Rust读取配置文件

cargo init read-conf

cd read-conf

read-conf git:(master) ✗ ls
Cargo.lock  Cargo.toml  config.json config.toml config.yaml src         target

读取并解析json文件

config.json:

{
  "mysql": {
    "host": "localhost",
    "port": 3306,
    "username": "your_mysql_username",
    "password": "your_mysql_password",
    "database": "your_database_name",
    "charset": "utf8mb4",
    "collation": "utf8mb4_unicode_ci"
  },
  "redis": {
    "host": "localhost",
    "port": 6379,
    "password": "your_redis_password",
    "db": 0,
    "prefix": "myapp:",
    "options": {
      "abort_on_connect_fail": false,
      "read_timeout": 0,
      "retry_interval": 15,
      "retry_limit": 0
    }
  }
}

Cargo.toml:

[package]
name = "read-conf"
version = "0.1.0"
edition = "2021"

[dependencies]
serde = { version = "1", features = ["derive"] }
serde_json = "1"

main.rs:

use std::fs;
use std::io::Read;
use serde::Deserialize; // 修改了这里

#[derive(Deserialize, Debug)]
struct Config {
    mysql: MySqlConfig,
    redis: RedisConfig,
}

#[derive(Deserialize, Debug)]
struct MySqlConfig {
    host: String,
    port: u16,
    username: String,
    password: String,
    database: String,
    charset: String,
    collation: String,
}

#[derive(Deserialize, Debug)]
struct RedisConfig {
    host: String,
    port: u16,
    password: Option<String>,
    db: u8,
    prefix: String,
    options: RedisOptions,
}

#[derive(Deserialize, Debug)]
struct RedisOptions {
    abort_on_connect_fail: bool,
    read_timeout: u64,
    retry_interval: u64,
    retry_limit: u64,
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut file = fs::File::open("config.json")?;
    let mut contents = String::new();
    file.read_to_string(&mut contents)?;

    let config: Config = serde_json::from_str(&contents)?;

    println!("MySQL Config:");
    println!("  Host: {}", config.mysql.host);
    println!("  Port: {}", config.mysql.port);
    println!("  Username: {}", config.mysql.username);
    println!("  Password: {}", config.mysql.password);
    println!("  Database: {}", config.mysql.database);
    println!("  Charset: {}", config.mysql.charset);
    println!("  Collation: {}", config.mysql.collation);


    println!("MySQL Config:");
    println!("  Host: {}", config.redis.host);
    println!("  Port: {}", config.redis.port);
    //  println!("  Password: {}", config.redis.password);// `std::option::Option<std::string::String>` cannot be formatted with the default formatter

    // 使用unwrap_or_else来处理Option<String>
    if let Some(password) = config.redis.password {
        println!("  Password: {}", password);
    } else {
        println!("  Password: <not set>");
    }

    println!("  Db: {}", config.redis.db);
    println!("  Prefix: {}", config.redis.prefix);
    println!("  abort_on_connect_fail: {}", config.redis.options.abort_on_connect_fail);
    println!("  read_timeout: {}", config.redis.options.read_timeout);
    println!("  retry_interval: {}", config.redis.options.retry_interval);
    println!("  retry_limit: {}", config.redis.options.retry_limit);

    Ok(())
}

输出:

MySQL Config:
  Host: localhost
  Port: 3306
  Username: your_mysql_username
  Password: your_mysql_password
  Database: your_database_name
  Charset: utf8mb4
  Collation: utf8mb4_unicode_ci
MySQL Config:
  Host: localhost
  Port: 6379
  Password: your_redis_password
  Db: 0
  Prefix: myapp:
  abort_on_connect_fail: false
  read_timeout: 0
  retry_interval: 15
  retry_limit: 0

读取并解析yaml文件

config.yaml:

users:
  - user: Alice
    age: 28
    hometown: New York
  - user: Bob
    age: 35
    hometown: San Francisco
  - user: Charlie
    age: 22
    hometown: Chicago

Cargo.toml:

[dependencies]
serde = { version = "1", features = ["derive"] }
serde_yaml = "0.8"

main.rs:

use serde::Deserialize;
use std::fs::File;
use std::io::Read;

#[derive(Deserialize, Debug)]
struct User {
    user: String,
    age: u32,
    hometown: String,
}

#[derive(Deserialize, Debug)]
struct UsersConfig {
    users: Vec<User>,
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 打开YAML文件
    let mut file = File::open("config.yaml")?;

    // 读取文件内容
    let mut content = String::new();
    file.read_to_string(&mut content)?;

    // 将字符串解析为Rust结构体
    let config: UsersConfig = serde_yaml::from_str(&content)?;


    // 打印解析后的结果
    println!("{:#?}", config);


    // 访问第一个用户的hometown
    if let Some(first_user) = config.users.first() {
        println!("第一个用户的家乡是: {}", first_user.hometown);
    } else {
        println!("YAML文件中没有用户");
    }

    // 访问第二个用户的user名
    if let Some(second_user) = config.users.get(1) { // 索引1 即第二个元素
        println!("第二个用户的名称是: {}", second_user.user);
    } else {
        println!("YAML文件中没有第二个用户");
    }


    Ok(())
}

输出:

UsersConfig {
    users: [
        User {
            user: "Alice",
            age: 28,
            hometown: "New York",
        },
        User {
            user: "Bob",
            age: 35,
            hometown: "San Francisco",
        },
        User {
            user: "Charlie",
            age: 22,
            hometown: "Chicago",
        },
    ],
}
第一个用户的家乡是: New York
第二个用户的名称是: Bob

读取并解析toml文件

config.toml:

# config.toml
# 中国四大名著的作者、籍贯、年代等信息

# 书籍信息
[[books]]
title = "三国演义"
author = "罗贯中"
origin = "山西太原（或浙江杭州）"
dynasty = "元末明初"
years = "约1330年-约1400年"

[[books]]
title = "水浒传"
author = "施耐庵"
origin = "江苏兴化"
dynasty = "元末明初"
years = "1296年-1370年"

[[books]]
title = "西游记"
author = "吴承恩"
origin = "江苏淮安"
dynasty = "明朝"
years = "1501年-1582年"

[[books]]
title = "红楼梦"
author = "曹雪芹"
origin = "辽宁辽阳"
dynasty = "清朝"
years = "约1715年-约1763年"

# 主要人物及简介
[[main_characters]]
book = "三国演义"
name = "诸葛亮"
description = "字孔明，号卧龙，蜀汉丞相，智谋过人，运筹帷幄之中，决胜千里之外。"

[[main_characters]]
book = "三国演义"
name = "曹操"
description = "字孟德，一代枭雄，多疑而爱惜人才，奠定了曹魏政权的基础。"

[[main_characters]]
book = "水浒传"
name = "宋江"
description = "字公明，梁山泊好汉的首领，讲义气，仗义疏财，领导梁山好汉反抗朝廷。"

[[main_characters]]
book = "水浒传"
name = "武松"
description = "行者武松，嫉恶如仇，行侠仗义，敢作敢为，曾打虎景阳冈，血溅鸳鸯楼。"

[[main_characters]]
book = "西游记"
name = "孙悟空"
description = "又名美猴王，不畏自然艰险，具有锄强扶弱、抱打不平的英雄本色，嫉恶如仇。"

[[main_characters]]
book = "西游记"
name = "唐僧"
description = "取经人，法名玄奘，又称三藏，宅心仁厚，有点不辨善恶，是孙悟空等人的师父。"

[[main_characters]]
book = "红楼梦"
name = "贾宝玉"
description = "贾家公子，对封建正统思想不满，追求自由，与林黛玉、薛宝钗等人物有深厚的情感纠葛。"

[[main_characters]]
book = "红楼梦"
name = "林黛玉"
description = "贾家表亲，聪明伶俐，多愁善感，与贾宝玉有深厚的感情，是书中重要的女性角色。"

Cargo.toml:

[dependencies]  
toml = "0.5"

把书籍名称作为key，书中主要人物作为value，组成一个hash,并打印出来

use std::collections::HashMap;
use std::fs::File;
use std::io::Read;
use toml::Value;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 打开TOML文件
    let mut file = File::open("config.toml")?;

    // 读取文件内容
    let mut content = String::new();
    file.read_to_string(&mut content)?;

    // 解析TOML字符串为Value
    let toml_value: Value = toml::from_str(&content)?;

    // 创建一个空的HashMap来存储书籍和其主要人物
    let mut books_characters: HashMap<String, Vec<String>> = HashMap::new();

    // 假设每个书籍的主要人物都存储在main_characters数组中
    if let Some(books) = toml_value.get("books").and_then(|a| a.as_array()) {
        for book in books {
            if let Some(title) = book.get("title").and_then(|t| t.as_str()) {
                let mut characters = Vec::new();

                // 获取与当前书籍相关的主要人物
                if let Some(main_characters) = toml_value.get("main_characters").and_then(|a| a.as_array()) {
                    for character in main_characters {
                        if let Some(book_name) = character.get("book").and_then(|b| b.as_str()) {
                            if book_name == title {
                                if let Some(name) = character.get("name").and_then(|n| n.as_str()) {
                                    characters.push(name.to_string());
                                }
                            }
                        }
                    }
                }

                // 将书籍名称和主要人物列表添加到HashMap中
                books_characters.insert(title.to_string(), characters);
            }
        }
    }

    // 打印HashMap的内容
    for (title, characters) in &books_characters {
        println!("{} 的主要人物有: {:?}", title, characters);
    }

    Ok(())
}

输出:

三国演义 的主要人物有: ["诸葛亮", "曹操"]
西游记 的主要人物有: ["孙悟空", "唐僧"]
红楼梦 的主要人物有: ["贾宝玉", "林黛玉"]
水浒传 的主要人物有: ["宋江", "武松"]