146 lines
3.8 KiB
Java
146 lines
3.8 KiB
Java
/**
|
||
* Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
|
||
*
|
||
* 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.expr.ast;
|
||
|
||
import java.lang.reflect.Array;
|
||
import java.util.Collection;
|
||
import java.util.Iterator;
|
||
import java.util.Map;
|
||
import com.jfinal.template.TemplateException;
|
||
import com.jfinal.template.expr.Sym;
|
||
import com.jfinal.template.stat.Location;
|
||
import com.jfinal.template.stat.ParseException;
|
||
import com.jfinal.template.stat.Scope;
|
||
|
||
/**
|
||
* Logic
|
||
*
|
||
* 支持逻辑运算： ! && ||
|
||
*/
|
||
public class Logic extends Expr {
|
||
|
||
private Sym op;
|
||
private Expr left; // ! 运算没有 left 参数
|
||
private Expr right;
|
||
|
||
/**
|
||
* 构造 || && 结点
|
||
*/
|
||
public Logic(Sym op, Expr left, Expr right, Location location) {
|
||
if (left == null) {
|
||
throw new ParseException("The target of \"" + op.value() + "\" operator on the left side can not be blank", location);
|
||
}
|
||
if (right == null) {
|
||
throw new ParseException("The target of \"" + op.value() + "\" operator on the right side can not be blank", location);
|
||
}
|
||
this.op = op;
|
||
this.left = left;
|
||
this.right = right;
|
||
this.location = location;
|
||
}
|
||
|
||
/**
|
||
* 构造 ! 结点，left 为 null
|
||
*/
|
||
public Logic(Sym op, Expr right, Location location) {
|
||
if (right == null) {
|
||
throw new ParseException("The target of \"" + op.value() + "\" operator on the right side can not be blank", location);
|
||
}
|
||
this.op = op;
|
||
this.left = null;
|
||
this.right = right;
|
||
this.location = location;
|
||
}
|
||
|
||
public Object eval(Scope scope) {
|
||
switch (op) {
|
||
case NOT:
|
||
return evalNot(scope);
|
||
case AND:
|
||
return evalAnd(scope);
|
||
case OR:
|
||
return evalOr(scope);
|
||
default:
|
||
throw new TemplateException("Unsupported operator: " + op.value(), location);
|
||
}
|
||
}
|
||
|
||
Object evalNot(Scope scope) {
|
||
return ! isTrue(right.eval(scope));
|
||
}
|
||
|
||
Object evalAnd(Scope scope) {
|
||
return isTrue(left.eval(scope)) && isTrue(right.eval(scope));
|
||
}
|
||
|
||
Object evalOr(Scope scope) {
|
||
return isTrue(left.eval(scope)) || isTrue(right.eval(scope));
|
||
}
|
||
|
||
/**
|
||
* 规则：
|
||
* 1：null 返回 false
|
||
* 2：boolean 类型，原值返回
|
||
* 3：Map、Connection(List被包括在内) 返回 size() > 0
|
||
* 4：数组，返回 length > 0
|
||
* 5：String、StringBuilder、StringBuffer 等继承自 CharSequence 类的对象，返回 length > 0
|
||
* 6：Number 类型，返回 value != 0
|
||
* 7：Iterator 返回 hasNext() 值
|
||
* 8：其它返回 true
|
||
*/
|
||
public static boolean isTrue(Object v) {
|
||
if (v == null) {
|
||
return false;
|
||
}
|
||
if (v instanceof Boolean) {
|
||
return (Boolean)v;
|
||
}
|
||
if (v instanceof Collection) {
|
||
return ((Collection<?>)v).size() > 0;
|
||
}
|
||
if (v instanceof Map) {
|
||
return ((Map<?, ?>)v).size() > 0;
|
||
}
|
||
if (v.getClass().isArray()) {
|
||
return Array.getLength(v) > 0;
|
||
}
|
||
if (v instanceof CharSequence) {
|
||
return ((CharSequence)v).length() > 0;
|
||
}
|
||
if (v instanceof Number) {
|
||
if (v instanceof Double) {
|
||
return ((Number)v).doubleValue() != 0;
|
||
}
|
||
if (v instanceof Float) {
|
||
return ((Number)v).floatValue() != 0;
|
||
}
|
||
return ((Number)v).intValue() != 0;
|
||
}
|
||
if (v instanceof Iterator) {
|
||
return ((Iterator<?>)v).hasNext();
|
||
}
|
||
return true;
|
||
}
|
||
|
||
public static boolean isFalse(Object v) {
|
||
return !isTrue(v);
|
||
}
|
||
}
|
||
|
||
|
||
|