HttpResponse.java

import java.io.* ;
import java.net.* ;
import java.util.* ;
import com.google.gson.*;
class HttpResponse {
    final static String CRLF = "\r\n";
    DataOutputStream os;
	int statuscode;
	String statusmsg;
	Map<String, String> headers;
	Template bodyTemplate;
	FileInputStream bodyFis;
	String bodyString;
	public HttpResponse(Socket socket) throws IOException {
		final DataOutputStream os = new DataOutputStream(socket.getOutputStream());
		this.os = os;
		headers = new HashMap<String, String>();
		setStatus(200, "OK");
		setHeader("Server", "lucos");
	}
	public void setHeader(String key, String value) {
		headers.put(key, value);
	}
	public void setFileName(String fileName) {
		setHeader("Content-type", contentType(fileName));
	}
	private void clearBody() {
		bodyFis = null;
		bodyTemplate = null;
		bodyString = null;
	}
	private void setStatus(int statuscode, String statusmsg) {
		this.statuscode = statuscode;
		this.statusmsg = statusmsg;
	}
	public void setBody(Template template) {
		clearBody();
		bodyTemplate = template;
		setFileName(template.getFileName());
	}
	public void setBody(FileInputStream fis) {
		clearBody();
		bodyFis = fis;
	}
	private void setBody(String string) {
		clearBody();
		bodyString = string;
		setHeader("Content-type", "text/plain");
	}
	public void setError(int statuscode, String errormsg) {
		setStatus(statuscode, errormsg);
		try {
			Template errorTemplate = new Template("error", "html");
			errorTemplate.setData("errormsg", errormsg);
			setBody(errorTemplate);
		} catch (IOException e) {
			setBody(errormsg);
		}
	}
	public void redirect(String url, int statuscode) {
		if (statuscode < 300 || statuscode >= 400) {
			Manager.logErr("Invalid redirect status code: "+statuscode+".  Must be in the 3xx range");
			redirect(url);
			return;
		}
		clearBody();
		setStatus(statuscode, "Redirect");
		setHeader("Location", url);
	}
	public void redirect(String url) {
		redirect(url, 302);
	}
	public void notFound(String type) {
		String msg = type + " Not Found";
		setError(404, msg);
	}
	public void notFound() {
		notFound("File");
	}
	public void setJson(Object output) {
		clearBody();
		Gson gson = new Gson();
		bodyString = gson.toJson(output);
		setHeader("Content-type", "application/json");
	}
	
    private static String contentType(String fileName) {
        if(fileName.endsWith(".htm") || fileName.endsWith(".html")) {
            return "text/html";
        }
        if(fileName.endsWith(".xhtml")) {
            return "application/xhtml+xml";
        }
        if(fileName.endsWith(".png")) {
            return "image/png";
        }
        if(fileName.endsWith(".gif")) {
            return "image/gif";
        }
        if(fileName.endsWith(".jpg")) {
            return "image/jpeg";
        }
        if(fileName.endsWith(".css")) {
            return "text/css";
        }
        if(fileName.endsWith(".js")) {
            return "text/javascript";
        }
        if(fileName.endsWith(".mp3")) {
            return "audio/mpeg";
        }
        if(fileName.endsWith("manifest")) {
            return "text/cache-manifest";
        }
        if(fileName.endsWith("ico")) {
            return "image/x-icon";
        }
        return "application/octet-stream";
    }
    private void sendHeaders() throws IOException {
        os.writeBytes("HTTP/1.1 "+ statuscode +" "+ statusmsg + CRLF);
        Iterator iter = headers.entrySet().iterator();
        while (iter.hasNext()) {
            Map.Entry header = (Map.Entry)iter.next();
            os.writeBytes(header.getKey()+": "+header.getValue() + CRLF);
        }
        os.writeBytes(CRLF);
    }
	
	public void send() throws IOException {
		sendHeaders();
		if (bodyTemplate != null) {
			os.writeBytes(bodyTemplate.toString());
		} else if (bodyString != null) {
			os.writeBytes(bodyString);
		} else if (bodyFis != null) {
			
			// Construct a 1K buffer to hold bytes on their way to the socket.
			byte[] buffer = new byte[1024];
			int bytes = 0;
			
			// Copy requested file into the socket's output stream.
			while((bytes = bodyFis.read(buffer)) != -1 ) {
				os.write(buffer, 0, bytes);
			}
			bodyFis.close();
		}
		os.close();
	}
}