juneau-core/juneau-marshall/src/main/java/org/apache/juneau/json/JsonSerializer.java - juneau - Git at Google

 // ***************************************************************************************************************************
 // * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
 // * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
 // * to you 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 org.apache.juneau.json;

 import java.util.*;
 import java.util.concurrent.*;

 import org.apache.juneau.*;
 import org.apache.juneau.annotation.*;
 import org.apache.juneau.serializer.*;

 /**
  * Serializes POJO models to JSON.
  *
  * <h5 class='topic'>Media types</h5>
  *
  * Handles <c>Accept</c> types:  <bc>application/json, text/json</bc>
  * <p>
  * Produces <c>Content-Type</c> types:  <bc>application/json</bc>
  *
  * <h5 class='topic'>Description</h5>
  *
  * The conversion is as follows...
  * <ul class='spaced-list'>
  * 	<li>
  * 		Maps (e.g. {@link HashMap HashMaps}, {@link TreeMap TreeMaps}) are converted to JSON objects.
  * 	<li>
  * 		Collections (e.g. {@link HashSet HashSets}, {@link LinkedList LinkedLists}) and Java arrays are converted to
  * 		JSON arrays.
  * 	<li>
  * 		{@link String Strings} are converted to JSON strings.
  * 	<li>
  * 		{@link Number Numbers} (e.g. {@link Integer}, {@link Long}, {@link Double}) are converted to JSON numbers.
  * 	<li>
  * 		{@link Boolean Booleans} are converted to JSON booleans.
  * 	<li>
  * 		{@code nulls} are converted to JSON nulls.
  * 	<li>
  * 		{@code arrays} are converted to JSON arrays.
  * 	<li>
  * 		{@code beans} are converted to JSON objects.
  * </ul>
  *
  * <p>
  * The types above are considered "JSON-primitive" object types.
  * Any non-JSON-primitive object types are transformed into JSON-primitive object types through
  * {@link org.apache.juneau.transform.PojoSwap PojoSwaps} associated through the
  * {@link BeanContextBuilder#pojoSwaps(Class...)} method.
  * Several default transforms are provided for transforming Dates, Enums, Iterators, etc...
  *
  * <p>
  * This serializer provides several serialization options.
  * Typically, one of the predefined DEFAULT serializers will be sufficient.
  * However, custom serializers can be constructed to fine-tune behavior.
  *
  * <h5 class='topic'>Behavior-specific subclasses</h5>
  *
  * The following direct subclasses are provided for convenience:
  * <ul class='spaced-list'>
  * 	<li>
  * 		{@link SimpleJsonSerializer} - Default serializer, single quotes, simple mode.
  * 	<li>
  * 		{@link SimpleJsonSerializer.Readable} - Default serializer, single quotes, simple mode, with whitespace.
  * </ul>
  *
  * <h5 class='section'>Example:</h5>
  * <p class='bcode w800'>
  * 	<jc>// Use one of the default serializers to serialize a POJO</jc>
  * 	String json = JsonSerializer.<jsf>DEFAULT</jsf>.serialize(someObject);
  *
  * 	<jc>// Create a custom serializer for lax syntax using single quote characters</jc>
  * 	JsonSerializer serializer = JsonSerializer.<jsm>create</jsm>().simple().sq().build();
  *
  * 	<jc>// Clone an existing serializer and modify it to use single-quotes</jc>
  * 	JsonSerializer serializer = JsonSerializer.<jsf>DEFAULT</jsf>.builder().sq().build();
  *
  * 	<jc>// Serialize a POJO to JSON</jc>
  * 	String json = serializer.serialize(someObject);
  * </p>
  */
 @ConfigurableContext
 public class JsonSerializer extends WriterSerializer implements JsonMetaProvider, JsonCommon {

 	//-------------------------------------------------------------------------------------------------------------------
 	// Configurable properties
 	//-------------------------------------------------------------------------------------------------------------------

 	static final String PREFIX = "JsonSerializer";

 	/**
 	 * Configuration property:  Add <js>"_type"</js> properties when needed.
 	 *
 	 * <h5 class='section'>Property:</h5>
 	 * <ul class='spaced-list'>
 	 * 	<li><b>ID:</b>  {@link org.apache.juneau.json.JsonSerializer#JSON_addBeanTypes JSON_addBeanTypes}
 	 * 	<li><b>Name:</b>  <js>"JsonSerializer.addBeanTypes.b"</js>
 	 * 	<li><b>Data type:</b>  <jk>boolean</jk>
 	 * 	<li><b>System property:</b>  <c>JsonSerializer.addBeanTypes</c>
 	 * 	<li><b>Environment variable:</b>  <c>JSONSERIALIZER_ADDBEANTYPES</c>
 	 * 	<li><b>Default:</b>  <jk>false</jk>
 	 * 	<li><b>Session property:</b>  <jk>false</jk>
 	 * 	<li><b>Annotations:</b>
 	 * 		<ul>
 	 * 			<li class='ja'>{@link org.apache.juneau.json.annotation.JsonConfig#addBeanTypes()}
 	 * 		</ul>
 	 * 	<li><b>Methods:</b>
 	 * 		<ul>
 	 * 			<li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#addBeanTypes(boolean)}
 	 * 		</ul>
 	 * </ul>
 	 *
 	 * <h5 class='section'>Description:</h5>
 	 * <p>
 	 * If <jk>true</jk>, then <js>"_type"</js> properties will be added to beans if their type cannot be inferred
 	 * through reflection.
 	 *
 	 * <p>
 	 * When present, this value overrides the {@link #SERIALIZER_addBeanTypes} setting and is
 	 * provided to customize the behavior of specific serializers in a {@link SerializerGroup}.
 	 */
 	public static final String JSON_addBeanTypes = PREFIX + ".addBeanTypes.b";

 	/**
 	 * Configuration property:  Prefix solidus <js>'/'</js> characters with escapes.
 	 *
 	 * <h5 class='section'>Property:</h5>
 	 * <ul class='spaced-list'>
 	 * 	<li><b>ID:</b>  {@link org.apache.juneau.json.JsonSerializer#JSON_escapeSolidus JSON_escapeSolidus}
 	 * 	<li><b>Name:</b>  <js>"JsonSerializer.escapeSolidus.b"</js>
 	 * 	<li><b>Data type:</b>  <jk>boolean</jk>
 	 * 	<li><b>System property:</b>  <c>JsonSerializer.escapeSolidus</c>
 	 * 	<li><b>Environment variable:</b>  <c>JSONSERIALIZER_ESCAPESOLIDUS</c>
 	 * 	<li><b>Default:</b>  <jk>false</jk>
 	 * 	<li><b>Session property:</b>  <jk>false</jk>
 	 * 	<li><b>Annotations:</b>
 	 * 		<ul>
 	 * 			<li class='ja'>{@link org.apache.juneau.json.annotation.JsonConfig#escapeSolidus()}
 	 * 		</ul>
 	 * 	<li><b>Methods:</b>
 	 * 		<ul>
 	 * 			<li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#escapeSolidus(boolean)}
 	 * 			<li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#escapeSolidus()}
 	 * 		</ul>
 	 * </ul>
 	 *
 	 * <h5 class='section'>Description:</h5>
 	 * <p>
 	 * If <jk>true</jk>, solidus (e.g. slash) characters should be escaped.
 	 * The JSON specification allows for either format.
 	 * <br>However, if you're embedding JSON in an HTML script tag, this setting prevents confusion when trying to serialize
 	 * <xt>&lt;\/script&gt;</xt>.
 	 *
 	 * <h5 class='section'>Example:</h5>
 	 * <p class='bcode w800'>
 	 * 	<jc>// Create a JSON serializer that escapes solidus characters.</jc>
 	 * 	WriterSerializer s = JsonSerializer
 	 * 		.<jsm>create</jsm>()
 	 * 		.simple()
 	 * 		.escapeSolidus()
 	 * 		.build();
 	 *
 	 * 	<jc>// Same, but use property.</jc>
 	 * 	WriterSerializer s = JsonSerializer
 	 * 		.<jsm>create</jsm>()
 	 * 		.simple()
 	 * 		.set(<jsf>JSON_escapeSolidus</jsf>, <jk>true</jk>)
 	 * 		.build();
 	 *
 	 * 	<jc>// Produces: "{foo:'&lt;\/bar&gt;'"</jc>
 	 * 	String json = s.serialize(<jk>new</jk> ObjectMap().append(<js>"foo"</js>, <js>"&lt;/bar&gt;"</js>);
 	 * </p>
 	 */
 	public static final String JSON_escapeSolidus = PREFIX + ".escapeSolidus.b";

 	/**
 	 * Configuration property:  Simple JSON mode.
 	 *
 	 * <h5 class='section'>Property:</h5>
 	 * <ul class='spaced-list'>
 	 * 	<li><b>ID:</b>  {@link org.apache.juneau.json.JsonSerializer#JSON_simpleMode JSON_simpleMode}
 	 * 	<li><b>Name:</b>  <js>"JsonSerializer.simpleMode.b"</js>
 	 * 	<li><b>Data type:</b>  <jk>boolean</jk>
 	 * 	<li><b>System property:</b>  <c>JsonSerializer.simpleMode</c>
 	 * 	<li><b>Environment variable:</b>  <c>JSONSERIALIZER_SIMPLEMODE</c>
 	 * 	<li><b>Default:</b>  <jk>false</jk>
 	 * 	<li><b>Session property:</b>  <jk>false</jk>
 	 * 	<li><b>Annotations:</b>
 	 * 		<ul>
 	 * 			<li class='ja'>{@link org.apache.juneau.json.annotation.JsonConfig#simpleMode()}
 	 * 		</ul>
 	 * 	<li><b>Methods:</b>
 	 * 		<ul>
 	 * 			<li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#simple(boolean)}
 	 * 			<li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#simple()}
 	 * 			<li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#ssq()}
 	 * 		</ul>
 	 * </ul>
 	 *
 	 * <h5 class='section'>Description:</h5>
 	 * <p>
 	 * If <jk>true</jk>, JSON attribute names will only be quoted when necessary.
 	 * <br>Otherwise, they are always quoted.
 	 *
 	 * <p>
 	 * Attributes do not need to be quoted when they conform to the following:
 	 * <ol class='spaced-list'>
 	 * 	<li>They start with an ASCII character or <js>'_'</js>.
 	 * 	<li>They contain only ASCII characters or numbers or <js>'_'</js>.
 	 * 	<li>They are not one of the following reserved words:
 	 * 		<p class='bcode w800'>
 	 * 	arguments, break, case, catch, class, const, continue, debugger, default,
 	 * 	delete, do, else, enum, eval, export, extends, false, finally, for, function,
 	 * 	if, implements, import, in, instanceof, interface, let, new, null, package,
 	 * 	private, protected, public, return, static, super, switch, this, throw,
 	 * 	true, try, typeof, var, void, while, with, undefined, yield
 	 * 		</p>
 	 * </ol>
 	 *
 	 * <h5 class='section'>Example:</h5>
 	 * <p class='bcode w800'>
 	 * 	<jc>// Create a JSON serializer in normal mode.</jc>
 	 * 	WriterSerializer s1 = JsonSerializer
 	 * 		.<jsm>create</jsm>()
 	 * 		.build();
 	 *
 	 * 	<jc>// Create a JSON serializer in simple mode.</jc>
 	 * 	WriterSerializer s2 = JsonSerializer
 	 * 		.<jsm>create</jsm>()
 	 * 		.simple()
 	 * 		.build();
 	 *
 	 * 	ObjectMap m = <jk>new</jk> ObjectMap()
 	 * 		.append(<js>"foo"</js>, <js>"x1"</js>)
 	 * 		.append(<js>"_bar"</js>, <js>"x2"</js>)
 	 * 		.append(<js>" baz "</js>, <js>"x3"</js>)
 	 * 		.append(<js>"123"</js>, <js>"x4"</js>)
 	 * 		.append(<js>"return"</js>, <js>"x5"</js>);
 	 * 		.append(<js>""</js>, <js>"x6"</js>);
 	 *
 	 * 	<jc>// Produces:</jc>
 	 * 	<jc>// {</jc>
 	 * 	<jc>// 	"foo": "x1"</jc>
 	 * 	<jc>// 	"_bar": "x2"</jc>
 	 * 	<jc>// 	" baz ": "x3"</jc>
 	 * 	<jc>// 	"123": "x4"</jc>
 	 * 	<jc>// 	"return": "x5"</jc>
 	 * 	<jc>// 	"": "x6"</jc>
 	 * 	<jc>// }</jc>
 	 * 	String json1 = s1.serialize(m);
 	 *
 	 * 	<jc>// Produces:</jc>
 	 * 	<jc>// {</jc>
 	 * 	<jc>// 	foo: "x1"</jc>
 	 * 	<jc>// 	_bar: "x2"</jc>
 	 * 	<jc>// 	" baz ": "x3"</jc>
 	 * 	<jc>// 	"123": "x4"</jc>
 	 * 	<jc>// 	"return": "x5"</jc>
 	 * 	<jc>// 	"": "x6"</jc>
 	 * 	<jc>// }</jc>
 	 * 	String json2 = s2.serialize(m);
 	 * </p>
 	 */
 	public static final String JSON_simpleMode = PREFIX + ".simpleMode.b";

 	//-------------------------------------------------------------------------------------------------------------------
 	// Predefined instances
 	//-------------------------------------------------------------------------------------------------------------------

 	/** Default serializer, all default settings.*/
 	public static final JsonSerializer DEFAULT = new JsonSerializer(PropertyStore.DEFAULT);

 	/** Default serializer, all default settings.*/
 	public static final JsonSerializer DEFAULT_READABLE = new Readable(PropertyStore.DEFAULT);


 	//-------------------------------------------------------------------------------------------------------------------
 	// Predefined subclasses
 	//-------------------------------------------------------------------------------------------------------------------

 	/** Default serializer, with whitespace. */
 	public static class Readable extends JsonSerializer {

 		/**
 		 * Constructor.
 		 *
 		 * @param ps The property store containing all the settings for this object.
 		 */
 		public Readable(PropertyStore ps) {
 			super(
 				ps.builder().set(WSERIALIZER_useWhitespace, true).build()
 			);
 		}
 	}

 	/**
 	 * Default serializer, single quotes, simple mode, with whitespace and recursion detection.
 	 * Note that recursion detection introduces a small performance penalty.
 	 */
 	public static class ReadableSafe extends JsonSerializer {

 		/**
 		 * Constructor.
 		 *
 		 * @param ps The property store containing all the settings for this object.
 		 */
 		public ReadableSafe(PropertyStore ps) {
 			super(
 				ps.builder()
 					.set(JSON_simpleMode, true)
 					.set(WSERIALIZER_quoteChar, '\'')
 					.set(WSERIALIZER_useWhitespace, true)
 					.set(BEANTRAVERSE_detectRecursions, true)
 					.build()
 			);
 		}
 	}


 	//-------------------------------------------------------------------------------------------------------------------
 	// Instance
 	//-------------------------------------------------------------------------------------------------------------------

 	private final boolean
 		simpleMode,
 		escapeSolidus,
 		addBeanTypes;
 	private final Map<ClassMeta<?>,JsonClassMeta> jsonClassMetas = new ConcurrentHashMap<>();
 	private final Map<BeanPropertyMeta,JsonBeanPropertyMeta> jsonBeanPropertyMetas = new ConcurrentHashMap<>();

 	private volatile JsonSchemaSerializer schemaSerializer;

 	/**
 	 * Constructor.
 	 *
 	 * @param ps
 	 * 	The property store containing all the settings for this object.
 	 */
 	public JsonSerializer(PropertyStore ps) {
 		this(ps, "application/json", "application/json,text/json");
 	}

 	/**
 	 * Constructor.
 	 *
 	 * @param ps
 	 * 	The property store containing all the settings for this object.
 	 * @param produces
 	 * 	The media type that this serializer produces.
 	 * @param accept
 	 * 	The accept media types that the serializer can handle.
 	 * 	<p>
 	 * 	Can contain meta-characters per the <c>media-type</c> specification of {@doc RFC2616.section14.1}
 	 * 	<p>
 	 * 	If empty, then assumes the only media type supported is <c>produces</c>.
 	 * 	<p>
 	 * 	For example, if this serializer produces <js>"application/json"</js> but should handle media types of
 	 * 	<js>"application/json"</js> and <js>"text/json"</js>, then the arguments should be:
 	 * 	<p class='bcode w800'>
 	 * 	<jk>super</jk>(ps, <js>"application/json"</js>, <js>"application/json,text/json"</js>);
 	 * 	</p>
 	 * 	<br>...or...
 	 * 	<p class='bcode w800'>
 	 * 	<jk>super</jk>(ps, <js>"application/json"</js>, <js>"*&#8203;/json"</js>);
 	 * 	</p>
 	 * <p>
 	 * The accept value can also contain q-values.
 	 */
 	public JsonSerializer(PropertyStore ps, String produces, String accept) {
 		super(ps, produces, accept);

 		simpleMode = getBooleanProperty(JSON_simpleMode, false);
 		escapeSolidus = getBooleanProperty(JSON_escapeSolidus, false);
 		addBeanTypes = getBooleanProperty(JSON_addBeanTypes, getBooleanProperty(SERIALIZER_addBeanTypes, false));
 	}

 	@Override /* Context */
 	public JsonSerializerBuilder builder() {
 		return new JsonSerializerBuilder(getPropertyStore());
 	}

 	/**
 	 * Instantiates a new clean-slate {@link JsonSerializerBuilder} object.
 	 *
 	 * <p>
 	 * This is equivalent to simply calling <code><jk>new</jk> JsonSerializerBuilder()</code>.
 	 *
 	 * @return A new {@link JsonSerializerBuilder} object.
 	 */
 	public static JsonSerializerBuilder create() {
 		return new JsonSerializerBuilder();
 	}

 	/**
 	 * Returns the schema serializer based on the settings of this serializer.
 	 *
 	 * <p>
 	 * Note that this method creates a builder initialized to all default settings, whereas {@link #builder()} copies
 	 * the settings of the object called on.
 	 *
 	 * @return The schema serializer.
 	 */
 	public JsonSchemaSerializer getSchemaSerializer() {
 		if (schemaSerializer == null)
 			schemaSerializer = builder().build(JsonSchemaSerializer.class);
 		return schemaSerializer;
 	}

 	//-----------------------------------------------------------------------------------------------------------------
 	// Entry point methods
 	//-----------------------------------------------------------------------------------------------------------------

 	@Override /* Context */
 	public JsonSerializerSession createSession() {
 		return createSession(createDefaultSessionArgs());
 	}

 	@Override /* Serializer */
 	public JsonSerializerSession createSession(SerializerSessionArgs args) {
 		return new JsonSerializerSession(this, args);
 	}

 	//-----------------------------------------------------------------------------------------------------------------
 	// Extended metadata
 	//-----------------------------------------------------------------------------------------------------------------

 	@Override /* JsonMetaProvider */
 	public JsonClassMeta getJsonClassMeta(ClassMeta<?> cm) {
 		JsonClassMeta m = jsonClassMetas.get(cm);
 		if (m == null) {
 			m = new JsonClassMeta(cm, this);
 			jsonClassMetas.put(cm, m);
 		}
 		return m;
 	}

 	@Override /* JsonMetaProvider */
 	public JsonBeanPropertyMeta getJsonBeanPropertyMeta(BeanPropertyMeta bpm) {
 		if (bpm == null)
 			return JsonBeanPropertyMeta.DEFAULT;
 		JsonBeanPropertyMeta m = jsonBeanPropertyMetas.get(bpm);
 		if (m == null) {
 			m = new JsonBeanPropertyMeta(bpm.getDelegateFor(), this);
 			jsonBeanPropertyMetas.put(bpm, m);
 		}
 		return m;
 	}

 	//-----------------------------------------------------------------------------------------------------------------
 	// Properties
 	//-----------------------------------------------------------------------------------------------------------------

 	/**
 	 * Configuration property:  Add <js>"_type"</js> properties when needed.
 	 *
 	 * @see #JSON_addBeanTypes
 	 * @return
 	 * 	<jk>true</jk> if <js>"_type"</js> properties will be added to beans if their type cannot be inferred
 	 * 	through reflection.
 	 */
 	@Override
 	protected final boolean isAddBeanTypes() {
 		return addBeanTypes;
 	}

 	/**
 	 * Configuration property:  Prefix solidus <js>'/'</js> characters with escapes.
 	 *
 	 * @see #JSON_escapeSolidus
 	 * @return
 	 * 	<jk>true</jk> if solidus (e.g. slash) characters should be escaped.
 	 */
 	protected final boolean isEscapeSolidus() {
 		return escapeSolidus;
 	}

 	/**
 	 * Configuration property:  Simple JSON mode.
 	 *
 	 * @see #JSON_simpleMode
 	 * @return
 	 * 	<jk>true</jk> if JSON attribute names will only be quoted when necessary.
 	 * 	<br>Otherwise, they are always quoted.
 	 */
 	protected final boolean isSimpleMode() {
 		return simpleMode;
 	}

 	//-----------------------------------------------------------------------------------------------------------------
 	// Other methods
 	//-----------------------------------------------------------------------------------------------------------------

 	@Override /* Context */
 	public ObjectMap toMap() {
 		return super.toMap()
 			.append("JsonSerializer", new DefaultFilteringObjectMap()
 				.append("simpleMode", simpleMode)
 				.append("escapeSolidus", escapeSolidus)
 				.append("addBeanTypes", addBeanTypes)
 			);
 	}
 }
	// ***************************************************************************************************************************
	// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file *
	// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file *
	// * to you 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 org.apache.juneau.json;

	import java.util.*;
	import java.util.concurrent.*;

	import org.apache.juneau.*;
	import org.apache.juneau.annotation.*;
	import org.apache.juneau.serializer.*;

	/**
	* Serializes POJO models to JSON.
	*
	* <h5 class='topic'>Media types</h5>
	*
	* Handles <c>Accept</c> types: <bc>application/json, text/json</bc>
	* <p>
	* Produces <c>Content-Type</c> types: <bc>application/json</bc>
	*
	* <h5 class='topic'>Description</h5>
	*
	* The conversion is as follows...
	* <ul class='spaced-list'>
	* <li>
	* Maps (e.g. {@link HashMap HashMaps}, {@link TreeMap TreeMaps}) are converted to JSON objects.
	* <li>
	* Collections (e.g. {@link HashSet HashSets}, {@link LinkedList LinkedLists}) and Java arrays are converted to
	* JSON arrays.
	* <li>
	* {@link String Strings} are converted to JSON strings.
	* <li>
	* {@link Number Numbers} (e.g. {@link Integer}, {@link Long}, {@link Double}) are converted to JSON numbers.
	* <li>
	* {@link Boolean Booleans} are converted to JSON booleans.
	* <li>
	* {@code nulls} are converted to JSON nulls.
	* <li>
	* {@code arrays} are converted to JSON arrays.
	* <li>
	* {@code beans} are converted to JSON objects.
	* </ul>
	*
	* <p>
	* The types above are considered "JSON-primitive" object types.
	* Any non-JSON-primitive object types are transformed into JSON-primitive object types through
	* {@link org.apache.juneau.transform.PojoSwap PojoSwaps} associated through the
	* {@link BeanContextBuilder#pojoSwaps(Class...)} method.
	* Several default transforms are provided for transforming Dates, Enums, Iterators, etc...
	*
	* <p>
	* This serializer provides several serialization options.
	* Typically, one of the predefined DEFAULT serializers will be sufficient.
	* However, custom serializers can be constructed to fine-tune behavior.
	*
	* <h5 class='topic'>Behavior-specific subclasses</h5>
	*
	* The following direct subclasses are provided for convenience:
	* <ul class='spaced-list'>
	* <li>
	* {@link SimpleJsonSerializer} - Default serializer, single quotes, simple mode.
	* <li>
	* {@link SimpleJsonSerializer.Readable} - Default serializer, single quotes, simple mode, with whitespace.
	* </ul>
	*
	* <h5 class='section'>Example:</h5>
	* <p class='bcode w800'>
	* <jc>// Use one of the default serializers to serialize a POJO</jc>
	* String json = JsonSerializer.<jsf>DEFAULT</jsf>.serialize(someObject);
	*
	* <jc>// Create a custom serializer for lax syntax using single quote characters</jc>
	* JsonSerializer serializer = JsonSerializer.<jsm>create</jsm>().simple().sq().build();
	*
	* <jc>// Clone an existing serializer and modify it to use single-quotes</jc>
	* JsonSerializer serializer = JsonSerializer.<jsf>DEFAULT</jsf>.builder().sq().build();
	*
	* <jc>// Serialize a POJO to JSON</jc>
	* String json = serializer.serialize(someObject);
	* </p>
	*/
	@ConfigurableContext
	public class JsonSerializer extends WriterSerializer implements JsonMetaProvider, JsonCommon {

	//-------------------------------------------------------------------------------------------------------------------
	// Configurable properties
	//-------------------------------------------------------------------------------------------------------------------

	static final String PREFIX = "JsonSerializer";

	/**
	* Configuration property: Add <js>"_type"</js> properties when needed.
	*
	* <h5 class='section'>Property:</h5>
	* <ul class='spaced-list'>
	* <li><b>ID:</b> {@link org.apache.juneau.json.JsonSerializer#JSON_addBeanTypes JSON_addBeanTypes}
	* <li><b>Name:</b> <js>"JsonSerializer.addBeanTypes.b"</js>
	* <li><b>Data type:</b> <jk>boolean</jk>
	* <li><b>System property:</b> <c>JsonSerializer.addBeanTypes</c>
	* <li><b>Environment variable:</b> <c>JSONSERIALIZER_ADDBEANTYPES</c>
	* <li><b>Default:</b> <jk>false</jk>
	* <li><b>Session property:</b> <jk>false</jk>
	* <li><b>Annotations:</b>
	* <ul>
	* <li class='ja'>{@link org.apache.juneau.json.annotation.JsonConfig#addBeanTypes()}
	* </ul>
	* <li><b>Methods:</b>
	* <ul>
	* <li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#addBeanTypes(boolean)}
	* </ul>
	* </ul>
	*
	* <h5 class='section'>Description:</h5>
	* <p>
	* If <jk>true</jk>, then <js>"_type"</js> properties will be added to beans if their type cannot be inferred
	* through reflection.
	*
	* <p>
	* When present, this value overrides the {@link #SERIALIZER_addBeanTypes} setting and is
	* provided to customize the behavior of specific serializers in a {@link SerializerGroup}.
	*/
	public static final String JSON_addBeanTypes = PREFIX + ".addBeanTypes.b";

	/**
	* Configuration property: Prefix solidus <js>'/'</js> characters with escapes.
	*
	* <h5 class='section'>Property:</h5>
	* <ul class='spaced-list'>
	* <li><b>ID:</b> {@link org.apache.juneau.json.JsonSerializer#JSON_escapeSolidus JSON_escapeSolidus}
	* <li><b>Name:</b> <js>"JsonSerializer.escapeSolidus.b"</js>
	* <li><b>Data type:</b> <jk>boolean</jk>
	* <li><b>System property:</b> <c>JsonSerializer.escapeSolidus</c>
	* <li><b>Environment variable:</b> <c>JSONSERIALIZER_ESCAPESOLIDUS</c>
	* <li><b>Default:</b> <jk>false</jk>
	* <li><b>Session property:</b> <jk>false</jk>
	* <li><b>Annotations:</b>
	* <ul>
	* <li class='ja'>{@link org.apache.juneau.json.annotation.JsonConfig#escapeSolidus()}
	* </ul>
	* <li><b>Methods:</b>
	* <ul>
	* <li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#escapeSolidus(boolean)}
	* <li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#escapeSolidus()}
	* </ul>
	* </ul>
	*
	* <h5 class='section'>Description:</h5>
	* <p>
	* If <jk>true</jk>, solidus (e.g. slash) characters should be escaped.
	* The JSON specification allows for either format.
	* <br>However, if you're embedding JSON in an HTML script tag, this setting prevents confusion when trying to serialize
	* <xt><\/script></xt>.
	*
	* <h5 class='section'>Example:</h5>
	* <p class='bcode w800'>
	* <jc>// Create a JSON serializer that escapes solidus characters.</jc>
	* WriterSerializer s = JsonSerializer
	* .<jsm>create</jsm>()
	* .simple()
	* .escapeSolidus()
	* .build();
	*
	* <jc>// Same, but use property.</jc>
	* WriterSerializer s = JsonSerializer
	* .<jsm>create</jsm>()
	* .simple()
	* .set(<jsf>JSON_escapeSolidus</jsf>, <jk>true</jk>)
	* .build();
	*
	* <jc>// Produces: "{foo:'<\/bar>'"</jc>
	* String json = s.serialize(<jk>new</jk> ObjectMap().append(<js>"foo"</js>, <js>"</bar>"</js>);
	* </p>
	*/
	public static final String JSON_escapeSolidus = PREFIX + ".escapeSolidus.b";

	/**
	* Configuration property: Simple JSON mode.
	*
	* <h5 class='section'>Property:</h5>
	* <ul class='spaced-list'>
	* <li><b>ID:</b> {@link org.apache.juneau.json.JsonSerializer#JSON_simpleMode JSON_simpleMode}
	* <li><b>Name:</b> <js>"JsonSerializer.simpleMode.b"</js>
	* <li><b>Data type:</b> <jk>boolean</jk>
	* <li><b>System property:</b> <c>JsonSerializer.simpleMode</c>
	* <li><b>Environment variable:</b> <c>JSONSERIALIZER_SIMPLEMODE</c>
	* <li><b>Default:</b> <jk>false</jk>
	* <li><b>Session property:</b> <jk>false</jk>
	* <li><b>Annotations:</b>
	* <ul>
	* <li class='ja'>{@link org.apache.juneau.json.annotation.JsonConfig#simpleMode()}
	* </ul>
	* <li><b>Methods:</b>
	* <ul>
	* <li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#simple(boolean)}
	* <li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#simple()}
	* <li class='jm'>{@link org.apache.juneau.json.JsonSerializerBuilder#ssq()}
	* </ul>
	* </ul>
	*
	* <h5 class='section'>Description:</h5>
	* <p>
	* If <jk>true</jk>, JSON attribute names will only be quoted when necessary.
	* <br>Otherwise, they are always quoted.
	*
	* <p>
	* Attributes do not need to be quoted when they conform to the following:
	* <ol class='spaced-list'>
	* <li>They start with an ASCII character or <js>'_'</js>.
	* <li>They contain only ASCII characters or numbers or <js>'_'</js>.
	* <li>They are not one of the following reserved words:
	* <p class='bcode w800'>
	* arguments, break, case, catch, class, const, continue, debugger, default,
	* delete, do, else, enum, eval, export, extends, false, finally, for, function,
	* if, implements, import, in, instanceof, interface, let, new, null, package,
	* private, protected, public, return, static, super, switch, this, throw,
	* true, try, typeof, var, void, while, with, undefined, yield
	* </p>
	* </ol>
	*
	* <h5 class='section'>Example:</h5>
	* <p class='bcode w800'>
	* <jc>// Create a JSON serializer in normal mode.</jc>
	* WriterSerializer s1 = JsonSerializer
	* .<jsm>create</jsm>()
	* .build();
	*
	* <jc>// Create a JSON serializer in simple mode.</jc>
	* WriterSerializer s2 = JsonSerializer
	* .<jsm>create</jsm>()
	* .simple()
	* .build();
	*
	* ObjectMap m = <jk>new</jk> ObjectMap()
	* .append(<js>"foo"</js>, <js>"x1"</js>)
	* .append(<js>"_bar"</js>, <js>"x2"</js>)
	* .append(<js>" baz "</js>, <js>"x3"</js>)
	* .append(<js>"123"</js>, <js>"x4"</js>)
	* .append(<js>"return"</js>, <js>"x5"</js>);
	* .append(<js>""</js>, <js>"x6"</js>);
	*
	* <jc>// Produces:</jc>
	* <jc>// {</jc>
	* <jc>// "foo": "x1"</jc>
	* <jc>// "_bar": "x2"</jc>
	* <jc>// " baz ": "x3"</jc>
	* <jc>// "123": "x4"</jc>
	* <jc>// "return": "x5"</jc>
	* <jc>// "": "x6"</jc>
	* <jc>// }</jc>
	* String json1 = s1.serialize(m);
	*
	* <jc>// Produces:</jc>
	* <jc>// {</jc>
	* <jc>// foo: "x1"</jc>
	* <jc>// _bar: "x2"</jc>
	* <jc>// " baz ": "x3"</jc>
	* <jc>// "123": "x4"</jc>
	* <jc>// "return": "x5"</jc>
	* <jc>// "": "x6"</jc>
	* <jc>// }</jc>
	* String json2 = s2.serialize(m);
	* </p>
	*/
	public static final String JSON_simpleMode = PREFIX + ".simpleMode.b";

	//-------------------------------------------------------------------------------------------------------------------
	// Predefined instances
	//-------------------------------------------------------------------------------------------------------------------

	/** Default serializer, all default settings.*/
	public static final JsonSerializer DEFAULT = new JsonSerializer(PropertyStore.DEFAULT);

	/** Default serializer, all default settings.*/
	public static final JsonSerializer DEFAULT_READABLE = new Readable(PropertyStore.DEFAULT);


	//-------------------------------------------------------------------------------------------------------------------
	// Predefined subclasses
	//-------------------------------------------------------------------------------------------------------------------

	/** Default serializer, with whitespace. */
	public static class Readable extends JsonSerializer {

	/**
	* Constructor.
	*
	* @param ps The property store containing all the settings for this object.
	*/
	public Readable(PropertyStore ps) {
	super(
	ps.builder().set(WSERIALIZER_useWhitespace, true).build()
	);
	}
	}

	/**
	* Default serializer, single quotes, simple mode, with whitespace and recursion detection.
	* Note that recursion detection introduces a small performance penalty.
	*/
	public static class ReadableSafe extends JsonSerializer {

	/**
	* Constructor.
	*
	* @param ps The property store containing all the settings for this object.
	*/
	public ReadableSafe(PropertyStore ps) {
	super(
	ps.builder()
	.set(JSON_simpleMode, true)
	.set(WSERIALIZER_quoteChar, '\'')
	.set(WSERIALIZER_useWhitespace, true)
	.set(BEANTRAVERSE_detectRecursions, true)
	.build()
	);
	}
	}


	//-------------------------------------------------------------------------------------------------------------------
	// Instance
	//-------------------------------------------------------------------------------------------------------------------

	private final boolean
	simpleMode,
	escapeSolidus,
	addBeanTypes;
	private final Map<ClassMeta<?>,JsonClassMeta> jsonClassMetas = new ConcurrentHashMap<>();
	private final Map<BeanPropertyMeta,JsonBeanPropertyMeta> jsonBeanPropertyMetas = new ConcurrentHashMap<>();

	private volatile JsonSchemaSerializer schemaSerializer;

	/**
	* Constructor.
	*
	* @param ps
	* The property store containing all the settings for this object.
	*/
	public JsonSerializer(PropertyStore ps) {
	this(ps, "application/json", "application/json,text/json");
	}

	/**
	* Constructor.
	*
	* @param ps
	* The property store containing all the settings for this object.
	* @param produces
	* The media type that this serializer produces.
	* @param accept
	* The accept media types that the serializer can handle.
	* <p>
	* Can contain meta-characters per the <c>media-type</c> specification of {@doc RFC2616.section14.1}
	* <p>
	* If empty, then assumes the only media type supported is <c>produces</c>.
	* <p>
	* For example, if this serializer produces <js>"application/json"</js> but should handle media types of
	* <js>"application/json"</js> and <js>"text/json"</js>, then the arguments should be:
	* <p class='bcode w800'>
	* <jk>super</jk>(ps, <js>"application/json"</js>, <js>"application/json,text/json"</js>);
	* </p>
	* <br>...or...
	* <p class='bcode w800'>
	* <jk>super</jk>(ps, <js>"application/json"</js>, <js>"*/json"</js>);
	* </p>
	* <p>
	* The accept value can also contain q-values.
	*/
	public JsonSerializer(PropertyStore ps, String produces, String accept) {
	super(ps, produces, accept);

	simpleMode = getBooleanProperty(JSON_simpleMode, false);
	escapeSolidus = getBooleanProperty(JSON_escapeSolidus, false);
	addBeanTypes = getBooleanProperty(JSON_addBeanTypes, getBooleanProperty(SERIALIZER_addBeanTypes, false));
	}

	@Override /* Context */
	public JsonSerializerBuilder builder() {
	return new JsonSerializerBuilder(getPropertyStore());
	}

	/**
	* Instantiates a new clean-slate {@link JsonSerializerBuilder} object.
	*
	* <p>
	* This is equivalent to simply calling <code><jk>new</jk> JsonSerializerBuilder()</code>.
	*
	* @return A new {@link JsonSerializerBuilder} object.
	*/
	public static JsonSerializerBuilder create() {
	return new JsonSerializerBuilder();
	}

	/**
	* Returns the schema serializer based on the settings of this serializer.
	*
	* <p>
	* Note that this method creates a builder initialized to all default settings, whereas {@link #builder()} copies
	* the settings of the object called on.
	*
	* @return The schema serializer.
	*/
	public JsonSchemaSerializer getSchemaSerializer() {
	if (schemaSerializer == null)
	schemaSerializer = builder().build(JsonSchemaSerializer.class);
	return schemaSerializer;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Entry point methods
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* Context */
	public JsonSerializerSession createSession() {
	return createSession(createDefaultSessionArgs());
	}

	@Override /* Serializer */
	public JsonSerializerSession createSession(SerializerSessionArgs args) {
	return new JsonSerializerSession(this, args);
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Extended metadata
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* JsonMetaProvider */
	public JsonClassMeta getJsonClassMeta(ClassMeta<?> cm) {
	JsonClassMeta m = jsonClassMetas.get(cm);
	if (m == null) {
	m = new JsonClassMeta(cm, this);
	jsonClassMetas.put(cm, m);
	}
	return m;
	}

	@Override /* JsonMetaProvider */
	public JsonBeanPropertyMeta getJsonBeanPropertyMeta(BeanPropertyMeta bpm) {
	if (bpm == null)
	return JsonBeanPropertyMeta.DEFAULT;
	JsonBeanPropertyMeta m = jsonBeanPropertyMetas.get(bpm);
	if (m == null) {
	m = new JsonBeanPropertyMeta(bpm.getDelegateFor(), this);
	jsonBeanPropertyMetas.put(bpm, m);
	}
	return m;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Properties
	//-----------------------------------------------------------------------------------------------------------------

	/**
	* Configuration property: Add <js>"_type"</js> properties when needed.
	*
	* @see #JSON_addBeanTypes
	* @return
	* <jk>true</jk> if <js>"_type"</js> properties will be added to beans if their type cannot be inferred
	* through reflection.
	*/
	@Override
	protected final boolean isAddBeanTypes() {
	return addBeanTypes;
	}

	/**
	* Configuration property: Prefix solidus <js>'/'</js> characters with escapes.
	*
	* @see #JSON_escapeSolidus
	* @return
	* <jk>true</jk> if solidus (e.g. slash) characters should be escaped.
	*/
	protected final boolean isEscapeSolidus() {
	return escapeSolidus;
	}

	/**
	* Configuration property: Simple JSON mode.
	*
	* @see #JSON_simpleMode
	* @return
	* <jk>true</jk> if JSON attribute names will only be quoted when necessary.
	* <br>Otherwise, they are always quoted.
	*/
	protected final boolean isSimpleMode() {
	return simpleMode;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Other methods
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* Context */
	public ObjectMap toMap() {
	return super.toMap()
	.append("JsonSerializer", new DefaultFilteringObjectMap()
	.append("simpleMode", simpleMode)
	.append("escapeSolidus", escapeSolidus)
	.append("addBeanTypes", addBeanTypes)
	);
	}
	}