92 lines
2.6 KiB
Java
92 lines
2.6 KiB
Java
/**
|
||
* Copyright (c) 2011-2019, 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.util.List;
|
||
import com.jfinal.template.TemplateException;
|
||
import com.jfinal.template.stat.Location;
|
||
import com.jfinal.template.stat.ParseException;
|
||
import com.jfinal.template.stat.Scope;
|
||
|
||
/**
|
||
* index : expr '[' expr ']'
|
||
*
|
||
* 支持 a[i]、 a[b[i]]、a[i][j]、a[i][j]...[n]
|
||
*/
|
||
public class Index extends Expr {
|
||
|
||
private Expr expr;
|
||
private Expr index;
|
||
|
||
public Index(Expr expr, Expr index, Location location) {
|
||
if (expr == null || index == null) {
|
||
throw new ParseException("array/list/map and their index can not be null", location);
|
||
}
|
||
this.expr = expr;
|
||
this.index = index;
|
||
this.location = location;
|
||
}
|
||
|
||
@SuppressWarnings("rawtypes")
|
||
public Object eval(Scope scope) {
|
||
Object target = expr.eval(scope);
|
||
if (target == null) {
|
||
if (scope.getCtrl().isNullSafe()) {
|
||
return null;
|
||
}
|
||
throw new TemplateException("The index access operation target can not be null", location);
|
||
}
|
||
|
||
Object idx = index.eval(scope);
|
||
if (idx == null) {
|
||
if (scope.getCtrl().isNullSafe()) {
|
||
return null;
|
||
}
|
||
|
||
if (target instanceof java.util.Map) {
|
||
// Map 的 key 可以是 null，不能抛异常
|
||
} else {
|
||
throw new TemplateException("The index of list and array can not be null", location);
|
||
}
|
||
}
|
||
|
||
if (target instanceof List) {
|
||
if (idx instanceof Integer) {
|
||
return ((List<?>)target).get((Integer)idx);
|
||
}
|
||
throw new TemplateException("The index of list must be integer", location);
|
||
}
|
||
|
||
if (target instanceof java.util.Map) {
|
||
return ((java.util.Map)target).get(idx);
|
||
}
|
||
|
||
if (target.getClass().isArray()) {
|
||
if (idx instanceof Integer) {
|
||
return java.lang.reflect.Array.get(target, (Integer)idx);
|
||
}
|
||
throw new TemplateException("The index of array must be integer", location);
|
||
}
|
||
|
||
throw new TemplateException("Only the list array and map is supported by index access", location);
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|