Aria2是一个非常成熟的下载程序，基于命令行调用。它也提供上RPC、WebSocket的调用方式。下面我会通过前端WebSocket调用的方式实现一个简单的下载功能
- 首先下载对应的Aria2可执行文件，并且命令行启动。aria2c默认会监听本地6800端口
aria2c --enable-rpc --rpc-listen-all=true --rpc-allow-origin-all
- 前端建立WebSocket连接，地址是：
ws://localhost:6800/jsonrpc，具体代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>aria2</title>
</head>
<body>
<div style="margin-bottom: 32px;">
<input type="text" id="ipt"> 下载进度：<span id="progress"></span> 下载速度：<span id="speed"></span>
</div>
<button id="start">开始下载</button>
<button id="pause">暂停下载</button>
<button id="unpause">恢复下载</button>
<script>
// Create WebSocket connection.
const socket = new WebSocket('ws://localhost:6800/jsonrpc');
// Connection opened
socket.addEventListener('open', function (event) {
socket.send('Hello Server!');
console.log(event)
});
let timer = {}
let gid = ''
// Listen for messages
socket.addEventListener('message', function (event) {
const data = JSON.parse(event.data)
console.log('Message from server ', event.data)
if (data.id === 'tellStatus') {
const progress = parseInt(Number(data.result.completedLength) / Number(data.result.totalLength) * 100) + '%'
const speed = parseInt(Number(data.result.downloadSpeed) / 1000) + ' kb/s'
document.querySelector('#progress').innerHTML = progress
document.querySelector('#speed').innerHTML = speed
}
if (data.method === 'aria2.onDownloadStart') {
gid = data.params[0].gid
const jsonData = {
'jsonrpc':'2.0',
'id':'tellStatus',
'method':'aria2.tellStatus',
'params': [gid]
}
if (!timer[gid]) {
timer[gid] = setInterval(() => {
socket.send(JSON.stringify(jsonData))
console.log('发送 tellStatus')
}, 1000)
}
}
if (data.method === 'aria2.onDownloadComplete') {
gid = data.params[0].gid
clearInterval(timer[gid])
delete timer[gid]
document.querySelector('#progress').innerHTML = '100%'
document.querySelector('#speed').innerHTML = '0 kb/s'
}
});
const startBtn = document.querySelector('#start')
startBtn.addEventListener('click', function () {
const jsonData = {
'jsonrpc':'2.0',
'id':'qwer',
'method':'aria2.addUri',
'params': [[ document.querySelector('#ipt').value ]]
}
socket.send(JSON.stringify(jsonData))
})
const pauseBtn = document.querySelector('#pause')
const unpauseBtn = document.querySelector('#unpause')
pauseBtn.addEventListener('click', function () {
const jsonData = {
'jsonrpc':'2.0',
'id':'qwer',
'method':'aria2.pause',
'params': [gid]
}
socket.send(JSON.stringify(jsonData))
})
unpauseBtn.addEventListener('click', function () {
const jsonData = {
'jsonrpc':'2.0',
'id':'qwer',
'method':'aria2.unpause',
'params': [gid]
}
socket.send(JSON.stringify(jsonData))
})
</script>
</body>
</html>