com.jfinal.template.stat.Scope Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of enjoy-sql Show documentation
Show all versions of enjoy-sql Show documentation
the jfinal enjoy plugin for normal java program to use sql management function.
/**
* Copyright (c) 2011-2017, James Zhan 詹波 ([email protected]).
*
* 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.jfinal.template.stat;
import java.util.HashMap;
import java.util.Map;
/**
* Scope
* 1：顶层 scope.parent 为 null
* 2：scope.set(...) 自内向外查找赋值
* 3：scope.get(...) 自内向外查找获取
*/
@SuppressWarnings({"rawtypes", "unchecked"})
public class Scope {
private final Scope parent;
private final Ctrl ctrl;
private Map data;
private Map sharedObjectMap;
/**
* 构建顶层 Scope， parent 为 null 是顶层 Scope 的标志
* @param data 用于在模板中使用的数据，data 支持 null 值
* @param sharedObjectMap 共享对象
*/
public Scope(Map data, Map sharedObjectMap) {
this.parent = null;
this.ctrl = new Ctrl();
this.data = data;
this.sharedObjectMap = sharedObjectMap;
}
/**
* 构建 AST 执行过程中作用域栈
*/
public Scope(Scope parent) {
if (parent == null) {
throw new IllegalArgumentException("parent can not be null.");
}
this.parent = parent;
this.ctrl = parent.ctrl;
this.data = null;
this.sharedObjectMap = parent.sharedObjectMap;
}
public Ctrl getCtrl() {
return ctrl;
}
/**
* 设置变量
* 自内向外在作用域栈中查找变量，如果找到则改写变量值，否则将变量存放到顶层 Scope
*/
public void set(Object key, Object value) {
for (Scope cur = this; true; cur=cur.parent) {
// HashMap 允许有 null 值 value，必须要做 containsKey 判断
if (cur.data != null && cur.data.containsKey(key)) {
cur.data.put(key, value);
return ;
}
if (cur.parent == null) {
if (cur.data == null) { // 支持顶层 data 为 null 值
cur.data = new HashMap();
}
cur.data.put(key, value);
return ;
}
}
}
/**
* 获取变量
* 自内向外在作用域栈中查找变量，返回最先找到的变量
*/
public Object get(Object key) {
for (Scope cur = this; cur!=null; cur=cur.parent) {
// if (cur.data != null && cur.data.containsKey(key)) {
// return cur.data.get(key);
// }
if (cur.data != null) {
Object ret = cur.data.get(key);
if (ret != null) {
return ret;
}
if (cur.data.containsKey(key)) {
return null;
}
}
}
// return null;
return sharedObjectMap != null ? sharedObjectMap.get(key) : null;
}
/**
* 移除变量
* 自内向外在作用域栈中查找变量，移除最先找到的变量
*/
public void remove(Object key) {
for (Scope cur = this; cur!=null; cur=cur.parent) {
if (cur.data != null && cur.data.containsKey(key)) {
cur.data.remove(key);
return ;
}
}
}
/**
* 设置局部变量
*/
public void setLocal(Object key, Object value) {
if (data == null) {
data = new HashMap();
}
data.put(key, value);
}
/**
* 获取局部变量
*/
public Object getLocal(Object key) {
return data != null ? data.get(key) : null;
}
/**
* 移除局部变量
*/
public void removeLocal(Object key) {
if (data != null) {
data.remove(key);
}
}
/**
* 设置全局变量
* 全局作用域是指本次请求的整个 template
*/
public void setGlobal(Object key, Object value) {
for (Scope cur = this; true; cur=cur.parent) {
if (cur.parent == null) {
cur.data.put(key, value);
return ;
}
}
}
/**
* 获取全局变量
* 全局作用域是指本次请求的整个 template
*/
public Object getGlobal(Object key) {
for (Scope cur = this; true; cur=cur.parent) {
if (cur.parent == null) {
return cur.data.get(key);
}
}
}
/**
* 移除全局变量
* 全局作用域是指本次请求的整个 template
*/
public void removeGlobal(Object key) {
for (Scope cur = this; true; cur=cur.parent) {
if (cur.parent == null) {
cur.data.remove(key);
return ;
}
}
}
/**
* 自内向外在作用域栈中查找变量，获取变量所在的 Map，主要用于 IncDec
*/
public Map getMapOfValue(Object key) {
for (Scope cur = this; cur!=null; cur=cur.parent) {
if (cur.data != null && cur.data.containsKey(key)) {
return cur.data;
}
}
return null;
}
/**
* 获取本层作用域 data，可能为 null 值
*/
public Map getData() {
return data;
}
/**
* 设置/替换本层作用域 data，通常用于在扩展指令中使用现成可用的 Map 来存放数据，
* 从而避免 Scope 内部创建 data，节省时空
*
* 注意：本方法会替换掉已经存在的 data 对象
*/
public void setData(Map data) {
this.data = data;
}
/**
* 获取顶层作用域 data，可能为 null 值
*/
public Map getRootData() {
for (Scope cur = this; true; cur=cur.parent) {
if (cur.parent == null) {
return cur.data;
}
}
}
/**
* 设置/替换顶层作用域 data，可以在扩展指令之中通过此方法切换掉顶层作用域
* 实现作用域完全隔离的功能
*
* 注意：本方法会替换掉顶层已经存在的 data 对象
*/
public void setRootData(Map data) {
for (Scope cur = this; true; cur=cur.parent) {
if (cur.parent == null) {
cur.data = data;
return ;
}
}
}
/**
* 自内向外在作用域栈中查找变量是否存在
*/
public boolean exists(Object key) {
for (Scope cur = this; cur!=null; cur=cur.parent) {
if (cur.data != null && cur.data.containsKey(key)) {
return true;
}
}
return false;
}
}