[SalesForce] How to merge multiple Map/JSON Object into One Map

I am trying to build a json out of List of Maps but I need to merge few maps together when matching key is found.

How can I merge few Apex Map Object values ?

For example:

Map<String,Object> parent1 = new Map<String,Object>{
      'field1' =>  'value'
    };
Map<String,Object> root1 = new Map<String,Object>{
      'root' => parent1
};
Map<String,Object> parent2 = new Map<String,Object>{
      'field2' =>  'value'
    };
Map<String,Object> root2 = new Map<String,Object>{
      'root' => parent2
};

If Ill add each Map root1 and root2 to a List:

List<Map<String,Object>> listOfMap =new List<Map<String,Object>>();  
listOfMap.add(root1);
listOfMap.add(root2);

Results will look like this :

[{"root":{"field1":"value"}},{"root":{"field2":"value"}}]

Which is closer, But what I'm trying to do is to merge this results into one Object.

For example my end result should look like :

{
    "root": {
      "field1": "value",
      "field2": "value"
    }
  }

If ill place those 2 Maps using putAll() – Instead of appending the values I will always get the last.

{"root":{"field2":"value"}}

Best Answer

Something like this?

Map<String,Object> jsonMap = new Map<String,Object>{'root'=> new Map<String,Object>{'field1'=>'value','field2'=>'value'}};
System.debug(JSON.serialize(jsonMap));

Your parent map key is root, so if you wanna add field3, you can

((Map<String,Object>)jsonMap.get('root')).put('field3','value');

Related Solutions

[SalesForce] deserializing JSON returns a null object

I think you just need to use saJSONwrapper class when you deserialize instead of saJSON:

List<saJSON> saj=(List<saJSONwrapper >) JSON.deserialize(body,List<saJSONwrapper >.class);

because in your JSON you have list of saJSONwrapper not saJSON.

[SalesForce] How to sort keys in MAP while grouping

Java has multiple map classes such as LinkedHashMap that preserve insertion order but Apex only has one map type which does not. So in Apex a work-around is to keep a separate list of the keys as lists preserve insertion order and get the keys to iterate through from the list:

private Map<string, groupingWrapClass> map_lineitems_Group
        = new Map<string, groupingWrapClass>();
private List<String> ordered_keys = new List<String>();

private void addToMap(String key, groupingWrapClass grouping) {
    map_lineitems_Group.put(key, grouping);
    ordered_keys.add(key);
}

private void xyz() {
    ...
    addToMap('XYZ', keyvalues);
    addToMap('ABC', keyvalues);
    ...
    // Run through the map keys in insertion order
    for (String key : ordered_keys) {
        groupingWrapClass grouping = map_lineitems_Group.get(key);
        ...
    }
}

PS

On exposing this to Visualforce, make both ordered_keys and map_lineitems_Group visible (add getters or make properties) and then e.g.:

<apex:pageBlockTable value="{!ordered_keys}" var="ordered_key">
<apex:column headerValue="Year Name" value="{!map_lineitems_Group[ordered_key].yearname}"/>
...
</apex:pageBlockTable>

as expressions in Visualforce use [] for map access.

You could also add an apex:variable to factor out the common map_lineitems_Group[ordered_key] expression.

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