此时我们把equals方法给加上:
public class HashTest { private int i; public int getI() { return i; } public void setI(int i) { this.i = i; } <span style="color:#3366FF;"><strong>public boolean equals(Object object) { if (object == null) { return false; } if (object == this) { return true; } if (!(object instanceof HashTest)) { return false; } HashTest other = (HashTest) object; if (other.getI() == this.getI()) { return true; } return false; }</strong></span> public int hashCode() { return i % 10; } public final static void main(String[] args) { HashTest a = new HashTest(); HashTest b = new HashTest(); a.setI(1); b.setI(1); Set<HashTest> set = new HashSet<HashTest>(); set.add(a); set.add(b); System.out.println(a.hashCode() == b.hashCode()); System.out.println(a.equals(b)); System.out.println(set); } } |
此时得到的结果就会如下:
true
true
[com.ubs.sae.test.HashTest@1]
从结果我们可以看出,现在两个对象就完全相等了,HashSet中也只存放了一份对象。