Spring MongoDB REST API without HAL? - spring

This Guide shows how to easily create a RESTful interface to a Mongo Database. It produces Json-data in HAL format(Hypertext Application Language), but unfortunately I am unable to find a working Android Client that supports HAL.
Is there any way to disable this HAL format an just GET the documents from the DB without any extra? So that it can be directly parsed into my datatype classes?
It would be really nice to use this approach to somehow automatically generate the REST interface, I cannot go back to manually writing all the methods in controllers after seeing this very short code.
This post seems to deal with the same topic, but I do not understand how to do this configuration.

The guide you are linking to is specifically aimed at using Spring Data REST + Spring Data MongoDB, so to disable the hypermedia for a project designed to generate hypermedia, i.e. a RESTful interface, sounds very strange.
On a mobile platform like Android, the question is what are you trying to do? Are you trying to query for a single, small piece of JSON from MongoDB? The risk of not having any type of hypermedia layer in the middle is that you could query for a giant (i.e. humongous data set) and cripple both the server and mobile device.
For more details about hypermedia and Spring Data REST, check out Oliver Gierke's answer at Disable Hypertext Application Language (HAL) in JSON?.
Regarding the ability to communicate between Android and a HAL backend, of course it's possible. You may wish to look at Roy Clarkson's sample Android app used to talk to a HAL backend that was used at SpringOne 2014 at https://github.com/SpringOne2GX-2014/spring-a-gram-android.
The slides from that presentations are at https://speakerdeck.com/gregturn/springone2gx-2014-spring-data-rest-data-meets-hypermedia.

Related

Web client for spring-data-rest CRUD endpoints?

Spring Data REST creates a CRUD web server with a discoverable API, so it seems it should be possible to write a generalized web client application for it. Is there such an application?
May be you are looking for a HAL browser
https://www.baeldung.com/spring-rest-hal
or
something like https://www.npmjs.com/package/angular-spring-data-rest
https://www.npmjs.com/package/angular4-hal
I hope you mean sample client stubs. Actually a web client cannot be generalized beyond the resources it has. That will not be quite meaningful.
You can try below with swagger. Using swagger here would be really convenient (over raml etc) since spring-data-rest generates swagger it self for you.
Take your swagger spec
Paste it at https://editor.swagger.io/.
Go Generate Client => Your favorite programming language.
Then it will generate sample client stubs for you in the language you have selected.
I think this should be the far most generalized point that makes sense.
-Addition-
The primary problem spring-data-rest has solved is abstracting out all the common functionalities attached to controller (ex: response/request mapping etc) and making them readily available and configurable, so that the developer no longer needs to re-invent/duplicate them every time when they are coding a new endpoint.
So as you have suggested generating client-stubs is completely out of spring-data-rest scope. Please read the documentation for more info.

Spring boot , Elasticsearch

Searched over the net but unable to find the satisfying approach.
I am new to spring boot and aware of starter dependancies,
I want to develop a springboot app using elastic search as a storage system.
Wherever i searched i found that somewhere my service class will have to implement some interface from springframework for ES crud operations.
Is there any other way without implementing or extending the components.
I myself want to create transport client and want to query ES by my code or methods not by overidden ones.
Please if you ahve ever seen any projects you can redirect me to that link .
Thanks.
Assuming I understand you correctly, you can use the Elasticsearch REST client: https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html
You supply the JSON entities for the queries and parse the responses yourself. Its pretty basic in what it does, so you're not dependent on a lot of third party stuff to perform operations.

When to use default Spring Data REST behavior?

I recently worked on a project which uses Spring Data REST with Spring Boot. While it is GREAT to harness the power of Spring Data REST and build a powerful web service in no time, I have come to regret one thing: how tightly coupled the "presentation" layer (JSON returns) is to the underlying data structure.
Sure, I have used Projections and ResourceProcessors to manipulate the JSON, but that still does not completely sever ties with the database structure.
I want to introduce Controllers to the project, to integrate some of the "old" ways of building a web service in Spring. But how should I draw the line? I don't want to eradicate Spring Data REST from my project.
I am sure many of you have faced similar decisions, so any advice would be most appreciated!

Document Management System

At the company I work for, we are developing a billing web application with Spring and Vaadin. The trouble is that the number of files to manage is becoming too large; bill,offers contract, etc. We currently store each document as a file on the server, but in this way it is too hard to manage them. This is tedious and error-prone, and it also means we lack any sort of security for accessing these documents.
Now, I'm looking a Document Management System to manage this document. I saw Alfresco Document Management, but I don't know how to integrate it with my application.
Any suggestions?
Alfresco has REST API, so you can use it in your Spring + Vaadin application. Spring has RestTemplate based on Jackson who will help you with REST client implementation.
There are several ways to integrate with alfresco. My two favorite ways to integrate with Alfresco are:
Using the CMIS api
http://wiki.alfresco.com/wiki/CMIS
Using your own custom webscripts or java back end webscripts. These allow you to quickly develop your own rest api with alfresco.
http://docs.alfresco.com/4.0/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Fconcepts%2Fws-architecture.html
There are many different ways to integrate. They have webdav, cifs, ftp, and several other ways to integrate. Here is some documentation from alfresco about it
http://docs.alfresco.com/4.2/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Fconcepts%2Fintegration-options.html

Spring data alternatives

Currently We have an enterprise application that works with spring and JPA.
Today we are planning our next generation server.
We are debating whether to use spring-data in our project? It seems to increase productivity and development times.
Are there any alternatives to spring-data to consider? Why not using spring and JPA alone?
What do you suggest?
Bear in mind we are starting to develop from scratch so no constraints are available other than:
we use mysql and mongoDB
we code in java
we will develop client side code in GWT.
Currently we have a layered architecture.
We have a Service layer and a manager layer, which takes care for persisting and business logic. Whoever built that didn't see a good reason to insert the third DAO layer.
There are some technical benefits of Spring Data over Spring + JPA, which in a pure SQL environment, I think give Spring Data an advantage:
Spring Data uses the same CrudRepository interface for all implementations, so you'll have less effort to switch between JPA to MongoDB
Spring Data saves you writing the same methods again and again. You just add the method to the interface and it'll generate it for you (e.g. UserRepository.findByUsername())
You can save boilerplate on REST implementations for JPA, MongoDB and others (see http://projects.spring.io/spring-data-rest/)
If you wanted to experiment with other persistence or indexing services, then there are Spring Data implementations for both mature and newer technologies such as for Neo4j, Hadoop, Solr, ElasticSearch, fuzzydb.
Given that you use MySQL and MongoDB, I think Spring Data is a strong candidate, as it allows developers to code to a single data access API (Spring Data) instead of two (JPA and the MongoDB Java Client).
Regarding the existing architecture, it sounds as though your manager layer is implementing either a Rich Domain pattern, or Active Record.
Spring Data is in my view very well suited to Rich Domain when combined with injection of services using Spring's #Configurable.
Lastly, I'd say that Spring Data also gives a significant advantage when needing to implement services for things like Spring Security and Spring Social, which use MongoDB or others instead of SQL.
We did this in the fuzzydb sample webapp that can be found here. (Disclaimer: I'm the currently sole recent committer on fuzzydb, and haven't touched it for a number of years, but we did have a live service, www.fridgemountain.com, based on that code, but neglected to promote it)

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