nodejs服务器读取图片返回给前端（浏览器）显示

2018-09-10 01:07:05来源：博客园阅读 ()

1 前言

项目需要用nodejs服务器给前端传递图片，网上找了好多资料，多数都是怎么在前端上传图片的，然后通过看runoob.com菜鸟教程，发现其实是非常简单，用express框架就行了。

2 代码

2.1 用原生的版本（包含了返回网页功能）

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var http = require('http');
var fs = require('fs');
var url = require('url');
// 创建服务器
http.createServer( function (request, response) {  
   // 解析请求，包括文件名
   var pathname = url.parse(request.url).pathname;
   // 输出请求的文件名
   console.log("Request for " + pathname + " received.");
   // 从文件系统中读取请求的文件内容
   fs.readFile(pathname.substr(1), function (err, data) {
   var urlContent = pathname.substr(1);
   if(urlContent.lastIndexOf("png") > -1){
       if (err) {
         console.log(err);
         // HTTP 状态码: 404 : NOT FOUND
         // Content Type: text/plain
         response.writeHead(404, {'Content-Type': 'text/html'});
      }else{             
         // HTTP 状态码: 200 : OK
         // Content Type: text/plain
         response.writeHead(200, {'Content-Type': 'image/png'});
        var imageFilePath = pathname.substr(1);
        var stream = fs.createReadStream( imageFilePath );
        var responseData = [];//存储文件流
        if (stream) {//判断状态
            stream.on( 'data', function( chunk ) {
              responseData.push( chunk );
            });
            stream.on( 'end', function() {
               var finalData = Buffer.concat( responseData );
               response.write( finalData );
               response.end();
            });
        }              
      }
   }else if(urlContent.lastIndexOf("html") > -1){
　　   if (err) {
         console.log(err);
         // HTTP 状态码: 404 : NOT FOUND
         // Content Type: text/plain
         response.writeHead(404, {'Content-Type': 'text/html'});
      }else{             
         // HTTP 状态码: 200 : OK
         // Content Type: text/plain
         response.writeHead(200, {'Content-Type': 'text/html'});            
         // 响应文件内容
         response.write(data.toString());        
      }
      //  发送响应数据
      response.end();
   }else{
     console.log("unSupport Type, Please contact Administrator err url="+urlContent);  
   }     
   });   
}).listen(80);

　2.2 用Express框架版本

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var express = require('express');
var app = express();
 
app.use(express.static('public'));
 
app.get('/public/images/*', function (req, res) {
    res.sendFile( __dirname + "/" + req.url );
    console.log("Request for " + req.url + " received.");
})
  
app.get('/public/html/index.html', function (req, res) {
   res.sendFile( __dirname + "/" + "/public/html/index.html" );
   console.log("Request for " + req.url + " received.");
})
 
//如果访问网页和本地同名，可以使用以下版本
app.get('/public/html/*.html', function (req, res) {
   res.sendFile( __dirname + "/" + req.url );
   console.log("Request for " + req.url + " received.");
})
 
app.get('/public/register', function (req, res) {
   res.sendFile( __dirname + "/" + "/public/html/register.html" );
   console.log("Request for " + req.url + " received.");
})
 
var server = app.listen(80, function () {
  console.log('Server running at http://127.0.0.1:80/');
})