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Thread: how to access a hashmap which is inside a MultiMap

  1. #1
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    Default how to access a hashmap which is inside a MultiMap

    I am having a Multimap which contains key as sitename and Values is another hashmap.
    I am getting these values from Database.

    LinkedHashMap> thisHash = new <LinkedHashMap();
        thisHash.put(fiscal_date,avg_RT);
        siteMap.put(site_name,thisHash);


    The sample value in my hashmap is


    Key: New York, Value: {06/13/2012=1.3}. Value: {06/14/2012=1.48}.
    Key: Bangalore, Value: {06/13/2012=2.53}. Value: {06/14/2012=3.08}.
    Key: San Jose, Value: {06/13/2012=1.25}. Value: {06/14/2012=1.28}.
    Key: Amsterdam, Value: {06/13/2012=1.71}. Value: {06/14/2012=2.27}.


    Now I need to access the LinkedHashMap which is inside this multimap and get the key and value seperately. Please help me to do the same.


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: how to access a hashmap which is inside a MultiMap

    What is a multimap? Is that a class you have defined?
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
    Super Moderator pbrockway2's Avatar
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    Default Re: how to access a hashmap which is inside a MultiMap

    Now I need to access the LinkedHashMap which is inside this multimap and get the key and value seperately.
    Reverse the steps you use to put the data into the collection. That is, take the collection and get the map associated with the site name. Then take this latter map and get whatever data you want from it. (eg the value for a given date, or the complete set of date/value pairs etc).

    -----

    If you get stuck, post code which at least compiles. Multimaps are not a standard Java collection, so identify what package you are getting this from (Google, Apache etc...).

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    Default Re: how to access a hashmap which is inside a MultiMap

    MultiMap is a Apache Package.
    I am importing import org.apache.commons.collections.MultiMap.*;

    I have tried to get the Value of Collection into a HashMap. But as it is only 1 parameter, I am getting error.
    Set keySet = siteMap.keySet();
    Iterator keyIterator = keySet.iterator( );

    while( keyIterator.hasNext( ) ) {
    Object key = keyIterator.next( );
    System.out.print( "Key: " + key + ", " );

    Collection values = (Collection) siteMap.get( key );
    Iterator valuesIterator = values.iterator( );
    while( valuesIterator.hasNext( ) ) {
    LinkedHashMap Hash1 = new LinkedHashMap();
    Hash1 = valuesIterator.next();
    System.out.print( "Value: " + valuesIterator.next( ) + ". " );
    System.out.print("List value" + Hash1);
    }
    System.out.print( "\n" );
    }
    Here data types for Hash1 is LinkedHashMap and valuesIterator.next() is returning java.lang.object.

    Please help.
    Last edited by vidyasure; June 20th, 2012 at 01:38 AM.

  5. #5
    Super Moderator Norm's Avatar
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    Default Re: how to access a hashmap which is inside a MultiMap

    I am getting error.
    Please post the full text of the error message and show the code causing it.
    If you don't understand my answer, don't ignore it, ask a question.

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