com.feilong.servlet.ServletContextUtil Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of feilong Show documentation
Show all versions of feilong Show documentation
feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
/*
* Copyright (C) 2008 feilong
*
* 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
*
* http://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 com.feilong.servlet;
import static com.feilong.core.Validator.isNullOrEmpty;
import static com.feilong.core.util.MapUtil.newLinkedHashMap;
import static java.util.Collections.emptyMap;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Map;
import java.util.TreeMap;
import javax.servlet.ServletContext;
import com.feilong.lib.lang3.ArrayUtils;
/**
* {@link javax.servlet.ServletContext} 工具类.
*
* @author feilong
* @since 1.0.2
*/
public final class ServletContextUtil{
/** The Constant EXCLUDE_KEYS. */
public static final String[] EXCLUDE_KEYS = {
"org.apache.catalina.jsp_classpath",
"org.apache.catalina.resources",
"org.apache.jasper.compiler.ELInterpreter",
"org.apache.jasper.compiler.TldLocationsCache",
"org.apache.jasper.runtime.JspApplicationContextImpl",
"org.apache.tomcat.InstanceManager",
"org.apache.tomcat.JarScanner",
"org.apache.tomcat.util.scan.MergedWebXml" };
//---------------------------------------------------------------
/** Don't let anyone instantiate this class. */
private ServletContextUtil(){
//AssertionError不是必须的. 但它可以避免不小心在类的内部调用构造器. 保证该类在任何情况下都不会被实例化.
//see 《Effective Java》 2nd
throw new AssertionError("No " + getClass().getName() + " instances for you!");
}
//---------------------------------------------------------------
/**
* servletContext.log servletContext相关信息,一般启动时调用.
*
* @param servletContext
* the servlet context
* @return the servlet context info map for log
*/
public static Map getServletContextInfoMapForLog(ServletContext servletContext){
Map map = newLinkedHashMap();
// 返回servlet运行的servlet 容器的版本和名称.
map.put("serverInfo", servletContext.getServerInfo());
// 返回这个servlet容器支持的Java Servlet API的主要版本.所有符合2.5版本的实现,必须有这个方法返回的整数2.
// 返回这个servlet容器支持的Servlet API的次要版本.所有符合2.5版本的实现,必须有这个方法返回整数5.
map.put("version", servletContext.getMajorVersion() + "." + servletContext.getMinorVersion());
map.put("contextPath", servletContext.getContextPath());
map.put("servletContextName", servletContext.getServletContextName());
return map;
}
//---------------------------------------------------------------
/**
* 遍历显示servletContext的 {@link javax.servlet.ServletContext#getAttributeNames() ServletContext.getAttributeNames()},将 name/attributeValue
* 存入到map.
*
* @param servletContext
* the servlet context
* @return 如果{@link javax.servlet.ServletContext#getAttributeNames() ServletContext.getAttributeNames()} 是null或者empty,返回
* {@link Collections#emptyMap()}
*/
public static Map getAttributeMap(ServletContext servletContext){
return getAttributeMap(servletContext, true);
}
/**
* 遍历显示servletContext的 {@link javax.servlet.ServletContext#getAttributeNames() ServletContext.getAttributeNames()},将 name/attributeValue
* 存入到map.
*
* @param servletContext
* the servlet context
* @param ignoreContainerAttribute
* 忽略容器自带的属性, 如果是true 那么将忽略
* @return 如果{@link javax.servlet.ServletContext#getAttributeNames() ServletContext.getAttributeNames()} 是null或者empty,返回
* {@link Collections#emptyMap()}
* @since 1.10.4
*/
public static Map getAttributeMap(ServletContext servletContext,boolean ignoreContainerAttribute){
Enumeration attributeNames = servletContext.getAttributeNames();
if (isNullOrEmpty(attributeNames)){
return emptyMap();
}
//---------------------------------------------------------------
Map map = new TreeMap<>();
while (attributeNames.hasMoreElements()){
String name = attributeNames.nextElement();
if (ignoreContainerAttribute && ArrayUtils.contains(EXCLUDE_KEYS, name)){
continue;
}
map.put(name, servletContext.getAttribute(name));
}
return map;
}
//---------------------------------------------------------------
/**
* 遍历显示servletContext的 {@link ServletContext#getInitParameterNames()},将 name /attributeValue 存入到map返回.
*
* @param servletContext
* the servlet context
* @return 如果 {@link javax.servlet.ServletContext#getInitParameterNames() ServletContext.getInitParameterNames()} 是null或者empty,返回
* {@link Collections#emptyMap()}
* @see javax.servlet.ServletContext#getInitParameterNames()
* @see "org.springframework.web.context.support#registerEnvironmentBeans(ConfigurableListableBeanFactory, ServletContext)"
*/
public static Map getInitParameterMap(ServletContext servletContext){
Enumeration initParameterNames = servletContext.getInitParameterNames();
if (isNullOrEmpty(initParameterNames)){
return emptyMap();
}
//---------------------------------------------------------------
Map map = new TreeMap<>();
while (initParameterNames.hasMoreElements()){
String name = initParameterNames.nextElement();
map.put(name, servletContext.getInitParameter(name));
}
return map;
}
}