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Java-arraylist-object-looping-through-multiple-values-and-keys

devanshi2806 profile image devanshi2806 ・2 min read

I'm new to Java and I'm making Following json by using a single arraylist with for loop and if statement.But I'm stuck with my for loop logic part.

Here is my java program.

main.java

public static void main(String args[]) throws JsonProcessingException {

    List<Map<Object, Object>> dataProviderList = new LinkedList<>();

    List<Object> yearList = new LinkedList<>();

    yearList.add(2009);
    yearList.add(2010);
    yearList.add(2011);
    yearList.add(2012);
    yearList.add(2013);
    yearList.add(2014);

    yearList.add(21.4);
    yearList.add(31.3);
    yearList.add(15.6);
    yearList.add(34.8);
    yearList.add(20.1);
    yearList.add(27.3);

    yearList.add(20.3);
    yearList.add(43.1);
    yearList.add(19.8);
    yearList.add(34.7);
    yearList.add(24.4);
    yearList.add(21.9);

    for (int i = 0; i < (yearList.size() - (i + 6)); i++) {

        Map<Object, Object> dataProviderValueMap = new LinkedHashMap<>();

        dataProviderValueMap.put("year", yearList.get(i));
        for (int j = 0; j < (yearList.size() + (i - 6)); j++) {
            dataProviderValueMap.put("income", yearList.get(j));
            for (int k = 0; k < (yearList.size() + (i - 6)); k++) {
                dataProviderValueMap.put("expenses", yearList.get(k));

                // for year 2014
                if (k == (yearList.size() - 2)) {

                    dataProviderValueMap.put("dashLengthLine", 0);
                    dataProviderValueMap.put("dashLengthColumn", 5);
                    dataProviderValueMap.put("alpha", 0.5);
                    dataProviderValueMap.put("additional", "(projection)");
                }

                // for year 2013
                if (k == (yearList.size() - 3)) {

                    dataProviderValueMap.put("dashLengthLine", 5);
                }
            }
        }
        dataProviderList.add(dataProviderValueMap);
    }


    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.enable(SerializationFeature.INDENT_OUTPUT);

    String mapToJson = objectMapper.writeValueAsString(dataProviderList);
    System.out.println(mapToJson);

}

I want following output:

required output:

"dataProvider" : [ {
"year" : 2009,
"income" : 21.4,
"expenses" : 20.3
}, {
"year" : 2010,
"income" : 31.3,
"expenses" : 43.1
}, {
"year" : 2011,
"income" : 15.6,
"expenses" : 9.8
}, {
"year" : 2012,
"income" : 34.8,
"expenses" : 34.7
}, {
"year" : 2013,
"income" : 20.1,
"expenses" : 24.4,
"dashLengthLine" : 5
}, {
"year" : 2014,
"income" : 27.3,
"expenses" : 21.9,
"dashLengthLine" : 0,
"dashLengthColumn" : 5,
"alpha" : 0.5,
"additional" : "(projection)"
} ]
How can i make this loop more concrete and enhanced for loop ? i only want to use one arraylist and for loop with if statement having Map inside the for loop. thanks for the help!

java for-loop if-statement arraylist dynamic

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