Edit: Figured it out, check my posted answer if you're having similar issues.
I know there are several questions about this issue, but none of their solutions are working for me.
In my model class I have made sure to use List instead of Arraylist to avoid Firebase issues, but am still getting this error. It's a lot of code but most questions ask for all the code so I'll post it all.
TemplateModelClass.java
//
I've used this basic model successfully many times. For the
HashMaps<String, List<String>>,
the String is an incremented Integer converted to String. The List's are just Strings in a List. Here's some sample JSON from Firebase:
//
Formatted that as best as I could. If you need a picture of it let me know and I'll get a screenshot
And am getting this error, as stated in the title:
com.google.firebase.database.DatabaseException: Expected a Map while deserializing, but got a class java.util.ArrayList
The most upvoted question about this seems to have something to do with a problem using an integer as a key, but I think I've avoided that by always using an integer converted to a string. It may be interpreting it strangely, so I'll try some more stuff in the meantime. Thanks for reading!
Alright, figured it out. If anyone reading this has this problem and are using incremented ints/longs/whatever that get converted to strings, you must add some characters to the converted int. Firebase apparently converts these keys back into non-Strings if it can be converted.
For example, if you do something like this:
int inc = 0;
inc++; // 1
map.put(String.valueOf(inc), someList);
Firebase interprets that key as 1 instead of "1".
So, to force Fb to intepret as a string, do something like this:
int inc = 0;
inc++; // 1
map.put(String.valueOf(inc) + "_key", someList);
And everything works out perfectly. Obviously if you also need to read those Strings back to ints, just split the string with "[_]" and you're good to go.
The main issue is that you are using a List instead of a Map. As your error said, while deserializing it is expectig a Map but is found an ArrayList.
So in order to solve this problem youd need to change all the lists in your model with maps like this:
private Map<String, Object> mMapOne;
After changing all those fileds like this, you need also to change your public setters and getters.
Hope it helps.
Related
This is the first time I stored binaries in rethinkdb and it went quiet well for storing them. The approach was quite simple (as documented in the command reference of ReQl. Also retrieving the binary from the Database again is fairly easy, yet I am struggling to convert it into a byte[]. The documentation says that r.binary() should return byte[] but in my case it returns a MapObject with a key called data. When retrieving that, data is an object but cannot be casted to byte[].
My code
MapObject mo = (MapObject)r.binary(continents.get("visibleMapImageBinary")).build();
//^^ is the MapObject that I can retrieve
String b = (String)tempor.get("data");
However I do not know how to get this back into a byte[]. Also tried to convert the String into a byte array, which also failed.
Thanks for any advice :)
After some trying out (and googling for what [B is, which I just thought stood for nothing but actually is the primtive of byte[]). This is my solution, no need to build() or even cast to the MapObject.
byte[] temp = (byte[])continents.get("visibleMapImageBinary");
I actually thought I tried this before, but it seems like I didn't ... well :)
I have a very simple question...
In my Android app i'm forming a JSON string to send to my server... there are no error in my code, but Java (or Android) puts the values in a different order of mine and I don't know why...
I want to solve this issue, because I need to process that JSON string in the server to update some tables of my database... my PHP code in the server uses the same order I used in my app to decode the JSON string, but because of Android (or Java) that changes the order, I'm having troubles to update the tables...
Any ideas? Thanks in advance!
I'm talking about this:
In my app:
json_data.put("id_visit", visits.getString(visits.getColumnIndexOrThrow("id_visit")));
json_data.put("id_form", visits.getString(visits.getColumnIndexOrThrow("id_form")));
json_data.put("id_establishment", visits.getString(visits.getColumnIndexOrThrow("id_establishment")));
json_data.put("id_promoter", visits.getString(visits.getColumnIndexOrThrow("id_promoter")));
json_data.put("actual_date", visits.getString(visits.getColumnIndexOrThrow("actual_date")));
json_data.put("receiver", visits.getString(visits.getColumnIndexOrThrow("receiver")));
json_data.put("observations", visits.getString(visits.getColumnIndexOrThrow("observations")));
json_data.put("gps_coordinates", visits.getString(visits.getColumnIndexOrThrow("gps_coordinates")));
In the LogCat:
{
"id_promoter":"1",
"id_establishment":"5",
"id_visit":"1",
"receiver":"brenda lopez",
"gps_coordinates":"10.4905567 -66.8710966",
"actual_date":"2012-11-27",
"id_form":"1",
"observations":"observaciones"
}
As you can see, its not te same order! Why is this?
I apologize for not taking the time of checking if someone else already asked this, but I'm in a little hurry, so... Sorry!! xD
Object keys are not ordered in JSON. If you need a specific order, I suggest you use an array:
[
{"id_promoter":"1"},
{"id_establishment":"5"},
{"id_visit":"1"},
{"receiver":"brenda lopez"},
{"gps_coordinates":"10.4905567 -66.8710966"},
{"actual_date":"2012-11-27"},
{"id_formu":"1"},
{"observations":"observaciones"}
]
It's gross, but order is what arrays are for.
Another approach is to define an array with the key names in the desired order. Then you can use your original object structure but access it through keys defined by the array. This takes more coding, obviously, but it can also solve your problem.
hy,
this question is pretty similar to SingleColumnValueFilter not returning proper number of rows .
I use four SingleColumnValueFilter's w/ operator EQUAL and add them to a FilterList with Operator MUST_PASS_ONE. the number of results is the same as w/o setting the FilterList. The value to compare is a byte[] that should be correct as I just store the values from previous results. (it is an IP address that I convert to InetAddress, new InetAddress(value as byte[]), when retrieving the data, and for the query described I just call InetAddress.getAddress which returns a byte[])
Do you have any ideas what might be the problem? Am I using the Filter wrong?
EDIT:
I also used the original values retrieved by the query as value for SingleColumnValueFilter, and there was no difference in the results, thus the byte[] contents can't be the problem.
I think I can give the answer myself, sorry for not debugging and checking all the hbase code before.
I just checked the implementation of the compare algorithm (which is lexicographically), and thus i realized that the length is not taken into account, though I thought it would be filled up w/ zero's; unfortunately it is not.
The only reasonable option would be to create a custom comparator (eg see How do you use a custom comparator with SingleColumnValueFilter on HBase?)
I want to work with Open Street Map (OSM). OSM keeps its data formats as flexible as possible by using key value pairs. I am developing an application for Android and I am going to send it a JSON string of OSM data. What should I do if I do not know what the JSON will look like in advance? What would be the best library?
Thanks for your help,
Chris
This may be what you are looking for
http://code.google.com/p/google-gson/
Cheers
First of all, you need to know if the JSON file contains an array or an object. If the first nonwhite space character is a [, it's an array, if it's a {, it's an object. Creating JSONArray when the first char is a { or vice versa will throw a Runtime Exception.
Second off all, once you have your JSONObject, you're going to want to get data from it. So you have to know the name of the keys to get the values, i.e.
myStreet = myJsonOjbect.getString("street name")
If you're not going to get data from it, what's the point of having the json file? Surely you can open the JSON in a Lint to see what the structure is.
hope this helps!
Sorry if my question sounds dumb. But some time small things create big problem for you and take your whole time to solve it. But thanks to stackoverflow where i can get GURU advices. :)
So here is my problem. i search for a word in a string and put 0 where that word occur.
For example : search word is DOG and i have string "never ever let dog bite you" so the string
would be 000100 . Now when I try to convert this string into INT it produce result 100 :( which is bad. I also can not use int array i can only use string as i am concatinating it, also using somewhere else too in program.
Now i am sure you are wondering why i want to convert it into INT. So here my answer. I am using 3 words from each string to make this kind of binary string. So lets say i used three search queries like ( dog, dog, ever ) so all three strings would be
000100
000100
010000
Then I want to SUM them it should produce result like this "010200" while it produce result "10200" which is wrong. :(
Thanks in advance
Of course the int representation won't retain leading zeros. But you can easily convert back to a String after summing and pad the zeros on the left yourself - just store the maximum length of any string (assuming they can have different lengths). Or if you wanted to get even fancier you could use NumberFormat, but you might find this to be overkill for your needs.
Also, be careful - you will get some unexpected results with this code if any word appears in 10 or more strings.
Looks like you might want to investigate java.util.BitSet.
You could prefix your value with a '1', that would preserve your leading 0's. You can then take that prefix into account you do your sum in the end.
That all is assuming you work through your 10 overflow issue that was mentioned in another comment.
Could you store it as a character array instead? Your using an int, which is fine, but your really not wanting an int - you want each position in the int to represent words in a string, and you turn them on or off (1 or 0). Seems like storing them in a character array would make more sense.