001/* 002 * Copyright 2002-2013 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.context.support; 018 019import javax.servlet.ServletConfig; 020import javax.servlet.ServletContext; 021 022import org.springframework.core.env.Environment; 023import org.springframework.core.env.MutablePropertySources; 024import org.springframework.core.env.PropertySource; 025import org.springframework.core.env.PropertySource.StubPropertySource; 026import org.springframework.core.env.StandardEnvironment; 027import org.springframework.jndi.JndiLocatorDelegate; 028import org.springframework.jndi.JndiPropertySource; 029import org.springframework.web.context.ConfigurableWebEnvironment; 030 031/** 032 * {@link Environment} implementation to be used by {@code Servlet}-based web 033 * applications. All web-related (servlet-based) {@code ApplicationContext} classes 034 * initialize an instance by default. 035 * 036 * <p>Contributes {@code ServletConfig}, {@code ServletContext}, and JNDI-based 037 * {@link PropertySource} instances. See {@link #customizePropertySources} method 038 * documentation for details. 039 * 040 * @author Chris Beams 041 * @since 3.1 042 * @see StandardEnvironment 043 */ 044public class StandardServletEnvironment extends StandardEnvironment implements ConfigurableWebEnvironment { 045 046 /** Servlet context init parameters property source name: {@value} */ 047 public static final String SERVLET_CONTEXT_PROPERTY_SOURCE_NAME = "servletContextInitParams"; 048 049 /** Servlet config init parameters property source name: {@value} */ 050 public static final String SERVLET_CONFIG_PROPERTY_SOURCE_NAME = "servletConfigInitParams"; 051 052 /** JNDI property source name: {@value} */ 053 public static final String JNDI_PROPERTY_SOURCE_NAME = "jndiProperties"; 054 055 056 /** 057 * Customize the set of property sources with those contributed by superclasses as 058 * well as those appropriate for standard servlet-based environments: 059 * <ul> 060 * <li>{@value #SERVLET_CONFIG_PROPERTY_SOURCE_NAME} 061 * <li>{@value #SERVLET_CONTEXT_PROPERTY_SOURCE_NAME} 062 * <li>{@value #JNDI_PROPERTY_SOURCE_NAME} 063 * </ul> 064 * <p>Properties present in {@value #SERVLET_CONFIG_PROPERTY_SOURCE_NAME} will 065 * take precedence over those in {@value #SERVLET_CONTEXT_PROPERTY_SOURCE_NAME}, and 066 * properties found in either of the above take precedence over those found in 067 * {@value #JNDI_PROPERTY_SOURCE_NAME}. 068 * <p>Properties in any of the above will take precedence over system properties and 069 * environment variables contributed by the {@link StandardEnvironment} superclass. 070 * <p>The {@code Servlet}-related property sources are added as 071 * {@link StubPropertySource stubs} at this stage, and will be 072 * {@linkplain #initPropertySources(ServletContext, ServletConfig) fully initialized} 073 * once the actual {@link ServletContext} object becomes available. 074 * @see StandardEnvironment#customizePropertySources 075 * @see org.springframework.core.env.AbstractEnvironment#customizePropertySources 076 * @see ServletConfigPropertySource 077 * @see ServletContextPropertySource 078 * @see org.springframework.jndi.JndiPropertySource 079 * @see org.springframework.context.support.AbstractApplicationContext#initPropertySources 080 * @see #initPropertySources(ServletContext, ServletConfig) 081 */ 082 @Override 083 protected void customizePropertySources(MutablePropertySources propertySources) { 084 propertySources.addLast(new StubPropertySource(SERVLET_CONFIG_PROPERTY_SOURCE_NAME)); 085 propertySources.addLast(new StubPropertySource(SERVLET_CONTEXT_PROPERTY_SOURCE_NAME)); 086 if (JndiLocatorDelegate.isDefaultJndiEnvironmentAvailable()) { 087 propertySources.addLast(new JndiPropertySource(JNDI_PROPERTY_SOURCE_NAME)); 088 } 089 super.customizePropertySources(propertySources); 090 } 091 092 @Override 093 public void initPropertySources(ServletContext servletContext, ServletConfig servletConfig) { 094 WebApplicationContextUtils.initServletPropertySources(getPropertySources(), servletContext, servletConfig); 095 } 096 097}