jakarta.servlet.jsp.jstl.core.Config Maven / Gradle / Ivy
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/*
* Copyright (c) 1997-2020 Oracle and/or its affiliates. All rights reserved.
* Copyright 2004 The Apache Software Foundation
* Copyright (c) 2021-2021 Contributors to the Eclipse Foundation
*
* 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 jakarta.servlet.jsp.jstl.core;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.http.HttpSession;
import jakarta.servlet.jsp.PageContext;
/**
* Class supporting access to configuration settings.
*/
public class Config {
/*
* I18N/Formatting actions related configuration data
*/
/**
* Name of configuration setting for application- (as opposed to browser-) based preferred locale
*/
public static final String FMT_LOCALE = "jakarta.servlet.jsp.jstl.fmt.locale";
/**
* Name of configuration setting for fallback locale
*/
public static final String FMT_FALLBACK_LOCALE = "jakarta.servlet.jsp.jstl.fmt.fallbackLocale";
/**
* Name of configuration setting for i18n localization context
*/
public static final String FMT_LOCALIZATION_CONTEXT = "jakarta.servlet.jsp.jstl.fmt.localizationContext";
/**
* Name of localization setting for time zone
*/
public static final String FMT_TIME_ZONE = "jakarta.servlet.jsp.jstl.fmt.timeZone";
/*
* SQL actions related configuration data
*/
/**
* Name of configuration setting for SQL data source
*/
public static final String SQL_DATA_SOURCE = "jakarta.servlet.jsp.jstl.sql.dataSource";
/**
* Name of configuration setting for maximum number of rows to be included in SQL query result
*/
public static final String SQL_MAX_ROWS = "jakarta.servlet.jsp.jstl.sql.maxRows";
/*
* Private constants
*/
private static final String PAGE_SCOPE_SUFFIX = ".page";
private static final String REQUEST_SCOPE_SUFFIX = ".request";
private static final String SESSION_SCOPE_SUFFIX = ".session";
private static final String APPLICATION_SCOPE_SUFFIX = ".application";
/**
* Looks up a configuration variable in the given scope.
*
*
* The lookup of configuration variables is performed as if each scope had its own name space, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param pageContext Page context in which the configuration variable is to be looked up
* @param name Configuration variable name
* @param scope Scope in which the configuration variable is to be looked up
*
* @return The java.lang.Object associated with the configuration variable, or null if it is not defined.
*/
public static Object get(PageContext pageContext, String name, int scope) {
switch (scope) {
case PageContext.PAGE_SCOPE:
return pageContext.getAttribute(name + PAGE_SCOPE_SUFFIX, scope);
case PageContext.REQUEST_SCOPE:
return pageContext.getAttribute(name + REQUEST_SCOPE_SUFFIX, scope);
case PageContext.SESSION_SCOPE:
return get(pageContext.getSession(), name);
case PageContext.APPLICATION_SCOPE:
return pageContext.getAttribute(name + APPLICATION_SCOPE_SUFFIX, scope);
default:
throw new IllegalArgumentException("unknown scope");
}
}
/**
* Looks up a configuration variable in the "request" scope.
*
*
* The lookup of configuration variables is performed as if each scope had its own name space, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param request Request object in which the configuration variable is to be looked up
* @param name Configuration variable name
*
* @return The java.lang.Object associated with the configuration variable, or null if it is not defined.
*/
public static Object get(ServletRequest request, String name) {
return request.getAttribute(name + REQUEST_SCOPE_SUFFIX);
}
/**
* Looks up a configuration variable in the "session" scope.
*
*
* The lookup of configuration variables is performed as if each scope had its own name space, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
*
* @param session Session object in which the configuration variable is to be looked up
* @param name Configuration variable name
*
* @return The java.lang.Object associated with the configuration variable, or null if it is not defined, if
* session is null, or if the session is invalidated.
*/
public static Object get(HttpSession session, String name) {
Object ret = null;
if (session != null) {
try {
ret = session.getAttribute(name + SESSION_SCOPE_SUFFIX);
} catch (IllegalStateException ex) {
} // when session is invalidated
}
return ret;
}
/**
* Looks up a configuration variable in the "application" scope.
*
*
* The lookup of configuration variables is performed as if each scope had its own name space, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param context Servlet context in which the configuration variable is to be looked up
* @param name Configuration variable name
*
* @return The java.lang.Object associated with the configuration variable, or null if it is not defined.
*/
public static Object get(ServletContext context, String name) {
return context.getAttribute(name + APPLICATION_SCOPE_SUFFIX);
}
/**
* Sets the value of a configuration variable in the given scope.
*
*
* Setting the value of a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param pageContext Page context in which the configuration variable is to be set
* @param name Configuration variable name
* @param value Configuration variable value
* @param scope Scope in which the configuration variable is to be set
*/
public static void set(PageContext pageContext, String name, Object value, int scope) {
switch (scope) {
case PageContext.PAGE_SCOPE:
pageContext.setAttribute(name + PAGE_SCOPE_SUFFIX, value, scope);
break;
case PageContext.REQUEST_SCOPE:
pageContext.setAttribute(name + REQUEST_SCOPE_SUFFIX, value, scope);
break;
case PageContext.SESSION_SCOPE:
pageContext.setAttribute(name + SESSION_SCOPE_SUFFIX, value, scope);
break;
case PageContext.APPLICATION_SCOPE:
pageContext.setAttribute(name + APPLICATION_SCOPE_SUFFIX, value, scope);
break;
default:
throw new IllegalArgumentException("unknown scope");
}
}
/**
* Sets the value of a configuration variable in the "request" scope.
*
*
* Setting the value of a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param request Request object in which the configuration variable is to be set
* @param name Configuration variable name
* @param value Configuration variable value
*/
public static void set(ServletRequest request, String name, Object value) {
request.setAttribute(name + REQUEST_SCOPE_SUFFIX, value);
}
/**
* Sets the value of a configuration variable in the "session" scope.
*
*
* Setting the value of a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param session Session object in which the configuration variable is to be set
* @param name Configuration variable name
* @param value Configuration variable value
*/
public static void set(HttpSession session, String name, Object value) {
session.setAttribute(name + SESSION_SCOPE_SUFFIX, value);
}
/**
* Sets the value of a configuration variable in the "application" scope.
*
*
* Setting the value of a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not replace one stored in a different scope.
*
* @param context Servlet context in which the configuration variable is to be set
* @param name Configuration variable name
* @param value Configuration variable value
*/
public static void set(ServletContext context, String name, Object value) {
context.setAttribute(name + APPLICATION_SCOPE_SUFFIX, value);
}
/**
* Removes a configuration variable from the given scope.
*
*
* Removing a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not impact one stored in a different scope.
*
* @param pageContext Page context from which the configuration variable is to be removed
* @param name Configuration variable name
* @param scope Scope from which the configuration variable is to be removed
*/
public static void remove(PageContext pageContext, String name, int scope) {
switch (scope) {
case PageContext.PAGE_SCOPE:
pageContext.removeAttribute(name + PAGE_SCOPE_SUFFIX, scope);
break;
case PageContext.REQUEST_SCOPE:
pageContext.removeAttribute(name + REQUEST_SCOPE_SUFFIX, scope);
break;
case PageContext.SESSION_SCOPE:
pageContext.removeAttribute(name + SESSION_SCOPE_SUFFIX, scope);
break;
case PageContext.APPLICATION_SCOPE:
pageContext.removeAttribute(name + APPLICATION_SCOPE_SUFFIX, scope);
break;
default:
throw new IllegalArgumentException("unknown scope");
}
}
/**
* Removes a configuration variable from the "request" scope.
*
*
* Removing a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not impact one stored in a different scope.
*
* @param request Request object from which the configuration variable is to be removed
* @param name Configuration variable name
*/
public static void remove(ServletRequest request, String name) {
request.removeAttribute(name + REQUEST_SCOPE_SUFFIX);
}
/**
* Removes a configuration variable from the "session" scope.
*
*
* Removing a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not impact one stored in a different scope.
*
* @param session Session object from which the configuration variable is to be removed
* @param name Configuration variable name
*/
public static void remove(HttpSession session, String name) {
session.removeAttribute(name + SESSION_SCOPE_SUFFIX);
}
/**
* Removes a configuration variable from the "application" scope.
*
*
* Removing a configuration variable is performed as if each scope had its own namespace, that is, the same
* configuration variable name in one scope does not impact one stored in a different scope.
*
* @param context Servlet context from which the configuration variable is to be removed
* @param name Configuration variable name
*/
public static void remove(ServletContext context, String name) {
context.removeAttribute(name + APPLICATION_SCOPE_SUFFIX);
}
/**
* Finds the value associated with a specific configuration setting identified by its context initialization parameter
* name.
*
*
* For each of the JSP scopes (page, request, session, application), get the value of the configuration variable
* identified by name using method get(). Return as soon as a non-null value is found. If no value is
* found, get the value of the context initialization parameter identified by name.
*
* @param pageContext Page context in which the configuration setting is to be searched
* @param name Context initialization parameter name of the configuration setting
*
* @return The java.lang.Object associated with the configuration setting identified by name, or null
* if it is not defined.
*/
public static Object find(PageContext pageContext, String name) {
Object ret = get(pageContext, name, PageContext.PAGE_SCOPE);
if (ret == null) {
ret = get(pageContext, name, PageContext.REQUEST_SCOPE);
if (ret == null) {
if (pageContext.getSession() != null) {
// check session only if a session is present
ret = get(pageContext, name, PageContext.SESSION_SCOPE);
}
if (ret == null) {
ret = get(pageContext, name, PageContext.APPLICATION_SCOPE);
if (ret == null) {
ret = pageContext.getServletContext().getInitParameter(name);
}
}
}
}
return ret;
}
}