jAgg is a Java 5.0 API that supports “group by” operations on Lists of Java objects: aggregate operations such as count, sum, max, min, avg, and many more. It supports Super Aggregation: Rollups, Cube, and Grouping Sets. It supports analytic operations such as lag/lead and row number and more. It also allows custom aggregate and analytic operations.
- Ability to apply "group by" functionality to an arbitrary List of Objects
- Specify "group by" properties by making List items Comparable or by supplying a list of property names, like a SQL "group by"
- 20 Built-in Aggregators: Sum, Count, Avg, Max, Min, Collect, Concat, Correlation, Covariance, CovariancePop, GeometricMean, HarmonicMean, LinearRegression, Mode, Percentile, Product, StdDev, StdDevPop, Variance, VariancePop
- Customizable Aggregators
- Parallel processing available
- Multiset Discrimination
- Super Aggregation: Rollups, Cube, and Grouping Sets
- Analytic Functions, including all built-in Aggregators plus 9 Built-in Analytic-only functions
Jagg is good! Thanks.