Package org.json

Class JSONArray

java.lang.Object
org.json.JSONArray

public class JSONArray extends 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 nonfinal, 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
    Description
    Creates a JSONArray with no values.
    Creates a new JSONArray with values from the given primitive array.
    Creates a new JSONArray with values from the JSON string.
    Creates a new JSONArray by copying all values from the given collection.
    Creates a new JSONArray with values from the next array in the tokener.
  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
     
    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.
    getJSONArray(int index)
    Returns the value at index if it exists and is a JSONArray.
    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.
    getString(int index)
    Returns the value at index if it exists, coercing it if necessary.
    int
     
    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.
    join(String separator)
    Returns a new string by alternating this array's values with separator.
    int
    Returns the number of values in this array.
    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.
    optJSONArray(int index)
    Returns the value at index if it exists and is a JSONArray.
    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.
    optString(int index)
    Returns the value at index if it exists, coercing it if necessary.
    optString(int index, String fallback)
    Returns the value at index if it exists, coercing it if necessary.
    put(boolean value)
    Appends value to the end of this array.
    put(double value)
    Appends value to the end of this array.
    put(int value)
    Appends value to the end of this array.
    put(int index, boolean value)
    Sets the value at index to value, null padding this array to the required length if necessary.
    put(int index, double value)
    Sets the value at index to value, null padding this array to the required length if necessary.
    put(int index, int value)
    Sets the value at index to value, null padding this array to the required length if necessary.
    put(int index, long value)
    Sets the value at index to value, null padding this array to the required length if necessary.
    put(int index, Object value)
    Sets the value at index to value, null padding this array to the required length if necessary.
    put(long value)
    Appends value to the end of this array.
    put(Object value)
    Appends value to the end of this array.
    remove(int index)
    Removes and returns the value at index, or null if the array has no value at index.
    Returns a new object whose values are the values in this array, and whose names are the values in names.
    Encodes this array as a compact JSON string, such as:
    toString(int indentSpaces)
    Encodes this array as a human readable JSON string for debugging, such as:

    Methods inherited from class java.lang.Object

    getClass, notify, notifyAll, wait, wait, wait
  • Constructor Details

    • JSONArray

      public JSONArray()
      Creates a JSONArray with no values.
    • JSONArray

      public JSONArray(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(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(Object array) throws JSONException
      Creates a new JSONArray with values from the given primitive array.
      Throws:
      JSONException
  • Method Details

    • length

      public int length()
      Returns the number of values in this array.
    • put

      public JSONArray put(boolean value)
      Appends value to the end of this array.
      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
    • put

      public JSONArray put(int value)
      Appends value to the end of this array.
      Returns:
      this array.
    • put

      public JSONArray put(long value)
      Appends value to the end of this array.
      Returns:
      this array.
    • put

      public JSONArray put(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.
      Returns:
      this array.
      Throws:
      JSONException
    • 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:
      value - a finite value. May not be NaNs or infinities.
      Returns:
      this array.
      Throws:
      JSONException
    • 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.
      Returns:
      this array.
      Throws:
      JSONException
    • 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.
      Returns:
      this array.
      Throws:
      JSONException
    • put

      public JSONArray put(int index, 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:
      value - a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, JSONObject.NULL, or null. May not be NaNs or infinities.
      Returns:
      this array.
      Throws:
      JSONException
    • 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.
    • get

      public Object get(int index) throws JSONException
      Returns the value at index.
      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 Object opt(int index)
      Returns the value at index, or null if the array has no value at index.
    • remove

      public Object remove(int index)
      Removes and returns the value at index, or null if the array has no value at index.
    • 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.
      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.
    • 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.
    • 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.
      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.
    • 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.
    • 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.
      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.
    • 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.
    • 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.
      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.
    • 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.
    • getString

      public String getString(int index) throws JSONException
      Returns the value at index if it exists, coercing it if necessary.
      Throws:
      JSONException - if no such value exists.
    • optString

      public 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.
    • optString

      public String optString(int index, String fallback)
      Returns the value at index if it exists, coercing it if necessary. Returns fallback if no such value exists.
    • getJSONArray

      public JSONArray getJSONArray(int index) throws JSONException
      Returns the value at index if it exists and is a JSONArray.
      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.
    • getJSONObject

      public JSONObject getJSONObject(int index) throws JSONException
      Returns the value at index if it exists and is a JSONObject.
      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.
    • 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.
      Throws:
      JSONException
    • join

      public String join(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"
      Throws:
      JSONException
    • toString

      public String toString()
      Encodes this array as a compact JSON string, such as:
      [94043,90210]
      Overrides:
      toString in class Object
    • toString

      public 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.
      Throws:
      JSONException
    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object
    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object