingActionButton        android:id="@+id/fab"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="end|bottom"        android:layout_margin="16dp"        android:clickable="true"        android:src="@mipmap/next"        app:borderWidth="1dp"        app:elevation="3dp"        app:pressedTranslationZ="6dp"        app:rippleColor="#ffffff" /></FrameLayout>