上传头像（接口）

权限

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.INTERNET"/>

ok+retorfit

public class OkHttp {
    public Api api;

    private OkHttp(){
        OkHttpClient builder = new OkHttpClient.Builder()
                .writeTimeout(3000,TimeUnit.SECONDS)
                .connectTimeout(3000,TimeUnit.SECONDS)
                .readTimeout(3000,TimeUnit.SECONDS)
                //.addInterceptor(new HeadIntertor())
                .build();
        Retrofit retrofit = new Retrofit.Builder()
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl("http://172.17.8.100/")
                .client(builder)
                .build();
        api = retrofit.create(Api.class);
    }

    public static OkHttp getInstance() {
        return http.OK_HTTP;
    }
    public static class http{
        public static final OkHttp OK_HTTP=new OkHttp();
    }

api管理

public interface Api {
    @Multipart
    @POST("small/user/verify/v1/modifyHeadPic")
    Observable<TouEntity>getTou(@Header("userId")String userId, @Header("sessionId")String sessionId, @Part MultipartBody.Part filePart);

}

mainactivityoncreate方法

public class MainActivity extends AppCompatActivity implements IView {

    @BindView(R.id.img)
    ImageView img;
    private Presenter presenter;
    private String userId ="228";
    private String sessionId="1557024340090228";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        presenter = new Presenter();
        presenter.setView(this);
        //presenter.getTou(userId,sessionId,image);
        img.setOnClickListener(new View.OnClickListener() {

            private AlertDialog.Builder builder;

            @Override
            public void onClick(View v) {
                builder = new AlertDialog.Builder(MainActivity.this);
                builder.setMessage("上传头像");
                builder.setPositiveButton("相册", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // Intent.ACTION_PICK 这个对应的就是图库
                        Intent intent1 = new Intent(Intent.ACTION_PICK);
                        // 第四步:设置显式MIME数据类型
                        intent1.setType("image/*");
                        // 第五步：跳转回
                        startActivityForResult(intent1, 2);
                    }
                });

                builder.setNegativeButton("相机", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //权限  是否调用摄像头    这个权限在模拟器上运行需要改动版本
                            Intent intent = new Intent();
                            // 指定开启系统相机的Action
                            intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
                            intent.addCategory(Intent.CATEGORY_DEFAULT);
                            startActivityForResult(intent, 1);
                    }
                });
                builder.show();
            }
        });
    }

mainactivity创建onActivityResult结果处理

protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
        //相册
        if (requestCode == 2) {
            Uri uri = data.getData();
            img.setImageURI(uri);
            //uri转换成file文件
            String[] arr = {MediaStore.Images.Media.DATA};
            Cursor cursor = managedQuery(uri,arr,null,null,null);
            int img_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            String img_path = cursor.getString(img_index);
            File file = new File(img_path);
            if(file!=null && file.exists()){
                RequestBody requestBody = RequestBody.create(MediaType.parse("image/*"),file.getAbsoluteFile());
                MultipartBody.Part part = MultipartBody.Part.createFormData("image",file.getName(),requestBody);
                presenter.getTou(userId,sessionId,part);
            }else{
                Toast.makeText(MainActivity.this,"请选择文件",Toast.LENGTH_SHORT).show();
            }
        }
        //相机
        if(requestCode == 1){
            Bundle bundle = data.getExtras();
            Bitmap bitmap = (Bitmap)bundle.get("data");
            img.setImageBitmap(bitmap);

            File file = new File("storage/emulated/legacy/s.jpg");//将要保存图片的路径
            try {
                BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file));
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bos);
                RequestBody requestBody = RequestBody.create(MediaType.parse("image/*"),file.getAbsoluteFile());
                MultipartBody.Part part = MultipartBody.Part.createFormData("image",file.getName(),requestBody);
                presenter.getTou(userId,sessionId,part);
                bos.flush();
                bos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
}

mainactivity成功失败处理

public void Success(Object o, int isWhat) {
    if(isWhat==1){
        TouEntity touEntity = (TouEntity) o;
        String message = touEntity.getMessage();
        Toast.makeText(MainActivity.this,message,Toast.LENGTH_SHORT).show();
    }
}

@Override
public void False(String mess) {

}