001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.shiro.web.servlet;
020
021import javax.servlet.ServletContext;
022
023/**
024 * Base implementation for any components that need to access the web application's {@link ServletContext ServletContext}.
025 *
026 * @since 0.2
027 */
028public class ServletContextSupport {
029
030    //TODO - complete JavaDoc
031    private ServletContext servletContext = null;
032
033    public ServletContext getServletContext() {
034        return servletContext;
035    }
036
037    public void setServletContext(ServletContext servletContext) {
038        this.servletContext = servletContext;
039    }
040
041    @SuppressWarnings({"UnusedDeclaration"})
042    protected String getContextInitParam(String paramName) {
043        return getServletContext().getInitParameter(paramName);
044    }
045
046    private ServletContext getRequiredServletContext() {
047        ServletContext servletContext = getServletContext();
048        if (servletContext == null) {
049            String msg = "ServletContext property must be set via the setServletContext method.";
050            throw new IllegalStateException(msg);
051        }
052        return servletContext;
053    }
054
055    @SuppressWarnings({"UnusedDeclaration"})
056    protected void setContextAttribute(String key, Object value) {
057        if (value == null) {
058            removeContextAttribute(key);
059        } else {
060            getRequiredServletContext().setAttribute(key, value);
061        }
062    }
063
064    @SuppressWarnings({"UnusedDeclaration"})
065    protected Object getContextAttribute(String key) {
066        return getRequiredServletContext().getAttribute(key);
067    }
068
069    protected void removeContextAttribute(String key) {
070        getRequiredServletContext().removeAttribute(key);
071    }
072
073    /**
074     * It is highly recommended not to override this method directly, and instead override the
075     * {@link #toStringBuilder() toStringBuilder()} method, a better-performing alternative.
076     *
077     * @return the String representation of this instance.
078     */
079    @Override
080    public String toString() {
081        return toStringBuilder().toString();
082    }
083
084    /**
085     * Same concept as {@link #toString() toString()}, but returns a {@link StringBuilder} instance instead.
086     *
087     * @return a StringBuilder instance to use for appending String data that will eventually be returned from a
088     *         {@code toString()} invocation.
089     */
090    protected StringBuilder toStringBuilder() {
091        return new StringBuilder(super.toString());
092    }
093}