jakarta.json.stream.JsonGenerator Maven / Gradle / Ivy
/*
* 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();
}