guava(二) Equivalence

Equivalence 一种判定两个实例是否相等的策略

全路径：com.google.common.base

声明：

@GwtCompatible

public abstract class Equivalence<T>

equivalent

public final boolean equivalent(@Nullable T a, @Nullable T b) {
    if (a == b) {
      return true;
    }
    if (a == null || b == null) {
      return false;
    }
    return doEquivalent(a, b);
  }