/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* 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.alibaba.citrus.service.requestcontext.session.impl;
import com.alibaba.citrus.service.requestcontext.session.SessionStore;
import com.alibaba.citrus.service.requestcontext.session.SessionStore.StoreContext;
import com.alibaba.citrus.util.ToStringBuilder;
import com.alibaba.citrus.util.ToStringBuilder.MapBuilder;
/**
* 代表session中的一个属性。
*
* @author Michael Zhou
*/
public class SessionAttribute {
private String storeName;
private SessionStore store;
private StoreContext storeContext;
private SessionImpl session;
private String name;
private Object value;
private boolean loaded;
private boolean modified;
/**
* 创建一个attribute。
*
* @param name attribute的名称
*/
public SessionAttribute(String name, SessionImpl session, String storeName, StoreContext storeContext) {
this.name = name;
this.session = session;
this.storeName = storeName;
this.store = session.getSessionRequestContext().getSessionConfig().getStores().getStore(storeName);
this.storeContext = storeContext;
}
/**
* 取得attribute的名字。
*
* @return attribute的名字
*/
public String getName() {
return name;
}
/**
* 取得attribute的值。
*
* @return attribute的值
*/
public Object getValue() {
if (!loaded && !modified) {
value = store.loadAttribute(getName(), session.getId(), storeContext);
loaded = true;
}
return value;
}
/**
* 设置attribute的值。
* <p>
* 当值为<code>null</code>时，表示该属性将被删除。
* </p>
*
* @param value attribute的值
*/
public void setValue(Object value) {
this.value = value;
this.modified = true;
}
/**
* 仅仅设置attribute值，但不改变其modified标志。
* <p>
* 用于设置session model。
* </p>
*/
void updateValue(Object value) {
this.value = value;
}
/**
* 值是否被改变。
*
* @return 如果被改变，则返回<code>true</code>
*/
public boolean isModified() {
return modified;
}
void setModified(boolean modified) {
this.modified = modified;
}
/**
* 取得store名称。
*
* @return store的名称
*/
public String getStoreName() {
return storeName;
}
/**
* 取得store。
*
* @return <code>SessionStore</code>实例
*/
public SessionStore getStore() {
return store;
}
@Override
public String toString() {
MapBuilder mb = new MapBuilder();
mb.append("name", name);
mb.append("value", value);
mb.append("storeName", storeName);
mb.append("loaded", loaded);
mb.append("modified", modified);
return new ToStringBuilder().append("SessionAttribute").append(mb).toString();
}
}