I just want to implement a service in java that will:
take some arguments, then search the database
return the JSON object of the fetched data
I need help to identify the ways through which I can implement this thing.
e.g. Suppose I am getting the name of the book as argument I want to render.
On service part, I have to fetch book data and convert it to JSON and write/return to response.
I was looking at the Apache Axis2 but I am not sure that I am going in the right direction.
So, pls help.
Need guidelines not implementation.
Thanks
I would suggest using JAX-RS based services which would be ideal for your scenario as you want json data. These are pretty easy to get started with. Jersey is a widely used frameworks. Also see RESTEasy.
If you are returning the data in JSON then you probably don't need to implement a full web service, which uses XML for both the request and the response.
A normal dynamic web application (written as a Java Servlet) will be able to read request parameters in the HTTP payload and return a JSON-encoded HTTP response.
However you need to consider your clients; if they are only able to access web services then you need to forget about a JSON response and simply objectify the response. However if the clients can access web resources without issue then go with the servlet approach.
If you need to go with web services then look at the Metro 2 framework.
One way to do this is to keep it standards-based.
If you are using the JEE5/6 framework, your best bet would be to go with JAX-WS - comes built-in with the JSE too (if I remember correctly)
You really just have to annotate a POJO with #WebService to achieve this.
Regarding creating a JSON response, a good bet is to stick with the implementation from http://code.google.com/p/google-gson/ ; simple and straightforward
Axis2 can handle/support the webservice related part, iaw, transforming java objects into JSON and vice-versa and providing an easy-to-use API for the communication part.
Hibernate or JPA could be useful for database related tasks, although it might be easier to just use JDBC to send some simple SQL commands to the database (especially if the database already existst).
Related
I've 2 questions about Java Rest APIs
1'st:
I would like to create a Rest API with Java Servlets for using in the mobile applications(IOS and Android)
and before doing that I would like to clarify the rest api content. However as much as I search through google all I found was automatic API creators from your Java code. But what I want is different first I want to document our Json Rest API so mobile and server developers can start to work independently.
Do you know any tool for that?
2'nd:
What I want to achive in our java server application is simple. Get simple json requests from mobile clients and do some database query and respond back with simple json objects.
For achiving this do I need to use any additional Rest API framework such as spring mvc (or something else) or just using Java Servlets and parse the request in doPost method and respond it there
Which one do you suggest?
Thanks
Restlet Studio (http://restlet.com/technical-resources/restlet-studio) or APISpark (http://restlet.com/products/apispark/) can bring you what you expect.
Restlet Studio allows you to define / design you API with a Web IDE: resources and their methods, representations (exchanged data structures). You can then have access to corresponding Swagger content and generate online client SDKs and even server skeletons for your API (this is internally based on Swagger Codegen)...
To implement your RESTful applications, Restlet can help you. It's a Java REST framework to access and / or implement RESTful applications. Restlet can be used within a servlet container with its servlet extension (see this link https://github.com/restlet/restlet-tutorial/blob/master/modules/org.restlet.tutorial.markdown/02_Server_Side/04_Server_Deployment/02_Servlet_Deployment.md).
Hope it helps you.
Thierry
I aggree with Stephan comment.
With Spring Boot and Spring Data Rest, the only code you will need to write is the mapping between your DB and your DAO Entities.
To document your API before writing it, you can use in fact any regular tools.
REST APIs don't have anything specific compared to others APIs to be documented.
Much of the documentation of APIs I've written were using Ms-Word...
Swagger provide a Json syntax to document a REST API, but it is mainly useful when used with Swagger-Ui, which allow to request the deployed server dynamically. You can use Swagger for your documentation, but as there will be no already existing server, I'm not sure it is worth the cost of learning its syntax. The main benefits is to give you constraints (like predefined fields) to follow.
By the way, I think that writing a REST Api Mapping or just document it takes the same amount of time, so I'm not sure it is really worth making all the documentation in a stand-alone way.
im starting with web services. I'm working in a project that needs to communicate Android with a web server and I'd like to save some time chosing the appropriate protocol for the communication.
Between JSON ,REST and SOAP:
Which ones can I run in a non-dedicated server?
Whats the best choice for a high trafic server?
Thanks in advance
JSON and REST are not mututally exclusive. JSON is a data format that the REST interface can return.
You may run either on a non dedicated server. I would personally choose REST for rapid prototyping on Android as it is easier to get up and running. (With SOAP you will probably want to have a schema which takes time to put together)
There's a good comparison between REST and SOAP on the REST wiki article: http://en.wikipedia.org/wiki/Representational_State_Transfer#Concept
REST is more of a framework than a communications protocol. JSON and SOAP could be use to create a RESTful application.
If you're writing something with many resources, I'd use REST as it is far more structured. There are also a lot of libraries that will set most of things up for you. I find JSON and SOAP are better for custom functionality that you want to hack together quickly. They can be lightweight, but less structured.
What is the best way of save data using Restful web service without using Ajax? As a example I need to add a new Customer to the database using submit button.
What is the best way of transfer data format (text,json,xml) ?
How to read POST or GET data from HttpRequest object?
If you can please give me a example in java .
Thank you
I think you need to separate the concepts a bit. A "Restful Web Service" is a web service designed using REST principals, whereas AJAX is a set of technologies used often on the client side for asynchronous requests to multiple resources (without fully reloading the page). The web service really shouldn't care how the HTTP request is generated, just the contents of the HTTP request.
Now if you're concerned about writing a rest service in Java, I would highly recommend looking into JAX-RS and the reference implementation Jersey. There are lots of examples of how to get up and running. You can use MessageBodyReader implementations are to convert data from the HTTP request entity into Java objects.
Obviously this is not the only way to get started with writing a Restful web service in Java, but is one way.
It's very definitely worth your time to carefully study Richardson and Ruby's RESTful Web Services to learn the REST architectural style. In addition to #ach_l's recommendation to use Jersey, take a look at the Restlet Java framework, which is completely wonderful.
I have a very basic Java based web service requirement. Requirement is very simple, pass some String parameters, save them to database and generate a response ("success", "failed"). There is also a case where I need to return simple XML representation (SOAP message) of a simple Object:
<person>
<name>the name</name>
<address>the name</address>
......
</person>
Our current environment is Windows, Apache Tomcat 5, SQL Server.
I'm new to web services so I'm trying to figure out what technologies I could use to make this work. For example:
Do I really need Apache Axis 2 to implement this or would it be overkill?
I saw a tutorial online where all that was needed to create web service was Eclipse, Lomboz plugin for Eclipse and Apache Tomcat. Will I still need Apache Axis2 if I take this route?
Is it possible for Tomcat to process web service requests messages or do I need third party libraries?
I guess I'm looking for the easiest way to implement this. Thank you.
Do you actually need SOAP support? If you do, Axis is probably your best bet. Otherwise, I'd take a look at Jersey.
If it will be as simple as you have mentioned, why don't you look at RESTful Web Services? You can specify your resource calls through a GET, POST, DELETE or PUT HTTP methods.
There's a blog tutorial on how to achieve this. It also shows you how you can return JSON strings/XML (depending on what you want).
A web framework would make this much easier (and actually maintainable), but you could just write a raw servlet to handle requests. You'll want to use an XML object serialization method, though, or at the very least an xml parsing library.
I think you would need axis for this one. But I'll advice you to look at Apache CXF, if in future you will need more support with web service apps. CXF just like axis2 is an implimentation of jax-ws but with an advantage of supporting jax-rs (rest). This means you can expose both REST and SOAP web service interfaces.
Im a little confused on the varying definitions and implementations of web services available as implementations. Need some clarification please.
Ones I have used till now:
If a vendor gives me a specific format of XML that I can send populated with data to request and I make a simple HTTP POST over the internet passing in the XML String as the payload, is this a web service call ? If so, is there a specific name to it, this kind of web service ? Because obviously, it does not use anything like Axis, WSDL or SOAP to establish this connection.
A variant of this is If the vendor gives me an XSD, I use JAXB to make a java class out of it and pass in the serialized version of the object, which eventually works out to be the same as option 1.
RESTful web service: Vendor gives me a URL like http://restfulservice/products and I can make HTTP Requests to the URL and depending on what HTTP verb I use, the appropropriate action is called and the response sent over the wire.
Ones I have only read about\ have a vague idea about
SOAP. How does this work?.. Ive read the W3Schools tutorial and I undertsand that there is a very specific form of XML that is standardized according to W3C standards that we use to pass the same kind of messages as we did in option 1. But how does this work in real life? Vendor sends me what? Do I generate classes? Do I serialize some objects and http post them over to an address? Or do the generated objects themselves have connection methods that will do them for me?
What about WSDL? When does a vendor send me WSDL and what do I do with it ? I guess I can generate classes from it. If yes, then what do I do with the generated classes ?
When do I need that axis jar to generate classes from something that the vendor sends ?
As you can see, I have some clear and other mostly vague ideas about the different kinds of web services available. would help if someone ould clarify and\or point to more real-world resources. I've looked a little bit into Java Web Services on the internet and the numerous four letter acronyms that get thrown at me make me dizzy.
Thanks
If a vendor gives me a specific format
of XML that I can send populated with
data to request and I make a simple
HTTP POST over the internet passing in
the XML String as the payload, is this
a web service call ? If so, is there a
specific name to it, this kind of web
service ?
This is still a web service, yes. It doesn't have an "official" name, I usually refer to it as XML-over-HTTP, mainly because I can't think of a better name.
SOAP. How does this work?.. Ive read
the W3Schools tutorial and I
undertsand that there is a very
specific form of XML that is
standardized according to W3C
standards that we use to pass the same
kind of messages as we did in option 1
SOAP provides a standard wrapper layer around the sort of messages you were sending in (1). This wrapper provides information such as an indication as to which operation you are invoking. It can also provide security services, transaction information, and so on. It's a pretty thin layer, usually.
What about WSDL? When does a vendor
send me WSDL and what do I do with it
? I guess I can generate classes from
it. If yes, then what do I do with the
generated classes ?
Again, WSDL is a pretty thin layer, this time around an XML Schema. It defines the operations that SOAP messages will invoke at runtime, as well as the Schema types of the requests and responses. Its a way of formalising the XML document exchange interface.
Say, for example, you had an XML Schema, and have a web service as you described
Using JAXB to generate java source from the schema
Send XML documents conforming to that schema over HTTP to the web service
With WSDL and SOAP, you would extend this a bit :
Write a thin WSDL wrapper around the XML Schema, formalising which operations are available.
Use a WSDL import tool to generate client/server stubs for that WSDL/Schema. In Java, this often incorporates JAXB.
Use a SOAP client/server to invoke the web service
As you can see, it's essentially the same process. The difference is that SOAP/WSDL provides additional information and context to the tools, allowing those tools to do more of the work for you. It's not hugely different, though.
If you get a WSDL document from somewhere, all you really need to know is that it defines a service interface. You run it through your favourite language's binding generator to make some code that you can use to call the service. Typically that means you'll be talking over the wire to the service using SOAP messages over HTTP. SOAP's just a wrapper round sending pretty arbitrary XML messages.
Axis is a library for doing this stuff in Java (both client and server side). I suspect that there are better implementations in other libraries.