nodejs：express + js-mdict 网页查询英汉词典，能显示图片

向 DeepSeek R1 提问：
我想写一个Web 前端网页，后台用 nodejs + js-mdict , 实现在线查询英语单词，并能显示图片

1. 项目结构

首先，创建一个项目目录，结构如下：

mydict-app/
├── public/
│   ├── index.html
│   ├── styles.css
│   └── script.js
├── server/
│   └── server.js
├── package.json
└── README.md

英汉词典文件（.mdx , .mdd) 已经放在 /js/testdict/

2. 安装依赖

在项目根目录下运行以下命令，初始化项目并安装所需的依赖：
cd mydict-app
npm init -y
npm install express
added 69 packages in 6s

npm install js-mdict
added 3 packages in 2s

3. 创建前端页面

在 public/index.html 中创建一个简单的HTML页面，包含一个输入框和三个按钮用于查询单词：

<!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>查询英汉词典</title><script src="jquery.js"></script><style>
/* portrait 判断为竖屏 */
@media only screen and (orientation: portrait){#lab1 {display:none;}
} 
/* landscape 判断为横屏 */ 
@media only screen and (orientation: landscape){#lab1 {display: ;}
}    </style>
</head>
<body><form name="form" id="form" action="search" method="GET" target="iframe"><label id="lab1">请输入：</label><input type="text" name="word" id="word" size="30" placeholder="请输入英文单词"><input type="submit" name="eng_han" value="英译汉"><input type="button" name="btn1" id="btn1" value="前缀查询"><input type="button" name="btn2" id="btn2" value="模糊查询"></form><p></p>
<div style="float:left; width:100%;"><div id="result" style="float:left; width:75%; height:500; border:2px;"><iframe name="iframe" id="iframe" width="100%" height="500"> </iframe></div><div id="alist" style="float:right; width:25%; height:500; border:2px;"></div>
</div><script src="script.js"></script>
</body>
</html>

在 public 中添加一些英汉字典的样式：oalecd8e.css , oalecd8e.js , uk_pron.png, us_pron.png,
copy jquery-3.2.1.min.js pulibc\jquery.js

在 public/script.js 中编写前端逻辑：

  const iframe = $('#iframe')[0]; // 获取 iframe DOM 元素// 页面加载添加：监听iframe网页点击事件$(document).ready(function(){let listener = window.addEventListener('blur', function(){if (document.activeElement === document.getElementById('iframe')){$('iframe').contents().find('a').click(function(event){event.preventDefault();let a = $(this);if (a){let addr = a.attr('href');if (addr.indexOf('entry://')==0 && addr.indexOf('entry://#')!=0){               let word = encodeURIComponent(addr.substring(8));$.ajax({url: `/search?word=${word}`,method: 'GET',success: function (html) {// 将 HTML 内容加载到 iframe 中//$('#iframe').attr('srcdoc', html);let iframeDoc = iframe.contentDocument || iframe.contentWindow.document;if (html){// 写入 HTML 内容iframeDoc.open();iframeDoc.write(html);iframeDoc.close();}},error: function (error) {console.error('entry:请求失败:', error);}});} else if (addr.indexOf('sound://')==0){let url = "/data/" + addr.substring(8);let mp3 = new Audio(url);mp3.addEventListener("canplaythrough", (event)=> {mp3.play();});mp3.addEventListener('error', (e) => {console.error('play error:', e);});} else {console.log('href='+addr);}}});}});});// 前缀查询
$(function(){$("#btn1").click(function(){$.getJSON("/prefix?word="+$("#word").val(), function(data){let items = [];$.each(data, function(i, item){if (i<=20){items[i] = '<a href="/search?word=' +item+ '" target="iframe">' +item+ "</a><br>";}});let a = items.join('\n');if (a) $('#alist').html(a);})})
});// 模糊查询
$(function(){$("#btn2").click(function(){$.getJSON("/fuzzy?word="+$("#word").val(), function(data){let items = [];$.each(data, function(i, item){if (i<=20){items[i] = '<a href="/search?word=' +item+ '" target="iframe">' +item+ "</a><br>";}});let a = items.join('\n');if (a) $('#alist').html(a);})})
});

4. 创建后端服务器

在 server/server2.js 中编写Node.js服务器代码，使用 express 和 js-mdict 来处理查询请求：

const express = require('express');
const fs = require('fs');
const path = require('path');
const Mdict = require('js-mdict');
//console.log(Mdict);
const app = express();
const port = 8002;// 加载MDict词典文件
//const mdict = new Mdict('path/to/your/dictionary.mdx');
const mdx = new Mdict.MDX('/js/testdict/your英汉词典插图版.mdx');
const mdd = new Mdict.MDD('/js/testdict/your英汉词典插图版.mdd');
//console.log(mdd.locate('\\goods'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
// 提供静态文件
app.use(express.static(path.join(__dirname, '../public')));const isWord = (txt) => {// 只允许字母、/、空格、-return /^[a-zA-Z \/\-]+$/.test(txt);
};// 处理查询请求
app.get('/search', (req, res) => {let word = req.query.word;if (word) {let data = mdx.lookup(word);console.log("cha: "+ word);if(data.definition){res.send(data.definition);} else {res.status(200).send('this word not found.');}} else {res.status(400).send('error: No word input');}
});// 处理前缀查询请求
app.get('/prefix', (req, res) => {let word = req.query.word;// 检查word是否合法if (word.length>50 || !isWord(word)) {return res.status(400).send('Invalid input.');}if (word) {let alist = mdx.prefix(word);console.log("pre: "+ word);if(alist.length >0){let wordls = [];alist.forEach(function(value){wordls.push(value.keyText);});  res.json(wordls);} else {res.status(400).send('this word not found');}} else {res.status(400).send('error: No word input');}
});// 处理模糊查询请求
app.get('/fuzzy', (req, res) => {let word = req.query.word;// 检查word是否合法if (word.length>50 || !isWord(word)) {return res.status(400).send('Invalid input.');}if (word) {let alist = mdx.fuzzy_search(word,3,1);console.log("fuzzy: "+ word);if(alist.length >0){let wordls = [];alist.forEach(function(value){wordls.push(value.keyText);});  res.json(wordls);} else {res.status(400).send('this word not found');}} else {res.status(400).send('error: No word input');}
});// 指定目录
const dir1 = "/";// 实现image文件下载，不带路径
app.get('/:fileName', (req, res, next) => {let path1 = '/'; let fileName = req.params.fileName; // 捕获文件名// 检查路径中是否包含非法字符（如 ..）if (fileName.includes('..')) {return res.status(400).send('Invalid path: Path traversal is not allowed.');}//console.log(fileName);let extname = path.extname(fileName);let ext = extname.substring(1).toLowerCase();if (['bmp','gif','jpg','png'].includes(ext)){let filePath = path.join(path1, fileName);//console.log(filePath);let data = mdd.locate(filePath);if (data){console.log('key: '+ data.keyText);//console.log(Buffer.isBuffer(data.definition));if (data.definition){let binaryData = Buffer.from(data.definition, 'base64');//res.setHeader('Content-Type', 'application/octet-stream');res.set({'Content-Type': 'image','Content-Disposition': 'attachment;','Content-Length': Buffer.byteLength(binaryData)});//console.log('bytes: '+ Buffer.byteLength(binaryData));res.end(binaryData);} else {res.status(400).send('error: data.definition is null');}} else {res.status(400).send('error: data is null');}} else {res.status(400).send('filename.ext is not image');}
});// 实现image文件下载，*/是路径
app.get('/*/:fileName', (req, res, next) => {let path1 = req.params[0]; // 捕获 * 匹配的部分let fileName = req.params.fileName; // 捕获文件名// 检查路径中是否包含非法字符（如 ..）if (fileName.includes('..')) {return res.status(400).send('Invalid path: Path traversal is not allowed.');}//console.log(fileName);let extname = path.extname(fileName);let ext = extname.substring(1).toLowerCase();if (['bmp','gif','jpg','png'].includes(ext)){let filePath = path.join(dir1,path1, fileName);//console.log(filePath);let data = mdd.locate(filePath);if (data){console.log('key: '+ data.keyText);//console.log(Buffer.isBuffer(data.definition));if (data.definition){let binaryData = Buffer.from(data.definition, 'base64');//res.setHeader('Content-Type', 'application/octet-stream');res.set({'Content-Type': 'image','Content-Disposition': 'attachment;','Content-Length': Buffer.byteLength(binaryData)});//console.log('bytes: '+ Buffer.byteLength(binaryData));res.end(binaryData);} else {res.status(400).send('error: data.definition is null');}} else {res.status(400).send('error: data is null');}} else {res.status(400).send('filename.ext is not image');}
});app.listen(port, () => {console.log(`Server is running on http://localhost:${port}`);
});