Package com.storedobject.common

Class JSON

java.lang.Object

com.storedobject.common.JSON

Direct Known Subclasses:

JSON

public class JSON
extends Object

A simple wrapper around JSON processing classes. Developers can rely on this class rather than delving into the underlying implementation. The underlying implementation may change in the future.

Author:

Syam

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	JSON.Type	Type of JSON values.

Constructor Summary

Constructors

Constructor	Description
JSON()	Construct an empty JSON.
JSON(Object object)	Construct a JSON instance from an Object that could hopefully parse into a JSON compatible String.

Method Summary

Modifier and Type	Method	Description
boolean	containsKey(String key)	Check if this contains the given key or not.
static JSON	create()	Create a blank JSON.
static JSON	create(Object object)	Construct a JSON instance from an Object that could hopefully parse into a JSON compatible String.
static String	encode(String s)	Encode a String to replace escape double-quotes so that it can be stuffed into as a part of JSON string.
static JSON	fromJSS(String jss)	Create JSON from JSS (JavaScript Structure).
JSON	get(int n)	Get the value at position 'n' assuming that this is an array.
JSON	get(String key)	Get the value for the given key.
JSON	get(String key, int n)	Retrieve the value for the given key and get the value from the given position from that value, assuming that value is an array type.
int	getArraySize()	Get the array size.
Boolean	getBoolean()	Get this as a Boolean value.
Boolean	getBoolean(String key)	Get the value for the given key as a Boolean.
Boolean	getBoolean(String key, int n)	Retrieve the value for the given key and get the value from the given position as a Boolean from that value, assuming that value is an array type.
BigDecimal	getDecimal()	Get this as a BigDecimal value.
BigDecimal	getDecimal(String key)	Get the value for the given key as a BigDecimal.
BigDecimal	getDecimal(String key, int n)	Retrieve the value for the given key and get the value from the given position as a BigDecimal from that value, assuming that value is an array type.
Number	getNumber()	Get this as a Number.
Number	getNumber(String key)	Get the value for the given key as a Number.
Number	getNumber(String key, int n)	Retrieve the value for the given key and get the value from the given position as a Number from that value, assuming that value is an array type.
String	getString()	Get this as a String.
String	getString(String key)	Get the value for the given key as a String.
String	getString(String key, int n)	Retrieve the value for the given key and get the value from the given position as a String from that value, assuming that value is an array type.
JSON.Type	getType()	Get the JSON.Type of the JSON.
boolean	isNull()	Check whether the value is null or not.
List<String>	keys()	Get the top-level keys.
static String	parseJSS(String jss)	Parse a JSS (JavaScript Structure) string to a JSON compatible string.
static void	prettyWrite(Map<String,Object> map, Writer writer)	Convert a map to formatted JSON representation and write to a given Writer.
void	set(Object object)	Set JSON from an Object that could hopefully parse into a JSON compatible String.
Map<String,Object>	toMap()	Return the JSON as a Map of key/value pairs.
String	toPrettyString()	Return the JSON as a formatted (more human-readable) String.
static String	toPrettyString(Map<String,Object> map)	Convert a map to formatted JSON representation.
String	toString()	Return the JSON as a String.
static String	toString(Map<String,Object> map)	Convert a map to JSON representation.
static void	write(Map<String,Object> map, Writer writer)	Convert a map to JSON representation and write to a given Writer.

Methods inherited from class java.lang.Object

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

Constructor Details

JSON

public JSON()

Construct an empty JSON.

JSON

public JSON(Object object)

Construct a JSON instance from an Object that could hopefully parse into a JSON compatible String. Typically, it could be a Map or some sort of array or collection. It could also be a standalone object that can be converted to a valid JSON string. Otherwise, the following types are handled as special cases: (1) A JsonNode instance - directly set internally, (2) Another JSON instance - directly set internally, (3) An InputStream instance - expects a string value from the stream, (4) An instance of a Reader - expects a string value from it, (5) A URL instance - content of the URL is read and processed.

Parameters:

object - JSON to construct from this Object.

Method Details

create

public static JSON create()

Create a blank JSON.

Returns:

Empty JSON.

create

public static JSON create(Object object)

Construct a JSON instance from an Object that could hopefully parse into a JSON compatible String. Typically, it could be a Map or some sort of array or collection. It could also be a standalone object that can be converted to a valid JSON string. Otherwise, the following types are handled as special cases: (1) A JsonNode instance - directly set internally, (2) Another JSON instance - directly set internally, (3) An InputStream instance - expects a string value from the stream, (4) An instance of a Reader - expects a string value from it, (5) A URL instance - content of the URL is read and processed.

Parameters:

object - JSON to construct from this Object.

set

public void set(Object object)

Set JSON from an Object that could hopefully parse into a JSON compatible String. Typically, it could be a Map or some sort of array or collection. It could also be a standalone object that can be converted to a valid JSON string. Otherwise, the following types are handled as special cases: (1) A JsonNode instance - directly set internally, (2) Another JSON instance - directly set internally, (3) An InputStream instance - expects a string value from the stream, (4) An instance of a Reader - expects a string value from it, (5) A URL instance - content of the URL is read and processed.

Parameters:

object - JSON to construct from this Object.

keys

public List<String> keys()

Get the top-level keys.

Returns:

Keys as a List.

getType

public JSON.Type getType()

Get the JSON.Type of the JSON.

Returns:

Type.

getString

public String getString()

Get this as a String. If value is null or if the JSON.Type is different, null will be returned.

Returns:

The value.

getNumber

public Number getNumber()

Get this as a Number. If value is null or if the JSON.Type is different, null will be returned.

Returns:

The value.

getDecimal

public BigDecimal getDecimal()

Get this as a BigDecimal value. If value is null or if the JSON.Type is different, null will be returned.

Returns:

The value.

getBoolean

public Boolean getBoolean()

Get this as a Boolean value. If value is null or if the JSON.Type is different, null will be returned.

Returns:

The value.

getArraySize

public int getArraySize()

Get the array size. (If the JSON.Type is not an array or if it is null, 0 is returned).

Returns:

Size of the array.

get

public JSON get(int n)

Get the value at position 'n' assuming that this is an array. Null will be returned if this is null, not an array or position is outside the range.

Parameters:

n - Position.

Returns:

Value at the position.

get

public JSON get(String key)

Get the value for the given key. Null will be returned if this is null, key is null or no value exists for the given key.

Parameters:

key - Key.

Returns:

Value for the key.

containsKey

public boolean containsKey(String key)

Check if this contains the given key or not.

Parameters:

key - Key.

Returns:

True or false.

getString

public String getString(String key)

Get the value for the given key as a String. Null will be returned if this is null, key is null, no value exists for the given key or the value type is not matching.

Parameters:

key - Key.

Returns:

Value for the key.

getNumber

public Number getNumber(String key)

Get the value for the given key as a Number. Null will be returned if this is null, key is null, no value exists for the given key or the value type is not matching.

Parameters:

key - Key.

Returns:

Value for the key.

getDecimal

public BigDecimal getDecimal(String key)

Get the value for the given key as a BigDecimal. Null will be returned if this is null, key is null, no value exists for the given key or the value type is not matching.

Parameters:

key - Key.

Returns:

Value for the key.

getBoolean

public Boolean getBoolean(String key)

Get the value for the given key as a Boolean. Null will be returned if this is null, key is null, no value exists for the given key or the value type is not matching.

Parameters:

key - Key.

Returns:

Value for the key.

get

public JSON get(String key,
 int n)

Retrieve the value for the given key and get the value from the given position from that value, assuming that value is an array type. Null will be returned if this is null, key is null, no value exists for the given key, the value type is not an array or nothing found at the given position.

Parameters:

key - Key.

n - Position.

Returns:

Value for the key.

getString

public String getString(String key,
 int n)

Retrieve the value for the given key and get the value from the given position as a String from that value, assuming that value is an array type. Null will be returned if this is null, key is null, no value exists for the given key, the value type is not an array, nothing found at the given position or the value type at the position is not matching.

Parameters:

key - Key.

n - Position.

Returns:

Value for the key.

getNumber

public Number getNumber(String key,
 int n)

Retrieve the value for the given key and get the value from the given position as a Number from that value, assuming that value is an array type. Null will be returned if this is null, key is null, no value exists for the given key, the value type is not an array, nothing found at the given position or the value type at the position is not matching.

Parameters:

key - Key.

n - Position.

Returns:

Value for the key.

getDecimal

public BigDecimal getDecimal(String key,
 int n)

Retrieve the value for the given key and get the value from the given position as a BigDecimal from that value, assuming that value is an array type. Null will be returned if this is null, key is null, no value exists for the given key, the value type is not an array, nothing found at the given position or the value type at the position is not matching.

Parameters:

key - Key.

n - Position.

Returns:

Value for the key.

getBoolean

public Boolean getBoolean(String key,
 int n)

Retrieve the value for the given key and get the value from the given position as a Boolean from that value, assuming that value is an array type. Null will be returned if this is null, key is null, no value exists for the given key, the value type is not an array, nothing found at the given position or the value type at the position is not matching.

Parameters:

key - Key.

n - Position.

Returns:

Value for the key.

isNull

public boolean isNull()

Check whether the value is null or not.

Returns:

True/false.

toMap

public Map<String,Object> toMap()

Return the JSON as a Map of key/value pairs.

Returns:

Map of key/value pairs.

toString

public String toString()

Return the JSON as a String.

Overrides:

toString in class Object

Returns:

String representation.

toPrettyString

public String toPrettyString()

Return the JSON as a formatted (more human-readable) String.

Returns:

String representation.

encode

public static String encode(String s)

Encode a String to replace escape double-quotes so that it can be stuffed into as a part of JSON string.

Parameters:

s - String to encode.

Returns:

Encoded String.

toString

public static String toString(Map<String,Object> map)

Convert a map to JSON representation.

Parameters:

map - Map to convert.

Returns:

String in JSON representation.

toPrettyString

public static String toPrettyString(Map<String,Object> map)

Convert a map to formatted JSON representation.

Parameters:

map - Map to convert.

Returns:

String in JSON representation.

write

public static void write(Map<String,Object> map,
 Writer writer)
                  throws IOException

Convert a map to JSON representation and write to a given Writer.

Parameters:

map - Map to convert.

writer - Writer to write to.

Throws:

IOException - If writing fails.

prettyWrite

public static void prettyWrite(Map<String,Object> map,
 Writer writer)
                        throws IOException

Convert a map to formatted JSON representation and write to a given Writer.

Parameters:

map - Map to convert.

writer - Writer to write to.

Throws:

IOException - If writing fails.

fromJSS

public static JSON fromJSS(String jss)

Create JSON from JSS (JavaScript Structure). A JavaScript structure looks similar to JSON string with some differences: (a) Keys are not in double-quotes, (b) String values may use single-quotes or double-quotes, (c) Extraneous commas may be there after the last items. This method (a) inserts double-quotes around the keys, (b) replaces single-quotes with double-quotes and (c) removes extraneous commas. For escaping literal single-quotes or double-quotes, you should use a '\' character (backslash) just before it. In fact, any character following the backslash character will be copied to the output without any special processing. Example of a JSS is: { person: { name: 'Syam Pillai', age: 25 } }

Parameters:

jss - JSS string.

Returns:

JSON created from the parsed JSS.

parseJSS

public static String parseJSS(String jss)

Parse a JSS (JavaScript Structure) string to a JSON compatible string. A JavaScript structure looks similar to JSON string with some differences: (a) Keys are not in double-quotes, (b) String values may use single-quotes or double-quotes, (c) Extraneous commas may be there after the last items. This method (a) inserts double-quotes around the keys, (b) replaces single-quotes with double-quotes and (c) removes all extraneous commas. For escaping literal single-quotes or double-quotes, you should use a '\' character (backslash) just before it. In fact, any character following the backslash character will be copied to the output without any special processing. Example of a JSS is: { person: { name: 'Syam Pillai', age: 25 } }

Parameters:

jss - JSS string.

Returns:

A JSON compatible string.