org.json

Class JSONArray

java.lang.Object

org.json.JSONArray

public class JSONArray
extends java.lang.Object

A dense indexed sequence of values. Values may be any mix of JSONObjects, other JSONArrays, Strings, Booleans, Integers, Longs, Doubles, null or JSONObject.NULL. Values may not be NaNs, infinities, or of any type not listed here. JSONArray has the same type coercion behavior and optional/mandatory accessors as JSONObject. See that class' documentation for details. Warning: this class represents null in two incompatible ways: the standard Java null reference, and the sentinel value JSONObject.NULL. In particular, get fails if the requested index holds the null reference, but succeeds if it holds JSONObject.NULL. Instances of this class are not thread safe. Although this class is non-final, it was not designed for inheritance and should not be subclassed. In particular, self-use by overridable methods is not specified. See Effective Java Item 17, "Design and Document or inheritance or else prohibit it" for further information.

Constructor Summary

Constructors

Constructor and Description
JSONArray() Creates a JSONArray with no values.
JSONArray(java.util.Collection<?> copyFrom) Creates a new JSONArray by copying all values from the given collection.
JSONArray(JSONTokener readFrom) Creates a new JSONArray with values from the next array in the tokener.
JSONArray(java.lang.Object array) Creates a new JSONArray with values from the given primitive array.
JSONArray(java.lang.String json) Creates a new JSONArray with values from the JSON string.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
java.lang.Object	get(int index) Returns the value at index.
boolean	getBoolean(int index) Returns the value at index if it exists and is a boolean or can be coerced to a boolean.
double	getDouble(int index) Returns the value at index if it exists and is a double or can be coerced to a double.
int	getInt(int index) Returns the value at index if it exists and is an int or can be coerced to an int.
JSONArray	getJSONArray(int index) Returns the value at index if it exists and is a JSONArray.
JSONObject	getJSONObject(int index) Returns the value at index if it exists and is a JSONObject.
long	getLong(int index) Returns the value at index if it exists and is a long or can be coerced to a long.
java.lang.String	getString(int index) Returns the value at index if it exists, coercing it if necessary.
int	hashCode()
boolean	isNull(int index) Returns true if this array has no value at index, or if its value is the null reference or JSONObject.NULL.
java.lang.String	join(java.lang.String separator) Returns a new string by alternating this array's values with separator.
int	length()
java.lang.Object	opt(int index) Returns the value at index, or null if the array has no value at index.
boolean	optBoolean(int index) Returns the value at index if it exists and is a boolean or can be coerced to a boolean.
boolean	optBoolean(int index, boolean fallback) Returns the value at index if it exists and is a boolean or can be coerced to a boolean.
double	optDouble(int index) Returns the value at index if it exists and is a double or can be coerced to a double.
double	optDouble(int index, double fallback) Returns the value at index if it exists and is a double or can be coerced to a double.
int	optInt(int index) Returns the value at index if it exists and is an int or can be coerced to an int.
int	optInt(int index, int fallback) Returns the value at index if it exists and is an int or can be coerced to an int.
JSONArray	optJSONArray(int index) Returns the value at index if it exists and is a JSONArray.
JSONObject	optJSONObject(int index) Returns the value at index if it exists and is a JSONObject.
long	optLong(int index) Returns the value at index if it exists and is a long or can be coerced to a long.
long	optLong(int index, long fallback) Returns the value at index if it exists and is a long or can be coerced to a long.
java.lang.String	optString(int index) Returns the value at index if it exists, coercing it if necessary.
java.lang.String	optString(int index, java.lang.String fallback) Returns the value at index if it exists, coercing it if necessary.
JSONArray	put(boolean value) Appends value to the end of this array.
JSONArray	put(java.util.Collection<?> value) Appends value wrapped by JSONArray to the end of this array.
JSONArray	put(double value) Appends value to the end of this array.
JSONArray	put(int value) Appends value to the end of this array.
JSONArray	put(int index, boolean value) Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray	put(int index, java.util.Collection<?> value) Sets the value at index to value wrapped into JSONArray, null padding this array to the required length if necessary.
JSONArray	put(int index, double value) Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray	put(int index, int value) Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray	put(int index, long value) Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray	put(int index, java.lang.Object value) Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray	put(long value) Appends value to the end of this array.
JSONArray	put(java.lang.Object value) Appends value to the end of this array.
java.lang.Object	remove(int index) Removes and returns the value at index, or null if the array has no value at index.
JSONObject	toJSONObject(JSONArray names) Returns a new object whose values are the values in this array, and whose names are the values in names.
java.lang.String	toString() Encodes this array as a compact JSON string, such as:
java.lang.String	toString(int indentSpaces) Encodes this array as a human readable JSON string for debugging, such as:

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

JSONArray

public JSONArray()

Creates a JSONArray with no values.

JSONArray

public JSONArray(java.util.Collection<?> copyFrom)

Creates a new JSONArray by copying all values from the given collection.

Parameters:

copyFrom - a collection whose values are of supported types. Unsupported values are not permitted and will yield an array in an inconsistent state.

JSONArray

public JSONArray(JSONTokener readFrom)
          throws JSONException

Creates a new JSONArray with values from the next array in the tokener.

Parameters:

readFrom - a tokener whose nextValue() method will yield a JSONArray.

Throws:

JSONException - if the parse fails or doesn't yield a JSONArray.

JSONArray

public JSONArray(java.lang.String json)
          throws JSONException

Creates a new JSONArray with values from the JSON string.

Parameters:

json - a JSON-encoded string containing an array.

Throws:

JSONException - if the parse fails or doesn't yield a JSONArray.

JSONArray

public JSONArray(java.lang.Object array)
          throws JSONException

Creates a new JSONArray with values from the given primitive array.

Parameters:

array - The values to use.

Throws:

JSONException - if any of the values are non-finite double values (i.e. NaN or infinite)

Method Detail

length

public int length()

Returns:

Returns the number of values in this array.

put

public JSONArray put(boolean value)

Appends value to the end of this array.

Parameters:

value - The value to append.

Returns:

this array.

put

public JSONArray put(double value)
              throws JSONException

Appends value to the end of this array.

Parameters:

value - a finite value. May not be NaNs or infinities.

Returns:

this array.

Throws:

JSONException - If the value is unacceptable.

put

public JSONArray put(int value)

Appends value to the end of this array.

Parameters:

value - The value to append.

Returns:

this array.

put

public JSONArray put(long value)

Appends value to the end of this array.

Parameters:

value - The value to append.

Returns:

this array.

put

public JSONArray put(java.util.Collection<?> value)

Appends value wrapped by JSONArray to the end of this array.

Parameters:

value - any collection.

Returns:

this array.

put

public JSONArray put(java.lang.Object value)

Appends value to the end of this array.

Parameters:

value - a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, JSONObject.NULL, or null. May not be NaNs or infinities. Unsupported values are not permitted and will cause the array to be in an inconsistent state.

Returns:

this array.

put

public JSONArray put(int index,
                     boolean value)
              throws JSONException

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters:

index - Where to put the value.

value - The value to set.

Returns:

this array.

Throws:

JSONException - This should never happen.

put

public JSONArray put(int index,
                     double value)
              throws JSONException

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters:

index - Where to put the value.

value - a finite value. May not be NaNs or infinities.

Returns:

this array.

Throws:

JSONException - If the value is not a finite value.

put

public JSONArray put(int index,
                     int value)
              throws JSONException

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters:

index - Where to put the value.

value - The value to set.

Returns:

this array.

Throws:

JSONException - Should never actually happen.

put

public JSONArray put(int index,
                     long value)
              throws JSONException

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters:

index - Where to put the value.

value - The value to set.

Returns:

this array.

Throws:

JSONException - Should never actually happen.

put

public JSONArray put(int index,
                     java.util.Collection<?> value)
              throws JSONException

Sets the value at index to value wrapped into JSONArray, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters:

index - Where to put the value.

value - The value to set.

Returns:

this array.

Throws:

JSONException - Should never actually happen.

put

public JSONArray put(int index,
                     java.lang.Object value)
              throws JSONException

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters:

index - Where to put the value.

value - a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, JSONObject.NULL, or null. May not be NaNs or infinities.

Returns:

this array.

Throws:

JSONException - If the value cannot be represented as a finite double value.

isNull

public boolean isNull(int index)

Returns true if this array has no value at index, or if its value is the null reference or JSONObject.NULL.

Parameters:

index - Which value to check.

Returns:

true if the value is null.

get

public java.lang.Object get(int index)
                     throws JSONException

Returns the value at index.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if this array has no value at index, or if that value is the null reference. This method returns normally if the value is JSONObject#NULL.

opt

public java.lang.Object opt(int index)

Returns the value at index, or null if the array has no value at index.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

remove

public java.lang.Object remove(int index)

Removes and returns the value at index, or null if the array has no value at index.

Parameters:

index - Which value to remove.

Returns:

The value previously at the specified location.

getBoolean

public boolean getBoolean(int index)
                   throws JSONException

Returns the value at index if it exists and is a boolean or can be coerced to a boolean.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if the value at index doesn't exist or cannot be coerced to a boolean.

optBoolean

public boolean optBoolean(int index)

Returns the value at index if it exists and is a boolean or can be coerced to a boolean. Returns false otherwise.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

optBoolean

public boolean optBoolean(int index,
                          boolean fallback)

Returns the value at index if it exists and is a boolean or can be coerced to a boolean. Returns fallback otherwise.

Parameters:

index - Which value to get.

fallback - the fallback value to return if no value exists.

Returns:

the value at the specified location or the fallback value.

getDouble

public double getDouble(int index)
                 throws JSONException

Returns the value at index if it exists and is a double or can be coerced to a double.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if the value at index doesn't exist or cannot be coerced to a double.

optDouble

public double optDouble(int index)

Returns the value at index if it exists and is a double or can be coerced to a double. Returns NaN otherwise.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

optDouble

public double optDouble(int index,
                        double fallback)

Returns the value at index if it exists and is a double or can be coerced to a double. Returns fallback otherwise.

Parameters:

index - Which value to get.

fallback - The fallback value to use if no value is at the specified location.

Returns:

the value at the specified location or the fallback value.

getInt

public int getInt(int index)
           throws JSONException

Returns the value at index if it exists and is an int or can be coerced to an int.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if the value at index doesn't exist or cannot be coerced to a int.

optInt

public int optInt(int index)

Returns the value at index if it exists and is an int or can be coerced to an int. Returns 0 otherwise.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

optInt

public int optInt(int index,
                  int fallback)

Returns the value at index if it exists and is an int or can be coerced to an int. Returns fallback otherwise.

Parameters:

index - Which value to get.

fallback - The fallback value to use if no value is at the specified location.

Returns:

the value at the specified location or the fallback value.

getLong

public long getLong(int index)
             throws JSONException

Returns the value at index if it exists and is a long or can be coerced to a long.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if the value at index doesn't exist or cannot be coerced to a long.

optLong

public long optLong(int index)

Returns the value at index if it exists and is a long or can be coerced to a long. Returns 0 otherwise.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

optLong

public long optLong(int index,
                    long fallback)

Returns the value at index if it exists and is a long or can be coerced to a long. Returns fallback otherwise.

Parameters:

index - Which value to get.

fallback - The fallback value to use if no value is at the specified location.

Returns:

the value at the specified location or the fallback value.

getString

public java.lang.String getString(int index)
                           throws JSONException

Returns the value at index if it exists, coercing it if necessary.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if no such value exists.

optString

public java.lang.String optString(int index)

Returns the value at index if it exists, coercing it if necessary. Returns the empty string if no such value exists.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

optString

public java.lang.String optString(int index,
                                  java.lang.String fallback)

Returns the value at index if it exists, coercing it if necessary. Returns fallback if no such value exists.

Parameters:

index - Which value to get.

fallback - The fallback value to use if no value is at the specified location.

Returns:

the value at the specified location or the fallback value.

getJSONArray

public JSONArray getJSONArray(int index)
                       throws JSONException

Returns the value at index if it exists and is a JSONArray.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if the value doesn't exist or is not a JSONArray.

optJSONArray

public JSONArray optJSONArray(int index)

Returns the value at index if it exists and is a JSONArray. Returns null otherwise.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

getJSONObject

public JSONObject getJSONObject(int index)
                         throws JSONException

Returns the value at index if it exists and is a JSONObject.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

Throws:

JSONException - if the value doesn't exist or is not a JSONObject.

optJSONObject

public JSONObject optJSONObject(int index)

Returns the value at index if it exists and is a JSONObject. Returns null otherwise.

Parameters:

index - Which value to get.

Returns:

the value at the specified location.

toJSONObject

public JSONObject toJSONObject(JSONArray names)
                        throws JSONException

Returns a new object whose values are the values in this array, and whose names are the values in names. Names and values are paired up by index from 0 through to the shorter array's length. Names that are not strings will be coerced to strings. This method returns null if either array is empty.

Parameters:

names - The names to apply to the returned values.

Returns:

the newly constructed object.

Throws:

JSONException - Should not be possible.

join

public java.lang.String join(java.lang.String separator)
                      throws JSONException

Returns a new string by alternating this array's values with separator. This array's string values are quoted and have their special characters escaped. For example, the array containing the strings '12" pizza', 'taco' and 'soda' joined on '+' returns this:

 "12\" pizza" + "taco" + "soda"
 

Parameters:

separator - The string used to separate the returned values.

Returns:

the conjoined values.

Throws:

JSONException - Only if there is a coding error.

toString

public java.lang.String toString()

Encodes this array as a compact JSON string, such as:

 [94043,90210]
 

Overrides:

toString in class java.lang.Object

Returns:

The string form of this array.

toString

public java.lang.String toString(int indentSpaces)
                          throws JSONException

Encodes this array as a human readable JSON string for debugging, such as:

 [
     94043,
     90210
 ]
 

Parameters:

indentSpaces - the number of spaces to indent for each level of nesting.

Returns:

The string form of this array.

Throws:

JSONException - Only if there is a coding error.

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object