/*
* Copyright 2002-2009 the original author or authors.
*
* 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 net.sf.json;
import java.io.IOException;
import java.io.Writer;
import java.lang.ref.SoftReference;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;
import net.sf.json.util.JSONUtils;
import net.sf.json.util.JsonEventListener;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Base class for JSONObject and JSONArray.
*
* @author Andres Almiray <aalmiray@users.sourceforge.net>
*/
abstract class AbstractJSON implements JSON {
private static class CycleSet extends ThreadLocal {
protected Object initialValue() {
return new SoftReference(new HashSet());
}
public Set getSet() {
Set set = (Set) ((SoftReference)get()).get();
if( set == null ) {
set = new HashSet();
set(new SoftReference(set));
}
return set;
}
}
private static CycleSet cycleSet = new CycleSet();
private static final Log log = LogFactory.getLog( AbstractJSON.class );
/**
* Adds a reference for cycle detection check.
*
* @param instance the reference to add
* @return true if the instance has not been added previously, false
* otherwise.
*/
protected static boolean addInstance( Object instance ) {
return getCycleSet().add( instance );
}
/**
* Fires an end of array event.
*/
protected static void fireArrayEndEvent( JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onArrayEnd();
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires a start of array event.
*/
protected static void fireArrayStartEvent( JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onArrayStart();
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires an element added event.
*
* @param index the index where the element was added
* @param element the added element
*/
protected static void fireElementAddedEvent( int index, Object element, JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onElementAdded( index, element );
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires an error event.
*
* @param jsone the thrown exception
*/
protected static void fireErrorEvent( JSONException jsone, JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onError( jsone );
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires an end of object event.
*/
protected static void fireObjectEndEvent( JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onObjectEnd();
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires a start of object event.
*/
protected static void fireObjectStartEvent( JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onObjectStart();
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires a property set event.
*
* @param key the name of the property
* @param value the value of the property
* @param accumulated if the value has been accumulated over 'key'
*/
protected static void firePropertySetEvent( String key, Object value, boolean accumulated,
JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onPropertySet( key, value, accumulated );
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Fires a warning event.
*
* @param warning the warning message
*/
protected static void fireWarnEvent( String warning, JsonConfig jsonConfig ) {
if( jsonConfig.isEventTriggeringEnabled() ){
for( Iterator listeners = jsonConfig.getJsonEventListeners()
.iterator(); listeners.hasNext(); ){
JsonEventListener listener = (JsonEventListener) listeners.next();
try{
listener.onWarning( warning );
}catch( RuntimeException e ){
log.warn( e );
}
}
}
}
/**
* Removes a reference for cycle detection check.
*/
protected static void removeInstance( Object instance ) {
Set set = getCycleSet();
set.remove( instance );
if(set.size() == 0) {
cycleSet.remove();
}
}
protected Object _processValue( Object value, JsonConfig jsonConfig ) {
if( JSONNull.getInstance().equals( value ) ) {
return JSONNull.getInstance();
} else if( Class.class.isAssignableFrom( value.getClass() ) || value instanceof Class ) {
return ((Class) value).getName();
} else if( JSONUtils.isFunction( value ) ) {
if( value instanceof String ) {
value = JSONFunction.parse( (String) value );
}
return value;
} else if( value instanceof JSONString ) {
return JSONSerializer.toJSON( (JSONString) value, jsonConfig );
} else if( value instanceof JSON ) {
return JSONSerializer.toJSON( value, jsonConfig );
} else if( JSONUtils.isArray( value ) ) {
return JSONArray.fromObject( value, jsonConfig );
} else if( JSONUtils.isString( value ) ) {
String str = String.valueOf( value );
if( JSONUtils.hasQuotes( str ) ){
String stripped = JSONUtils.stripQuotes( str );
if( JSONUtils.isFunction( stripped )){
return JSONUtils.DOUBLE_QUOTE + stripped + JSONUtils.DOUBLE_QUOTE;
}
if(stripped.startsWith("[") && stripped.endsWith("]")) {
return stripped;
}
if(stripped.startsWith("{") && stripped.endsWith("}")) {
return stripped;
}
return str;
} else if( JSONUtils.isJsonKeyword( str, jsonConfig ) ) {
if( jsonConfig.isJavascriptCompliant() && "undefined".equals( str )){
return JSONNull.getInstance();
}
return str;
} else if( JSONUtils.mayBeJSON( str ) ) {
try {
return JSONSerializer.toJSON( str, jsonConfig );
} catch( JSONException jsone ) {
return str;
}
}
return str;
} else if( JSONUtils.isNumber( value ) ) {
JSONUtils.testValidity( value );
return JSONUtils.transformNumber( (Number) value );
} else if( JSONUtils.isBoolean( value ) ) {
return value;
} else {
JSONObject jsonObject = JSONObject.fromObject( value, jsonConfig );
if( jsonObject.isNullObject() ) {
return JSONNull.getInstance();
} else {
return jsonObject;
}
}
}
private static Set getCycleSet() {
return cycleSet.getSet();
}
public final Writer write(Writer writer) throws IOException {
write(writer,NORMAL);
return writer;
}
public final Writer writeCanonical(Writer writer) throws IOException {
write(writer,CANONICAL);
return writer;
}
protected abstract void write(Writer w, WritingVisitor v) throws IOException;
interface WritingVisitor {
Collection keySet(JSONObject o);
void on(JSON o, Writer w) throws IOException;
void on(Object value, Writer w) throws IOException;
}
private static final WritingVisitor NORMAL = new WritingVisitor() {
public Collection keySet(JSONObject o) {
return o.keySet();
}
public void on(JSON o, Writer w) throws IOException {
o.write(w);
}
public void on(Object value, Writer w) throws IOException {
w.write(JSONUtils.valueToString(value));
}
};
private static final WritingVisitor CANONICAL = new WritingVisitor() {
public Collection keySet(JSONObject o) {
return new TreeSet(o.keySet()); // sort them alphabetically
}
public void on(JSON o, Writer w) throws IOException {
o.writeCanonical(w);
}
public void on(Object value, Writer w) throws IOException {
w.write(JSONUtils.valueToCanonicalString(value));
}
};
}