src/jsr311-api/src/javax/ws/rs/Path.java

/*
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 * 
 * You can obtain a copy of the license at
 * http://www.opensource.org/licenses/cddl1.php
 * See the License for the specific language governing
 * permissions and limitations under the License.
 */

/*
 * Path.java
 *
 * Created on September 15, 2006, 2:33 PM
 *
 */

package javax.ws.rs;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Identifies the URI path that a resource class or class method will serve 
 * requests for.
 *
 * <p>Paths are relative. For an annotated class the base URI is the 
 * application path, see {@link javax.ws.rs.ApplicationPath}. For an annotated
 * method the base URI is the
 * effective URI of the containing class. For the purposes of absolutizing a
 * path against the base URI , a leading '/' in a path is 
 * ignored and base URIs are treated as if they ended in '/'. E.g.:</p>
 * 
 * <pre>&#64;Path("widgets")
 *public class WidgetsResource {
 *  &#64;GET
 *  String getList() {...}
 * 
 *  &#64;GET &#64;Path("{id}")
 *  String getWidget(&#64;PathParam("id") String id) {...}
 *}</pre>
 * 
 * <p>In the above, if the application path is
 * <code>catalogue</code> and the application is deployed at
 * <code>http://example.com/</code>, then <code>GET</code> requests for
 * <code>http://example.com/catalogue/widgets</code> will be handled by the
 * <code>getList</code> method while requests for
 * <code>http://example.com/catalogue/widgets/<i>nnn</i></code> (where 
 * <code><i>nnn</i></code> is some value) will be handled by the
 * <code>getWidget</code> method. The same would apply if the value of either
 * <code>&#64;Path</code> annotation started with '/'.
 * 
 * <p>Classes and methods may also be annotated with {@link Consumes} and 
 * {@link Produces} to filter the requests they will receive.</p>
 * 
 * @see Consumes
 * @see Produces
 * @see PathParam
 */
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Path {
    /**
     * Defines a URI template for the resource class or method, must not 
     * include matrix parameters.
     * 
     * <p>Embedded template parameters are allowed and are of the form:</p>
     * 
     * <pre> param = "{" *WSP name *WSP [ ":" *WSP regex *WSP ] "}"
     * name = (ALPHA / DIGIT / "_")*(ALPHA / DIGIT / "." / "_" / "-" ) ; \w[\w\.-]*
     * regex = *( nonbrace / "{" *nonbrace "}" ) ; where nonbrace is any char other than "{" and "}"</pre>
     * 
     * <p>See {@link <a href="http://tools.ietf.org/html/rfc5234">RFC 5234</a>} 
     * for a description of the syntax used above and the expansions of 
     * {@code WSP}, {@code ALPHA} and {@code DIGIT}. In the above {@code name}
     * is the template parameter name and the optional {@code regex} specifies 
     * the contents of the capturing group for the parameter. If {@code regex}
     * is not supplied then a default value of {@code [^/]+} which terminates at
     * a path segment boundary, is used. Matching of request URIs to URI 
     * templates is performed against encoded path values and implementations
     * will not escape literal characters in regex automatically, therefore any
     * literals in {@code regex} should be escaped by the author according to
     * the rules of
     * {@link <a href="http://tools.ietf.org/html/rfc3986#section-3.3">RFC 3986 section 3.3</a>}.
     * Caution is recommended in the use of {@code regex}, incorrect use can
     * lead to a template parameter matching unexpected URI paths. See 
     * {@link <a href="http://java.sun.com/j2se/1.5.0/docs/api/java/util/regex/Pattern.html">Pattern</a>}
     * for further information on the syntax of regular expressions.
     * Values of template parameters may be extracted using {@link PathParam}.
     *
     * <p>The literal part of the supplied value (those characters
     * that are not part of a template parameter) is automatically percent 
     * encoded to conform to the {@code path} production of 
     * {@link <a href="http://tools.ietf.org/html/rfc3986#section-3.3">RFC 3986 section 3.3</a>}.
     * Note that percent encoded values are allowed in the literal part of the
     * value, an implementation will recognize such values and will not double
     * encode the '%' character.</p>
     */
    String value();
    
}