001/* 002 * Copyright 2002-2015 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.bind.annotation; 018 019import java.lang.annotation.Documented; 020import java.lang.annotation.ElementType; 021import java.lang.annotation.Inherited; 022import java.lang.annotation.Retention; 023import java.lang.annotation.RetentionPolicy; 024import java.lang.annotation.Target; 025 026import org.springframework.core.annotation.AliasFor; 027 028/** 029 * Annotation that indicates the session attributes that a specific handler uses. 030 * 031 * <p>This will typically list the names of model attributes which should be 032 * transparently stored in the session or some conversational storage, 033 * serving as form-backing beans. <b>Declared at the type level</b>, applying 034 * to the model attributes that the annotated handler class operates on. 035 * 036 * <p><b>NOTE:</b> Session attributes as indicated using this annotation 037 * correspond to a specific handler's model attributes, getting transparently 038 * stored in a conversational session. Those attributes will be removed once 039 * the handler indicates completion of its conversational session. Therefore, 040 * use this facility for such conversational attributes which are supposed 041 * to be stored in the session <i>temporarily</i> during the course of a 042 * specific handler's conversation. 043 * 044 * <p>For permanent session attributes, e.g. a user authentication object, 045 * use the traditional {@code session.setAttribute} method instead. 046 * Alternatively, consider using the attribute management capabilities of the 047 * generic {@link org.springframework.web.context.request.WebRequest} interface. 048 * 049 * <p><b>NOTE:</b> When using controller interfaces (e.g. for AOP proxying), 050 * make sure to consistently put <i>all</i> your mapping annotations — 051 * such as {@code @RequestMapping} and {@code @SessionAttributes} — on 052 * the controller <i>interface</i> rather than on the implementation class. 053 * 054 * @author Juergen Hoeller 055 * @author Sam Brannen 056 * @since 2.5 057 */ 058@Target({ElementType.TYPE}) 059@Retention(RetentionPolicy.RUNTIME) 060@Inherited 061@Documented 062public @interface SessionAttributes { 063 064 /** 065 * Alias for {@link #names}. 066 */ 067 @AliasFor("names") 068 String[] value() default {}; 069 070 /** 071 * The names of session attributes in the model that should be stored in the 072 * session or some conversational storage. 073 * <p><strong>Note</strong>: This indicates the <em>model attribute names</em>. 074 * The <em>session attribute names</em> may or may not match the model attribute 075 * names. Applications should therefore not rely on the session attribute 076 * names but rather operate on the model only. 077 * @since 4.2 078 */ 079 @AliasFor("value") 080 String[] names() default {}; 081 082 /** 083 * The types of session attributes in the model that should be stored in the 084 * session or some conversational storage. 085 * <p>All model attributes of these types will be stored in the session, 086 * regardless of attribute name. 087 */ 088 Class<?>[] types() default {}; 089 090}