CODEWITHSUNDEEP
javadatabasedata-structuresarraylisthashmap
Zeb
Zeb

Reputation: 2777

Manage/Fill data in Hash-Map in proper format

Actually I retrieve data from database which is surely in the form of table. I want to manage data (table) in hash-map in specific format. Firstly I show you the following code and it's output in a console:

Code:

 ResultSetMetaData rsmd = resultSet.getMetaData();
    int columnsNumber = rsmd.getColumnCount();
    while (resultSet.next()) {
        for (int i = 1; i <= columnsNumber; i++) {
           if (i > 1) System.out.print(",  ");
           String columnValue = resultSet.getString(i);
           System.out.print(columnValue );
           }
         System.out.println("");
    }

Output:

 ID      SkillGroup

 47010,  EN.SG
 47013,  shabber_hassan
 47014,  CAM.SG
 47014,  CIM.SG
 47014,  EN.SG
 47014,  JZskillGroup
 47014,  camp_agent.SG
 999,    EN.SG
 3333,   absaara_test2.SG
 3333,   absaara_test3.SG

I want to make a Hasp-Map which should be filled with following way:

Key: Should be the ID.
Value: All the skillgroup (maybe in Arraylist) related to one ID

How I Can Do This:

ID   --->  [All skill group related to associated ID]
47010 ---> [EN.SG]
47013 ---> [shabber_hassan,]
47014 ---> [CAM.SG,CIM.SG,EN.SG,JZskillGroup,camp_agent.SG]
999   ---> [EN.SG]
333   ---> [ab_test2.SG,ab_test3.SG]

Some help would be apppreciated !!

Upvotes: 2

Views: 182

Answers (1)

Eran
Eran

Reputation: 393791

Use a HashMap<Integer,List<String>>.

Assuming your table has two columns (ID and Skill Group), based on your output :

Map<Integer,List<String>> map = new HashMap<>();
while (resultSet.next()) {
    String key = resultSet.getInt(1);
    String value = resultSet.getString(2);
    List<String> values = map.get(key);
    if (values == null) {
        values = new ArrayList<String>();
        map.put(key,values);
    }
    values.add(value);
}

Upvotes: 3

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