CODEWITHSUNDEEP
javaguava
WolfiG
WolfiG

Reputation: 1163

How to instanciate a guava Table dynamically?

I'm stuck with the follwoing problem: I want to use guava tables as they provide a convenient transpose operation. In Java 8 a guava table can be instanciated like this:

Table<R,C,V> table = HashBasedTable.createTable();

All examples I found use static instanciation concerning the types and the number of columns. Unfortunately, I do not know the number of columns at design time, so I have to find a way to instanciate the Table with arguemtns which I have to determine at run time.

Any ideas?

Upvotes: 2

Views: 454

Answers (1)

WolfiG
WolfiG

Reputation: 1163

Ok, I found it out myself, I misunderstood the documentation:

First I thought, a guava Table is instanciated like:

Table<T,....,T> table = HashBasedTable.createTable();

With N type definitions for each column.

But Reading the documentation more carefully, I found out that the instanciation is done by 

Table<R, C, V> table = HashBasedTable.createTable();

Where R is the type of the row key, C type column key, V value type. Hence one can for instance instanciate a matrix of Double values via:

Table<Integer, Integer, Double> matrix = HashBasedTable.createTable();

and access the matix via the cell indices (Integer, Integer).

Upvotes: 1

Related Questions