Retrofit2.0 使用教程

版权声明，转载请著名出处：http://blog.csdn.net/wo_ha/article/details/77866493

引言

俗话说：代码是程序员的最好的教程，这篇文章记录的是我在学习使用Retrofit的代码笔记，其中里面的很多注解或原理我也没有弄明白，但是这不影响我的正常使用啊，当然这篇文章针对的是初学者，如果是老司机的话就请绕道了，如果大家有更好的看法或建议可以在文末进行评论，我会及时更新到文章中，近期我也会更新RxJava的简单使用和RxJava结合Retrofit使用的教程，希望大家喜欢，欢迎大家持续关注！

开始使用

导入依赖

    //  retrofit的依赖    compile 'com.squareup.retrofit2:retrofit:2.1.0'    //将JSON字符串转换为对象需要使用的依赖    compile 'com.squareup.retrofit2:converter-gson:2.1.0'

IpMode类由Json字符串GsonFromat生成

{    "code": 0,    "data": {        "country": "中国",        "country_id": "CN",        "area": "西南",        "area_id": "500000",        "region": "四川省",        "region_id": "510000",        "city": "成都市",        "city_id": "510100",        "county": "",        "county_id": "-1",        "isp": "电信",        "isp_id": "100017",        "ip": "118.114.168.175"    }}

1. Get简单请求

注：Retrofit2 的baseUlr 必须以 /（斜线） 结束，不然会抛出一个IllegalArgumentException,所以如果你看到别的教程没有以 / 结束，那么多半是直接从Retrofit 1.X 照搬过来的。

//请求的接口public interface IpService {    @Headers({            "Accept-Encoding: application/json",            "User-Agent: MoonRetrofit"  //必须要有这个Hearder，否则报错 java.lang.IllegalArgumentException: @Headers annotation is empty.    })    @GET("getIpInfo.php?ip=59.108.54.37")    Call<IpMode> getIpMsgGet();    /**     * 采用指定的全路径访问     * @param url   网址的全路径     * @return     */    @Headers({            "User-Agent: MoonRetrofit"    })    @GET    Call<IpMode> getIpMsgGet1(@Url String url);｝

 public void getSimple(View view) {        // Get简单请求        final String url = "http://ip.taobao.com/service/";        Retrofit retrofit = new Retrofit                .Builder()                .baseUrl(url)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        Call<IpMode> ipMsg = ipService.getIpMsgGet();        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });        getSimple();// Get简单请求 ，采用全路径来访问    }    private void getSimple() {        // Get简单请求 ，采用全路径来访问        final String url = "http://ip.taobao.com/service/";        Retrofit retrofit = new Retrofit                .Builder()                .baseUrl(url)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        Call<IpMode> ipMsg = ipService.getIpMsgGet1("http://ip.taobao.com/service/getIpInfo.php?ip=118.114.168.175");        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }

2. Get带参数请求(路径)可以通过参数动态修改网址的路径

    /**     * 指定路径的访问     *     * @param pathStr 路径     * @return     */    @Headers({            "Accept-Encoding: application/json",            "User-Agent: MoonRetrofit"    })    @GET("{path}/getIpInfo.php?ip=59.108.54.37")//{path}与@Path("path")参数对应，接受参数后{path}被替换    Call<IpMode> getIpMsgGet(@Path("path") String pathStr);

    public void getParamesPath(View view) {//        Get带参数请求(路径)        final String baseUrl = "http://ip.taobao.com/";        Retrofit retrofit = new Retrofit                .Builder()                .baseUrl(baseUrl)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        Call<IpMode> ipMsg = ipService.getIpMsgGet("service");   //,"getIpInfo.php?ip=59.108.54.37"        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }

3. Get带参数请求(IP)可以动态修改网址？后面的参数

    /**     * 指定IP访问     * 会组成全路径：http://ip.taobao.com/service/getIpInfo.php?ip=118.114.168.175     * 在路径后自动添加  ?ip=ipStr     *     * @param ipStr     * @return     */    @Headers({            "Accept-Encoding: application/json",            "User-Agent: MoonRetrofit"    })    @GET("service/getIpInfo.php")    Call<IpMode> getIpMsgFromIpGet(@Query("ip") String ipStr);

    public void getParamesIp(View view) {//        Get带参数请求(IP)        final String baseUrl = "http://ip.taobao.com/";        Retrofit retrofit = new Retrofit                .Builder()                .baseUrl(baseUrl)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        Call<IpMode> ipMsg = ipService.getIpMsgFromIpGet("59.108.54.37");   //,"getIpInfo.php?ip=59.108.54.37"        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }

4. Get带参数请求(路径和IP)可以通过参数动态修改网址的路径和网址？后面的请求参数

    @Headers({            "Accept-Encoding: application/json",            "User-Agent: MoonRetrofit"    })    @GET("{path}")    Call<IpMode> getIpMsgGet(@Path("path") String pathStr, @Query("ip") String ipStr);

    public void getParamesPathIp(View view) {//        Get带参数请求(路径和IP)        final String baseUrl = "http://ip.taobao.com/";        Retrofit retrofit = new Retrofit                .Builder()                .baseUrl(baseUrl)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        Call<IpMode> ipMsg = ipService.getIpMsgGet("service/getIpInfo.php", "59.108.54.37");   //,"getIpInfo.php?ip=59.108.54.37"        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }

5.Get带参数请求(动态指定查询条件组)

    /**     * 动态指定查询条件组     *     * @param quaryMap     * @return     */    @Headers({            "Accept-Encoding: application/json",            "User-Agent: MoonRetrofit"    })    @GET("service/getIpInfo.php")    Call<IpMode> getIpMsgGet(@QueryMap Map<String, String> quaryMap);

    public void getParamesQuaryMap(View view) {//        Get带参数请求(动态指定查询条件组)        final String baseUrl = "http://ip.taobao.com/";        Retrofit retrofit = new Retrofit                .Builder()                .baseUrl(baseUrl)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        HashMap<String, String> hashMap = new HashMap<>();        hashMap.put("ip", "59.108.54.37"); //Key 和 Value要对应，其中Key名要与网站对应        Call<IpMode> ipMsg = ipService.getIpMsgGet(hashMap);        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }

6.Post带参数请求

    /**     * 带参数的POST请求     * 用@Field("ip")标注请求的参数键值     *     * @param ip     * @return     */    @Headers({            "Accept-Encoding: application/json", //            "User-Agent: MoonRetrofit"    })    @FormUrlEncoded  //注明是一个表单请求    @POST("service/getIpInfo.php")    Call<IpMode> getIpMsgPost(@Field("ip") String ip);    @Headers({            "Accept-Encoding: application/json", //            "User-Agent: MoonRetrofit"    })    @FormUrlEncoded  //注明是一个表单请求    @POST("service/getIpInfo.php")    Call<IpMode> getIpMsgPost(@FieldMap Map<String, String> quaryMap);

    public void postParames(View view) {//        Post带参数请求        String url = "http://ip.taobao.com/";        Retrofit retrofit = new Retrofit.Builder()                .baseUrl(url)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);//        Call<IpMode> ipMsg = ipService.getIpMsgPost("59.108.54.37");        HashMap<String, String> hashMap = new HashMap<>();        hashMap.put("ip", "59.108.54.37");        Call<IpMode> ipMsg = ipService.getIpMsgPost(hashMap);        ipMsg.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                IpMode ipMode = response.body();                Log.e(TAG, "onResponse: " + ipMode);                Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }

7. 下载图片或文件

    /**     * 下载图片，返回的是OkHttp库的Call<ResponseBody>， ResponseBody里面是字节数据     * 百度的首页图     *     * @return     */    @Headers({            "Accept-Encoding: application/json",            "User-Agent: MoonRetrofit"    })    @Streaming    @GET("5aV1bjqh_Q23odCf/static/superman/img/logo/logo_white_fe6da1ec.png")    Call<ResponseBody> getImgMsgGet();    /**     * 使用全路径的网址下载图片     *     * @param fileUrl     * @return     */    @GET    Call<ResponseBody> getImgMsgGet(@Url String fileUrl);

    public void getDownloadImg(View view) {//        Get下载图片        String url = "https://ss0.bdstatic.com/";        Retrofit retrofit = new Retrofit.Builder()                .baseUrl(url)                .build();        IpService ipService = retrofit.create(IpService.class);        Call<ResponseBody> imgMsgGet = ipService.getImgMsgGet();        imgMsgGet.enqueue(new Callback<ResponseBody>() {            @Override            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {                try {                    byte[] bytes = response.body().bytes();                    Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);                    imageview.setImageBitmap(bitmap);                } catch (IOException e) {                    e.printStackTrace();                }                Log.e(TAG, "onResponse: 图片请求成功");                Toast.makeText(MainActivity.this, "图片请求成功", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<ResponseBody> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });        //使用全路径        Call<ResponseBody> imgMsgGet2 = ipService.getImgMsgGet("http://img1.3lian.com/2015/a1/105/d/40.jpg");        imgMsgGet2.enqueue(new Callback<ResponseBody>() {            @Override            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {                File file = new File(MainActivity.this.getCacheDir(), "laowang.jpg");                try {                    byte[] bytes = response.body().bytes();                    Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);                    imageview.setImageBitmap(bitmap);                    //保存为文件                    FileOutputStream fileOutputStream = new FileOutputStream(file, false);                    fileOutputStream.write(bytes);                    fileOutputStream.flush();                    fileOutputStream.close();                } catch (Exception e) {                    e.printStackTrace();                }                Log.e(TAG, "onResponse: 图片请求成功２,ex=" + file.exists() + ",path=" + file.getAbsolutePath());                Toast.makeText(MainActivity.this, "图片请求成功２", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<ResponseBody> call, Throwable t) {                Log.e(TAG, "onFailure: ２");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "２", Toast.LENGTH_LONG).show();            }        });    }

8. POST上传文件

    /**     *  POST上传文件     *  注解@Multipart 表示允许多个@Part     *  如需要多个文件上传可以使用@PartMap     * @param file     * @return     */    @Multipart      @POST("fileService")    Call<IpMode> uploadFile(@Part MultipartBody.Part file);

    public void postUpImg(View view) {// POST上传图片        File file = new File(MainActivity.this.getCacheDir(), "laowang.jpg");        RequestBody body = RequestBody.create(MediaType.parse("application/otcet-stream"), file);//构建文件的RequestBody        MultipartBody.Part part = MultipartBody.Part.createFormData("file", file.getName(), body);//构建文件的Part        String url = "https://ss0.bdstatic.com/";        Retrofit retrofit = new Retrofit.Builder()                .baseUrl(url)                .addConverterFactory(GsonConverterFactory.create())                .build();        IpService ipService = retrofit.create(IpService.class);        Call<IpMode> call = ipService.uploadFile(part);        call.enqueue(new Callback<IpMode>() {            @Override            public void onResponse(Call<IpMode> call, Response<IpMode> response) {                Log.e(TAG, "onResponse: 图片上传成功," + response.headers());                Toast.makeText(MainActivity.this, "图片上传成功", Toast.LENGTH_LONG).show();            }            @Override            public void onFailure(Call<IpMode> call, Throwable t) {                Log.e(TAG, "onFailure: ");                t.printStackTrace();                Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();            }        });    }