org.springframework.security.web.context.support.SecurityWebApplicationContextUtils.java Source code

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Here is the source code for org.springframework.security.web.context.support.SecurityWebApplicationContextUtils.java

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/*
 * Copyright 2002-2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * 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 org.springframework.security.web.context.support;

import java.util.Enumeration;
import javax.servlet.ServletContext;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

/**
 * Spring Security extension to Spring's {@link WebApplicationContextUtils}.
 *
 * @author Rob Winch
 */
public abstract class SecurityWebApplicationContextUtils extends WebApplicationContextUtils {

    /**
     * Find a unique {@code WebApplicationContext} for this web app: either the
     * root web app context (preferred) or a unique {@code WebApplicationContext}
     * among the registered {@code ServletContext} attributes (typically coming
     * from a single {@code DispatcherServlet} in the current web application).
     * <p>Note that {@code DispatcherServlet}'s exposure of its context can be
     * controlled through its {@code publishContext} property, which is {@code true}
     * by default but can be selectively switched to only publish a single context
     * despite multiple {@code DispatcherServlet} registrations in the web app.
     * @param servletContext ServletContext to find the web application context for
     * @return the desired WebApplicationContext for this web app
     * @see #getWebApplicationContext(ServletContext)
     * @see ServletContext#getAttributeNames()
     * @throws IllegalStateException if no WebApplicationContext can be found
     */
    public static WebApplicationContext findRequiredWebApplicationContext(ServletContext servletContext) {
        WebApplicationContext wac = _findWebApplicationContext(servletContext);
        if (wac == null) {
            throw new IllegalStateException("No WebApplicationContext found: no ContextLoaderListener registered?");
        }
        return wac;
    }

    /**
     * Copy of {@link #findWebApplicationContext(ServletContext)} for compatibility with spring framework 4.1.x.
     * @see #findWebApplicationContext(ServletContext)
     */
    private static WebApplicationContext _findWebApplicationContext(ServletContext sc) {
        WebApplicationContext wac = getWebApplicationContext(sc);
        if (wac == null) {
            Enumeration<String> attrNames = sc.getAttributeNames();
            while (attrNames.hasMoreElements()) {
                String attrName = attrNames.nextElement();
                Object attrValue = sc.getAttribute(attrName);
                if (attrValue instanceof WebApplicationContext) {
                    if (wac != null) {
                        throw new IllegalStateException("No unique WebApplicationContext found: more than one "
                                + "DispatcherServlet registered with publishContext=true?");
                    }
                    wac = (WebApplicationContext) attrValue;
                }
            }
        }
        return wac;
    }
}