Route.java

/*
 * Copyright 2011- Per Wendel
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *  
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package spark;

import spark.Request;
import spark.Response;


/**
 * A Route is built up by a path (for url-matching) and the implementation of the 'handle' method.
 * When a request is made, if present, the matching routes 'handle' method is invoked. The object
 * that is returned from 'handle' will be set to the response body (toString()).
 *
 * @author Per Wendel
 */
public abstract class Route extends AbstractRoute {

    private static final String DEFAULT_ACCEPT_TYPE = "*/*";
    
	private String path;
    private String acceptType;
    
    /**
     * Constructor
     * 
     * @param path The route path which is used for matching. (e.g. /hello, users/:name) 
     */
    protected Route(String path) {
        this(path, DEFAULT_ACCEPT_TYPE);
    }
    
    /**
     * Constructor
     * 
     * @param path The route path which is used for matching. (e.g. /hello, users/:name) 
     * @param acceptType The accept type which is used for matching.
     */
    protected Route(String path, String acceptType) {
    	this.path = path;
    	this.acceptType = acceptType;
    }
    
    /**
     * Invoked when a request is made on this route's corresponding path e.g. '/hello'
     * 
     * @param request The request object providing information about the HTTP request
     * @param response The response object providing functionality for modifying the response
     * 
     * @return The content to be set in the response
     */
    public abstract Object handle(Request request, Response response);

    /**
     * This method should render the given element into something that can be send through Response element.
     * By default this method returns the result of calling toString method in given element, but can be overridden.
     * 
     * @param element to be rendered.
     * @return body content.
     */
    //TODO change String return type to Stream. It should be done in another issue.
    public String render(Object element) {
    	if(element != null) {
    		return element.toString();    		
    	} else {
    		return null;
    	}
    }
    
    public String getAcceptType() {
		return acceptType;
	}
    
    /**
     * Returns this route's path
     */
    String getPath() {
        return this.path;
    }
    
}