com.jfinal.template.expr.ast.FieldGetters Maven / Gradle / Ivy
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/**
* Copyright (c) 2011-2023, 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.expr.ast;
import java.lang.reflect.Array;
import com.jfinal.kit.StrKit;
/**
* FieldGetters 封装官方默认 FieldGetter 实现
*/
public class FieldGetters {
/**
* NullFieldGetter
*
* 用于消除 FieldKit.getFieldGetter(...) 中的 instanceof 判断，并且让 Map fieldGetterCache
* 中的 value 不必使用 Object 类型。还消除了 Field.exec(...) 中的 null 值判断
*/
public static class NullFieldGetter extends FieldGetter {
public static final NullFieldGetter me = new NullFieldGetter();
public boolean notNull() {
return false;
}
public FieldGetter takeOver(Class targetClass, String fieldName) {
throw new RuntimeException("The method takeOver(Class, String) of NullFieldGetter should not be invoked");
}
public Object get(Object target, String fieldName) throws Exception {
throw new RuntimeException("The method get(Object, String) of NullFieldGetter should not be invoked");
}
}
/**
* GetterMethodFieldGetter
*
* 使用 getter 方法获取 target.field 表达式的值
*/
public static class GetterMethodFieldGetter extends FieldGetter {
protected java.lang.reflect.Method getterMethod;
public GetterMethodFieldGetter(java.lang.reflect.Method getterMethod) {
this.getterMethod = getterMethod;
}
public FieldGetter takeOver(Class targetClass, String fieldName) {
if (MethodKit.isForbiddenClass(targetClass)) {
throw new RuntimeException("Forbidden class: " + targetClass.getName());
}
String getterName = "get" + StrKit.firstCharToUpperCase(fieldName);
java.lang.reflect.Method[] methodArray = targetClass.getMethods();
for (java.lang.reflect.Method method : methodArray) {
if (method.getName().equals(getterName) && method.getParameterCount() == 0) {
// if (MethodKit.isForbiddenMethod(getterName)) {
// throw new RuntimeException("Forbidden method: " + getterName);
// }
return new GetterMethodFieldGetter(method);
}
}
return null;
}
public Object get(Object target, String fieldName) throws Exception {
return getterMethod.invoke(target, ExprList.NULL_OBJECT_ARRAY);
}
public String toString() {
return getterMethod.toString();
}
}
/**
* IsMethodFieldGetter
*
* 使用 target.isXxx() 方法获取值，默认不启用该功能，用户可以通过如下方式启用：
* Engine.addLastFieldGetter(new FieldGetters.IsMethodFieldGetter());
*/
public static class IsMethodFieldGetter extends FieldGetter {
protected java.lang.reflect.Method isMethod;
// 此构造方法仅为了方便在 Engine.addFieldGetter(...) 添加时不用为构造方法传参
public IsMethodFieldGetter() {
}
public IsMethodFieldGetter(java.lang.reflect.Method isMethod) {
this.isMethod = isMethod;
}
public FieldGetter takeOver(Class targetClass, String fieldName) {
if (MethodKit.isForbiddenClass(targetClass)) {
throw new RuntimeException("Forbidden class: " + targetClass.getName());
}
String isMethodName = "is" + StrKit.firstCharToUpperCase(fieldName);
java.lang.reflect.Method[] methodArray = targetClass.getMethods();
for (java.lang.reflect.Method method : methodArray) {
if (method.getName().equals(isMethodName) && method.getParameterCount() == 0) {
Class returnType = method.getReturnType();
if (returnType == Boolean.class || returnType == boolean.class) {
return new IsMethodFieldGetter(method);
}
}
}
return null;
}
public Object get(Object target, String fieldName) throws Exception {
return isMethod.invoke(target, ExprList.NULL_OBJECT_ARRAY);
}
public String toString() {
return isMethod.toString();
}
}
/**
* ModelFieldGetter
*
* 使用 Model.get(String) 获取值
*/
public static class ModelFieldGetter extends FieldGetter {
// 所有 Model 可以共享 ModelFieldGetter 获取属性
static final ModelFieldGetter singleton = new ModelFieldGetter();
public FieldGetter takeOver(Class targetClass, String fieldName) {
if (com.jfinal.plugin.activerecord.Model.class.isAssignableFrom(targetClass)) {
return singleton;
} else {
return null;
}
}
public Object get(Object target, String fieldName) throws Exception {
return ((com.jfinal.plugin.activerecord.Model)target).get(fieldName);
}
}
/**
* RecordFieldGetter
*
* 使用 Record.get(String) 获取值
*/
public static class RecordFieldGetter extends FieldGetter {
// 所有 Record 可以共享 RecordFieldGetter 获取属性
static final RecordFieldGetter singleton = new RecordFieldGetter();
public FieldGetter takeOver(Class targetClass, String fieldName) {
if (com.jfinal.plugin.activerecord.Record.class.isAssignableFrom(targetClass)) {
return singleton;
} else {
return null;
}
}
public Object get(Object target, String fieldName) throws Exception {
return ((com.jfinal.plugin.activerecord.Record)target).get(fieldName);
}
}
/**
* MapFieldGetter
*
* 使用 Map.get(Object) 获取值
*/
public static class MapFieldGetter extends FieldGetter {
// 所有 Map 可以共享 MapFieldGetter 获取属性
static final MapFieldGetter singleton = new MapFieldGetter();
public FieldGetter takeOver(Class targetClass, String fieldName) {
if (java.util.Map.class.isAssignableFrom(targetClass)) {
return singleton;
} else {
return null;
}
}
public Object get(Object target, String fieldName) throws Exception {
return ((java.util.Map)target).get(fieldName);
}
}
/**
* RealFieldGetter
*
* 使用 target.field 获取值
*/
public static class RealFieldGetter extends FieldGetter {
protected java.lang.reflect.Field field;
public RealFieldGetter(java.lang.reflect.Field field) {
this.field = field;
}
public FieldGetter takeOver(Class targetClass, String fieldName) {
java.lang.reflect.Field[] fieldArray = targetClass.getFields();
for (java.lang.reflect.Field field : fieldArray) {
if (field.getName().equals(fieldName)) {
return new RealFieldGetter(field);
}
}
return null;
}
public Object get(Object target, String fieldName) throws Exception {
return field.get(target);
}
public String toString() {
return field.toString();
}
}
/**
* ArrayLengthGetter
*
* 获取数组长度： array.length
*/
public static class ArrayLengthGetter extends FieldGetter {
// 所有数组可以共享 ArrayLengthGetter 获取属性
static final ArrayLengthGetter singleton = new ArrayLengthGetter();
public FieldGetter takeOver(Class targetClass, String fieldName) {
if ("length".equals(fieldName) && targetClass.isArray()) {
return singleton;
} else {
return null;
}
}
public Object get(Object target, String fieldName) throws Exception {
return Array.getLength(target);
}
}
}
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