39 lines
1.1 KiB
Java
39 lines
1.1 KiB
Java
// onjava/FillMap.java
|
|
// (c)2020 MindView LLC: see Copyright.txt
|
|
// We make no guarantees that this code is fit for any purpose.
|
|
// Visit http://OnJava8.com for more book information.
|
|
package onjava;
|
|
import java.util.*;
|
|
import java.util.function.*;
|
|
import java.util.stream.*;
|
|
|
|
public class FillMap {
|
|
public static <K, V> Map<K,V>
|
|
basic(Supplier<Pair<K,V>> pairGen, int size) {
|
|
return Stream.generate(pairGen)
|
|
.limit(size)
|
|
.collect(Collectors
|
|
.toMap(Pair::key, Pair::value));
|
|
}
|
|
public static <K, V> Map<K,V>
|
|
basic(Supplier<K> keyGen,
|
|
Supplier<V> valueGen, int size) {
|
|
return Stream.generate(
|
|
() -> Pair.make(keyGen.get(), valueGen.get()))
|
|
.limit(size)
|
|
.collect(Collectors
|
|
.toMap(Pair::key, Pair::value));
|
|
}
|
|
public static <K, V, M extends Map<K,V>>
|
|
M create(Supplier<K> keyGen,
|
|
Supplier<V> valueGen,
|
|
Supplier<M> mapSupplier, int size) {
|
|
return Stream.generate( () ->
|
|
Pair.make(keyGen.get(), valueGen.get()))
|
|
.limit(size)
|
|
.collect(Collectors
|
|
.toMap(Pair::key, Pair::value,
|
|
(k, v) -> k, mapSupplier));
|
|
}
|
|
}
|