Tricky filling an Array with values from JSON
Before I begin, this is my JSON: (The structure is rigid, an开发者_StackOverflow中文版d cant be changed)
[
{"_id":{"country":"au", "industry":"foo"}, "value":{"count":2}},
{"_id":{"country":"au", "industry":"bar"}, "value":{"count":1}},
{"_id":{"country":"be", "industry":"baz"}, "value":{"count":2}},
..
]
I cant have duplicate country names, and industry names. I have an array that is to be filled with values as
array[au][foo] = 2
array[au][bar] = 1
array[be][baz] = 2
the values are unsorted in the JSON, and all countries might not have the same industries.
How do i go about doing that? This is my current code:
for (int i = 0; i < jsonArray.size(); i++) {
JSONObject jsonValue = jsonArray.get(i).isObject();
JSONObject _id = jsonValue.get("_id").isObject();
JSONObject value = jsonValue.get("value").isObject();
String country = _id.get("country").isString().toString();
setCountry.add(country);
String industry = _id.get("industry").isString().toString();
setIndustry.add(industry);
int count = Integer.parseInt(value.get("count").isNumber()
.toString());
}
Im adding the country and industry to a set, to remove the duplicates. thats what causing the issue about the count. I dont care for it to be elegant, a hackjob will also do.
Thanks.
I think you can make use of enum's for your problem.Define all the known country names and Industry in an enum like this.
public enum Country {
au,
be;
int Int=this.ordinal();//just a short name for ordinal
}
and
public enum Industry {
foo,
bar,
baz;
int Int=this.ordinal();
}
Now define a 2d int array and you can set the value's using the enum's like this :
int[][] value=new int[Country.values().length][Industry.values().length];
value[Country.au.Int][Industry.bar.Int]=2;
//Read from JSON
value[Country.valueOf("au").Int][Industry.valueOf("bar").Int]=2;
You can add this code to the end of your current for loop if your using enum's:
value[Country.valueOf(country).Int][Industry.valueOf(industry).Int]=count;
Another option is to avoid an array and use Map instead:
Map<Country,Map<Industry,Integer>> m=new HashMap<Country,Map<Industry,Integer>>();
or simply without enums :
Map<String,Map<String,Integer>> m=new HashMap<String,Map<String,Integer>>();
The problem with map is that it is a bit tricky to add and retrieve value's from it but you can write common method's to do this job.
UPDATE:
Adding values to inner map:
String[][] countryAndIndustry= {{"au","foo"},{"au","bar"},{"be","baz"}};
Integer[] count= {2,1,2};
HashMap<String,HashMap<String,Integer>> hm=new HashMap<String, HashMap<String,Integer>>();
for(int i=0;i<count.length;i++)
{
HashMap<String,Integer> innerMap=hm.get(countryAndIndustry[i][0]);
if(innerMap==null)
{
innerMap=new HashMap<String, Integer>();
hm.put(countryAndIndustry[i][0],innerMap);
}
innerMap.put(countryAndIndustry[i][1],count[i]);
}
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