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    private ServletContext servletContext;
031
032    public ServletContext getServletContext() {
033        return servletContext;
034    }
035
036    public void setServletContext(ServletContext servletContext) {
037        this.servletContext = servletContext;
038    }
039
040    @SuppressWarnings({"UnusedDeclaration"})
041    protected String getContextInitParam(String paramName) {
042        return getServletContext().getInitParameter(paramName);
043    }
044
045    private ServletContext getRequiredServletContext() {
046        ServletContext servletContext = getServletContext();
047        if (servletContext == null) {
048            String msg = "ServletContext property must be set via the setServletContext method.";
049            throw new IllegalStateException(msg);
050        }
051        return servletContext;
052    }
053
054    @SuppressWarnings({"UnusedDeclaration"})
055    protected void setContextAttribute(String key, Object value) {
056        if (value == null) {
057            removeContextAttribute(key);
058        } else {
059            getRequiredServletContext().setAttribute(key, value);
060        }
061    }
062
063    @SuppressWarnings({"UnusedDeclaration"})
064    protected Object getContextAttribute(String key) {
065        return getRequiredServletContext().getAttribute(key);
066    }
067
068    protected void removeContextAttribute(String key) {
069        getRequiredServletContext().removeAttribute(key);
070    }
071
072    /**
073     * It is highly recommended not to override this method directly, and instead override the
074     * {@link #toStringBuilder() toStringBuilder()} method, a better-performing alternative.
075     *
076     * @return the String representation of this instance.
077     */
078    @Override
079    public String toString() {
080        return toStringBuilder().toString();
081    }
082
083    /**
084     * Same concept as {@link #toString() toString()}, but returns a {@link StringBuilder} instance instead.
085     *
086     * @return a StringBuilder instance to use for appending String data that will eventually be returned from a
087     * {@code toString()} invocation.
088     */
089    protected StringBuilder toStringBuilder() {
090        return new StringBuilder(super.toString());
091    }
092}