我的rails应用程序返回http 200代码很好，但如果有错误，我希望我的控制器将错误传递给JSON，以便我可以在我的Android应用程序中处理它。
如果投票成功，我会在我的rails服务器中获得以下内容：
Started PUT "/articles/10/dislike" for 49.199.139.48 at 2016-03-18 11:46:08 +0000
Cannot render console from 49.199.139.48! Allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255
Processing by ArticlesController#downvote as JSON
Parameters: {"votes"=>{"votable_id"=>"10", "votable_type"=>"Article", "voter_id"=>"3", "voter_type"=>"User", "vote_flag"=>"f", "vote_weight"=>"1"}, "article"=>"10", "id"=>"10"}
User Load (0.4ms) SELECT "users".* FROM "users" WHERE "users"."email" = ? ORDER BY "users"."id" ASC LIMIT 1 [["email", "adam1st@hotmail.com"]]
Article Load (0.2ms) SELECT "articles".* FROM "articles" WHERE "articles"."id" = ? ORDER BY "articles"."created_at" DESC LIMIT 1 [["id", 10]]
(0.2ms) SELECT COUNT(*) FROM "votes" WHERE "votes"."votable_id" = ? AND "votes"."votable_type" = ? AND "votes"."voter_id" = ? AND "votes"."voter_type" = ? AND "votes"."vote_scope" IS NULL [["votable_id", 10], ["votable_type", "Article"], ["voter_id", 3], ["voter_type", "User"]]
ActsAsVotable::Vote Load (0.2ms) SELECT "votes".* FROM "votes" WHERE "votes"."votable_id" = ? AND "votes"."votable_type" = ? AND "votes"."voter_id" = ? AND "votes"."voter_type" = ? AND "votes"."vote_scope" IS NULL ORDER BY "votes"."id" DESC LIMIT 1 [["votable_id", 10], ["votable_type", "Article"], ["voter_id", 3], ["voter_type", "User"]]
(0.2ms) begin transaction
(0.1ms) commit transaction
Completed 200 OK in 12ms (Views: 0.2ms | ActiveRecord: 1.1ms)
如果不成功（因为该人已经投票），我会得到以下结果：
Started PUT "/articles/10/dislike" for 49.199.139.48 at 2016-03-18 11:46:53 +0000
Cannot render console from 49.199.139.48! Allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255
Processing by ArticlesController#downvote as JSON
Parameters: {"votes"=>{"votable_id"=>"10", "votable_type"=>"Article", "voter_id"=>"3", "voter_type"=>"User", "vote_flag"=>"f", "vote_weight"=>"1"}, "article"=>"10", "id"=>"10"}
User Load (0.3ms) SELECT "users".* FROM "users" WHERE "users"."email" = ? ORDER BY "users"."id" ASC LIMIT 1 [["email", "adam1st@hotmail.com"]]
Article Load (0.3ms) SELECT "articles".* FROM "articles" WHERE "articles"."id" = ? ORDER BY "articles"."created_at" DESC LIMIT 1 [["id", 10]]
(0.3ms) SELECT COUNT(*) FROM "votes" WHERE "votes"."votable_id" = ? AND "votes"."votable_type" = ? AND "votes"."voter_id" = ? AND "votes"."voter_type" = ? AND "votes"."vote_scope" IS NULL [["votable_id", 10], ["votable_type", "Article"], ["voter_id", 3], ["voter_type", "User"]]
ActsAsVotable::Vote Load (0.4ms) SELECT "votes".* FROM "votes" WHERE "votes"."votable_id" = ? AND "votes"."votable_type" = ? AND "votes"."voter_id" = ? AND "votes"."voter_type" = ? AND "votes"."vote_scope" IS NULL ORDER BY "votes"."id" DESC LIMIT 1 [["votable_id", 10], ["votable_type", "Article"], ["voter_id", 3], ["voter_type", "User"]]
(0.1ms) begin transaction
(0.1ms) commit transaction
Completed 302 Found in 140ms (Views: 0.5ms | ActiveRecord: 84.9ms)
问题是我没有将Completed 302 Found响应传递回我的Android应用程序。它只是传回空白。
控制器：
def upvote
@article.upvote_by current_user
if @article.vote_registered?
flash[:success] = "Successfully liked"
respond_to do |format|
format.html {redirect_to :back }
format.json { render json: { count: @article.get_upvotes.size } }
end
else
flash[:danger] = "You have already liked this"
respond_to do |format|
format.html {redirect_to :back }
format.json { render json: { status: :found }, status: 302 }
end
end
end
处理投票的Android应用程序和String webResponse如果出现错误则会返回空白。如果它是未经授权的401，302被发现等等，那么它仍然是空白的：
非常感谢。
private class VoteTask extends UrlJsonAsyncTask {
public VoteTask(Context context) {
super(context);
}
@Override
protected JSONObject doInBackground(String... urls) {
DefaultHttpClient webClient = new DefaultHttpClient();
HttpPut put = new HttpPut(urls[0]);
JSONObject holder = new JSONObject();
JSONObject voteObj = new JSONObject();
JSONObject json = new JSONObject();
try {
try {
// setup the returned values in case
// something goes wrong
//json.put("success", false);
// json.put("info", "Something went wrong. Retry!");
//get stored values to prove the user is authorised
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
String id = sharedPreferences.getString("userId", "default value");
String authToken = sharedPreferences.getString("AuthToken", "default value");
String email = sharedPreferences.getString("email", "default value");
voteObj.put("votable_id",articleId);
voteObj.put("votable_type", "Article");
voteObj.put("voter_id", id);
voteObj.put("voter_type", "User");
voteObj.put("vote_flag", voteFlag);
voteObj.put("vote_weight", "1");
holder.put("votes", voteObj);
holder.put("article", articleId);
StringEntity se = new StringEntity(holder.toString());
put.setEntity(se);
// setup the request headers
put.setHeader("Accept", "application/json");
put.setHeader("Content-Type", "application/json");
// add email and auth token to validate
put.setHeader("X-User-Email", email);
put.setHeader("X-User-Token", authToken);
//response = webClient.execute(put);
//json = new JSONObject(response);
webResponse = String.valueOf(webClient.execute(put).getStatusLine().getStatusCode());
json = new JSONObject(webResponse);
} catch (HttpResponseException e) {
e.printStackTrace();
Log.e("ClientProtocol", "" + e);
json.put("info", "Email and/or password are invalid. Retry!");
} catch (IOException e) {
e.printStackTrace();
Log.e("IO", "" + e);
}
} catch (JSONException e) {
e.printStackTrace();
Log.e("JSON", "" + e);
}
return json;
}
答案 0 :(得分：0)
经过几天的搜索和比较我的代码后，它显示99％正常工作。我遗失的一件事是：
http://guides.rubyonrails.org/layouts_and_rendering.html#the-status-option
基本上302找到的响应类被标记为重定向，所以我从来没有从服务器得到响应。我将错误更改为409冲突，其响应类是客户端错误，我在webResponse中收到它，所以如果我收到409则意味着用户已经投票。
def upvote
@article.upvote_by current_user
if @article.vote_registered?
flash[:success] = "Successfully liked"
respond_to do |format|
format.html {redirect_to :back }
format.json { render json: { count: @article.get_upvotes.size } }
end
else
flash[:danger] = "You have already liked this"
respond_to do |format|
format.html {redirect_to :back }
format.json { head :conflict }
end
end
end