今天就跟大家聊聊有关使用Node怎么实现一个中转服务器转发接口，可能很多人都不太了解，为了让大家更加了解，小编给大家总结了以下内容，希望大家根据这篇文章可以有所收获。
1.项目比较特殊，后台拥有两个平台，一个java一个donet，比较鸡肋，具体什么原因就不解释了。
2.当做node转发时，刚开始没有转发文件的操作，就做的很简单，用户传过来啥就，拦截到，进行转发，一切都很ok！
3.文件转发，就很麻烦。我的思路，将用户上传的文件存到node服务器。使用formidable 。
通过npm安装：
npm install formidable@latest
使用它进行文件转存，保存到临时目录得到文件信息。
再通过文件包重组。进行上传。注意此处上传必须遵循w3c上传文件表单标准，具体自己查资料。
其实思路很简单，但是实际操作起来还是挺麻烦，我中间也趟了好多坑，也是自己node不成熟，毕竟只是用来做中转！
直接上代码吧：看代码还是清晰：
server.js,用于启动服务并转发。
var http = require("http");
var url = require("url");
var fs = require('fs');
const querystring = require("querystring");
var path = require('path');
var formidable = require('formidable'),
os = require('os'),
util = require('util');
var config = require('./config').types; //
var netServerUrlFlag = require('./config').netServerUrlFlag;
var netServerhost = require('./config').netServerhost;
var netServerport = require('./config').netServerport;
var javaServerUrlFlag = require('./config').javaServerUrlFlag;
var javaServerhost = require('./config').javaServerhost;
var javaServerport = require('./config').javaServerport;
var fileServerUrlFlag = require('./config').fileServerUrlFlag;
var webapp = require('./config').webapp;
var PORT = require('./config').webport;
/**
* 上传文件
* @param files 经过formidable处理过的文件
* @param req httpRequest对象
* @param postData 额外提交的数据
*/
function uploadFile(files, req, postData) {
var boundaryKey = Math.random().toString(16);
var endData = '\r\n----' + boundaryKey + '--';
var filesLength = 0, content;
// 初始数据，把post过来的数据都携带上去
content = (function (obj) {
var rslt = [];
Object.keys(obj).forEach(function (key) {
arr = ['\r\n----' + boundaryKey + '\r\n'];
arr.push('Content-Disposition: form-data; name="' + obj[key][0] + '"\r\n\r\n');
arr.push(obj[key][1]);
rslt.push(arr.join(''));
});
return rslt.join('');
})(postData);
// 组装数据
Object.keys(files).forEach(function (key) {
if (!files.hasOwnProperty(key)) {
delete files.key;
return;
}
content += '\r\n----' + boundaryKey + '\r\n' +
'Content-Type: application/octet-stream\r\n' +
'Content-Disposition: form-data; name="' + files[key][0] + '"; ' +
'filename="' + files[key][1].name + '"; \r\n' +
'Content-Transfer-Encoding: binary\r\n\r\n';
files[key].contentBinary = new Buffer(content, 'utf-8');;
filesLength += files[key].contentBinary.length + fs.statSync(files[key][1].path).size;
});
req.setHeader('Content-Type', 'multipart/form-data; boundary=--' + boundaryKey);
req.setHeader('Content-Length', filesLength + Buffer.byteLength(endData));
// 执行上传
var allFiles = Object.keys(files);
var fileNum = allFiles.length;
var uploadedCount = 0;
allFiles.forEach(function (key) {
req.write(files[key].contentBinary);
console.log("files[key].path:" + files[key][1].path);
var fileStream = fs.createReadStream(files[key][1].path, { bufferSize: 4 * 1024 });
fileStream.on('end', function () {
// 上传成功一个文件之后，把临时文件删了
fs.unlink(files[key][1].path);
uploadedCount++;
if (uploadedCount == fileNum) {
// 如果已经是最后一个文件，那就正常结束
req.end(endData);
}
});
fileStream.pipe(req, { end: false });
});
}
var server = http.createServer(function (request, response) {
var clientUrl = request.url;
var url_parts = url.parse(clientUrl); //解析路径
var pathname = url_parts.pathname;
var sreq = request;
var sres = response;
// .net 转发请求
if (pathname.match(netServerUrlFlag) != null) {
var clientUrl2 = clientUrl.replace("/" + netServerUrlFlag, '');
console.log(".net转发请求......" + clientUrl2);
var pramsJson = '';
sreq.on("data", function (data) {
pramsJson += data;
}).on("end", function () {
var contenttype = request.headers['content-type'];
if (contenttype == undefined || contenttype == null || contenttype == '') {
var opt = {
host: netServerhost, //跨域访问的主机ip
port: netServerport,
path: clientUrl2,
method: request.method,
headers: {
'Content-Length': Buffer.byteLength(pramsJson)
}
}
} else {
var opt = {
host: netServerhost, //跨域访问的主机ip
port: netServerport,
path: clientUrl2,
method: request.method,
headers: {
'Content-Type': request.headers['content-type'],
'Content-Length': Buffer.byteLength(pramsJson)
}
}
}
console.log('method', opt.method);
var body = '';
var req = http.request(opt, function (res) {
res.on('data', function (data) {
body += data;
}).on('end', function () {
response.write(body);
response.end();
});
}).on('error', function (e) {
response.end('内部错误，请联系管理员！MSG:' + e);
console.log("error: " + e.message);
})
req.write(pramsJson);
req.end();
})
} else
// java 转发请求
if (pathname.match(javaServerUrlFlag) != null) {
response.setHeader("Content-type", "text/plain;charset=UTF-8");
var clientUrl2 = clientUrl.replace("/" + javaServerUrlFlag, '');
console.log(".java转发请求......http://" + javaServerhost + ":" + javaServerport + "" + clientUrl2);
var prams = '';
sreq.on("data", function (data) {
prams += data;
}).on("end", function () {
console.log("client pramsJson>>>>>" + prams);
const postData = prams;
console.log("client pramsJson>>>>>" + postData);
var contenttype = request.headers['content-type'];
if (contenttype == undefined || contenttype == null || contenttype == '') {
var opt = {
host: javaServerhost, //跨域访问的主机ip
port: javaServerport,
path: "/hrrp" + clientUrl2,
method: request.method,
headers: {
'Content-Length': Buffer.byteLength(postData)
}
}
} else {
var opt = {
host: javaServerhost, //跨域访问的主机ip
port: javaServerport,
path: "/hrrp" + clientUrl2,
method: request.method,
headers: {
'Content-Type': request.headers['content-type'],
'Content-Length': Buffer.byteLength(postData)
}
}
}
var body = '';
console.log('method', opt.method);
var req = http.request(opt, function (res) {
//console.log("response: " + res.statusCode);
res.on('data', function (data) {
body += data;
}).on('end', function () {
response.write(body);
response.end();
//console.log("end:>>>>>>>" + body);
});
}).on('error', function (e) {
response.end('内部错误，请联系管理员！MSG:' + e);
console.log("error: " + e.message);
})
req.write(postData);
req.end();
})
} else if (pathname.match(fileServerUrlFlag) != null) {
//文件拦截保存到本地
var form = new formidable.IncomingForm(),
files = [],
fields = [];
form.uploadDir = os.tmpdir();
form.on('field', function (field, value) {
console.log(field, value);
fields.push([field, value]);
}).on('file', function (field, file) {
console.log(field, file);
files.push([field, file]);
}).on('end', function () {
//
var clientUrl2 = clientUrl.replace("/" + fileServerUrlFlag, '');
var opt = {
host: netServerhost, //跨域访问的主机ip
port: netServerport,
path: clientUrl2,
method: request.method
}
var body = '';
var req = http.request(opt, function (res) {
res.on('data', function (data) {
body += data;
}).on('end', function () {
response.write(body);
response.end();
});
}).on('error', function (e) {
response.end('内部错误，请联系管理员！MSG:' + e);
console.log("error: " + e.message);
})
//文件上传
uploadFile(files, req, fields);
});
form.parse(sreq);
}
else {
var realPath = path.join(webapp, pathname); //这里设置自己的文件名称;
var ext = path.extname(realPath);
ext = ext ? ext.slice(1) : 'unknown';
fs.exists(realPath, function (exists) {
//console.log("file is exists："+exists+" file path: " + realPath + "");
if (!exists) {
response.writeHead(404, {
'Content-Type': 'text/plain'
});
response.write("This request URL " + pathname + " was not found on this server.");
response.end();
} else {
fs.readFile(realPath, "binary", function (err, file) {
if (err) {
response.writeHead(500, {
'Content-Type': 'text/plain'
});
//response.end(err);
response.end("内部错误，请联系管理员");
} else {
var contentType = config[ext] || "text/plain";
response.writeHead(200, {
'Content-Type': contentType
});
response.write(file, "binary");
response.end();
}
});
}
});
}
});
server.listen(PORT);
console.log("Server runing at port: " + PORT + ".");config.js，用于配置。
exports.types = {
"css": "text/css",
"gif": "image/gif",
"html": "text/html",
"htm": "text/html",
"ico": "image/x-icon",
"jpeg": "image/jpeg",
"jpg": "image/jpeg",
"js": "text/javascript",
"json": "application/json",
"pdf": "application/pdf",
"png": "image/png",
"svg": "image/svg+xml",
"swf": "application/x-shockwave-flash",
"tiff": "image/tiff",
"txt": "text/plain",
"wav": "audio/x-wav",
"wma": "audio/x-ms-wma",
"wmv": "video/x-ms-wmv",
"xml": "text/xml"
};
exports.netServerUrlFlag = "NETSERVER";
exports.netServerhost = "";
exports.netServerport = "";
exports.javaServerUrlFlag = "JAVASERVER";
exports.javaServerhost = ""; //转发的地址
exports.javaServerport = "";//转发的端口
exports.fileServerUrlFlag="FileUpload";
exports.webapp = "public";//项目目录
exports.webport = "82"; //项目启动端口看完上述内容，你们对使用Node怎么实现一个中转服务器转发接口有进一步的了解吗？如果还想了解更多知识或者相关内容，请关注亿速云行业资讯频道，感谢大家的支持。
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