大致分为这三步

首先在usercontroller中增加updatePwd方法

@PatchMapping ("/updatePwd")
    public Result updatePwd(@RequestBody Map<String,String> params){
        //1.校验参数
        String oldPwd = params.get("old_pwd");
        String newPwd = params.get("new_pwd");
        String rePwd = params.get("re_pwd");

        if (!StringUtils.hasLength(oldPwd)||!StringUtils.hasLength(newPwd)||!StringUtils.hasLength(rePwd)){
            return Result.error("参数有误");
        }

        //原密码是否正确
        //调用userservice根据用户名拿到原密码，再和old_pwd进行比较
        Map<String,Object> map=ThreadLocalUtil.get();
        String username = (String) map.get("username");
        User loginUser = userService.findByUsername(username);
        if (!loginUser.getPassword().equals(Md5Util.getMD5String(oldPwd))){
            return Result.error("原密码错误");
        }

        //newPwd和rePwd是否一样
        if (!newPwd.equals(rePwd)){
            return Result.error("两次密码不一致");
        }
        //2.调用service完成密码更新

        userService.updatePwd(newPwd);
        return Result.success();

    }```


然后再userservice中增加
//更新密码
    void updatePwd(String newPwd);

再在userserviceimpl实现类中增加

```java
@Override
    public void updatePwd(String newPwd) {
        Map<String,Object> map= ThreadLocalUtil.get();
        Integer id = (Integer) map.get("id");
        userMapper.updatePwd(Md5Util.getMD5String(newPwd),id);
    }

最后修改mapper层代码

@Update("update user set password=#{md5String},update_time=now() where id=#{id}")
    void updatePwd(String md5String, Integer id);

okk~