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
    JSONArray()
    Creates a JSONArray with no values.
    JSONArray​(Object array)
    Creates a new JSONArray with values from the given primitive array.
    JSONArray​(String json)
    Creates a new JSONArray with values from the JSON string.
    JSONArray​(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.

  • Method Summary

    Modifier and Type Method Description
    boolean equals​(Object o)
    Compares this instance with the specified object and indicates if they are equal.
    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.
    String getString​(int index)
    Returns the value at index if it exists, coercing it if necessary.
    int hashCode()
    Returns an integer hash code for this object.
    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.
    String join​(String separator)
    Returns a new string by alternating this array's values with separator.
    int length()
    Returns the number of values in this array.
    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.
    String optString​(int index)
    Returns the value at index if it exists, coercing it if necessary.
    String optString​(int index, 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​(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, 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, 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​(Object value)
    Appends value to the end of this array.
    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.
    String toString()
    Encodes this array as a compact JSON string, such as:
    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 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
      Returns:
      a printable representation of this 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)
      Description copied from class: Object
      Compares this instance with the specified object and indicates if they are equal. In order to be equal, o must represent the same object as this instance using a class-specific comparison. The general contract is that this comparison should be reflexive, symmetric, and transitive. Also, no object reference other than null is equal to null.

      The default implementation returns true only if this == o. See Writing a correct equals method if you intend implementing your own equals method.

      The general contract for the equals and Object.hashCode() methods is that if equals returns true for any two objects, then hashCode() must return the same value for these objects. This means that subclasses of Object usually override either both methods or neither of them.

      Overrides:
      equals in class Object
      Parameters:
      o - the object to compare this instance with.
      Returns:
      true if the specified object is equal to this Object; false otherwise.
      See Also:
      Object.hashCode()

    • hashCode

      public int hashCode()
      Description copied from class: Object
      Returns an integer hash code for this object. By contract, any two objects for which Object.equals(java.lang.Object) returns true must return the same hash code value. This means that subclasses of Object usually override both methods or neither method.

      Note that hash values must not change over time unless information used in equals comparisons also changes.

      See Writing a correct hashCode method if you intend implementing your own hashCode method.

      Overrides:
      hashCode in class Object
      Returns:
      this object's hash code.
      See Also:
      Object.equals(java.lang.Object)