重写equals和hashcode达到HashSet对象集去重的实现

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/dreamzuora/article/details/88630560

public class Contract {

    private String contractId;
    private String contractName;

    private Date begin;
    private Date end;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Contract contract = (Contract) o;
        //自己的判断条件是时间段重合的算做同一个对象
        return false;
    }

    @Override
    public int hashCode() {
        //通过Objects类提供的hash方法
        int hash = Objects.hash(contractId, contractName);
        return hash;
    }

转载：https://www.cnblogs.com/sansamh/p/9025030.html