Initialize a hashmap in a more compact way without external libraries

Question

Is there a way to make this code more compact? With less lines without using libraries?
I am using Java 7

public enum CustomType {
    TYPE_A,
    TYPE_B,
    TYPE_C,
}

private static final Map<Integer, CustomType> typeMappings = new HashMap<>();

static {
    typeMappings.put(513, CustomType.TYPE_A);
    typeMappings.put(520, CustomType.TYPE_A);
    typeMappings.put(528, CustomType.TYPE_A);
    typeMappings.put(530, CustomType.TYPE_A);
    typeMappings.put(532, CustomType.TYPE_A);
    typeMappings.put(501, CustomType.TYPE_B);
    typeMappings.put(519, CustomType.TYPE_B);
    typeMappings.put(529, CustomType.TYPE_B);
}

Answer 1

Assuming that you have full control over both the mapping, and the enum classes, then the more traditional way to solve this problem is to embed the mapping in to the enums.

public enum CustomType {
    TYPE_A(513, 520, 528, 530, 532),
    TYPE_B(501, 519, 529),
    TYPE_C();

    private static final Map<Integer, CustomType> typeMappings = new HashMap<>();

    static {
        for (CustomType ct : values()) {
            for (int v : ct.mapto) {
                typeMappings.put(v, ct);
            }
        }
    }

    private final int mapto[];
    CustomType(int ... mapto) {
        this.mapto = mapto;
    }
}