答案是不加东西当然不能的，返回值直接返回一个null

	@Autowired
	private PriceRuleMapper priceRuleMapper;

	@Test
	public void contextLoads() {
		PriceRule priceRule=new PriceRule();
		priceRule.setName("abc");
		priceRuleMapper.insert(priceRule);
		System.out.println(priceRule.getId());
	}

}

但是，你在mapper层，在方法体加上：
@Options(useGeneratedKeys=true, keyProperty=“id”, keyColumn=“id”)

  @Insert({
        "insert into price_rule (id, name)",
        "values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR})"
    })
    @Options(useGeneratedKeys=true, keyProperty="id", keyColumn="id")
    int insert(PriceRule record);

就能得到新增的id了！