processing.data

Class JSONArray

Object

JSONArray

public class JSONArray
extends Object

A JSONArray is an ordered sequence of values. Its external text form is a string wrapped in square brackets with commas separating the values. The internal form is an object having get and opt methods for accessing the values by index, and put methods for adding or replacing values. The values can be any of these types: Boolean, JSONArray, JSONObject, Number, String, or the JSONObject.NULL object.

The constructor can convert a JSON text into a Java object. The toString method converts to JSON text.

A get method returns a value if one can be found, and throws an exception if one cannot be found. An opt method returns a default value instead of throwing an exception, and so is useful for obtaining optional values.

The generic get() and opt() methods return an object which you can cast or query for type. There are also typed get and opt methods that do type checking and type coercion for you.

The texts produced by the toString methods strictly conform to JSON syntax rules. The constructors are more forgiving in the texts they will accept:

• An extra , (comma) may appear just before the closing bracket.
• The null value will be inserted when there is , (comma) elision.
• Strings may be quoted with ' (single quote).
• Strings do not need to be quoted at all if they do not begin with a quote or single quote, and if they do not contain leading or trailing spaces, and if they do not contain any of these characters: { } [ ] / \ : , = ; # and if they do not look like numbers and if they are not the reserved words true, false, or null.
• Values can be separated by ; (semicolon) as well as by , (comma).

See Also:

JSONObject, PApplet.loadJSONObject(String), PApplet.loadJSONArray(String), PApplet.saveJSONObject(JSONObject, String), PApplet.saveJSONArray(JSONArray, String)

Constructor Summary

Constructors

Constructor and Description
JSONArray() Construct an empty JSONArray.
JSONArray(FloatList list)
JSONArray(IntList list)
JSONArray(Reader reader)
JSONArray(StringList list)

Method Summary

Modifier and Type	Method and Description
JSONArray	append(boolean value) Append a boolean value.
JSONArray	append(double value) Append a double value.
JSONArray	append(float value) Append a float value.
JSONArray	append(int value) Append an int value.
JSONArray	append(JSONArray value)
JSONArray	append(JSONObject value)
JSONArray	append(long value) Append an long value.
JSONArray	append(String value) Append an String value.
String	format(int indentFactor) Make a pretty-printed JSON text of this JSONArray.
Object	get(int index) Get the object value associated with an index.
boolean	getBoolean(int index) Get the boolean value associated with an index.
boolean	getBoolean(int index, boolean defaultValue) Get the optional boolean value associated with an index.
boolean[]	getBooleanArray() Get this entire array as a boolean array.
double	getDouble(int index) Get the double value associated with an index.
double	getDouble(int index, double defaultValue) Get the optional double value associated with an index.
double[]	getDoubleArray() Get this entire array as a double array.
float	getFloat(int index) Get a value from an index as a float.
float	getFloat(int index, float defaultValue)
float[]	getFloatArray() Get this entire array as a float array.
int	getInt(int index) Get the int value associated with an index.
int	getInt(int index, int defaultValue) Get the optional int value associated with an index.
int[]	getIntArray() Get this entire array as an int array.
JSONArray	getJSONArray(int index) Get the JSONArray associated with an index.
JSONArray	getJSONArray(int index, JSONArray defaultValue)
JSONObject	getJSONObject(int index) Get the JSONObject associated with an index.
JSONObject	getJSONObject(int index, JSONObject defaultValue)
long	getLong(int index) Get the long value associated with an index.
long	getLong(int index, long defaultValue) Get the optional long value associated with an index.
long[]	getLongArray() Get this entire array as a long array.
String	getString(int index) Get the string associated with an index.
String	getString(int index, String defaultValue) Get the optional string associated with an index.
String[]	getStringArray() Get this entire array as a String array.
boolean	isNull(int index) Determine if the value is null.
String	join(String separator) Make a string from the contents of this JSONArray.
static JSONArray	parse(String source) Construct a JSONArray from a source JSON text.
Object	remove(int index) Remove an index and close the hole.
boolean	save(File file, String options)
JSONArray	setBoolean(int index, boolean value) Put or replace a boolean value in the JSONArray.
JSONArray	setDouble(int index, double value) Put or replace a double value.
JSONArray	setFloat(int index, float value) Put or replace a float value.
JSONArray	setInt(int index, int value) Put or replace an int value.
JSONArray	setJSONArray(int index, JSONArray value)
JSONArray	setJSONObject(int index, JSONObject value)
JSONArray	setLong(int index, long value) Put or replace a long value.
JSONArray	setString(int index, String value) Put or replace a String value.
int	size() Get the number of elements in the JSONArray, included nulls.
String	toString() Return the JSON data formatted with two spaces for indents.
boolean	write(PrintWriter output)
boolean	write(PrintWriter output, String options)

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

JSONArray

public JSONArray()

Construct an empty JSONArray.

JSONArray

public JSONArray(Reader reader)

JSONArray

public JSONArray(IntList list)

JSONArray

public JSONArray(FloatList list)

JSONArray

public JSONArray(StringList list)

Method Detail

parse

public static JSONArray parse(String source)

Construct a JSONArray from a source JSON text.

Parameters:

source - A string that begins with [ (left bracket) and ends with ] (right bracket).

Returns:

null if there is a syntax error.

get

public Object get(int index)

Get the object value associated with an index.

Parameters:

index - must be between 0 and length() - 1

Returns:

An object value.

Throws:

RuntimeException - If there is no value for the index.

getString

public String getString(int index)

Get the string associated with an index.

Parameters:

index - must be between 0 and length() - 1

Returns:

A string value.

Throws:

RuntimeException - If there is no string value for the index.

See Also:

getInt(int), getFloat(int), getBoolean(int)

In brief:

Gets the String value associated with an index

getString

public String getString(int index,
                        String defaultValue)

Get the optional string associated with an index. The defaultValue is returned if the key is not found.

Parameters:

index - The index must be between 0 and length() - 1.

defaultValue - The default value.

Returns:

A String value.

getInt

public int getInt(int index)

Get the int value associated with an index.

Parameters:

index - must be between 0 and length() - 1

Returns:

The value.

Throws:

RuntimeException - If the key is not found or if the value is not a number.

See Also:

getFloat(int), getString(int), getBoolean(int)

In brief:

Gets the int value associated with an index

getInt

public int getInt(int index,
                  int defaultValue)

Get the optional int value associated with an index. The defaultValue is returned if there is no value for the index, or if the value is not a number and cannot be converted to a number.

Parameters:

index - The index must be between 0 and length() - 1.

defaultValue - The default value.

Returns:

The value.

getLong

public long getLong(int index)

Get the long value associated with an index.

Parameters:

index - The index must be between 0 and length() - 1

Returns:

The value.

Throws:

RuntimeException - If the key is not found or if the value cannot be converted to a number.

getLong

public long getLong(int index,
                    long defaultValue)

Get the optional long value associated with an index. The defaultValue is returned if there is no value for the index, or if the value is not a number and cannot be converted to a number.

Parameters:

index - The index must be between 0 and length() - 1.

defaultValue - The default value.

Returns:

The value.

getFloat

public float getFloat(int index)

Get a value from an index as a float. JSON uses 'double' values internally, so this is simply getDouble() cast to a float.

Parameters:

index - must be between 0 and length() - 1

See Also:

getInt(int), getString(int), getBoolean(int)

In brief:

Gets the float value associated with an index

getFloat

public float getFloat(int index,
                      float defaultValue)

getDouble

public double getDouble(int index)

Get the double value associated with an index.

Parameters:

index - must be between 0 and length() - 1

Returns:

The value.

Throws:

RuntimeException - If the key is not found or if the value cannot be converted to a number.

getDouble

public double getDouble(int index,
                        double defaultValue)

Get the optional double value associated with an index. The defaultValue is returned if there is no value for the index, or if the value is not a number and cannot be converted to a number.

Parameters:

index - subscript

defaultValue - The default value.

Returns:

The value.

getBoolean

public boolean getBoolean(int index)

Get the boolean value associated with an index. The string values "true" and "false" are converted to boolean.

Parameters:

index - must be between 0 and length() - 1

Returns:

The truth.

Throws:

RuntimeException - If there is no value for the index or if the value is not convertible to boolean.

See Also:

getInt(int), getFloat(int), getString(int)

In brief:

Gets the boolean value associated with an index

getBoolean

public boolean getBoolean(int index,
                          boolean defaultValue)

Get the optional boolean value associated with an index. It returns the defaultValue if there is no value at that index or if it is not a Boolean or the String "true" or "false" (case insensitive).

Parameters:

index - The index must be between 0 and length() - 1.

defaultValue - A boolean default.

Returns:

The truth.

getJSONArray

public JSONArray getJSONArray(int index)

Get the JSONArray associated with an index.

Parameters:

index - must be between 0 and length() - 1

Returns:

A JSONArray value.

Throws:

RuntimeException - If there is no value for the index. or if the value is not a JSONArray

See Also:

getJSONObject(int), setJSONObject(int, JSONObject), setJSONArray(int, JSONArray)

In brief:

Gets the JSONArray associated with an index value

getJSONArray

public JSONArray getJSONArray(int index,
                              JSONArray defaultValue)

getJSONObject

public JSONObject getJSONObject(int index)

Get the JSONObject associated with an index.

Parameters:

index - the index value of the object to get

Returns:

A JSONObject value.

Throws:

RuntimeException - If there is no value for the index or if the value is not a JSONObject

See Also:

getJSONArray(int), setJSONObject(int, JSONObject), setJSONArray(int, JSONArray)

In brief:

Gets the JSONObject associated with an index value

getJSONObject

public JSONObject getJSONObject(int index,
                                JSONObject defaultValue)

getStringArray

public String[] getStringArray()

Get this entire array as a String array.

See Also:

getIntArray()

In brief:

Gets the entire array as an array of Strings

getIntArray

public int[] getIntArray()

Get this entire array as an int array. Everything must be an int.

See Also:

getStringArray()

In brief:

Gets the entire array as array of ints

getLongArray

public long[] getLongArray()

Get this entire array as a long array. Everything must be an long.

getFloatArray

public float[] getFloatArray()

Get this entire array as a float array. Everything must be an float.

getDoubleArray

public double[] getDoubleArray()

Get this entire array as a double array. Everything must be an double.

getBooleanArray

public boolean[] getBooleanArray()

Get this entire array as a boolean array. Everything must be a boolean.

append

public JSONArray append(String value)

Append an String value. This increases the array's length by one.

Parameters:

value - a String value

Returns:

this.

See Also:

size(), remove(int)

In brief:

Appends a value, increasing the array's length by one

append

public JSONArray append(int value)

Append an int value. This increases the array's length by one.

Parameters:

value - an int value

Returns:

this.

append

public JSONArray append(long value)

Append an long value. This increases the array's length by one.

Parameters:

value - A long value.

Returns:

this.

append

public JSONArray append(float value)

Append a float value. This increases the array's length by one. This will store the value as a double, since there are no floats in JSON.

Parameters:

value - a float value

Returns:

this.

Throws:

RuntimeException - if the value is not finite.

append

public JSONArray append(double value)

Append a double value. This increases the array's length by one.

Parameters:

value - A double value.

Returns:

this.

Throws:

RuntimeException - if the value is not finite.

append

public JSONArray append(boolean value)

Append a boolean value. This increases the array's length by one.

Parameters:

value - a boolean value

Returns:

this.

append

public JSONArray append(JSONArray value)

Parameters:

value - a JSONArray value

append

public JSONArray append(JSONObject value)

Parameters:

value - a JSONObject value

setString

public JSONArray setString(int index,
                           String value)

Put or replace a String value. If the index is greater than the length of the JSONArray, then null elements will be added as necessary to pad it out.

Parameters:

index - an index value

value - the value to assign

Returns:

this.

Throws:

RuntimeException - If the index is negative.

See Also:

setInt(int, int), setFloat(int, float), setBoolean(int, boolean)

In brief:

Put a String value in the JSONArray

setInt

public JSONArray setInt(int index,
                        int value)

Put or replace an int value. If the index is greater than the length of the JSONArray, then null elements will be added as necessary to pad it out.

Parameters:

index - an index value

value - the value to assign

Returns:

this.

Throws:

RuntimeException - If the index is negative.

See Also:

setFloat(int, float), setString(int, String), setBoolean(int, boolean)

In brief:

Put an int value in the JSONArray

setLong

public JSONArray setLong(int index,
                         long value)

Put or replace a long value. If the index is greater than the length of the JSONArray, then null elements will be added as necessary to pad it out.

Parameters:

index - The subscript.

value - A long value.

Returns:

this.

Throws:

RuntimeException - If the index is negative.

setFloat

public JSONArray setFloat(int index,
                          float value)

Put or replace a float value. If the index is greater than the length of the JSONArray, then null elements will be added as necessary to pad it out. There are no 'double' values in JSON, so this is passed to setDouble(value).

Parameters:

index - an index value

value - the value to assign

Returns:

this.

Throws:

RuntimeException - If the index is negative or if the value is not finite.

See Also:

setInt(int, int), setString(int, String), setBoolean(int, boolean)

In brief:

Put a float value in the JSONArray

setDouble

public JSONArray setDouble(int index,
                           double value)

Put or replace a double value. If the index is greater than the length of the JSONArray, then null elements will be added as necessary to pad it out.

Parameters:

index - The subscript.

value - A double value.

Returns:

this.

Throws:

RuntimeException - If the index is negative or if the value is not finite.

setBoolean

public JSONArray setBoolean(int index,
                            boolean value)

Put or replace a boolean value in the JSONArray. If the index is greater than the length of the JSONArray, then null elements will be added as necessary to pad it out.

Parameters:

index - an index value

value - the value to assign

Returns:

this.

Throws:

RuntimeException - If the index is negative.

See Also:

setInt(int, int), setFloat(int, float), setString(int, String)

In brief:

Put a boolean value in the JSONArray

setJSONArray

public JSONArray setJSONArray(int index,
                              JSONArray value)

Parameters:

index - the index value to target

value - the value to assign

See Also:

setJSONObject(int, JSONObject), getJSONObject(int), getJSONArray(int)

In brief:

Sets the JSONArray value associated with an index value

setJSONObject

public JSONArray setJSONObject(int index,
                               JSONObject value)

Parameters:

index - the index value to target

value - the value to assign

See Also:

setJSONArray(int, JSONArray), getJSONObject(int), getJSONArray(int)

In brief:

Sets the JSONObject value associated with an index value

size

public int size()

Get the number of elements in the JSONArray, included nulls.

Returns:

The length (or size).

See Also:

append(String), remove(int)

In brief:

Gets the number of elements in the JSONArray

isNull

public boolean isNull(int index)

Determine if the value is null.

Parameters:

index - must be between 0 and length() - 1

Returns:

true if the value at the index is null, or if there is no value.

remove

public Object remove(int index)

Remove an index and close the hole.

Parameters:

index - the index value of the element to be removed

Returns:

The value that was associated with the index, or null if there was no value.

See Also:

size(), append(String)

In brief:

Removes an element

save

public boolean save(File file,
                    String options)

write

public boolean write(PrintWriter output)

write

public boolean write(PrintWriter output,
                     String options)

toString

public String toString()

Return the JSON data formatted with two spaces for indents. Chosen to do this since it's the most common case (e.g. with println()). Same as format(2). Use the format() function for more options.

Overrides:

toString in class Object

format

public String format(int indentFactor)

Make a pretty-printed JSON text of this JSONArray. Warning: This method assumes that the data structure is acyclical.

Parameters:

indentFactor - The number of spaces to add to each level of indentation. Use -1 to specify no indentation and no newlines.

Returns:

a printable, displayable, transmittable representation of the object, beginning with [ (left bracket) and ending with ] (right bracket).

join

public String join(String separator)

Make a string from the contents of this JSONArray. The separator string is inserted between each element. Warning: This method assumes that the data structure is acyclic.

Parameters:

separator - A string that will be inserted between the elements.

Returns:

a string.

Throws:

RuntimeException - If the array contains an invalid number.