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| |
| {8.0.0-updated, 8.1.0-updated} |
| RootResources |
| |
| <p> |
| The <l>RootResources</l> class is the main page for the REST microservice. |
| It serves as the jumping-off point for the other resources. |
| </p> |
| <p> |
| The class hierarchy for this class is: |
| </p> |
| <ul class='javatree'> |
| <li class='jac'> |
| {@link oajr.RestServlet} - Contains all the REST servlet logic. |
| <ul> |
| <li class='jac'> |
| {@link oajr.BasicRestServlet} - Defines default serializers and parsers, and OPTIONs page logic. |
| <ul> |
| <li class='jac'> |
| {@link oajr.BasicRestServletGroup} - Specialized subclass for grouping other resources. |
| <ul> |
| <li class='jac'> |
| {@link oaj.rest.BasicRestServletJenaGroup} - Group resource with added RDF support. |
| <ul> |
| <li class='jc'> |
| <c>RootResources</c> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| <p> |
| Pointing a browser to the resource shows the following: |
| </p> |
| <p class='bpcode w800'> |
| http://localhost:10000 |
| </p> |
| <img class='bordered w800' src='doc-files/juneau-examples-rest.RootResources.1.png'> |
| <p> |
| The <l>RootResources</l> class can also be defined as a servlet in a <l>web.xml</l> file: |
| </p> |
| <p class='bpcode w800'> |
| <xt><web-app</xt> <xa>version</xa>=<xs>'3.0'</xs><xt>></xt> |
| <xt><servlet></xt> |
| <xt><servlet-name></xt>RootResources<xt></servlet-name></xt> |
| <xt><servlet-class></xt>org.apache.juneau.examples.rest.RootResources<xt></servlet-class></xt> |
| <xt></servlet></xt> |
| <xt><servlet-mapping></xt> |
| <xt><servlet-name></xt>RootResources<xt></servlet-name></xt> |
| <xt><url-pattern></xt>/*<xt></url-pattern></xt> |
| <xt></servlet-mapping></xt> |
| <xt></web-app></xt> |
| </p> |
| <p> |
| The <l>RootResources</l> class consists entirely of annotations: |
| </p> |
| |
| <h5 class='figure'>RootResources.java</h5> |
| <p class='bpcode w800'> |
| <jd>/** |
| * Sample REST resource showing how to implement a "router" resource page. |
| */</jd> |
| <ja>@Rest</ja>( |
| path=<js>"/"</js>, |
| title=<js>"Root resources"</js>, |
| description=<js>"Example of a router resource page."</js>, |
| htmldoc=<ja>@HtmlDoc</ja>( |
| widgets={ |
| ContentTypeMenuItem.<jk>class</jk>, |
| StyleMenuItem.<jk>class</jk> |
| }, |
| navlinks={ |
| <js>"options: ?method=OPTIONS"</js>, |
| <js>"$W{ContentTypeMenuItem}"</js>, |
| <js>"$W{StyleMenuItem}"</js>, |
| <js>"source: $C{Source/gitHub}/org/apache/juneau/examples/rest/$R{servletClassSimple}.java"</js> |
| }, |
| aside={ |
| <js>"<div style='max-width:400px' class='text'>"</js>, |
| <js>" <p>This is an example of a 'router' page that serves as a jumping-off point to child resources.</p>"</js>, |
| <js>" <p>Resources can be nested arbitrarily deep through router pages.</p>"</js>, |
| <js>" <p>Note the <span class='link'>options</span> link provided that lets you see the generated swagger doc for this page.</p>"</js>, |
| <js><js>" <p>Also note the <span class='link'>sources</span> link on these pages to view the source code for the page.</p>"</js>, |
| " <p>All content on pages in the UI are serialized POJOs. In this case, it's a serialized array of beans with 2 properties, 'name' and 'description'.</p>"</js>, |
| <js>" <p>Other features (such as this aside) are added through annotations.</p>"</js>, |
| <js>"</div>"</js> |
| } |
| ), |
| children={ |
| HelloWorldResource.<jk>class</jk>, |
| PetStoreResource.<jk>class</jk>, |
| DtoExamples.<jk>class</jk>, |
| ConfigResource.<jk>class</jk>, |
| LogsResource.<jk>class</jk>, |
| DebugResource.<jk>class</jk>, |
| ShutdownResource.<jk>class</jk> |
| } |
| ) |
| <ja>@SerializerConfig</ja>( |
| <jc>// For testing purposes, we want to use single quotes in all the serializers so it's easier to do simple |
| // String comparisons.</jc> |
| quoteChar=<js>"'"</js> |
| ) |
| <jk>public class</jk> RootResources <jk>extends</jk> BasicRestServletJenaGroup { |
| <jc>// No code!</jc> |
| } |
| </p> |
| <p> |
| The <l>children</l> annotation defines the child resources of this router resource. |
| These are resources whose paths are direct descendants to the parent resource. |
| </p> |
| <p> |
| Child resources must be annotated with the {@link oajr.annotation.Rest#path() @Rest(path)} annotation to |
| identify the subpath of the child. |
| Children CAN extend from {@link oajr.BasicRestServlet} but it is not a requirement. |
| </p> |
| <p> |
| Note that these router pages can be arbitrarily nested deep. |
| You can define many levels of router pages for arbitrarily hierarchical REST interfaces. |
| </p> |
| <p> |
| Let's step back and describe what's going on here: |
| </p> |
| <p> |
| During servlet initialization of the <l>RootResources</l> object, the toolkit looks for the |
| <l>@Rest(children)</l> annotation. |
| If it finds it, it instantiates instances of each class and recursively performs servlet initialization |
| on them. |
| It then associates the child resource with the parent by the name specified by the |
| <l>@Rest(path)</l> annotation on the child class. |
| </p> |
| <p> |
| When a request for the child URL (<l>/helloWorld</l>) is received, the <l>RootResources</l> servlet |
| gets the request and sees that the URL remainder matches one of its child resources. |
| It then forwards the request to the child resource for processing. |
| The request passed to the child resource is the same as if the child resource had been deployed |
| independently (e.g. path-info, resource-URI, and so forth). |
| </p> |
