想要快速创建Map，不用频繁new，最快的方法就是用Guava，使用ImmutableMap.of(“a”, 1, “b”, 2, “c”, 3);
GuavaMap left = ImmutableMap.of(“a”, 1, “b”, 2, “c”, 3);
java 9Map map = Map.of(1, “A”, 2, “B”, 3, “C”);
超过 10 组会不支持，那么就要这样：Map.ofEntries(
Map.entry( 1, false ),
Map.entry( 2, true ),
Map.entry( 3, false ),
Map.entry( 4, true ),
Map.entry( 5, false ),
Map.entry( 6, true ),
Map.entry( 7, false ),
Map.entry( 8, true ),
Map.entry( 9, false ),
Map.entry( 10, true ),
Map.entry( 11, false )
);
匿名Map mymap = new HashMap() {
{
put(1, “one”);
put(2, “two”);
}
};
Collections.unmodifiableMap(new HashMap() {
{
put(0, “zero”);
put(1, “one”);
put(2, “two”);
put(3, “three”);
put(4, “four”);
put(5, “five”);
put(6, “six”);
put(7, “seven”);
put(8, “eight”);
put(9, “nine”);
put(10, “ten”);
put(11, “eleven”);
put(12, “twelve”);
}
});