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Java jetty server example

Содержание
  1. Embedded Jetty
  2. Embedded Jetty
  3. Download Jetty
  4. Embedded Jetty
  5. ServerMain.java
  6. Command Line
  7. Example Project
  8. Compiling
  9. Running
  10. Servlets
  11. Hello world!
  12. Maven
  13. Example Project
  14. Maven Directory Structure
  15. pom.xml
  16. ServerMain.java
  17. Running a Server
  18. Homework

Embedded Jetty

Server Tutorials

Tomcat Setup

Jetty Setup

Embedded Jetty

Hello World: Embedded Jetty (Command Line)

Hello World: Embedded Jetty (Maven)

Anatomy of a Web App

Hello World: Static Website

Hello World: Command Line

Hello World: Maven

Client / Server Communication

Servlets

Social Feed Website Part 1: Servlets

JSP

Social Feed Website Part 2: JSP

JSP Unix Time

JSP Date

JSP Coin Flipper

JSP Zoo

JSP Header

Servlet JSP Date

Servlet JSP Date (Hidden JSP)

Eclipse EE

Post Requests

Social Feed Website Part 3: Post Requests

Name Input

Name List

Name List — JSP

Name List — Fetch

Libraries

Sanitizing User Input

Unsanitized User Input

Escaping User Input

Sessions

Social Feed Website Part 4: Sessions

Secure Password Storage

Hosting on AWS

Thread Safety

Social Feed Website Part 5: Thread Safety

Hosting on Google App Engine

Databases

Uploading Files

Creating a REST API

Struts

p5.js Tutorials

JavaScript Tutorials

Processing Tutorials

Java Tutorials

Server Tutorials

Google Cloud

Android Tutorials

LibGDX Tutorials

How-To Guides

Gallery

Blog

Teaching

github

etsy youtube RSS

Tutorials

Server Tutorials

Embedded Jetty

Embedded Jetty

This tutorial walks through the process of using Jetty to run a server on your computer. Running a local Jetty server is handy for testing things out without needing to update (or pay for) a live server.

Jetty is a popular Java server, especially because of its ability to run embedded in any Java application. That’s what this tutorial is about, but you can also follow the Jetty tutorial to use Jetty as its own server container.

Download Jetty

Jetty is bundled as a jetty-home directory inside a .zip file, which you can download from here.

Download that file, and then unzip the directory anywhere. I put mine on my desktop. You can always move it later.

Embedded Jetty

There are a couple of ways to use Jetty to create a server. You can either run a full server that you then add code to, or you can write code that runs an embedded Jetty server.

To learn about running a full Jetty server, check out this tutorial.

The rest of this tutorial walks you through running an embedded Jetty server.

ServerMain.java

Instead of running a server and then adding code to it, you can run a Jetty server directly from a normal Java class.

Here’s an example Java class that runs an embedded Jetty server:

package io.happycoding; import java.net.URL; import org.eclipse.jetty.server.Server; import org.eclipse.jetty.webapp.WebAppContext; /** * Starts up a server that serves static files from the top-level directory. */ public class ServerMain  public static void main(String[] args) throws Exception  // Create a server that listens on port 8080. Server server = new Server(8080); WebAppContext webAppContext = new WebAppContext(); server.setHandler(webAppContext); // Load static content from the top level directory. URL webAppDir = ServerMain.class.getClassLoader().getResource("."); webAppContext.setResourceBase(webAppDir.toURI().toString()); // Start the server! 🚀 server.start(); System.out.println("Server started!"); // Keep the main thread alive while the server is running. server.join(); > >

This code creates a server that listens on port 8080 and loads static files (like index.html ) from the top level directory, and then it starts that server.

This code assumes you have a directory structure like this:

  • HelloWorld/
    • index.html
    • io/happycoding/ (this is a directory representing a package)
      • ServerMain.java

      Notably, the static files (like index.html ) are in the top-level directory, and the packages and classes are in that same top-level directory. You can also have a more complicated directory structure, but you’d have to change the corresponding lines in the ServerMain class.

      Command Line

      Eventually you’ll probably want to use an IDE like Eclipse or Intellij to compile and run your code, but I recommend using the command line the first few times so you really understand what’s going on behind the scenes.

      Example Project

      You can view and download an example project that uses the command line to deploy an embedded Jetty server here:

      This section of the tutorial walks through this example project.

      Compiling

      To compile this code, open a command line to the HelloWorld directory and then run this command:

      javac -cp /jetty-home/lib/* io/happycoding/ServerMain.java

      Don’t forget to change the classpath to your local copy of Jetty! For example, the command I would run is this:

      javac -cp C:/Users/kevin/Desktop/jetty-home-11.0.5/lib/* io/happycoding/ServerMain.java

      Running

      And then to run the ServerMain class, run this command:

      java -cp /jetty-home/lib/*;jetty-home/lib/annotations/*;jetty-home/lib/apache-jsp/*;jetty-home/lib/jaspi/*;/jetty-home/lib/logging/*;.; io.happycoding.ServerMain

      For example, the command I would run is this:

      java -cp C:\Users\kevin\Desktop\jetty-home-11.0.5\lib\*;C:\Users\kevin\Desktop\jetty-home-11.0.5\lib\annotations\*;C:\Users\kevin\Desktop\jetty-home-11.0.5\lib\apache-jsp\*;C:\Users\kevin\Desktop\jetty-home-11.0.5\lib\jaspi\*;C:\Users\kevin\Desktop\jetty-home-11.0.5\lib\logging\*;.; io.happycoding.ServerMain

      The classpath to run the server is a bit more complicated than the classpath to compile the server, because running the server requires a few other libraries that aren’t used directly by the ServerMain class.

      You should see Server started! in your command line. That means you can navigate to localhost:8080 to see the index.html file:

      index.html file in the browser

      Try changing your index.html file, restarting the server, and refreshing the page to see your changes!

      Servlets

      You’ll learn more about servlets in the servlets tutorial, but for now, let’s look at how the ServerMain.java file can also load server code.

      Let’s say you have this servlet class in the io.happycoding package:

      package io.happycoding; import java.io.IOException; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; @WebServlet("/hello") public class HelloWorldServlet extends HttpServlet  @Override public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException  response.setContentType("text/html;"); response.getWriter().println("
      Hello world!
      "      ); > >

      This servlet uses the @WebServlet annotation to map to the /hello URL and writes a hard-coded

      Hello world!

      message to the response.

      For the embedded Jetty server to see this class, you need to add this line of code to your ServerMain.java file:

      // Look for annotations in classes and packages in the top level directory. webAppContext.setAttribute( "org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern", ".*/");

      Then, to compile both the ServerMain.java file and the HelloWorldServlet.java file, cd into the HelloWorld directory and run this command:

      javac -cp /jetty-home/lib/* io.happycoding.*.java

      For example, here’s the command I would run:

      javac -cp C:/Users/kevin/Desktop/jetty-home-11.0.5/lib/* io.happycoding.*.java

      Then, run the ServerMain class:

      java -cp /jetty-home/lib/*;jetty-home/lib/annotations/*;jetty-home/lib/apache-jsp/*;jetty-home/lib/jaspi/*;/jetty-home/lib/logging/*;.; io.happycoding.ServerMain

      You should see Server started! in your command line, and you should still be able to navigate to localhost:8080 to see your index.html file. And you should now be able to navigate to localhost:8080/hello to see the content generated from the servlet!

      servlet response in the browser

      Maven

      So far, this tutorial has used the command line to compile and run the code. You can keep using that approach if you want, but it can get pretty annoying to handle the classpath yourself, especially as you start using other libraries.

      Maven is a tool that manages the classpath for you, and makes it easier to compile and build (and eventually deploy) your server. To use Maven, first download and install it from here.

      Example Project

      You can view and download an example project that uses Maven to deploy an embedded Jetty server here:

      The rest of this tutorial walks through this example project.

      Maven Directory Structure

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