如何在具有不同键的外部hashMap中传递具有相同键的内部hashMap？

Question

public static HashMap<String, HashMap<String,Object>> getDataDictionary() {
    // Virtual Data Creation - Simulating The 9 Fields HAR value
    HashMap<String,Object> valueFromEachOfThoseNineFields = new HashMap<String,Object>();
    HashMap<String, HashMap<String,Object>> fileNameConstrains = new HashMap<String,HashMap<String,Object>>();
    valueFromEachOfThoseNineFields.put("A", 10);
    valueFromEachOfThoseNineFields.put("B", 20);
    valueFromEachOfThoseNineFields.put("C", 30);
    valueFromEachOfThoseNineFields.put("D", 10);
    valueFromEachOfThoseNineFields.put("E", 5);
    valueFromEachOfThoseNineFields.put("F", 20);
    valueFromEachOfThoseNineFields.put("G", 1);
    valueFromEachOfThoseNineFields.put("H", 100);
    valueFromEachOfThoseNineFields.put("I", 66);
    fileNameConstrains.put("File1", valueFromEachOfThoseNineFields);
    valueFromEachOfThoseNineFields.put("A", 10);
    valueFromEachOfThoseNineFields.put("B", 50);
    valueFromEachOfThoseNineFields.put("C", 30);
    valueFromEachOfThoseNineFields.put("D", 90);
    valueFromEachOfThoseNineFields.put("E", 5);
    valueFromEachOfThoseNineFields.put("F", 20);
    valueFromEachOfThoseNineFields.put("G", 10);
    valueFromEachOfThoseNineFields.put("H", 90);
    valueFromEachOfThoseNineFields.put("I", 61);
    fileNameConstrains.put("File2", valueFromEachOfThoseNineFields);
    valueFromEachOfThoseNineFields.put("A", 10);
    valueFromEachOfThoseNineFields.put("B", 60);
    valueFromEachOfThoseNineFields.put("C", 30);
    valueFromEachOfThoseNineFields.put("D", 2);
    valueFromEachOfThoseNineFields.put("E", 13);
    valueFromEachOfThoseNineFields.put("F", 9);
    valueFromEachOfThoseNineFields.put("G", 15);
    valueFromEachOfThoseNineFields.put("H", 88);
    valueFromEachOfThoseNineFields.put("I", 69);
    fileNameConstrains.put("File3", valueFromEachOfThoseNineFields);

    return fileNameConstrains;
}

In this case, I am getting only the last set, all data are getting overridden, can anyone help me to figure out how can I pass data in the format like below?

{Key="File1", value={'a'=10,'b'=5}}

And so on.

Answer 1

You need to assign a new HashMap instance to valueFromEachOfThoseNineFields every time you want to store values into it and subsequently storing valueFromEachOfThoseNineFields into fileNameConstrains as follows:

import java.util.HashMap;

public class Main {

    public static void main(String[] args) {
        System.out.println(getDataDictionary());
    }

    public static HashMap<String, HashMap<String, Object>> getDataDictionary() {
        // Virtual Data Creation - Simulating The 9 Fields HAR value
        HashMap<String, Object> valueFromEachOfThoseNineFields;
        HashMap<String, HashMap<String, Object>> fileNameConstrains = new HashMap<String, HashMap<String, Object>>();

        valueFromEachOfThoseNineFields = new HashMap<String, Object>();
        valueFromEachOfThoseNineFields.put("A", 10);
        valueFromEachOfThoseNineFields.put("B", 20);
        valueFromEachOfThoseNineFields.put("C", 30);
        valueFromEachOfThoseNineFields.put("D", 10);
        valueFromEachOfThoseNineFields.put("E", 5);
        valueFromEachOfThoseNineFields.put("F", 20);
        valueFromEachOfThoseNineFields.put("G", 1);
        valueFromEachOfThoseNineFields.put("H", 100);
        valueFromEachOfThoseNineFields.put("I", 66);
        fileNameConstrains.put("File1", valueFromEachOfThoseNineFields);

        valueFromEachOfThoseNineFields = new HashMap<String, Object>();
        valueFromEachOfThoseNineFields.put("A", 10);
        valueFromEachOfThoseNineFields.put("B", 50);
        valueFromEachOfThoseNineFields.put("C", 30);
        valueFromEachOfThoseNineFields.put("D", 90);
        valueFromEachOfThoseNineFields.put("E", 5);
        valueFromEachOfThoseNineFields.put("F", 20);
        valueFromEachOfThoseNineFields.put("G", 10);
        valueFromEachOfThoseNineFields.put("H", 90);
        valueFromEachOfThoseNineFields.put("I", 61);
        fileNameConstrains.put("File2", valueFromEachOfThoseNineFields);

        valueFromEachOfThoseNineFields = new HashMap<String, Object>();
        valueFromEachOfThoseNineFields.put("A", 10);
        valueFromEachOfThoseNineFields.put("B", 60);
        valueFromEachOfThoseNineFields.put("C", 30);
        valueFromEachOfThoseNineFields.put("D", 2);
        valueFromEachOfThoseNineFields.put("E", 13);
        valueFromEachOfThoseNineFields.put("F", 9);
        valueFromEachOfThoseNineFields.put("G", 15);
        valueFromEachOfThoseNineFields.put("H", 88);
        valueFromEachOfThoseNineFields.put("I", 69);
        fileNameConstrains.put("File3", valueFromEachOfThoseNineFields);

        return fileNameConstrains;
    }
}

Output:

{File3={A=10, B=60, C=30, D=2, E=13, F=9, G=15, H=88, I=69}, File2={A=10, B=50, C=30, D=90, E=5, F=20, G=10, H=90, I=61}, File1={A=10, B=20, C=30, D=10, E=5, F=20, G=1, H=100, I=66}}

Answer 2

the reason why your data get overridden because you use the same key in the inner map as the documentations says the key for the map should be unique

so to solve your issue here you have to reinstate the map on every new file

HashMap<String,Object> Map1 = new HashMap<>();
    HashMap<String, HashMap<String,Object>> fileNameConstrains = new HashMap<>();
    Map1.put("A", 10);
    Map1.put("B", 20);
    fileNameConstrains.put("File1", Map1);
    Map1 = new HashMap<String,Object>();
    Map1.put("A", 10);
    Map1.put("B", 50);
    fileNameConstrains.put("File2", Map1);
    Map1 = new HashMap<String,Object>();
    Map1.put("A", 10);
    Map1.put("B", 60);
    fileNameConstrains.put("File3", Map1);