CODEWITHSUNDEEP
java
rickygrimes
rickygrimes

Reputation: 2716

Read info from a list and put in a map

I have the below code that reads information from two lists, and puts it in a map. I have close to 500 records, but I only see 75 records in the map. Please suggest what mistake I am making :(

private static Map<MyStore, List<String>> buildCache() {        
    for (MyStore myStores : myStoreList) {   //Contains a list of all the stores owned by me - has close to 600 stores.         
        for (HardwareInfo hardware : hardwareList) {    //Contains a list infrastructure information of these stores - These lists only have store number in common.
            if (myStores.getStoreNumber().equals(myStores.getStoreNumber())) {                      
                myCache.put(myStores, hardware.getHardwareInfo_East()); //myCache is a static map.
                myCache.put(myStores, hardware.getHardwareInfo_West());
                myCache.put(myStores,hardware.getHardwareInfo_South());
                myCache.put(myStores,hardware.getHardwareInfo_North());
                break;
            }

        }
    }


    for(Map.Entry<MyStore, List<String>> entry:myCache.entrySet())
    {
        System.out.println("ENTRY IS: " +entry.getKey()+ " AND VALUE IS: " +entry.getValue());
    }

    return myCache;
}
}

Upvotes: 0

Views: 71

Answers (1)

jlordo
jlordo

Reputation: 37813

A Map maps one key to one value. You're overriding the value many times.

This

if (myStores.getStoreNumber().equals(myStores.getStoreNumber())) {                      
    myCache.put(myStores, hardware.getHardwareInfo_East()); //myCache is a static map.
    myCache.put(myStores, hardware.getHardwareInfo_West());
    myCache.put(myStores,hardware.getHardwareInfo_South());
    myCache.put(myStores,hardware.getHardwareInfo_North());
    break;
}

is the same as 

if (myStores.getStoreNumber().equals(myStores.getStoreNumber())) {                      
    myCache.put(myStores,hardware.getHardwareInfo_North());
    break;
}

If you want to combine all the lists, you could do this:

if (myStores.getStoreNumber().equals(myStores.getStoreNumber())) {                      
    myCache.put(myStores, new ArrayList<String>(hardware.getHardwareInfo_East())); //myCache is a static map.
    List<String> list = myCache.get(myStores);
    list.addAll(hardware.getHardwareInfo_West());
    list.addAll(hardware.getHardwareInfo_South());
    list.addAll(hardware.getHardwareInfo_North());
    break;
}

Upvotes: 3

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