install mkcert
# apt install mkcert
go to root of netbeans project and create self sign certificate
$ mkcert localhost
Created a new local CA 💥
Note: the local CA is not installed in the system trust store.
Note: the local CA is not installed in the Firefox and/or Chrome/Chromium trust store.
Run "mkcert -install" for certificates to be trusted automatically ⚠️
Created a new certificate valid for the following names 📜
- "localhost"
The certificate is at "./localhost.pem" and the key at "./localhost-key.pem" ✅
It will expire on 8 September 2028 🗓
Convert to PKCS 12
$ openssl pkcs12 -export \
-in localhost.pem \
-inkey localhost-key.pem \
-out localhost.p12 \
-name localhost
Enter Export Password:
Verifying - Enter Export Password:
main java code
/*
* Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
*/
package com.dedetok.ddtescpos;
import com.alibaba.fastjson2.JSONObject;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpServer;
import com.sun.net.httpserver.HttpsConfigurator;
import com.sun.net.httpserver.HttpsExchange;
import com.sun.net.httpserver.HttpsServer;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertificateException;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
/**
*
* @author dedetok
*/
public class DdtEscPos {
final static String serviceString = "DdtEscPos";
final static String serviceVersion = "1.0";
public static void main(String[] args) {
System.out.println("DdtEscPos reading configuration file");
MyController.readConfig(); // if configuration not available, use hard code config
System.out.println(serviceString+" "+serviceVersion);
// =================
try {
HttpServer httpServer = createHttpService(MyController.http_port);
HttpsServer httpsServer = createHttpsService(MyController.https_port);
Runtime.getRuntime().addShutdownHook(new Thread(() -> {
System.out.println("Stopping HTTP & HTTPS server...");
httpServer.stop(5); // stop 5 second
System.out.println("HTTP server stopped");
httpsServer.stop(5); // stop 5 second
System.out.println("HTTPS server stopped");
}));
httpServer.start();
System.out.println("HTTP server running on http://localhost:" + MyController.http_port);
httpsServer.start();
System.out.println("HTTPS server running on http://localhost:" + MyController.https_port);
} catch (IOException | KeyStoreException | NoSuchAlgorithmException | CertificateException | UnrecoverableKeyException | KeyManagementException ex) {
System.getLogger(DdtEscPos.class.getName()).log(System.Logger.Level.ERROR, (String) null, ex);
}
}
/*
* create http service in httpPort
*/
static HttpsServer createHttpsService(int httpsPort) throws IOException, KeyStoreException, NoSuchAlgorithmException, CertificateException, UnrecoverableKeyException, KeyManagementException {
// Load PKCS12 keystore
char[] password = "escpos".toCharArray();
KeyStore ks = KeyStore.getInstance("PKCS12");
try (FileInputStream fis = new FileInputStream("localhost.p12")) {
ks.load(fis, password);
}
KeyManagerFactory kmf = KeyManagerFactory.getInstance(
KeyManagerFactory.getDefaultAlgorithm());
kmf.init(ks, password);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(kmf.getKeyManagers(), null, null);
// Create HTTPS server
HttpsServer httpsServer =
HttpsServer.create(
new InetSocketAddress("localhost", httpsPort),
0);
httpsServer.setHttpsConfigurator(new HttpsConfigurator(sslContext));
// Register endpoints
httpsServer.createContext("/", DdtEscPos::handleHttpRequest);
httpsServer.createContext("/printjson", DdtEscPos::handlePrintJson);
return httpsServer;
}
/*
* create http service in httpPort
*/
static HttpServer createHttpService(int httpPort) throws IOException {
HttpServer httpServer =
HttpServer.create(new InetSocketAddress("localhost", httpPort), 0);
httpServer.createContext("/", DdtEscPos::handleHttpRequest);
httpServer.createContext("/printjson", DdtEscPos::handlePrintJson);
return httpServer;
}
/*
* handling /
*/
static void handleHttpRequest(HttpExchange exchange) throws IOException {
// CORS
exchange.getResponseHeaders().add(
"Access-Control-Allow-Origin", "*");
exchange.getResponseHeaders().add(
"Access-Control-Allow-Headers",
"Content-Type, Authorization");
exchange.getResponseHeaders().add(
"Access-Control-Allow-Methods",
"GET, POST, OPTIONS");
if ("OPTIONS".equalsIgnoreCase(exchange.getRequestMethod())) {
exchange.sendResponseHeaders(204, -1);
return;
}
// UTF-8 text response
exchange.getResponseHeaders().add(
"Content-Type",
"text/plain; charset=UTF-8");
String response = infoService(exchange).toString();
byte[] responseBytes = response.getBytes(StandardCharsets.UTF_8);
exchange.sendResponseHeaders(200, responseBytes.length);
try (OutputStream os = exchange.getResponseBody()) {
os.write(responseBytes);
}
System.out.println("Servicing client done"); // debug
}
/*
* handling /printjson
*/
static void handlePrintJson(HttpExchange exchange) throws IOException {
// CORS
exchange.getResponseHeaders().add(
"Access-Control-Allow-Origin", "*");
exchange.getResponseHeaders().add(
"Access-Control-Allow-Headers",
"Content-Type, Authorization");
exchange.getResponseHeaders().add(
"Access-Control-Allow-Methods",
"GET, POST, OPTIONS");
if ("OPTIONS".equalsIgnoreCase(exchange.getRequestMethod())) {
exchange.sendResponseHeaders(204, -1);
return;
}
// UTF-8 text response
exchange.getResponseHeaders().add(
"Content-Type",
"text/plain; charset=UTF-8");
// get json from request
// Read request body
String requestBody;
try (InputStream is = exchange.getRequestBody()) {
requestBody = new String(is.readAllBytes(), StandardCharsets.UTF_8);
// Parse JSON
// Parse JSON and process
JSONObject json = JSONObject.parseObject(requestBody);
JSONObject responseJson = infoService(exchange);
try {
MyController.printJson(json.toString());
responseJson.put("status", "printing done");
} catch (IOException ex) {
responseJson.put("status", "printing fail");
responseJson.put("error", ex.getMessage());
}
byte[] bytes =
responseJson.toString().getBytes(StandardCharsets.UTF_8);
exchange.sendResponseHeaders(200, bytes.length);
OutputStream os = exchange.getResponseBody();
os.write(bytes);
os.flush();
}
}
/*
* standard info response
*/
static JSONObject infoService(HttpExchange exchange) {
JSONObject jsonObj = new JSONObject();
jsonObj.put("version", serviceVersion);
jsonObj.put("service", serviceString);
jsonObj.put("status", "running");
String host = exchange.getLocalAddress().getHostString();
int port = exchange.getLocalAddress().getPort();
String scheme = (exchange instanceof HttpsExchange)
? "https://"
: "http://";
String baseUrl = scheme + host + ":" + port;
jsonObj.put("endpoint",baseUrl+"/printjson");
return jsonObj;
}
}
to run service
$ java -jar target/DdtEscPos-1.0.jar
Hello World!
HTTP server running on http://localhost:50001
HTTPS server running on https://localhost:50002
Serviing client done
Serviing client done
using curl to send json to print http
$ curl -H "Content-Type: application/json" \
-d @exampleescpos.json \
http://localhost:50001/printjson
https
$ curl -k \
-H "Content-Type: application/json" \
-d @exampleescpos.json \
https://localhost:50002/printjson
or
$ curl --insecure \
-H "Content-Type: application/json" \
-d @exampleescpos.json \
https://localhost:50002/printjson
Credit: esc html using https://www.freeformatter.com/html-escape.html
