How to model hierarchical json in Java I'm a front end developer who is brand new to backend development. My task is to model json in a Java object. It's just some mock data for now that my controller returns. 

{
"data": {
    "objectId": 25,
    "columnName": [
        "myCategory",
        "myCategoryId"
    ],
    "columnValues": [
        [
            "Category One",
            1
        ],
        [
            "Category Two",
            2
        ],
        [
            "Category Three",
            3
        ],
        [
            "Category Four",
            4
        ],
        [
            "Category Five",
            5
        ]
    ]
}


}

And here's my attempt. The controller returns this json correctly. But isn't this too simple? What I believe should be done is extrapolate the columnName and columnValues arrays into separate classes but I'm not sure how. 

package com.category;

import java.util.List;

public class MyObjectData {
    private int objectId;
    private List columnName;
    private List columnValues;

    public int getObjectId() {
        return objectId;
    }
    public void setObjectId(int objectId) {
        this.objectId = objectId;
    }

    public List getColumnName() {
        return columnName;
    }

    public void setColumnName(List colName) {
        this.columnName = colName;
    }

    public List getColumnValues() {
        return columnValues;
    }

    public void setValues(List values) {
        this.columnValues = values;
    }

}


Regarding the columnNames and columnValues, I feel like I should be doing something like this in the model instead:

private List&lt;ColumnNames&gt; columnNames;
    private List&lt;ColumnValues&gt; columnValues;

    public List&lt;ColumnNames&gt; getColumnNames() {
        return columnNames;
    }

    public void setColumnNames(List&lt;ColumnNames&gt; columnNames) {
        this.columnNames = columnNames;
    }

    public List&lt;ColumnValues&gt; getColumnValues() {
        return columnValues;
    }

    public void setColumnValues(List&lt;ColumnValues&gt; columnValues) {
        this.columnValues = columnValues;
    }


And then I'd have two separate classes for them like this:

package com.category;

import java.util.List;

public class ColumnName {

    private String columnName;

    public String getColumnName() {
        return columnName;
    }

    public void setColumnName(String columnName) {
        this.columnName = columnName;
    }

}

package com.category;

import java.util.List;

public class ColumnValue {

    private String columnValue;
    private int columnValueId;

    public String getColumnValue() {
        return columnValue;
    }

    public void setColumnValue(String columnValue) {
        this.columnValue = columnValue;
    }

    public String getColumnValueId() {
        return columnValueId;
    }

    public void setColumnValueId(int columnValueId) {
        this.columnValueId = columnValueId;
    }

}


I feel like I have all the right pieces but just not sure if this is a better approach than my initial attempt...which works. Just looking for input. Thanks in advance.
You implied Json -> Java object, but have you considered the other way around?  If so, check out Java object to Json serialization/deserialization using Gson.  Get more at https://en.wikipedia.org/wiki/Gson and https://static.javadoc.io/com.google.code.gson/gson/2.8.5/com/google/gson/Gson.html