org.springframework.boot.web.servlet.DelegatingFilterProxyRegistrationBean Maven / Gradle / Ivy
/*
* Copyright 2012-2017 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.boot.web.servlet;
import javax.servlet.Filter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.util.Assert;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.filter.DelegatingFilterProxy;
/**
* A {@link ServletContextInitializer} to register {@link DelegatingFilterProxy}s in a
* Servlet 3.0+ container. Similar to the {@link ServletContext#addFilter(String, Filter)
* registration} features provided by {@link ServletContext} but with a Spring Bean
* friendly design.
*
* The bean name of the actual delegate {@link Filter} should be specified using the
* {@code targetBeanName} constructor argument. Unlike the {@link FilterRegistrationBean},
* referenced filters are not instantiated early. In fact, if the delegate filter bean is
* marked {@code @Lazy} it won't be instantiated at all until the filter is called.
*
* Registrations can be associated with {@link #setUrlPatterns URL patterns} and/or
* servlets (either by {@link #setServletNames name} or via a
* {@link #setServletRegistrationBeans ServletRegistrationBean}s. When no URL pattern or
* servlets are specified the filter will be associated to '/*'. The targetBeanName will
* be used as the filter name if not otherwise specified.
*
* @author Phillip Webb
* @since 1.4.0
* @see ServletContextInitializer
* @see ServletContext#addFilter(String, Filter)
* @see FilterRegistrationBean
* @see DelegatingFilterProxy
*/
public class DelegatingFilterProxyRegistrationBean
extends AbstractFilterRegistrationBean
implements ApplicationContextAware {
private ApplicationContext applicationContext;
private final String targetBeanName;
/**
* Create a new {@link DelegatingFilterProxyRegistrationBean} instance to be
* registered with the specified {@link ServletRegistrationBean}s.
* @param targetBeanName name of the target filter bean to look up in the Spring
* application context (must not be {@code null}).
* @param servletRegistrationBeans associate {@link ServletRegistrationBean}s
*/
public DelegatingFilterProxyRegistrationBean(String targetBeanName,
ServletRegistrationBean... servletRegistrationBeans) {
super(servletRegistrationBeans);
Assert.hasLength(targetBeanName, "TargetBeanName must not be null or empty");
this.targetBeanName = targetBeanName;
setName(targetBeanName);
}
@Override
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException {
this.applicationContext = applicationContext;
}
protected String getTargetBeanName() {
return this.targetBeanName;
}
@Override
public DelegatingFilterProxy getFilter() {
return new DelegatingFilterProxy(this.targetBeanName,
getWebApplicationContext()) {
@Override
protected void initFilterBean() throws ServletException {
// Don't initialize filter bean on init()
}
};
}
private WebApplicationContext getWebApplicationContext() {
Assert.notNull(this.applicationContext, "ApplicationContext be injected");
Assert.isInstanceOf(WebApplicationContext.class, this.applicationContext);
return (WebApplicationContext) this.applicationContext;
}
}