Can someone please let me know if we can use Restful web services or something similar to that to service HTTP requests without using a web server
All the Http requests are processed or identified by the servlet or ejb component in java.
1.We must deploy restful services server side code in webserver otherwise we cannot expose our functionality over the network
2.To access the rest resource we can use normal java program or any servlet or other.
3.Without using webserver you cannot expose your rest resource over the network at serverside.
Related
I am working on a project where I have two servers (tomcat), Server A gives initial snapshot of information from DB(MySQL) to the frontend. Server B to serve updates to server A, both servers need to communicate. How do I connect them? Thank you very much for your help.
There are many ways two Tomcat instances running on the same host could be set up to communicate with each other. It's quite common to implement a REST service in the "server" Tomcat instance and have the "client" Tomcat instance send the REST request to the other instance. It's common to use either the Jersey or CXF framework to implement a JAX-RS REST service, or you could use the Spring framework to implement a more general web request handler.
Tomcat typically accepts HTTP/S requests. So you could program your own servlets in Tomcat A (and publish them as URIs) to accept data which shall be updated to the DB. Then, Server B must act as a client to server A, initiating communication whenever it wants, and sending the data to Server A as HTTP requests.
Taking security into account, I'd also suggest that Server A should forbid any requests to the updating URIs which do not come from Server B. For instance, securizing the updating URIs through standard JEE security.
I have recently gone through rest web services(mainly spring). But I did not find much difference between rest based web service and web application.
In rest based web service, we have #RestControllerand in web application we have #Controller. The one difference from dev perspective I know is in rest that we have more
verbs like PUT, DELETE etc. but in web app we mainly use POST/GET . That is from receiver side. Even sender will just sends the http request for rest like sent in web application
Both maps the incoming url with method , mentions return format etc.
Yes there will be difference in authentication as in web application it will be form based authentication but web service it will be different like header based or something else.
So is there any major difference in protocol/sender/receiver or any perspective ?
From spring-frameworkrestcontroller-vs-controller
The key difference between a traditional Spring MVC controller and the RESTful web service controller is the way the HTTP response body is created. While the traditional MVC controller relies on the View technology, the RESTful web service controller simply returns the object and the object data is written directly to the HTTP response as JSON/XML
Rest of the things are more or less same
Web services are typically from application to application or machine to machine to exchange data it and the raw data usually is not human or browser friendly, ( encoded in json or xml or other agreed formats). The encoded data maybe later transformed or wrapped into pretty web pages as an output to view object data to be browser human-friendly for viewing.
I have multiple Java web applications deployed on the same server (Wildfly).
They all should use a single WebSocket implementation to send messages (object, not plain text) to the user.
Edit: WebApp1-3 are the applications with the business logic. The only purpose of WebApp4 is to update a Primefaces panel in the browser based on the messages generated by the other WebApps. Sorry for the missleading illustration.
WebApp1
WebApp2 --> ??? --> WebApp4 (WebSocket-Server) --> JS/Browser
WebApp3
Which is the best way/pattern/implementation to make WebApp4 available to the other applications? (RMI, JMS, WebSocket, WebService, ....?)
My advice, for a general way of exposing services, is to expose REST services since they are simpler than SOAP web service and easily allow interoperability (if in the future a PHP or a RUBY webapp needs to consume your services it's much easier with a REST interface than with one base on RMI or JMS). The content of the REST service may vary, I suggest you to look at XML or JSON as a way of transmitting information over http REST services.
If all webapps are in the same server, you should forward requests from one to another. From the point of view of webapps 1-3, they would not need to be aware of whether their incoming requests were coming from webapp 4 or from outside (to which it appears that they are not connected). Of course, you are free to alter requests before forwarding them - or to drop them altogether, for example if authentication fails.
To do this in tomcat: https://stackoverflow.com/a/8951090/15472
When forwarding requests, the external client is completely unaware of the existence of webapps 1-3 -- as far as the client is concerned, it has sent a request to webapp 4, and it will think it is receiving a response from that same server.
You may need to configure your web server to allow these kinds of calls, but I am unfamiliar with WildFly.
I'm not completely clear on one thing and am hoping some one here will probably answer this.
I worked on an enterprise application where we had a Java app consuming services with a WSDL interface in between and a .NET application on the other side producing the services.
I have been reading RESTful webservices where jersey API is used to route a request through a jersey servlet to an URI that eventually talks to a Java class to send the data back.
I'm not able to understand the point where diverse applications like .NET and Java can talk through a REST interface and how for this particular scenario Rest is useful.How does Rest work in this case?. for SOAP there is WSDL, what about for REST assuming a Java app is consuming from a .NET through a Restful service. Please explain how it works.
Thanks in advance!
Both REST and SOAP use HTTP for communication. Requests are sent over the wire using the HTTP protocol from client to server. The server replies using the same protocol. As long as the client and the server both send information using HTTP, it doesn't matter what language the client or server are written in.
RESTful APIs may use some combination of WADL, HATEOAS, and documentation to reveal their API to clients.
I have a web service built on Netbeans in Java where I want to send requests to different endpoints.
Ie, there is a certain method I want my web service to call, but each time from a different endpoint.
Is there a way to do this?
Or alternatively, can I insert into an existing WSDL file, another endpoint and then load the file into a Web service client and then decide within the Web service client to which endpoint I send the method call?