# RESTful API instruction of ePaper Manager
###### tags: RESTful API

## How To Use RESTful API
**Example API: <font style="background-color: yellow;">Get Tay By Agent id</font>**
#### If you want to retrieve EPD tag information by a specific agent id, you can use this API.

### Javascript
**Prerequisite:** Include jQuery CDN in the HTML head element

<script src="https://code.jquery.com/jquery.js"></script>

// Custom parameters
var agentid = "00000001-0000-0000-0012-4b001ae6ec05";
var url = "http://172.22.13.3:8080/esl/v1/tags/tag/?agentid=" + agentid; // URL-Path
var type = "GET"; // Method
var data = {}; // Request-body
var username = "root"; // ePaper Manager Username
var password = "P@ssw0rd"; // ePaper Manager Password
var auth = "Basic " + btoa(username + ":" + password); // Authorization

// Query API
api(url, type, data, auth, function(res){
    console.log(res);
});

// We use AJAX method to make a query
function api(url, type, data, auth, callback){
    $.ajax({
        url: url,
        type: type,
        data: JSON.stringify(data),
        dataType: "json",
        headers: {
            "Authorization": auth,
        },
        xhrFields: {
           withCredentials: true
        },
        contentType : 'application/json', // Content-Type: application/json
        error: function(xhr) {
            console.log("Ajax request error!"); // Response-body (Error)
        },
        success: function(res) {
            callback(res); // Response-body (Success)
        }
    });
}

### Java

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Base64;

import org.json.JSONObject;

public class Test {
	public static void main(String[] args) {
		try {
			// Custom parameters
			String agentid = "00000001-0000-0000-0012-4b001ae6ec05";
			String url = "http://172.22.13.3:8080/esl/v1/tags/tag/?agentid=" + agentid; // URL-Path
			String type = "GET"; // Method
			String username = "root"; // ePaper Manager Username
			String password = "P@ssw0rd"; // ePaper Manager Password
			String auth = "Basic " + Base64.getEncoder().encodeToString((username + ":" + password).getBytes("UTF-8"));
			JSONObject data = new JSONObject(); // Request-body

                       // Query API
			JSONObject result = api(url, type, auth, data);
			System.out.println(result);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}

	}

	private static JSONObject api(String url, String type, String auth, JSONObject data) {
		URL uri;
		HttpURLConnection conn = null;
		JSONObject result = new JSONObject();
		BufferedReader br = null;
		try {
			uri = new URL(url);
			conn = (HttpURLConnection) uri.openConnection();
			conn.setRequestMethod(type);
			conn.setConnectTimeout(30000);
			conn.setReadTimeout(30000);
			conn.setRequestProperty("Content-Type", "application/json"); // Content-Type: application/json
			conn.setRequestProperty("Authorization", auth);
			conn.setDoOutput(true);

			String reqBody = data.toString();
			if (!"{}".equals(reqBody)) {
				conn.setDoInput(true);
				DataOutputStream out = new DataOutputStream(conn.getOutputStream());
				out.write(reqBody.getBytes("utf-8"));
				out.flush();
				out.close();
			}
			conn.connect();

			System.out.println("StatusCode: " + conn.getResponseCode());
			br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
			String read = new String();
			while ((read = br.readLine()) != null) {
				result = new JSONObject(read); // Response-body
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (br != null)
					br.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (conn != null)
				conn.disconnect();
		}

		return result;
	}
}

### C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using Newtonsoft.Json.Linq;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            // Custom parameters
            string agentid = "00000001-0000-0000-0012-4b001ae6ec05";
            string url = "http://172.22.13.3:8080/esl/v1/tags/tag/?agentid=" + agentid; // URL-Path
            string type = "GET"; // Method
            string username = "root"; // ePaper Manager Username
            string password = "P@ssw0rd"; // ePaper Manager Passw0rd
            string privilege = string.Format("{0}:{1}", username, password);
            byte[] bytes = System.Text.Encoding.GetEncoding("utf-8").GetBytes(privilege);
            string auth = "Basic " + Convert.ToBase64String(bytes); // Authorization
            JObject data = new JObject(); // Request-body

            // Query API
            JObject result = api(url, type, auth, data);
            Console.WriteLine(result);
            Console.ReadKey();
        }


        static JObject api(string url, string type, string auth, JObject data)
        {
            JObject jsonObject = null;
            HttpWebRequest req = WebRequest.Create(url) as HttpWebRequest;
            req.Headers.Add("Authorization", auth);
            req.ContentType = "application/json";  // Content-Type: application/json
            req.Method = type;

            if (data.Properties().Count() > 0)
            {
                StringBuilder paramz = new StringBuilder();
                paramz.Append(data);
                byte[] formData = UTF8Encoding.UTF8.GetBytes(paramz.ToString());
                req.ContentLength = formData.Length;
                using (Stream post = req.GetRequestStream())
                {
                    post.Write(formData, 0, formData.Length);
                }
            }

            // Response:
            HttpWebResponse resp = null;
            try
            {
                resp = (HttpWebResponse)req.GetResponse();
            }
            catch (WebException ex)
            {
                resp = (HttpWebResponse)ex.Response;
            }
            if (resp != null)
            {
                switch (resp.StatusCode)
                {
                    case HttpStatusCode.OK:
                        StreamReader reader = new StreamReader(resp.GetResponseStream());
                        string result = reader.ReadToEnd(); // Response-body (Success)
                        jsonObject = JObject.Parse(result);
                        break;
                    default:
                        Console.WriteLine("[Error] " + resp.StatusCode + ": " + resp.StatusDescription);
                        break;
                }
                resp.Close();
            }

            return jsonObject;
        }
    }
}

### Python

import urllib.request
import urllib.parse
import base64
import json

def api(url, type, auth, data):
	req = urllib.request.Request(url)
	req.add_header('Authorization', auth)
	req.add_header('Content-Type', 'application/json') # Content-Type: application/json

	if len(data) > 0:
		jsondata = json.dumps(data) # json to string
		jsondataasbytes = jsondata.encode('utf-8') # needs to be bytes
		req.add_header('Content-Length', len(jsondataasbytes))                       
		res = urllib.request.urlopen(req, jsondataasbytes)
	else:
		res = urllib.request.urlopen(req)

	result = res.read() # Response-body
	jsonObject = json.loads(result) # string to json
	return jsonObject



# Custom parameters
username = 'root' # ePaper Manager Username
password = 'P@ssw0rd' # ePaper Manager Password
agentid = '00000001-0000-0000-0012-4b001ae6ec05'
url = 'http://172.22.13.3:8080/esl/v1/tags/tag/?agentid=' + agentid # URL-Path
type = 'POST' # Method
base64string = str(base64.encodebytes(('%s:%s' % (username, password)).encode()))[2: -3]
auth = 'Basic %s' % base64string # Authorization
data = {} # Request-body


# Query API
result = api(url, type, auth, data)
print(result)