Basic histogram in JFreeChart

Question

I need to create a simple histogram using JFreeChart. There should be 3 groups with numeric values assigned to each of these groups. The problem is that DefaultCategoryDataset requires specifying "Group" and "Subgroup" (i.e. dataset.setValue(5,"Subgroup1.1","Group1");), but I don´t have subgroups. What is the alternative of DefaultCategoryDataset? I need to get something like this:

DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.setValue(2, "Group1");
dataset.setValue(3, "Group2");
dataset.setValue(5, "Group3");

Solution

You can just use the same row key for each bin and vary the column key, like this:

DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(561, "Age", "1 - 10");
dataset.addValue(1231, "Age", "10 - 20");
dataset.addValue(12323, "Age", "20+");