com.cyclopsgroup.waterview.Link.java Source code

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Here is the source code for com.cyclopsgroup.waterview.Link.java

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/* ==========================================================================
 * Copyright 2002-2005 Cyclops Group Community
 *
 * Licensed under the Open Software License, Version 2.1 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://opensource.org/licenses/osl-2.1.php
 *
 *  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 com.cyclopsgroup.waterview;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import org.apache.commons.lang.StringUtils;

/**
 * @author <a href="mailto:jiaqi.guo@gmail.com">Jiaqi Guo</a>
 *
 * Link tool
 */
public class Link {
    /** Do action instruction */
    public static final String ACTION_INSTRUCTOR = "!do!";

    /** Encoding for parameters */
    public static final String ENCODING = "UTF-8";

    /** Get resource instructor */
    public static final String GET_INSTRUCTOR = "!get!";

    /** Name of this tool */
    private static final String NAME = "link";

    /** Show page instruction */
    public static final String PAGE_INSTRUCTOR = "!show!";

    /**
     * Get instance from runtime data
     *
     * @param data Runtime data
     * @return Link object
     */
    public synchronized static Link getInstance(RuntimeData data) {
        Link link = (Link) data.getRequestContext().get(Link.NAME);
        if (link == null) {
            link = new Link(data);
            data.getRequestContext().put(Link.NAME, link);
        }
        return link;
    }

    private RuntimeData data;

    private boolean disposed = false;

    private StringBuffer queryString;

    private StringBuffer requestPath = new StringBuffer();

    /**
     * Constructor for type LinkTool
     *
     * @param data Runtime data
     */
    protected Link(RuntimeData data) {
        this.data = data;
    }

    /**
     * Add action for current link
     *
     * @param action Action path
     * @return Link itself
     */
    public Link addAction(String action) {
        checkDisposed();
        requestPath.append('/').append(ACTION_INSTRUCTOR).append(getPath(action));
        return this;
    }

    /**
     * Add query parameter
     *
     * @param name Name of parameter
     * @param value Value of parameter
     * @return Link itself
     * @throws UnsupportedEncodingException Throw it out
     */
    public Link addQueryData(String name, Object value) throws UnsupportedEncodingException {
        if (queryString == null) {
            queryString = new StringBuffer();
        } else {
            queryString.append('&');
        }
        String v = value == null ? StringUtils.EMPTY : value.toString();
        queryString.append(name).append('=').append(URLEncoder.encode(v, ENCODING));
        return this;
    }

    /**
     * Add whole query string
     *
     * @param string Whole query string
     * @return Query string
     */
    public Link addQueryString(String string) {
        if (StringUtils.isEmpty(string)) {
            return this;
        }
        if (queryString == null) {
            queryString = new StringBuffer(string);
        } else {
            queryString.append('&').append(string);
        }
        return this;
    }

    private void checkDisposed() {
        if (disposed) {
            queryString = null;
            requestPath = new StringBuffer();
            disposed = false;
        }
    }

    private String getPath(String path) {
        if (StringUtils.isEmpty(path)) {
            return null;
        }
        if (path.charAt(0) == '/') {
            return path;
        }
        String currentPage = data.getPage().getFullPath();
        int lastSlash = currentPage.lastIndexOf('/');
        if (lastSlash == -1) {
            return '/' + path;
        }
        return currentPage.substring(0, lastSlash + 1) + path;
    }

    /**
     * Get resource path
     *
     * @param path Get resource path
     * @return Full resource path
     */
    public String getResource(String path) {
        StringBuffer sb = new StringBuffer(data.getPageBaseUrl());
        sb.append('/').append(GET_INSTRUCTOR);
        sb.append(getPath(path));
        return sb.toString();
    }

    /**
     * Set page with given page path
     *
     * @param path Path object
     * @return It self
     */
    public Link setPage(Path path) {
        setPage(path.getFullPath());
        return this;
    }

    /**
     * Set page
     *
     * @param path
     * @return Link tool itself
     */
    public Link setPage(String path) {
        checkDisposed();
        requestPath.append('/').append(PAGE_INSTRUCTOR).append(getPath(path));
        return this;
    }

    /**
     * Override method LinkTool in supper class
     *
     * @see java.lang.Object#toString()
     */
    public String toString() {
        StringBuffer url = new StringBuffer(data.getPageBaseUrl()).append(requestPath);
        if (queryString != null) {
            url.append('?').append(queryString);
        }
        disposed = true;
        return url.toString();
    }
}