import java.util.Objects;

public class User {
    private int id;
    private String name;
    private int age;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        User user = (User) o;
        return id == user.id &&
                age == user.age &&
                Objects.equals(name, user.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, name, age);
    }
}

try {
				sf=HibernateUtil.getSessionFactory(); 
				session=sf.getCurrentSession();
				ts=session.beginTransaction();
					
				User u3=session.get(User.class, 3);
				session.evict(u3);
				User u4=session.get(User.class, 3);
			
				System.out.println(u3==u4);
 
				ts.commit();
			} 

测试结果：

hashCode相同，对象不一定相同
必须要地址的散列码相同才可以是同一个对象
重写后比较的方式改变，将不再比地址