I need help developing a Basic Java Rest API using IntelliJ and terminal on my mac. I also have docker installed. I want to run a hello world on local host using the REST API Style
There's a ton of different java web frameworks that will help you build a REST endpoint. Here's some of those frameworks:
http://spring.io/
https://vertx.io/
https://www.playframework.com/
if you want to build it from scratch (not recommended) then checkout
https://www.tutorialspoint.com/servlets/servlets-first-example.htm
Related
I have a Spring Boot web application which is currently deployed Google App Engine. Now I am shifted to Docker and want to deploy the docker image of this application on to App Engine.
So far, I could not find any document related to this. Most of the documents explain how to deploy a docker image of Spring boot on Tomcat. Is there any way to achieve this?
First you need App Engine using the flexible environment , if you want deploy by docker image.
Here is the document Building Custom Runtimes.
A custom runtime allows you to use an alternate implementation of any supported App Engine flexible environment language, or to customize a Google-provided one. It also allows you to write code in any other language that can handle incoming HTTP requests (example). With a custom runtime, the App Engine flexible environment provides and manages your scaling, monitoring, and load balancing infrastructure for you, so you can focus on building your application.
In official case they have their sample DockeFile by jetty. But you can ignore the jetty part, just make your spring boot application executable ,and run it.
FROM gcr.io/google-appengine/jetty
ADD test-webapp-1.0-SNAPSHOT.war $JETTY_BASE/webapps/root.war
WORKDIR $JETTY_BASE
RUN java -jar $JETTY_HOME/start.jar --approve-all-licenses --add-to-startd=jmx,stats,hawtio
&& chown -R jetty:jetty $JETTY_BASE
Hopefully this helps:
https://github.com/GoogleCloudPlatform/getting-started-java/tree/master/helloworld-springboot
One compelling benefit with Docker containers is that, when the containers works on one runtime (e.g. Tomcat), it should be relatively straighttforward to swap in a different runtime (e.g. App Engine).
NB App Engine Flexible is the specific service that you want. It is similar to App Engine Standard but it schedules containers for you.
The primarily requirement for a container (image) to work with App Engine Flexible is that the container expose an HTTP endpoint on port 8080. As long as your container meets this obligation, you can run anything within it.
Quick Question: Is it possible to convert a Kotlin + Spring restful web service to a linux native application?
It works properly when run on the JVM, but I get compilation errors when I try to build it using kotlinc-native for linux.
I cannot find any definitive statement about whether I am trying to do something that is unsupported. Am I trying to swim upstream, here?
Thank you for your comments and help!
Mike
Here are some details...
Ubuntu 18.04
Latest versions of stable dependencies
You can not link a jvm library with kotlin-native. You must have a C library to be able to link it or convert the java code to kotlin.
If what you need is a embedded server executable you could check the ktor project.
The project have some client native examples and a embedded native http2-push.
I am having three modules in my Maven project:
parent
rest-api # Spring REST API
web-client # AngularJS web client
application # Project to bundle it all up for a standalone
I am not sure if I have here an "elegant" solution so please hit me with a stick if that is complete garbage, but this is how it works - or how it's supposed to work:
rest-api
Module rest-api does simply offer the REST API and other core functionality - basically it is pure server code. It is a jar artifact.
web-client
To separate client and server code I am having the module web-client. It is a war project that hold the client webapp.
application
This module is supposed to glue it all up. It depends on rest-api and web-client. It does two important things:
It's pom.xml uses the spring-boot-maven-plugin to build a standalone runnable jar - my ultimate goal
It provides the main(String args[]) method that starts the #SpringBootApplication with SpringApplication.run(EasyModelAccessServer.class, args);
What I am currently able to is tell Eclipse to run this in a servlet container. The server boots up and I my two resources, the rest-api and the web-client working. Everything is fine so far.
The issue
What is not fully working is the standalone. If I package up the whole thing and run the server:
$ path/to/application: mvn clean package
$ path/to/application: java -jar target/application.jar
Only the REST API will work. The reason is because the web-client is not added or introduced as a web app to the Spring built-in Tomcat.
The question
is how I can make this work. There are two options which come to my mind:
Somehow sneak in the web-client.war file into the application.jar such that it is available as a resource and programmatically call tomcat.addWebapp("/web-client", "path/to/web-client.war") (or something like that) to load the additional service
Hope that the spring-boot-maven-plugin or another Spring Maven plug-in can do that for me and find somebody that links me to an example.
I've tried it with 1. but I didn't succeed to move web-client.war into application.jar but I am also not sure if I should actually do that.
FAQ
Q: "Why do you separate everything instead of merge all those modules into a server module where the Spring Maven plug-in would do everything for you out of the box?"
A: I really want to separate the client code from the server code. I could however merge web-client into application but last time I tried that I had 10 other issues why this did not work out so I decided to keep it that way and that it actually shouldn't be so hard to load an additional server resource.
Q: "Can I take a look at the project?"
A: Yes, you can. Just take a look: https://github.com/silentsnooc/easy-model-access Please forgive me that I am currently using tabs instead of whitespaces - I am going to change that as soon as I got everything up and running.
I like Dart, I have been playing with it for a while. I'd like to integrate with my Maven web app project based on Spring Boot.
I suppose the correct way is to use dart-maven-plugin. But I'm not sure how to properly glue it in place. Spring Boot has its own structure, Maven as well and Dart makes that none the better.
I will need probably the entry point for Dart part, means Spring Boot templates folder needs to include the html resources from Dart.
I would appreciate any idea, best practices.
PS: the aforementioned dart-maven-plugin is not really vivid, should I be afraid using it at all, as I don't see any progress there, compared to Dart itself.
UPDATE
So this can be solution(note I have only one so called "entry point"- .dart file so far)
normal Dart structure in src/main/dart
user dart-maven-plugin's pub build command into ${project.build.directory}/dart
maven-resources-plugin:copy-resources from ${project.build.directory}/dart/web to ${project.build.directory}/classes/public/
make war
I'm still able to use Intellij's Dart integration from src/main/dart.
The Spring Boot maps classes/public/ folder to / so the dart file and html files are loaded properly.
It's not ideal, but it works so far. Please fell free to write down any comments.
I have tried a few times to use dart in a maven project myself and always ran into some problems. Right now I'm developing my dart apps in a separate module that I build with pub which connects to the maven based java backends with rest.
This has several advantages for me, for example:
I can use pub and avoid problems with outdated maven plugins
I use the serving mechanism that fits best for the static dart code and assets (in my case a docker image with nginx)
I have a clean separation of backend and frontend code with a tailored REST API
As I like the microservice approach I also use spring session together with zuul (via spring-cloud).
If you want to combine dart with generated html from for example JSPs or another templating engine, then this isn't a good approach for you. But IMHO dart is not yet very well suited for these kind of architectures.
I'm building "read-only" webservice (Google Cloud Endpoints as backend for an Android App) so I created a project using maven:
mvn archetype:generate -Dappengine-version=1.9.10 -Dfilter=com.google.appengine.archetypes:
and selecting archetype hello-endpoints-archetype to have some sample code to work on.
This works well and my app is correctly calling the service as expected (and the service is correctly supplying the data in return).
Now I have to implement an "update" service to periodically (4 to 6 times a dya) update the data supplied to the app. So I added a servlet to my project to be called by cron. Trouble is: one of the library used during this update uses multi-threads which cause an AccessControlException to be thrown because apparently multi-thread is only allowed in backend modules...
But after having read dozens of pages on google app engine, I still don't know how to "break" my application into modules so that particular servlet would be run as a backend module while the already existing servlet keep working as they do. So far, all I got was that I should use an EAR application composed of several WAR modules, but I don't even know if my current application is an EAR or not...
I'm using Eclipse Luna, maven 3.2.1 (embeded with Eclipse), google app engine 1.9.10, writing in Java
Could anyone please help me by explaining the directory structure and/or configuration files I have to look at, modify and/or add?
Thanks for any help provided!
You can find an example of multi-modules project here.
However, note that even in backend modules the threading is limited to 50 threads, as stated here.