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/*
 * Copyright (c) 2011, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package jakarta.json.stream;

import jakarta.json.JsonValue;
import java.io.Closeable;
import java.io.Flushable;
import java.math.BigDecimal;
import java.math.BigInteger;

/**
 * Writes JSON data to an output source in a streaming way. The class {@link jakarta.json.Json}
 * contains methods to create generators for character or output streams ({@link java.io.Writer} and
 * {@link java.io.OutputStream}).
 *
 * 

The following example shows how to create a JSON generator: * *

 * 
 * JsonGenerator generator = Json.createGenerator(...);
 * 
 * 
* *

The class {@link JsonGeneratorFactory} also contains methods to create {@code JsonGenerator} * instances. {@link JsonGeneratorFactory} should be used when creating multiple generator * instances, as in the following example: * *

 * 
 * JsonGeneratorFactory factory = Json.createGeneratorFactory();
 * JsonGenerator generator1 = factory.createGenerator(...);
 * JsonGenerator generator2 = factory.createGenerator(...);
 * 
 * 
* *

JSON objects can be created using {@code JsonGenerator} by calling the {@link * #writeStartObject()} method and then adding name/value pairs with the {@code write} method. * *

The following example shows how to generate an empty JSON object: * *

 * 
 * JsonGenerator generator = ...;
 * generator.writeStartObject().writeEnd().close();
 * 
 * 
* * JSON arrays can be created using {@code JsonGenerator} by calling the {@link #writeStartArray()} * method and then adding values with the {@code write} method. * *

The following example shows how to generate an empty JSON array: * *

 * 
 * JsonGenerator generator = ...;
 * generator.writeStartArray().writeEnd().close();
 * 
 * 
* *

Other JSON values (that are not JSON objects or arrays) can be created by calling the * appropiate {@code write} methods. * *

The following example shows how to generate a JSON string: * *


 * JsonGenerator generator = ...;
 * generator.write("message").close();
 * 
* * {@code JsonGenerator} methods can be chained as in the following example: * *
 * 
 * generator
 *     .writeStartObject()
 *         .write("firstName", "John")
 *         .write("lastName", "Smith")
 *         .write("age", 25)
 *         .writeStartObject("address")
 *             .write("streetAddress", "21 2nd Street")
 *             .write("city", "New York")
 *             .write("state", "NY")
 *             .write("postalCode", "10021")
 *         .writeEnd()
 *         .writeStartArray("phoneNumber")
 *             .writeStartObject()
 *  *                 .write("type", "home")
 *  *                 .write("number", "212 555-1234")
 *  *             .writeEnd()
 *             .writeStartObject()
 *                 .write("type", "fax")
 *                 .write("number", "646 555-4567")
 *             .writeEnd()
 *         .writeEnd()
 *     .writeEnd();
 * generator.close();
 * 
 * 
* * The example code above generates the following JSON (or equivalent): * *
 * 
 * {
 *   "firstName": "John", "lastName": "Smith", "age": 25,
 *   "address" : {
 *       "streetAddress": "21 2nd Street",
 *       "city": "New York",
 *       "state": "NY",
 *       "postalCode": "10021"
 *   },
 *   "phoneNumber": [
 *       {"type": "home", "number": "212 555-1234"},
 *       {"type": "fax", "number": "646 555-4567"}
 *    ]
 * }
 * 
 * 
* * The generated JSON text must strictly conform to the grammar defined in RFC 7159. * * @see jakarta.json.Json * @see JsonGeneratorFactory */ public interface JsonGenerator extends Flushable, /*Auto*/ Closeable { /** * Configuration property to generate JSON prettily. All providers must support this property. The * value of the property could be be anything. */ String PRETTY_PRINTING = "jakarta.json.stream.JsonGenerator.prettyPrinting"; /** * Writes the JSON start object character. It starts a new child object context within which JSON * name/value pairs can be written to the object. This method is valid only in an array context, * field context or in no context (when a context is not yet started). This method can only be * called once in no context. * * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is called within an object context or if it is * called more than once in no context. */ JsonGenerator writeStartObject(); /** * Writes the JSON name/start object character pair in the current object context. It starts a new * child object context within which JSON name/value pairs can be written to the object. * * @param name a name within the JSON name/object pair to be written * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context */ JsonGenerator writeStartObject(String name); /** * Writes the JSON name with a colon. It starts a field context, in which valid options are * writing a value, starting an object or an array. * *

Writing value closes field context, if object or array is started after field name, field * context will be closed after object/array close. * * @param name name of json field * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context * @since 1.1 */ JsonGenerator writeKey(String name); /** * Writes the JSON start array character. It starts a new child array context within which JSON * values can be written to the array. This method is valid only in an array context, field * context or in no context (when a context is not yet started). This method can only be called * once in no context. * * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is called within an object context or if called * more than once in no context */ JsonGenerator writeStartArray(); /** * Writes the JSON name/start array character pair with in the current object context. It starts a * new child array context within which JSON values can be written to the array. * * @param name a name within the JSON name/array pair to be written * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context */ JsonGenerator writeStartArray(String name); /** * Writes a JSON name/value pair in the current object context. * * @param name a name in the JSON name/value pair to be written in current JSON object * @param value a value in the JSON name/value pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context */ JsonGenerator write(String name, JsonValue value); /** * Writes a JSON name/string value pair in the current object context. The specified value is * written as JSON string value. * * @param name a name in the JSON name/string pair to be written in current JSON object * @param value a value in the JSON name/string pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context */ JsonGenerator write(String name, String value); /** * Writes a JSON name/number value pair in the current object context. The specified value is * written as a JSON number value. The string {@code new BigDecimal(value).toString()} is used as * the text value for writing. * * @param name a name in the JSON name/number pair to be written in current JSON object * @param value a value in the JSON name/number pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context. */ JsonGenerator write(String name, BigInteger value); /** * Writes a JSON name/number value pair in the current object context. The specified value is * written as a JSON number value. The specified value's {@code toString()} is used as the text * value for writing. * * @param name a name in the JSON name/number pair to be written in current JSON object * @param value a value in the JSON name/number pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context. */ JsonGenerator write(String name, BigDecimal value); /** * Writes a JSON name/number value pair in the current object context. The specified value is * written as a JSON number value. The string {@code new BigDecimal(value).toString()} is used as * the text value for writing. * * @param name a name in the JSON name/number pair to be written in current JSON object * @param value a value in the JSON name/number pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context. */ JsonGenerator write(String name, int value); /** * Writes a JSON name/number value pair in the current object context. The specified value is * written as a JSON number value. The string {@code new BigDecimal(value).toString()} is used as * the text value for writing. * * @param name a name in the JSON name/number pair to be written in current JSON object * @param value a value in the JSON name/number pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context. */ JsonGenerator write(String name, long value); /** * Writes a JSON name/number value pair in the current object context. The specified value is * written as a JSON number value. The string {@code BigDecimal.valueOf(double).toString()} is * used as the text value for writing. * * @param name a name in the JSON name/number pair to be written in current JSON object * @param value a value in the JSON name/number pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws NumberFormatException if the value is Not-a-Number (NaN) or infinity. * @throws JsonGenerationException if this method is not called within an object context */ JsonGenerator write(String name, double value); /** * Writes a JSON name/boolean value pair in the current object context. If value is true, it * writes the JSON {@code true} value, otherwise it writes the JSON {@code false} value. * * @param name a name in the JSON name/boolean pair to be written in current JSON object * @param value a value in the JSON name/boolean pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context. */ JsonGenerator write(String name, boolean value); /** * Writes a JSON name/null value pair in an current object context. * * @param name a name in the JSON name/null pair to be written in current JSON object * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an object context */ JsonGenerator writeNull(String name); /** * Writes the end of the current context. If the current context is an array context, this method * writes the end-of-array character (']'). If the current context is an object context, this * method writes the end-of-object character ('}'). After writing the end of the current context, * the parent context becomes the new current context. If parent context is field context, it is * closed. * * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is called in no context. */ JsonGenerator writeEnd(); /** * Writes the specified value as a JSON value within the current array, field or root context. * * @param value a value to be written in current JSON array * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. */ JsonGenerator write(JsonValue value); /** * Writes the specified value as a JSON string value within the current array, field or root * context. * * @param value a value to be written in current JSON array * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. */ JsonGenerator write(String value); /** * Writes the specified value as a JSON number value within the current array, field or root * context. The specified value's {@code toString()} is used as the the text value for writing. * * @param value a value to be written in current JSON array * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. * @see jakarta.json.JsonNumber */ JsonGenerator write(BigDecimal value); /** * Writes the specified value as a JSON number value within the current array, field or root * context. The string {@code new BigDecimal(value).toString()} is used as the text value for * writing. * * @param value a value to be written in current JSON array * @return this generator. * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. * @see jakarta.json.JsonNumber */ JsonGenerator write(BigInteger value); /** * Writes the specified value as a JSON number value within the current array, field or root * context. The string {@code new BigDecimal(value).toString()} is used as the text value for * writing. * * @param value a value to be written in current JSON array * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. */ JsonGenerator write(int value); /** * Writes the specified value as a JSON number value within the current array, field or root * context. The string {@code new BigDecimal(value).toString()} is used as the text value for * writing. * * @param value a value to be written in current JSON array * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. */ JsonGenerator write(long value); /** * Writes the specified value as a JSON number value within the current array, field or root * context. The string {@code BigDecimal.valueOf(value).toString()} is used as the text value for * writing. * * @param value a value to be written in current JSON array * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. * @throws NumberFormatException if the value is Not-a-Number (NaN) or infinity. */ JsonGenerator write(double value); /** * Writes a JSON true or false value within the current array, field or root context. If value is * true, this method writes the JSON {@code true} value, otherwise it writes the JSON {@code * false} value. * * @param value a {@code boolean} value * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. */ JsonGenerator write(boolean value); /** * Writes a JSON null value within the current array, field or root context. * * @return this generator * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if this method is not called within an array or root context. */ JsonGenerator writeNull(); /** * Closes this generator and frees any resources associated with it. This method closes the * underlying output source. * * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) * @throws JsonGenerationException if an incomplete JSON is generated */ @Override void close(); /** * Flushes the underlying output source. If the generator has saved any characters in a buffer, * writes them immediately to the underlying output source before flushing it. * * @throws jakarta.json.JsonException if an i/o error occurs (IOException would be cause of * JsonException) */ @Override void flush(); }





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