public class

JSONArray

extends Object
java.lang.Object
   ↳ com.neomades.json.JSONArray

Class Overview

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 coersion 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).
  • Numbers may have the 0- (octal) or 0x- (hex) prefix.
  • Comments written in the slashshlash, slashstar, and hash conventions will be ignored.

Summary

Public Constructors
JSONArray()
Construct an empty JSONArray.
JSONArray(JSONTokener x)
Construct a JSONArray from a JSONTokener.
JSONArray(String source)
Construct a JSONArray from a source JSON text.
JSONArray(Vector collection)
Construct a JSONArray from a Collection.
Public Methods
Object get(int index)
Get the object value associated with an index.
boolean getBoolean(int index)
Get the boolean value associated with an index.
double getDouble(int index)
Get the double value associated with an index.
int getInt(int index)
Get the int value associated with an index.
JSONArray getJSONArray(int index)
Get the JSONArray associated with an index.
JSONObject getJSONObject(int index)
Get the JSONObject associated with an index.
long getLong(int index)
Get the long value associated with an index.
String getString(int index)
Get the string associated with an index.
boolean isNull(int index)
Determine if the value is null.
String join(String separator)
Make a string from the contents of this JSONArray.
int length()
Get the number of elements in the JSONArray, included nulls.
Object opt(int index)
Get the optional object value associated with an index.
boolean optBoolean(int index)
Get the optional boolean value associated with an index.
boolean optBoolean(int index, boolean defaultValue)
Get the optional boolean value associated with an index.
double optDouble(int index)
Get the optional double value associated with an index.
double optDouble(int index, double defaultValue)
Get the optional double value associated with an index.
int optInt(int index)
Get the optional int value associated with an index.
int optInt(int index, int defaultValue)
Get the optional int value associated with an index.
JSONArray optJSONArray(int index)
Get the optional JSONArray associated with an index.
JSONObject optJSONObject(int index)
Get the optional JSONObject associated with an index.
long optLong(int index)
Get the optional long value associated with an index.
long optLong(int index, long defaultValue)
Get the optional long value associated with an index.
String optString(int index)
Get the optional string value associated with an index.
String optString(int index, String defaultValue)
Get the optional string associated with an index.
JSONArray put(int value)
Append an int value.
JSONArray put(long value)
Append an long value.
JSONArray put(int index, boolean value)
Put or replace a boolean value in the JSONArray.
JSONArray put(double value)
Append a double value.
JSONArray put(int index, Object value)
Put or replace an object value in the JSONArray.
JSONArray put(int index, long value)
Put or replace a long value.
JSONArray put(int index, int value)
Put or replace an int value.
JSONArray put(boolean value)
Append a boolean value.
JSONArray put(int index, double value)
Put or replace a double value.
JSONArray put(Object value)
Append an object value.
JSONObject toJSONObject(JSONArray names)
Produce a JSONObject by combining a JSONArray of names with the values of this JSONArray.
String toString()
Make a JSON text of this JSONArray.
String toString(int indentFactor)
Make a prettyprinted JSON text of this JSONArray.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public JSONArray ()

Construct an empty JSONArray.

public JSONArray (JSONTokener x)

Construct a JSONArray from a JSONTokener.

Parameters
x A JSONTokener
Throws
JSONException If there is a syntax error.

public JSONArray (String source)

Construct a JSONArray from a source JSON text.

Parameters
source A string that begins with [ (left bracket) and ends with ]  (right bracket).
Throws
JSONException If there is a syntax error.

public JSONArray (Vector collection)

Construct a JSONArray from a Collection.

Parameters
collection A Collection.

Public Methods

public Object get (int index)

Get the object value associated with an index.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • An object value.
Throws
JSONException If there is no value for the index.

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 The index must be between 0 and length() - 1.
Returns
  • The truth.
Throws
JSONException If there is no value for the index or if the value is not convertable to boolean.

public double getDouble (int index)

Get the double value associated with an index.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • The value.
Throws
JSONException If the key is not found or if the value cannot be converted to a number.

public int getInt (int index)

Get the int value associated with an index.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • The value.
Throws
JSONException If the key is not found or if the value cannot be converted to a number. if the value cannot be converted to a number.

public JSONArray getJSONArray (int index)

Get the JSONArray associated with an index.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • A JSONArray value.
Throws
JSONException If there is no value for the index. or if the value is not a JSONArray

public JSONObject getJSONObject (int index)

Get the JSONObject associated with an index.

Parameters
index subscript
Returns
  • A JSONObject value.
Throws
JSONException If there is no value for the index or if the value is not a JSONObject

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

public String getString (int index)

Get the string associated with an index.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • A string value.
Throws
JSONException If there is no value for the index.

public boolean isNull (int index)

Determine if the value is null.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • true if the value at the index is null, or if there is no value.

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 acyclical.

Parameters
separator A string that will be inserted between the elements.
Returns
  • a string.
Throws
JSONException If the array contains an invalid number.

public int length ()

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

Returns
  • The length (or size).

public Object opt (int index)

Get the optional object value associated with an index.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • An object value, or null if there is no object at that index.

public boolean optBoolean (int index)

Get the optional boolean value associated with an index. It returns false if there is no value at that index, or if the value is not Boolean.TRUE or the String "true".

Parameters
index The index must be between 0 and length() - 1.
Returns
  • The truth.

public boolean optBoolean (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.

public double optDouble (int index)

Get the optional double value associated with an index. NaN 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.
Returns
  • The value.

public double optDouble (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.

public int optInt (int index)

Get the optional int value associated with an index. Zero 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.
Returns
  • The value.

public int optInt (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.

public JSONArray optJSONArray (int index)

Get the optional JSONArray associated with an index.

Parameters
index subscript
Returns
  • A JSONArray value, or null if the index has no value, or if the value is not a JSONArray.

public JSONObject optJSONObject (int index)

Get the optional JSONObject associated with an index. Null is returned if the key is not found, or null if the index has no value, or if the value is not a JSONObject.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • A JSONObject value.

public long optLong (int index)

Get the optional long value associated with an index. Zero 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.
Returns
  • The value.

public long optLong (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.

public String optString (int index)

Get the optional string value associated with an index. It returns an empty string if there is no value at that index. If the value is not a string and is not null, then it is coverted to a string.

Parameters
index The index must be between 0 and length() - 1.
Returns
  • A String value.

public String optString (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.

public JSONArray put (int value)

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

Parameters
value An int value.
Returns
  • this.

public JSONArray put (long value)

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

Parameters
value A long value.
Returns
  • this.

public JSONArray put (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 The subscript.
value A boolean value.
Returns
  • this.
Throws
JSONException If the index is negative.

public JSONArray put (double value)

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

Parameters
value A double value.
Returns
  • this.
Throws
JSONException if the value is not finite.

public JSONArray put (int index, Object value)

Put or replace an object 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 The subscript.
value The value to put into the array. The value should be a Boolean, Double, Integer, JSONArray, JSONObject, Long, or String, or the JSONObject.NULL object.
Returns
  • this.
Throws
JSONException If the index is negative or if the the value is an invalid number.

public JSONArray put (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
JSONException If the index is negative.

public JSONArray put (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 The subscript.
value An int value.
Returns
  • this.
Throws
JSONException If the index is negative.

public JSONArray put (boolean value)

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

Parameters
value A boolean value.
Returns
  • this.

public JSONArray put (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
JSONException If the index is negative or if the value is not finite.

public JSONArray put (Object value)

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

Parameters
value An object value. The value should be a Boolean, Double, Integer, JSONArray, JSONObject, Long, or String, or the JSONObject.NULL object.
Returns
  • this.

public JSONObject toJSONObject (JSONArray names)

Produce a JSONObject by combining a JSONArray of names with the values of this JSONArray.

Parameters
names A JSONArray containing a list of key strings. These will be paired with the values.
Returns
  • A JSONObject, or null if there are no names or if this JSONArray has no values.
Throws
JSONException If any of the names are null.

public String toString ()

Make a JSON text of this JSONArray. For compactness, no unnecessary whitespace is added. If it is not possible to produce a syntactically correct JSON text then null will be returned instead. This could occur if the array contains an invalid number.

Warning: This method assumes that the data structure is acyclical.

Returns
  • a printable, displayable, transmittable representation of the array.

public String toString (int indentFactor)

Make a prettyprinted 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.
Returns
  • a printable, displayable, transmittable representation of the object, beginning with [ (left bracket) and ending with ]  (right bracket).
Throws
JSONException