Combining HashMaps

[tmiranda]

If I have two hash maps created by new_java_util_HashMap() how do I combine them into one? I thought I should use java_util_Map_putAll() but I can't get this to work properly. Maybe I have the syntax wrong?

In some cases the two maps I need to combine have no overlapping keys, in other cases the same key may appear in both maps. If the key does exist in both maps I want the resulting combined subgroup to contain all elements. (The same element will never exist in both maps I am trying to combine.)

Thanks in advance,

Tom

[GKusnick]

Originally Posted by tmiranda

Maybe I have the syntax wrong?

I don't mean to be snarky but we can't tell you if it's right or wrong unless you show us what you have.

Originally Posted by tmiranda

If the key does exist in both maps I want the resulting combined subgroup to contain all elements.

You will most likely have to write your own code to do that. Map.putAll() doesn't know about the internal structure of the map values and will just replace one value with another without trying to merge them. If the values are arrays or lists and you want them merged, you'll have to do that yourself.

[tmiranda]

Greg,

For _putAll I tried _putAll(List1, List2) hoping that it would combine everything from List1 into List2. I also tried it the other way around.

I'm using the maps to group Airings so the key for each map is whatever I am grouping by and each key returns one or more Airings.

Thanks for your continued help.

Tom

[PLUCKYHD]

Since you are not coding directly in java can you not do a dataunion or dataintersection before the grouping since in the end you are grouping the same anyways.

Pluckyhd

[tmiranda]

Originally Posted by PLUCKYHD

Since you are not coding directly in java can you not do a dataunion or dataintersection before the grouping since in the end you are grouping the same anyways.

Pluckyhd

I'm not grouping them the same. I am using GroupByMethod() on several different data sets (using different methods) and then combining the groups.

I decided just to combine the groups manually by spinning through all of the elements and using AddToGrouping(). It's not elegant but it works.

The bad news is that I have a lot to learn about java. The good news is that I've installed Netbeans and have started doing some experiments.

[PLUCKYHD]

Originally Posted by tmiranda

I'm not grouping them the same. I am using GroupByMethod() on several different data sets (using different methods) and then combining the groups.

I decided just to combine the groups manually by spinning through all of the elements and using AddToGrouping(). It's not elegant but it works.

The bad news is that I have a lot to learn about java. The good news is that I've installed Netbeans and have started doing some experiments.

Good start Tom trust me you will find netbeans allot easier to code in than studio once you get it going.