actually I am newbie, I want to use express in my web application, So I want support all the requests and response in my application should support
application/json, application/x-www-form-urlencoded and multipart/form-data
express is rather smart, and will automatically determine the header type, you can even use res.send(JSONObj) to send an object directly as JSON. If you want to manually set the header you can do so by using res.setHeader('Content-Type', 'application/json')
before you send any data.