okhttp获取版本更新—实例

    public void checkUpdate(final boolean showMessage){
        String url = "http://api.fir.im/apps/latest/57be8d56959d6960d5000327";
        OkHttpUtils
                .get()
                .url(url)
                .addParams("api_token", "a48b9bbcef61f34c51160bfed26aa6b2")
                .build()
                .execute(new StringCallback()
                {
                    @Override
                    public void onError(Call call, Exception e, int id) {
                        if (showMessage) {
                            Toast.makeText(MainActivity.this, "检查更新失败！", Toast.LENGTH_SHORT).show();
                        }
                    }

                    @Override
                    public void onResponse(String response, int id) {
                        try {
                            JSONObject jsonObject = new JSONObject(response);
                            String version = jsonObject.getString("version");
                            String versionCode = CommonUtil.getVersionCode(MainActivity.this) + "";
                            if (versionCode.compareTo(version) < 0){
                                showUpdateDialog(jsonObject.getString("name"),jsonObject.getString("versionShort"),jsonObject.getString("changelog"),jsonObject.getString("update_url"),MainActivity.this);
                            }else{
                                if (showMessage) {
                                    Toast.makeText(MainActivity.this, "已经是最新版本！", Toast.LENGTH_SHORT).show();
                                }
                            }
                        } catch (JSONException e) {
                            if (showMessage) {
                                Toast.makeText(MainActivity.this, "检查更新失败", Toast.LENGTH_SHORT).show();
                            }
                            e.printStackTrace();
                        }
                    }

                });

    }

    public static void showUpdateDialog(final String name, String version, String changelog, final String updateUrl, final Context context) {
        String title = "发现新版" + name + "，版本号：" + version;

        new android.support.v7.app.AlertDialog.Builder(context).setTitle(title)
                .setMessage(changelog)
                .setPositiveButton("下载", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Uri uri = Uri.parse(updateUrl);   //指定网址
                        Intent intent = new Intent();
                        intent.setAction(Intent.ACTION_VIEW);           //指定Action
                        intent.setData(uri);                            //设置Uri
                        context.startActivity(intent);        //启动Activity
                    }
                })
                .show();
    }