OKhttp上传图片

private void showChooseAlterDialog() {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("设置头像");
    String[] items = { "选择本地照片", "拍照" };
    builder.setNegativeButton("取消", null);
    builder.setItems(items, new DialogInterface.OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int which) {
            switch (which) {
                case CHOOSE_PICTURE: // 选择本地照片
                    Intent openAlbumIntent = new Intent(
                            Intent.ACTION_GET_CONTENT);
                    openAlbumIntent.setType("image/*");
                    startActivityForResult(openAlbumIntent, CHOOSE_PICTURE);
                    break;
                case TAKE_PICTURE: // 拍照
                    Intent openCameraIntent = new Intent(
                            MediaStore.ACTION_IMAGE_CAPTURE);
                    tempUri = Uri.fromFile(new File(Environment
                            .getExternalStorageDirectory(), "image.jpg"));
                    // 指定照片保存路径（SD卡），image.jpg为一个临时文件，每次拍照后这个图片都会被替换
                    openCameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, tempUri);
                    startActivityForResult(openCameraIntent, TAKE_PICTURE);
                    break;
            }
        }
    });
    builder.create().show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode == RESULT_OK) { // 如果返回码是可以用的
        switch (requestCode) {
            case TAKE_PICTURE:
                startPhotoZoom(tempUri); // 开始对图片进行裁剪处理
                break;
            case CHOOSE_PICTURE:
                startPhotoZoom(data.getData()); // 开始对图片进行裁剪处理
                break;
            case CROP_SMALL_PICTURE:
                if (data != null) {
                    setImageToView(data); // 让刚才选择裁剪得到的图片显示在界面上
                }
                break;
        }
    }
}
/**
 * 裁剪图片方法实现
 *
 * @param uri
 */
protected void startPhotoZoom(Uri uri) {
    if (uri == null) {
        Log.i("tag", "The uri is not exist.");
    }
    tempUri = uri;
    Intent intent = new Intent("com.android.camera.action.CROP");
    intent.setDataAndType(uri, "image/*");
    // 设置裁剪
    intent.putExtra("crop", "true");
    // aspectX aspectY 是宽高的比例
    intent.putExtra("aspectX", 1);
    intent.putExtra("aspectY", 1);
    // outputX outputY 是裁剪图片宽高
    intent.putExtra("outputX", 150);
    intent.putExtra("outputY", 150);
    intent.putExtra("return-data", true);
    startActivityForResult(intent, CROP_SMALL_PICTURE);
}
/**
 * 保存裁剪之后的图片数据
 *
 * @param
 *
 * @param
 */
protected void setImageToView(Intent data) {
    Bundle extras = data.getExtras();
    if (extras != null) {
        Bitmap photo = extras.getParcelable("data");
        Utils utils=new Utils();
        photo = utils.toRoundBitmap(photo); // 这个时候的图片已经被处理成圆形的了
        iv_touxiang.setImageBitmap(photo);
        uploadPic(photo);//下载图片
    }
}

private void uploadPic(Bitmap bitmap) {
    File file=new File("mnt/sdcard/Linkaipictures/a.jpg");
    try {
        BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(file));
        bitmap.compress(Bitmap.CompressFormat.JPEG,100,bos);
        bos.flush();
        bos.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

    Map params=new HashMap<>();
    params.put("uid",uid);
    OkHttpClient okHttpClient=new OkHttpClient();
    MultipartBody.Builder builder=new MultipartBody.Builder().setType(MultipartBody.FORM);
    RequestBody requestBody=RequestBody.create(MediaType.parse("image/*"),file);
    builder.addFormDataPart("file",file.getName(),requestBody);
    if(params!=null)
    {
        for (Map.Entry stringObjectEntry : params.entrySet()) {
            builder.addFormDataPart(stringObjectEntry.getKey(), (String) stringObjectEntry.getValue());
        }
    }
    Request request=new Request.Builder().post(builder.build()).url(Api.relepace).build();
    okHttpClient.newCall(request).enqueue(new Callback() {

        private String string;

        @Override
        public void onFailure(Call call, IOException e) {

        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            if(response!=null&&response.isSuccessful())
            {
                string = response.body().string();
                System.out.println("=======json==="+ string);
            }
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
               Toast.makeText(UserActivity.this, "====成功了===", Toast.LENGTH_SHORT).show();
                }
            });
        }
    });

}