Class 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 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​(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.
      JSONArray​(java.util.Collection copyFrom)
      Creates a new JSONArray by copying all values from the given collection.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method 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()
      Returns the number of values in this array.
      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​(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, 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.
        Throws:
        JSONException
    • Method Detail

      • 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​(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.
        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,
                             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:
        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 java.lang.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 java.lang.Object opt​(int index)
        Returns the value at index, or null if the array has no value at index.
      • 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.
      • 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 java.lang.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 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.
      • 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.
      • 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 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"
        Throws:
        JSONException
      • 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
      • 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.
        Throws:
        JSONException
      • 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