How to send Data from Tomcat Server to Client?

Question

I need to write a function that gets a Json via Spring and deliver a Data. The case is that a customer is sending me a Filename and im looking in a database where the file is and send him the data. I only need a little kickstart and someone who can answer me to my Questions:

• Do I really need Sockets for this?
• What for a Stream I should use (Its several Datatypes likes Pictures, Documents, Pdf....)
• How can I identify the Destination to send

Answer 1

You can use Response like this :

String yourData;
JsonWriter writer = new JsonWriter(response.getWriter());
    writer.beginObject();
    writer.name("data").value(yourData);
    writer.endObject();
    writer.close();