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;
}

在这种情况下，我只得到最后一组数据，所有数据都被覆盖了，谁能帮我弄清楚如何以如下格式传递数据？

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

等等。

Answer 1

每次要将值存储到valueFromEachOfThoseNineFields ，然后将valueFromEachOfThoseNineFields存储到fileNameConstrains时，您都需要为valueFromEachOfThoseNineFields分配一个新的HashMap实例，如下所示：

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;
    }
}

输出：

{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

您的数据被覆盖的原因是因为您在内部地图中使用与文档相同的键，说明地图的键应该是唯一的

所以要在这里解决您的问题，您必须在每个新文件上恢复地图

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);