Rust Web 全栈开发（九）：增加教师管理功能

Rust Web 全栈开发（九）：增加教师管理功能

参考视频：https://www.bilibili.com/video/BV1RP4y1G7KF

继续之前的 Actix 项目，项目现状如下所示：

新增教师结构体

在 models 目录下，新建一个 teacher.rs。

为 CreateTeacher 和 UpdateTeacher 分别实现了 From trait。

use actix_web::web;
use serde::{Deserialize, Serialize};#[derive(Deserialize, Serialize, Debug, Clone, sqlx::FromRow)]
pub struct Teacher {pub id: i32,pub name: String,pub picture_url: String,pub profile: String,
}#[derive(Deserialize, Debug, Clone)]
pub struct CreateTeacher {pub name: String,pub picture_url: String,pub profile: String,
}impl From<web::Json<CreateTeacher>> for CreateTeacher {fn from(new_teacher: web::Json<CreateTeacher>) -> Self {CreateTeacher {name: new_teacher.name.clone(),picture_url: new_teacher.picture_url.clone(),profile: new_teacher.profile.clone(),}}
}#[derive(Deserialize, Debug, Clone)]
pub struct UpdateTeacher {pub name: Option<String>,pub picture_url: Option<String>,pub profile: Option<String>,
}impl From<web::Json<UpdateTeacher>> for UpdateTeacher {fn from(update_teacher: web::Json<UpdateTeacher>) -> Self {UpdateTeacher {name: update_teacher.name.clone(),picture_url: update_teacher.picture_url.clone(),profile: update_teacher.profile.clone(),}}
}

对应要修改 models/mod.rs，新增：

pub mod teacher;

数据库准备

在名为 course 的 MySQL 数据库中，新建一个名为 teacher 的表：

新增访问 MySQL 数据库中 teacher 表的方法

在 dbaccess 目录下，新建一个 teacher.rs，其中涉及了对 teacher 表增删查改的方法。

use sqlx::MySqlPool;
use crate::errors::MyError;
use crate::models::teacher::{CreateTeacher, Teacher, UpdateTeacher};pub async fn post_new_teacher_db(pool: &MySqlPool, new_teacher: CreateTeacher) -> Result<(), MyError> {let _insert_query = sqlx::query!("INSERT INTO teacher (name, picture_url, profile)VALUES (?, ?, ?)",new_teacher.name,new_teacher.picture_url,new_teacher.profile,).execute(pool).await?;Ok(())
}pub async fn delete_teacher_db(pool: &MySqlPool, teacher_id: i32) -> Result<String, MyError> {let row = sqlx::query!("DELETE FROM teacherWHERE id = ?",teacher_id,).execute(pool).await.map_err(|_err| MyError::DBError("Unable to delete teacher".into()))?;Ok(format!("Deleted {:?} record", row))
}pub async fn update_teacher_details_db(pool: &MySqlPool,teacher_id: i32,update_teacher: UpdateTeacher
) -> Result<String, MyError> {let current_teacher_row: Teacher = sqlx::query_as("SELECT id, name, picture_url, profileFROM teacherWHERE id = ?").bind(teacher_id).fetch_one(pool) // 获取单条记录.await.map_err(|_err| MyError::NotFound("Teacher Id not found".into()))?;let teacher = Teacher {id: current_teacher_row.id,name: if let Some(name) = update_teacher.name {name} else {current_teacher_row.name},picture_url: if let Some(picture_url) = update_teacher.picture_url {picture_url} else {current_teacher_row.picture_url},profile: if let Some(profile) = update_teacher.profile {profile} else {current_teacher_row.profile},};let row = sqlx::query!("UPDATE teacherSET name = ?, picture_url = ?, profile = ?WHERE id = ?",teacher.name,teacher.picture_url,teacher.profile,teacher_id,).execute(pool).await?;Ok(format!("Update {:?} record", row))
}
pub async fn get_all_teachers_db(pool: &MySqlPool) -> Result<Vec<Teacher>, MyError> {let rows: Vec<Teacher> = sqlx::query_as("SELECT id, name, picture_url, profileFROM teacher").fetch_all(pool) // 获取所有记录.await?;match rows.len() {0 => Err(MyError::NotFound("Teacher not found".into())),_ => Ok(rows),}
}pub async fn get_teacher_details_db(pool: &MySqlPool, teacher_id: i32) -> Result<Teacher, MyError> {let row = sqlx::query_as("SELECT id, name, picture_url, profileFROM teacherWHERE id = ?").bind(teacher_id).fetch_one(pool) // 获取单条记录.await.map(|teacher: Teacher| Teacher {id: teacher.id,name: teacher.name,picture_url: teacher.picture_url,profile: teacher.profile,}).map_err(|_err| MyError::NotFound("Teacher Id not found".into()))?;Ok(row)
}

对应要修改 dbaccess/mod.rs，新增：

pub mod teacher;

新增 Handler

在 handlers 目录下，新建一个 teacher.rs。

其中的函数调用 dbaccess/teacher.rs 的方法，得到结果，转换为 HTTP Response。

use std::env;
use std::sync::Mutex;
use actix_web::{web, HttpResponse};
use actix_web::web::Data;
use dotenv::dotenv;
use sqlx::mysql::MySqlPoolOptions;
use crate::errors::MyError;
use crate::state::AppState;
use crate::dbaccess::teacher::*;
use crate::models::teacher::{CreateTeacher, UpdateTeacher};pub async fn post_new_teacher(new_teacher: web::Json<CreateTeacher>,app_state: web::Data<AppState>,
) -> Result<HttpResponse, MyError> {post_new_teacher_db(&app_state.db, new_teacher.into()).await.map(|_| HttpResponse::Ok().json("Post new teacher successfully."))
}pub async fn get_all_teachers(app_state: web::Data<AppState>) -> Result<HttpResponse, MyError> {get_all_teachers_db(&app_state.db).await.map(|teachers| HttpResponse::Ok().json(teachers))
}pub async fn get_teacher_detail(app_state: web::Data<AppState>,params: web::Path<i32>
) -> Result<HttpResponse, MyError> {let teacher_id = params.into_inner();get_teacher_details_db(&app_state.db, teacher_id).await.map(|teacher| HttpResponse::Ok().json(teacher))
}pub async fn update_teacher_detail(app_state: web::Data<AppState>,update_teacher: web::Json<UpdateTeacher>,params: web::Path<i32>
) -> Result<HttpResponse, MyError> {let teacher_id = params.into_inner();update_teacher_details_db(&app_state.db, teacher_id, update_teacher.into()).await.map(|msg| HttpResponse::Ok().json(msg))
}pub async fn delete_teacher(app_state: web::Data<AppState>,params: web::Path<i32>
) -> Result<HttpResponse, MyError> {let teacher_id = params.into_inner();delete_teacher_db(&app_state.db, teacher_id).await.map(|msg| HttpResponse::Ok().json(msg))
}#[cfg(test)]
mod tests {use super::*;use actix_web::http::StatusCode;use std::sync::Mutex;use dotenv::dotenv;use sqlx::mysql::MySqlPoolOptions;use std::env;use actix_web::ResponseError;// #[ignore]#[actix_rt::test]async fn post_new_teacher_success() {// 检测并读取 .env 文件中的内容，若不存在也会跳过异常dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");// 创建数据库连接池let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let teacher = web::Json(CreateTeacher {name: "A New Teacher".into(),picture_url: "https://i2.hdslb.com/bfs/article/[e-mail]".into(),profile: "This is a test profile".into(),});// 模拟添加教师的请求let response = post_new_teacher(teacher, app_state).await.unwrap();assert_eq!(response.status(), StatusCode::OK);}#[actix_rt::test]async fn get_all_teachers_success() {dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let response = get_all_teachers(app_state).await.unwrap();assert_eq!(response.status(), StatusCode::OK);}#[actix_rt::test]async fn get_teacher_detail_success() {dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let params: web::Path<i32> = web::Path::from(1);let response = get_teacher_detail(app_state, params).await.unwrap();assert_eq!(response.status(), StatusCode::OK);}#[actix_rt::test]async fn get_teacher_detail_failure() {dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let params: web::Path<i32> = web::Path::from(100);let response = get_teacher_detail(app_state, params).await;match response {Ok(_) => println!("Something went wrong"),Err(err) => assert_eq!(err.status_code(), StatusCode::NOT_FOUND),}}#[actix_rt::test]async fn update_teacher_success() {dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let params: web::Path<i32> = web::Path::from(2);let update_param = web::Json(UpdateTeacher {name: Some("Teacher name changed".into()),picture_url: Some("https://i2.hdslb.com/bfs/article/[e-mail]".into()),profile: Some("This is a update profile".into()),});let response = update_teacher_detail(app_state, update_param, params).await.unwrap();assert_eq!(response.status(), StatusCode::OK);}// #[ignore]#[actix_rt::test]async fn delete_teacher_success() {dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let params: web::Path<i32> = web::Path::from(3);let response = delete_teacher(app_state, params).await.unwrap();assert_eq!(response.status(), StatusCode::OK);}#[actix_rt::test]async fn delete_teacher_failure() {dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});let params: web::Path<i32> = web::Path::from(100);let response = delete_teacher(app_state, params).await;match response {Ok(_) => println!("Something went wrong"),Err(err) => assert_eq!(err.status_code(), StatusCode::NOT_FOUND),}}
}

对应要修改 handlers/mod.rs，新增：

pub mod teacher;

新增 Router

修改 routers.rs，新增关于教师的路由：

pub fn teacher_routes(cfg: &mut web::ServiceConfig) {cfg.service(web::scope("/teachers").route("/", web::post().to(post_new_teacher)).route("/", web::get().to(get_all_teachers)).route("/{teacher_id}", web::get().to(get_teacher_detail)).route("/{teacher_id}", web::put().to(update_teacher_detail)).route("/{teacher_id}", web::delete().to(delete_teacher)));
}

修改 Error

修改 errors.rs，在 MyError 中新增一种 InvalidInput 错误类型，表示输入参数错误。

#[derive(Debug, Serialize)]
pub enum MyError {DBError(String),ActixError(String),#[allow(dead_code)]NotFound(String),InvalidInput(String),
}

对应修改 MyError 的 error_response 方法，以及 error::ResponseError trait 中的 status_code 方法，发生输入参数错误时，返回 HTTP 400 Bad Request。

impl MyError {fn error_response(&self) -> String {match self {MyError::DBError(msg) => {println!("Database error occurred: {:?}", msg);"Database error".into()}MyError::ActixError(msg) => {println!("Server error occurred: {:?}", msg);"Internal server error".into()}MyError::NotFound(msg) => {println!("Not found error occurred: {:?}", msg);msg.into()}MyError::InvalidInput(msg) => {println!("Invalid input error occurred: {:?}", msg);msg.into()}}}
}impl error::ResponseError for MyError {fn status_code(&self) -> StatusCode {match self {MyError::DBError(_msg) | MyError::ActixError(_msg) => StatusCode::INTERNAL_SERVER_ERROR,MyError::NotFound(_msg) => StatusCode::NOT_FOUND,MyError::InvalidInput(_msg) => StatusCode::BAD_REQUEST,}}fn error_response(&self) -> HttpResponse {HttpResponse::build(self.status_code()).json(MyErrorResponse {error_message: self.error_response(),})}
}

修改 teacher_service

修改 webservice/bin/teacher_service.rs：

    let app = move || {App::new().app_data(shared_data.clone()).app_data(web::JsonConfig::default().error_handler(|_err, _req| {MyError::InvalidInput("Please provide valid json input".to_string()).into()})).configure(general_routes).configure(course_routes).configure(teacher_routes)};

Web 应用程序新增 teacher_routes 路由。

在应用程序执行前，先执行输入参数错误的 handler，返回 MyError::InvalidInput 错误信息。

测试

测试前的数据库 teacher 表：

cd 到 webservice，在终端执行命令 cargo test teacher，7 个关于教师的测试都通过了：

测试后的数据库 teacher 表：

可以看出：新插入了一个教师信息，删除了一个教师信息，更新了一个教师信息。

执行命令 cargo run，在浏览器中测试功能：

尾声

修改 handlers/teacher.rs，在 post_new_teacher_success 和 delete_teacher_success 两个测试函数上打上 #[ignore] 注释。

这样在之后执行命令 cargo test 时，会忽略这两个测试。

我们发现在 handlers/teacher.rs 的 test 模块的每一个测试函数中，都有这一段连接 MySQL 数据库、创建 AppState 的代码：

        // 检测并读取 .env 文件中的内容，若不存在也会跳过异常dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");// 创建数据库连接池let db_pool = MySqlPoolOptions::new().connect(&db_url).await.unwrap();let app_state: web::Data<AppState> = web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,});

我们将其提取为两个独立的函数：

    async fn create_db_pool() -> MySqlPool {// 检测并读取 .env 文件中的内容，若不存在也会跳过异常dotenv().ok();let db_url = env::var("DATABASE_URL").expect("DATABASE_URL 没有在 .env 文件里设置");// 创建数据库连接池MySqlPoolOptions::new().connect(&db_url).await.unwrap()}async fn create_app_state() -> web::Data<AppState> {let db_pool = create_db_pool().await;web::Data::new(AppState {health_check_response: "".to_string(),visit_count: Mutex::new(0),db: db_pool,})}

之后，在每一个测试函数中，创建 AppState 都可以用一行代码搞定：

let app_state = create_app_state().await;

同理，对 handlers/course.rs 中的 test 模块也这样优化。