HTTP.java

package edu.gatech.oad.rocket.findmythings.server.util;

import com.google.appengine.labs.repackaged.org.json.JSONException;
import com.google.appengine.labs.repackaged.org.json.JSONObject;
import com.google.common.base.Preconditions;

import org.apache.shiro.web.util.WebUtils;

import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


public final class HTTP {

	private HTTP() {}

	public static enum Status {
		OK(200),
		BAD_REQUEST(400),
		UNAUTHORIZED(401),
		NOT_FOUND(404),
		FORBIDDEN(403),
		INTERNAL_ERROR(500);

		private final int code;

		private Status(int code) {
			this.code = code;
		}

		public int toInt() {
			return code;
		}
		
		public String toString() {
			return Integer.toString(toInt());
		}
	}

	public static final class JSON {

		private JSON() {}

		static JSONObject fromArgs(Object... args) {
			Preconditions.checkArgument(args.length % 2 == 0, "There must be an even number of argument strings");
			try {
				JSONObject obj = new JSONObject();
				for (int i = 0; i < args.length; i += 2) {
					obj.put((String)args[i], args[i+1]);
				}
				return obj;
			} catch (JSONException e) {
				throw new RuntimeException(e);
			}
		}

	}

	public static void write(ServletResponse response, String mimeType, Status returnCode, String output) {
		write(WebUtils.toHttp(response), mimeType, returnCode, output);
	}

	public static void write(HttpServletResponse response, String mimeType, Status returnCode, String output) {
		try {
			response.setContentType(mimeType);
			response.setStatus(returnCode.toInt());
			response.getWriter().println(output);
			response.getWriter().flush();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	public static void writeError(ServletResponse response, Status error) {
		writeError(WebUtils.toHttp(response), error);
	}

	public static void writeError(HttpServletResponse response, Status error) {
		try {
			response.sendError(error.toInt());
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	public static void writeJSON(HttpServletResponse response, JSONObject obj) {
		write(response, MimeTypes.JSON, Status.OK, obj.toString());
	}

	public static void writeJSON(ServletResponse response, JSONObject obj) {
		write(response, MimeTypes.JSON, Status.OK, obj.toString());
	}

	public static void writeAsJSON(HttpServletResponse response, Object... args) {
		writeJSON(response, JSON.fromArgs(args));
	}

	public static void writeAsJSON(ServletResponse response, Object... args) {
		writeJSON(response, JSON.fromArgs(args));
	}

}