UrlBuilder.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.action.openwebif.internal.impl;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

import org.openhab.action.openwebif.internal.impl.config.OpenWebIfConfig;

/**
 * Builds a get url with the specified parameters.
 *
 * @author Gerhard Riegler
 * @since 1.6.0
 */
public class UrlBuilder {
    private static final String ENCODING = "UTF-8";
    private OpenWebIfConfig config;
    private String path;
    private Map<String, String> queryParams = new HashMap<String, String>();

    /**
     * Creates a UrlBuilder with the specified config and path.
     */
    public UrlBuilder(OpenWebIfConfig config, String path) {
        this.config = config;
        this.path = path;
    }

    /**
     * Adds a name/value parameter.
     */
    public UrlBuilder addParameter(String param, String value) {
        queryParams.put(param, value);
        return this;
    }

    /**
     * Builds the complete get url.
     */
    public String build() throws UnsupportedEncodingException {
        final StringBuilder sb = new StringBuilder();
        sb.append("http");
        if (config.isHttps()) {
            sb.append("s");
        }
        sb.append("://");
        sb.append(config.getHost());
        if (config.getPort() != 0) {
            sb.append(":").append(config.getPort());
        }
        sb.append(path);

        if (queryParams.size() > 0) {
            sb.append("?").append(buildParameter());
        }

        return sb.toString();
    }

    /**
     * Builds an encodes all parameters.
     */
    private String buildParameter() throws UnsupportedEncodingException {
        final StringBuilder result = new StringBuilder();
        for (String param : queryParams.keySet()) {
            String name = URLEncoder.encode(param, ENCODING);
            String value = URLEncoder.encode(queryParams.get(param), ENCODING);

            if (result.length() > 0) {
                result.append("&");
            }
            result.append(name);
            if (value != null) {
                result.append("=");
                result.append(value);
            }
        }
        return result.toString();
    }
}