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What Are RESTful Web Services? RESTful web services are built to work best on the Web. Representational State Transfer (REST) is an architectural style that specifies constraints, such as the uniform interface, that if applied to a web service induce desirable properties, such as performance, scalability, and modifiability, that enable services to work best on the Web. In the REST architectural style, data and functionality are considered resources and are accessed using Uniform Resource Identifiers (URIs), typically links on the Web. The resources are acted upon by using a set of simple, well-defined operations. The REST architectural style constrains an architecture to a client/server architecture and is designed to use a stateless communication protocol, typically HTTP. In the REST architecture style, clients and servers exchange representations of resources by using a standardized interface and protocol. Resource identification through URI: A RESTful web service exposes a set of resources that identify the targets of the interaction with its clients. Resources are identified by URIs, which provide a global addressing space for resource and service discovery.
See The @Path Annotation and URI Path Templates for more information. Uniform interface: Resources are manipulated using a fixed set of four create, read, update, delete operations: PUT, GET, POST, and DELETE. PUT creates a new resource, which can be then deleted by using DELETE. GET retrieves the current state of a resource in some representation. POST transfers a new state onto a resource. See Responding to HTTP Methods and Requests for more information. Self-descriptive messages: Resources are decoupled from their representation so that their content can be accessed in a variety of formats, such as HTML, XML, plain text, PDF, JPEG, JSON, and others. Metadata about the resource is available and used, for example, to control caching, detect transmission errors, negotiate the appropriate representation format, and perform authentication or access control. See Responding to HTTP Methods and Requests and Using Entity Providers to Map HTTP Response and Request Entity Bodies for more information. Stateful interactions through hyperlinks: Every interaction with a resource is stateless; that is, request messages are self-contained. Stateful interactions are based on the concept of explicit state transfer. Several techniques exist to exchange state, such as URI rewriting, cookies, and hidden form fields. State can be embedded in response messages to point to valid future states of the interaction. See Using Entity Providers to Map HTTP Response and Request Entity Bodies and “Building URIs” in the JAX-RS Overview document for more information.
It can be hard to knock the amenities -- movies on demand, music on the go, air conditioning in August. It's all good stuff. What else could a modern human need? Nature. Good, old-fashioned, ear-budless, non-digital, fresh-aired nature. Dirt, bugs and photosynthesis. Every option is wonderful -- but every option costs money and, typically, travel time. The idea of piling the kids into the car with all their gear can deter even the most outdoorsy of parents. But what if experiencing the great outdoors were as easy as stepping outside? Fun with nature doesn't have to charge an entry fee. It's right there for the taking, just outside your door. All that's required is a little ingenuity and some sort of outdoor space. A backyard is perfect, although you can take a nature walk on a well-decorated patio or even the city street outside your apartment. It's as easy as planning ahead with a quick Internet search, for a start. When you head into a National Park or a zoo for some nature time, it's easy to know what to look for: Just take a peek at one of the information brochures at the entrance.
Few of us have info packets in a pocket next to the back door, so it can be a bit harder to see what there is to see. So you might want to do some research. It's not that hard to find out what your backyard might have to offer. There are handy Web sites that will tell you what's in your area. Some may have a zip code search that lets you know which plant and animal species you could see around your home. Some city-government Web sites will often have similar information, as will local information kiosks. It can be helpful to give your yard a hand and hang a hummingbird feeder if you find out there are lots of them in your area, or install a birdbath or toss out some wildflower seeds in advance, just to make it extra interesting. Another crucial preparation, especially when kids are involved, is to know what interesting stuff not to touch, lest a perfectly lovely nature walk end in tears.
The only thing worse than a dull nature walk is a red, itchy one. Knowing what to avoid is at least as important as knowing what to seek out, especially if there are little ones getting up close and personal with nature. Any great nature walk, backyard or otherwise, is preceded by a brief lesson on how to recognize poison ivy and poison oak. Google "identify poison ivy poison oak" to see countless options, or check out the library's supply of plant reference books. Just look at pictures of the itchy stuff and perhaps do a little flashcard-style quiz before heading into the yard. If you're sure your yard has neither of the lamentable growths, meaning you've done a close and recent examination of the entire space, corners and all, you could probably skip this step -- although really, what harm can it do to learn to identify some plants?
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