This article talks about the basics of node, the understanding and cases of http module and module.exports export sharing, I hope it will be helpful to everyone!
The http module is a module officially provided by Node.js for creating web servers. [Related tutorial recommendations: nodejs video tutorial]
Through the http.createServer() method provided by the http module, you can easily turn an ordinary computer into a web server , thereby providing web resource services to the outside world.
Example: Listen to the 8080 service
// 导入 http 模块
const http = require('http')
// 创建 web 服务器实例
const server = http.createServer()
// 为服务器实例绑定 request 事件 监听客户端的请求
server.on('request', function (req, res) {
console.log('请求中...')
})
// 启动服务
server.listen(8080, function () {
console.log('http://127.0.0.1:8080')
})
As long as the server receives the client's request, it will call the request event processing function bound to the server through server.on()
Example: In the event handling function, access data or attributes related to the client
// 导入 http 模块
const http = require('http')
// 创建 web 服务器实例
const server = http.createServer()
// req 是请求对象 包含了与客户端相关的数据和属性
server.on('request', (req) => {
// req.url 客户端请求的 url 地址
const url = req.url
// req.method 是客户端请求的 method 类型
const method = req.method
const str = `Your request url is ${url} and request method is ${method}`
console.log(str)
})
// 启动服务
server.listen(8080, function () {
console.log('http://127.0.0.1:8080')
})
In the server's request event handling function, if you want to access server-related data or properties, you need to use response
Example: Request response
// 导入 http 模块
const http = require('http')
// 创建 web 服务器实例
const server = http.createServer()
// req 是请求对象 包含了与客户端相关的数据和属性
server.on('request', (req, res) => {
// req.url 客户端请求的 url 地址
const url = req.url
// req.method 是客户端请求的 method 类型
const method = req.method
const str = `Your request url is ${url} and request method is ${method}`
console.log(str)
// 调用 res.end() 方法 向客户端响应一些内容
res.end(str)
})
// 启动服务
server.listen(8080, function () {
console.log('http://127.0.0.1:8080')
})
When calling the res.end() method, report to the client When sending Chinese content, garbled characters will occur, and you need to manually set the encoding format of the content
Example: Solve Chinese garbled characters
// 导入 http 模块
const http = require('http')
// 创建 web 服务器实例
const server = http.createServer()
// req 是请求对象 包含了与客户端相关的数据和属性
server.on('request', (req, res) => {
// req.url 客户端请求的 url 地址
const url = req.url
// req.method 是客户端请求的 method 类型
const method = req.method
const str = `请求地址是 ${url} 请求方法是 ${method}`
console.log(str)
// 设置 Content-Type 响应头 解决中文乱码问题
res.setHeader('Content-Type', 'text/html; charset=utf-8')
// 调用 res.end() 方法 向客户端响应一些内容
res.end(str)
})
// 启动服务
server.listen(8080, function () {
console.log('http://127.0.0.1:8080')
})
Example: The steps are as follows
// 导入 http 模块
const http = require('http')
// 创建 web 服务器实例
const server = http.createServer()
// req 是请求对象 包含了与客户端相关的数据和属性
server.on('request', (req, res) => {
// req.url 客户端请求的 url 地址
const url = req.url
// 设置默认的内容为 404 Not Found
let content = '<h1>404 Not Found!</h1>'
// 用户请求页是首页
if(url === '/' || url === '/index.html') {
content = '<h1>首页</h1>'
} else if (url === '/about.html') {
content = '<h1>关于页面</h1>'
}
// 设置 Content-Type 响应头 防止中文乱码
res.setHeader('Content-Type', 'text/html; charset=utf-8')
// 调用 res.end() 方法 向客户端响应一些内容
res.end(content)
})
// 启动服务
server.listen(8080, function () {
console.log('http://127.0.0.1:8080')
})
index.js file
const username = '张三'
function say() {
console.log(username);
}test.js file
const custom = require('./index') console.log(custom)
for external use. When the external require() method imports a custom module, what is obtained is the object pointed to by module.exports
Example:
index.js fileconst blog = '前端杂货铺'
// 向 module.exports 对象上挂载属性
module.exports.username = '李四'
// 向 module.exports 对象上挂载方法
module.exports.sayHello = function () {
console.log('Hello!')
}
module.exports.blog = blogCopy after login
const m = require('./index')
console.log(m)
Copy after login
使用 require() 方法导入模块时，导入的结果，永远以 module.exports 指向的对象为准
示例：
index.js 文件
module.exports.username = '李四'
module.exports.sayHello = function () {
console.log('Hello!')
}
// 让 module.exports 指向一个新对象
module.exports = {
nickname: '张三',
sayHi() {
console.log('Hi!')
}
}test.js 文件
const m = require('./index') console.log(m)
默认情况下，exports 和 module.exports 指向同一个对象。
最终共享的结果，还是以 module.exports 指向的对象为准。
示例：
index1.js 文件
exports.username = '杂货铺'
module.exports = {
name: '前端杂货铺',
age: 21
}
index2.js 文件
module.exports.username = 'zs'
exports = {
gender: '男',
age: 22
}
index3.js 文件
exports.username = '杂货铺' module.exports.age = 21
index4.js 文件
exports = {
gender: '男',
age: 21
}
module.exports = exports
module.exports.username = 'zs'
对 index2.js 文件结果的解析如下：
对 index4.js 文件结果的解析如下：
注意：为防止混乱，尽量不要在同一个模块中同时使用 exports 和 module.exports
更多node相关知识，请访问：nodejs 教程！
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