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feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
/*
* Copyright (C) 2008 feilong
*
* 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.feilong.lib.json;
import java.lang.annotation.Annotation;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.apache.commons.beanutils.DynaBean;
import com.feilong.lib.beanutils.DynaProperty;
import com.feilong.lib.json.processors.JsonValueProcessor;
import com.feilong.lib.json.processors.JsonVerifier;
import com.feilong.lib.json.util.CycleDetectionStrategy;
import com.feilong.lib.json.util.CycleSetUtil;
import com.feilong.lib.json.util.JSONUtils;
import com.feilong.lib.json.util.PropertyFilter;
public class JSONObjectBuilder{
/** Don't let anyone instantiate this class. */
private JSONObjectBuilder(){
//AssertionError不是必须的. 但它可以避免不小心在类的内部调用构造器. 保证该类在任何情况下都不会被实例化.
//see 《Effective Java》 2nd
throw new AssertionError("No " + getClass().getName() + " instances for you!");
}
//---------------------------------------------------------------
/**
* Creates a JSONObject.
*
* Inspects the object type to call the correct JSONObject factory method.
* Accepts JSON formatted strings, Maps, DynaBeans and JavaBeans.
*
*
* @param object
* the object
* @param jsonConfig
* the json config
* @return the JSON object
*/
public static JSONObject build(Object object,JsonConfig jsonConfig){
if (object == null || JSONUtils.isNull(object)){
return new JSONObject(true);
}
if (object instanceof String){
String str = (String) object;
if ("null".equals(str)){
return new JSONObject(true);
}
return JSONTokenerParser.toJSONObject(new JSONTokener(str), jsonConfig);
}
//---------------------------------------------------------------
if (object instanceof JSONObject){
return fromJSONObject((JSONObject) object, jsonConfig);
}
if (object instanceof Map){
return fromMap((Map) object, jsonConfig);
}
if (JSONUtils.isNumber(object) || JSONUtils.isBoolean(object) || JSONUtils.isString(object)){
return new JSONObject();
}
if (object instanceof DynaBean){
return fromDynaBean((DynaBean) object, jsonConfig);
}
//---------------------------------------------------------------
if (object instanceof Enum){
throw new JSONException("'object' is an Enum. Use JSONArray instead");
}
if (object instanceof Annotation || object.getClass().isAnnotation()){
throw new JSONException("'object' is an Annotation.");
}
if (JSONUtils.isArray(object)){
throw new JSONException("'object' is an array. Use JSONArray instead");
}
//---------------------------------------------------------------
return fromBean(object, jsonConfig);
}
//---------------------------------------------------------------
/**
* From dyna bean.
*
* @param bean
* the bean
* @param jsonConfig
* the json config
* @return the JSON object
*/
private static JSONObject fromDynaBean(DynaBean bean,JsonConfig jsonConfig){
return build(bean, jsonObject -> {
DynaProperty[] dynaPropertys = bean.getDynaClass().getDynaProperties();
Collection exclusions = jsonConfig.getMergedExcludes();
PropertyFilter jsonPropertyFilter = jsonConfig.getJsonPropertyFilter();
for (DynaProperty dynaProperty : dynaPropertys){
boolean bypass = false;
String key = dynaProperty.getName();
if (exclusions.contains(key)){
continue;
}
Class type = dynaProperty.getType();
Object value = bean.get(dynaProperty.getName());
if (jsonPropertyFilter != null && jsonPropertyFilter.apply(bean, key, value)){
continue;
}
JsonValueProcessor jsonValueProcessor = jsonConfig.findJsonValueProcessor(type, key);
if (jsonValueProcessor != null){
value = jsonValueProcessor.processObjectValue(key, value, jsonConfig);
bypass = true;
if (!JsonVerifier.isValidJsonValue(value)){
throw new JSONException("Value is not a valid JSON value. " + value);
}
}
JSONObjectValueSetter.set(jsonObject, key, value, type, jsonConfig, bypass);
}
});
}
/**
* From map.
*
* @param map
* the map
* @param jsonConfig
* the json config
* @return the JSON object
*/
private static JSONObject fromMap(Map map,JsonConfig jsonConfig){
return build(map, jsonObject -> {
Collection exclusions = jsonConfig.getMergedExcludes();
PropertyFilter jsonPropertyFilter = jsonConfig.getJsonPropertyFilter();
for (Map.Entry entry : map.entrySet()){
Object k = entry.getKey();
if (k == null){
throw new JSONException("JSON keys can't be null.");
}
//---------------------------------------------------------------
String key = String.valueOf(k);
if ("null".equals(key)){
throw new NullPointerException("JSON keys must not be null nor the 'null' string.");
}
if (exclusions.contains(key)){
continue;
}
//---------------------------------------------------------------
Object value = entry.getValue();
if (jsonPropertyFilter != null && jsonPropertyFilter.apply(map, key, value)){
continue;
}
boolean bypass = false;
//---------------------------------------------------------------
if (value != null){
JsonValueProcessor jsonValueProcessor = jsonConfig.findJsonValueProcessor(value.getClass(), key);
if (jsonValueProcessor != null){
value = jsonValueProcessor.processObjectValue(key, value, jsonConfig);
bypass = true;
if (!JsonVerifier.isValidJsonValue(value)){
throw new JSONException("Value is not a valid JSON value. " + value);
}
}
JSONObjectValueSetter.set(jsonObject, key, value, value.getClass(), jsonConfig, bypass);
}else{
jsonObject.accumulate(key, JSONNull.getInstance(), new JsonConfig());
}
}
});
}
/**
* Creates a JSONObject from a POJO. Supports nested maps, POJOs, and arrays/collections.
*
* @param bean
* An object with POJO conventions
* @param jsonConfig
* the json config
* @return the JSON object
*/
private static JSONObject fromBean(Object bean,JsonConfig jsonConfig){
return build(bean, jsonObject -> DefaultBeanProcesser.process(bean, jsonObject, jsonConfig));
}
//---------------------------------------------------------------
/**
* From JSON object.
*
* @param inputJsonObject
* the object
* @param jsonConfig
* the json config
* @return the JSON object
*/
private static JSONObject fromJSONObject(JSONObject inputJsonObject,JsonConfig jsonConfig){
return build(inputJsonObject, jsonObject -> {
Collection exclusions = jsonConfig.getMergedExcludes();
PropertyFilter jsonPropertyFilter = jsonConfig.getJsonPropertyFilter();
List names = inputJsonObject.names(jsonConfig);
for (String key : names){
if (key == null){
throw new JSONException("JSON keys cannot be null.");
}
if ("null".equals(key)){
throw new NullPointerException("JSON keys must not be null nor the 'null' string.");
}
if (exclusions.contains(key)){
continue;
}
Object value = inputJsonObject.get(key);
if (jsonPropertyFilter != null && jsonPropertyFilter.apply(inputJsonObject, key, value)){
continue;
}
jsonObject.accumulate(key, value, jsonConfig);
}
});
}
private static JSONObject build(Object object,JsonHook jsonHook){
if (!CycleSetUtil.addInstance(object)){
try{
return CycleDetectionStrategy.LENIENT.handleRepeatedReferenceAsObject(object);
}catch (Exception e){
CycleSetUtil.removeInstance(object);
throw new JSONException("", e);
}
}
//---------------------------------------------------------------
JSONObject jsonObject = new JSONObject();
try{
jsonHook.handle(jsonObject);
CycleSetUtil.removeInstance(object);
return jsonObject;
}catch (Exception e){
CycleSetUtil.removeInstance(object);
throw new JSONException("", e);
}
}
}