comparable on a generic class java
public class DoubleKey<K extends Comparable<K>, J extends Comparable<J>> implements Comparable<DoubleKey<K, J>> { private K key1; private J key2; public DoubleKey(K key1, J key2) { this.key1 = key1; this.key2 = key2; } public K getFirstKey() { return this.key1; } public J getSecondKey() { return this.key2; } public int compareTo(DoubleKey<K, J> that) { int cmp = this.getFirstKey().compareTo(that.getFirstKey()); if (cmp == 0) cmp = this.getSecondKey().compareTo(that.getSecondKey()); return cmp; } }
