jakarta.json

Interface JsonReader

All Superinterfaces:

AutoCloseable, Closeable

public interface JsonReader
extends Closeable

Reads a JSON object or an array structure from an input source.

The class Json contains methods to create readers from input sources (InputStream and Reader).

The following example demonstrates how to read an empty JSON array from a string:

 
 JsonReader jsonReader = Json.createReader(new StringReader("[]"));
 JsonArray array = jsonReader.readArray();
 jsonReader.close();
 
 

The class JsonReaderFactory also contains methods to create JsonReader instances. A factory instance can be used to create multiple reader instances with the same configuration. This the preferred way to create multiple instances. A sample usage is shown in the following example:

 
 JsonReaderFactory factory = Json.createReaderFactory(config);
 JsonReader reader1 = factory.createReader(...);
 JsonReader reader2 = factory.createReader(...);
 
 

Method Summary

Modifier and Type	Method and Description
void	close() Closes this reader and frees any resources associated with the reader.
JsonStructure	read() Returns a JSON array or object that is represented in the input source.
JsonArray	readArray() Returns a JSON array that is represented in the input source.
JsonObject	readObject() Returns a JSON object that is represented in the input source.
default JsonValue	readValue() Returns a JSON value that is represented in the input source.

Method Detail

read

JsonStructure read()

Returns a JSON array or object that is represented in the input source. This method needs to be called only once for a reader instance.

Returns:

a JSON object or array

Throws:

JsonException - if a JSON object or array cannot be created due to i/o error (IOException would be cause of JsonException)

JsonParsingException - if a JSON object or array cannot be created due to incorrect representation

IllegalStateException - if read, readObject, readArray, readValue or close method is already called

readObject

JsonObject readObject()

Returns a JSON object that is represented in the input source. This method needs to be called only once for a reader instance.

Returns:

a JSON object

Throws:

JsonException - if a JSON object cannot be created due to i/o error (IOException would be cause of JsonException)

JsonParsingException - if a JSON object cannot be created due to incorrect representation

IllegalStateException - if read, readObject, readArray, readValue or close method is already called

readArray

JsonArray readArray()

Returns a JSON array that is represented in the input source. This method needs to be called only once for a reader instance.

Returns:

a JSON array

Throws:

JsonException - if a JSON array cannot be created due to i/o error (IOException would be cause of JsonException)

JsonParsingException - if a JSON array cannot be created due to incorrect representation

IllegalStateException - if read, readObject, readArray, readValue or close method is already called

readValue

default JsonValue readValue()

Returns a JSON value that is represented in the input source. This method needs to be called only once for a reader instance.

Returns:

a JSON value

Throws:

JsonException - if a JSON value be created due to i/o error (IOException would be cause of JsonException)

JsonParsingException - if a JSON value cannot be created due to incorrect representation

IllegalStateException - if read, readObject, readArray, readValue or close method is already called

Since:

1.1

close

void close()

Closes this reader and frees any resources associated with the reader. This method closes the underlying input source.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

JsonException - if an i/o error occurs (IOException would be cause of JsonException)