net.officefloor.web.HttpPathFactoryImpl Maven / Gradle / Ivy

Go to download
/*
 * OfficeFloor - http://www.officefloor.net
 * Copyright (C) 2005-2018 Daniel Sagenschneider
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see .
 */
package net.officefloor.web;

import net.officefloor.server.http.HttpException;
import net.officefloor.web.build.HttpPathFactory;
import net.officefloor.web.value.retrieve.ValueRetriever;

/**
 * Factory to create the HTTP path.
 * 
 * @author Daniel Sagenschneider
 */
public class HttpPathFactoryImpl implements HttpPathFactory {

	/**
	 * Segment of the path.
	 */
	public static abstract class Segment {

		/**
		 * Writes the values.
		 * 
		 * @param values
		 *            Values.
		 * @param target
		 *            {@link Appendable}.
		 * @throws Exception
		 *             Failure in writing value.
		 */
		protected abstract void write(T values, Appendable target) throws Exception;
	}

	/**
	 * Static {@link Segment}.
	 */
	public static class StaticSegment extends Segment {

		/**
		 * Static path.
		 */
		private final String staticPath;

		/**
		 * Instantiate.
		 * 
		 * @param staticPath
		 *            Static path.
		 */
		public StaticSegment(String staticPath) {
			this.staticPath = staticPath;
		}

		/*
		 * =================== Segment ===================
		 */

		@Override
		protected void write(Object values, Appendable target) throws Exception {
			target.append(this.staticPath);
		}
	}

	/**
	 * Parameter {@link Segment}.
	 */
	public static class ParameterSegment extends Segment {

		/**
		 * Property name to obtain value.
		 */
		private final String propertyName;

		/**
		 * {@link ValueRetriever} to obtain the value.
		 */
		private final ValueRetriever valueRetriever;

		/**
		 * Instantiate.
		 * 
		 * @param propertyName
		 *            Property name to obtain value.
		 * @param valueRetriever
		 *            {@link ValueRetriever} to obtain the value.
		 */
		public ParameterSegment(String propertyName, ValueRetriever valueRetriever) {
			this.propertyName = propertyName;
			this.valueRetriever = valueRetriever;
		}

		/*
		 * =================== Segment ===================
		 */

		@Override
		protected void write(T values, Appendable target) throws Exception {

			// Obtain the parameter value
			Object value = this.valueRetriever.retrieveValue(values, this.propertyName);
			if (value == null) {
				value = "";
			}

			// Write the value
			target.append(value.toString());
		}
	}

	/**
	 * {@link ThreadLocal} {@link StringBuilder}.
	 */
	private static ThreadLocal stringBuilder = new ThreadLocal() {
		@Override
		protected StringBuilder initialValue() {
			return new StringBuilder();
		}
	};

	/**
	 * Type to obtain values.
	 */
	private final Class valuesType;

	/**
	 * {@link Segment} instances to create the path.
	 */
	private final Segment[] segments;

	/**
	 * Instantiate.
	 * 
	 * @param valuesType
	 *            Type to obtain values.
	 * @param segments
	 *            {@link Segment} instances.
	 */
	public HttpPathFactoryImpl(Class valuesType, Segment[] segments) {
		this.valuesType = valuesType;
		this.segments = segments;
	}

	/*
	 * ==================== HttpPathFactory ====================
	 */

	@Override
	public Class getValuesType() {
		return this.valuesType;
	}

	@Override
	public String createApplicationClientPath(T values) throws HttpException {
		try {

			// Obtain the string builder to create the path
			StringBuilder buffer = stringBuilder.get();
			buffer.setLength(0);

			// Generate the path
			for (int i = 0; i < this.segments.length; i++) {
				Segment segment = this.segments[i];
				segment.write(values, buffer);
			}

			// Return the path
			return buffer.toString();

		} catch (Exception ex) {
			throw new HttpException(ex);
		}
	}

}