Nodejs：如何返回具有相同响应（文本和图像）的不同内容类型？ [英] Nodejs: How return different content types with same response (text and image)?
问题描述
我正在尝试学习nodejs，我认为最好的方法是在不使用express或任何其他非核心模块的情况下尝试做一些事情。我坚持试图获得一些文本和图像同时传递。我正在尝试的代码是：
I'm trying to learn nodejs and I thought the best way to do this would be to try doing some stuff without using express or any other non-core modules. I'm stuck on trying to get some text and an image to be delivered simultaneously. The code I'm trying is:
var http = require('http');
var fs = require('fs');
var server = http.createServer(function(request,response) {
fs.readFile('my_pic.jpg', function(error, file) {
response.writeHead(200, {'content-type':'text/html'});
response.write('<p>hi there!</p>');
response.writeHead(200, {'content-type':'image/jpg'});
response.write(file, 'image');
response.end();
});
});
var port = process.env.PORT || 8080;
server.listen(port, function() {
console.log('Listening on port ' + port);
});
理想情况下应该交付的是：
So ideally what should be delivered is:
<html>
<body>
<p>hi there</p>
<img src='my_pic.jpg'/>
</body>
</html>
但相反，什么都没有出现。
But instead, nothing is appearing.
我写了'hi there'后显示文本，然后尝试交换文本和图片的位置（标题包括），显示图片，但我无法弄清楚如何同时显示两者，就像在真实的网页上一样。
I tried putting a response.end() after writing 'hi there', which displays the text, and after that I tried swapping the places of the text and picture (headers included), which displayed the picture, but I can't figure out how to get both to display simultaneously, like on a real web page.
你能解释一下吗？要将不同类型的内容放入同一网页 - 他们是否需要采用不同的回复？我在另一个问题上遇到的事情：
Can you explain how to go about putting in different types of content onto the same webpage - do they need to be in different responses? Something I came across on another question:
这样的东西看起来像解决方案，但我无法想象如何应用于我的情况（我在服务器方面没有很多经验。）
Something like that looks like the solution, but I can't figure out how to apply this to my situation (I don't have a lot of experience in the server side of things.)
非常感谢
编辑：从user568109的回复开始工作：
got it working from user568109's reply:
var http = require('http');
var fs = require('fs');
var server = http.createServer(function(request,response) {
fs.readFile('my_pic.jpg', function(error, file) {
var imagedata = new Buffer(file).toString('base64');
response.writeHead(200, {'content-type':'text/html'});
response.write("hi there!<img src='data:my_pic.jpg;base64,"+imagedata+"'/>");
response.end();
});
});
var port = process.env.PORT || 8080;
server.listen(port, function() {
console.log('Listening on port' + port);
});
这似乎在嵌入图像方面做了很多工作 - 如果我想放置多个图像在，我必须继续嵌套那些文件流回调？
This seems like a lot of work in embedding images though - if I wanted to put more than one image in, I'd have to just keep nesting those filestream callbacks?
我也尝试过这种方式，但它不起作用：
I also tried it this way but it doesn't work:
var http = require('http');
var fs = require('fs');
var server = http.createServer(function(request,response) {
response.writeHead(200, {'content-type':'text/html'});
response.write("hi there!<img src='my_pic.jpg'/>");
response.end();
});
var port = process.env.PORT || 8080;
server.listen(port, function() {
console.log('Listening on port' + port);
});
我不确定这是否是人们所说的
I wasn't sure if this was what people meant by the line
response.write('<img src="my_pic.jpg"/>')
，因为服务器似乎没有代表我做另一个请求来获取图像？它只显示一个损坏的图标图像。
, because the server doesn't seem to be making another request on my behalf to go fetch the image? It's just showing a broken icon image.
推荐答案
如果你做 response.write（'< img src =my_pic.jpg/>'）; 如上所述，只有当浏览器为图像发送GET时才会发送图像文件。这将成为多部分请求。
If you do response.write('<img src="my_pic.jpg"/>'); as mentioned above the image file would be sent only when browser sends GET for the image. It would become multi-part request.
或者你可以这样做。可以用HTML以二进制形式发送图像。使用：
Or you can do it like this. It is possible to send your image in binary form in HTML. Use :
<img src="data:image/gif;base64,imagedata">
其中imagedata是gif图像的base64编码。所以在node.js中执行此操作：
where imagedata is a base64 encoding of gif image. So do this in node.js :
//Write text in response.
content = get-image-file-contents; //store image into content
imagedata = new Buffer(content).toString('base64'); //encode to base64
response.write('<img src="data:image/gif;base64,'+imagedata+'">');//send image
response.end();
点击此处查看正确的图片转换 NodeJS base64图像编码/解码不能正常工作
Check here for correct image conversion NodeJS base64 image encoding/decoding not quite working
这发送一个发送文本和图像的响应。响应只需要一个标题 response.writeHead（200，{'content-type'：'text / html'}）;
This sends one response which sends both text and image. Only one header is required for response response.writeHead(200, {'content-type':'text/html'});
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