Package eu.woolplatform.utils.json

Class JsonObjectStreamReader

java.lang.Object

eu.woolplatform.utils.json.JsonObjectStreamReader

All Implemented Interfaces:

Closeable, AutoCloseable

public class JsonObjectStreamReader
extends Object
implements Closeable

This class can read JSON values and tokens from a stream. This is a higher-level interface built upon JsonStreamReader, which returns atomic tokens. There are read methods that you can call when you expect a specific type of value (for example a string or an integer) or token (for example START_LIST). Each method validates and consumes the relevant tokens.

Constructor Summary

Constructors

Constructor	Description
JsonObjectStreamReader(JsonStreamReader reader)	Constructs a new JSON object stream reader.
JsonObjectStreamReader(InputStream input)	Constructs a new JSON object stream reader.
JsonObjectStreamReader(Reader reader)	Constructs a new JSON object stream reader.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this reader and the underlying reader.
int	getDocumentLine()	Returns the current line number in the document.
int	getDocumentLinePos()	Returns the current character number in the current line in the document.
JsonAtomicToken	getToken()	Returns the current token.
int	getTokenStartLine()	Returns the line number in the document where the current token starts.
int	getTokenStartLinePos()	Returns the character number in the line in the document where the current token starts.
boolean	readBoolean()	Reads a boolean value.
byte	readByte()	Reads a byte value.
double	readDouble()	Reads a number token and returns its double value.
float	readFloat()	Reads a number token and returns its float value.
int	readInt()	Reads an integer value.
List<?>	readList()	Reads a list value.
long	readLong()	Reads a long value.
Map<String,?>	readObject()	Reads an object value.
short	readShort()	Reads a short value.
String	readString()	Reads a string value (not null).
JsonAtomicToken	readToken()	Reads the next token.
JsonAtomicToken	readToken(JsonAtomicToken.Type type)	Reads the next token and validates that it has the specified type.
Object	readValue()	Reads a JSON value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JsonObjectStreamReader

public JsonObjectStreamReader(InputStream input)

Constructs a new JSON object stream reader. It reads UTF-8 characters from the specified input stream.

Parameters:

input - the input stream

JsonObjectStreamReader

public JsonObjectStreamReader(Reader reader)

Constructs a new JSON object stream reader.

Parameters:

reader - the underlying reader

JsonObjectStreamReader

public JsonObjectStreamReader(JsonStreamReader reader)

Constructs a new JSON object stream reader.

Parameters:

reader - the underlying reader

Method Detail

close

public void close()
           throws IOException

Closes this reader and the underlying reader.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException - if the underlying reader can't be closed

getDocumentLine

public int getDocumentLine()

Returns the current line number in the document. The first line is 1. If the reader is positioned at a token, then the document position is at the end of that token.

Returns:

the current line number

getDocumentLinePos

public int getDocumentLinePos()

Returns the current character number in the current line in the document. The first character is 1. If the reader is positioned at a token, then the document position is at the end of that token.

Returns:

the current character number

getTokenStartLine

public int getTokenStartLine()

Returns the line number in the document where the current token starts. The first line is 1. If the reader is before the first token, then this method returns 1. If the reader is after the last token, then this method return the line at the end of the document.

Returns:

the line number where the current token starts

getTokenStartLinePos

public int getTokenStartLinePos()

Returns the character number in the line in the document where the current token starts. The first character is 1. If the reader is before the first token, then this method returns 1. If the reader is after the last token, then this method return the line at the end of the document.

Returns:

the character number where the current token starts

getToken

public JsonAtomicToken getToken()
                         throws JsonParseException,
                                IOException

Returns the current token. If the reader is at the end of the document, this method returns null.

Returns:

the current token

Throws:

JsonParseException - if the JSON content is invalid

IOException - if a reading error occurs

readToken

public JsonAtomicToken readToken()
                          throws JsonParseException,
                                 IOException

Reads the next token. After this method the reader will be positioned after the returned token. If there are no more tokens, this method returns null.

Returns:

the token or null

Throws:

JsonParseException - if the JSON content is invalid

IOException - if a reading error occurs

readToken

public JsonAtomicToken readToken(JsonAtomicToken.Type type)
                          throws JsonParseException,
                                 IOException

Reads the next token and validates that it has the specified type. If this method succeeds, the reader will be positioned after the returned token. Otherwise it will remain at the current position.

Parameters:

type - the token type

Returns:

the token with the specified type

Throws:

JsonParseException - if the JSON content is invalid, there is no more token, or the next token has a different type

IOException - if a reading error occurs

readString

public String readString()
                  throws JsonParseException,
                         IOException

Reads a string value (not null). If this method succeeds, the reader will be positioned after the string.

Returns:

the string (not null)

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a string

IOException - if a reading error occurs

readByte

public byte readByte()
              throws JsonParseException,
                     IOException

Reads a byte value. This method validates whether the reader is positioned at a number token and its value is a byte. If this method succeeds, the reader will be positioned after the byte value.

Returns:

the byte value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a byte value

IOException - if a reading error occurs

readShort

public short readShort()
                throws JsonParseException,
                       IOException

Reads a short value. This method validates whether the reader is positioned at a number token and its value is a short. If this method succeeds, the reader will be positioned after the short value.

Returns:

the short value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a short value

IOException - if a reading error occurs

readInt

public int readInt()
            throws JsonParseException,
                   IOException

Reads an integer value. This method validates whether the reader is positioned at a number token and its value is an integer. If this method succeeds, the reader will be positioned after the integer.

Returns:

the integer value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of an integer

IOException - if a reading error occurs

readLong

public long readLong()
              throws JsonParseException,
                     IOException

Reads a long value. This method validates whether the reader is positioned at a number token and its value is a long. If this method succeeds, the reader will be positioned after the long value.

Returns:

the long value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a long value

IOException - if a reading error occurs

readFloat

public float readFloat()
                throws JsonParseException,
                       IOException

Reads a number token and returns its float value. If this method succeeds, the reader will be positioned after the number.

Returns:

the float value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a number

IOException - if a reading error occurs

readDouble

public double readDouble()
                  throws JsonParseException,
                         IOException

Reads a number token and returns its double value. If this method succeeds, the reader will be positioned after the number.

Returns:

the double value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a number

IOException - if a reading error occurs

readBoolean

public boolean readBoolean()
                    throws JsonParseException,
                           IOException

Reads a boolean value. If this method succeeds, the reader will be positioned after the boolean value.

Returns:

the boolean value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a boolean value

IOException - if a reading error occurs

readObject

public Map<String,?> readObject()
                               throws JsonParseException,
                                      IOException

Reads an object value. If this method succeeds, the reader will be positioned after the object value.

Returns:

the object value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of an object value

IOException - if a reading error occurs

readList

public List<?> readList()
                 throws JsonParseException,
                        IOException

Reads a list value. If this method succeeds, the reader will be positioned after the list value.

Returns:

the list value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a list value

IOException - if a reading error occurs

readValue

public Object readValue()
                 throws JsonParseException,
                        IOException

Reads a JSON value. If this method succeeds, the reader will be positioned after the value. It returns one of the following types:

• String
• Integer
• Long
• Double
• Boolean
• Map
• List
• null

Returns:

the value

Throws:

JsonParseException - if the JSON content is invalid or the reader is not positioned at the start of a value

IOException - if a reading error occurs