Package org.daypilot.json

Class JSONArray

java.lang.Object
org.daypilot.json.JSONArray
public class JSONArray extends Object
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 coercion 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.

  • Constructor Summary

    Constructors
    Constructor
    Description
    JSONArray()
    Construct an empty JSONArray.
    JSONArray(Object array)
    Construct a JSONArray from an array
    JSONArray(Object array, boolean includeSuperClass)
    Construct a JSONArray from an array with a bean.
    JSONArray(String source)
    Construct a JSONArray from a source JSON text.
    JSONArray(Collection collection)
    Construct a JSONArray from a Collection.
    JSONArray(Collection collection, boolean includeSuperClass)
    Construct a JSONArray from a collection of beans.
    JSONArray(JSONTokener x)
    Construct a JSONArray from a JSONTokener.

  • Method Summary

    Modifier and Type
    Method
    Description
    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(boolean value)
    Append a boolean value.
    JSONArray
    put(double value)
    Append a double value.
    JSONArray
    put(int value)
    Append an int value.
    JSONArray
    put(int index, boolean value)
    Put or replace a boolean value in the JSONArray.
    JSONArray
    put(int index, double value)
    Put or replace a double value.
    JSONArray
    put(int index, int value)
    Put or replace an int value.
    JSONArray
    put(int index, long value)
    Put or replace a long value.
    JSONArray
    put(int index, Object value)
    Put or replace an object value in the JSONArray.
    JSONArray
    put(int index, Collection value)
    Put a value in the JSONArray, where the value will be a JSONArray which is produced from a Collection.
    JSONArray
    put(int index, Map value)
    Put a value in the JSONArray, where the value will be a JSONObject which is produced from a Map.
    JSONArray
    put(long value)
    Append an long value.
    JSONArray
    put(Object value)
    Append an object value.
    JSONArray
    put(Collection value)
    Put a value in the JSONArray, where the value will be a JSONArray which is produced from a Collection.
    JSONArray
    put(Map value)
    Put a value in the JSONArray, where the value will be a JSONObject which is produced from a Map.
    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.
    Writer
    write(Writer writer)
    Write the contents of the JSONArray as JSON text to a writer.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • JSONArray

      public JSONArray()
      Construct an empty JSONArray.

    • JSONArray

      public JSONArray(JSONTokener x)
      Construct a JSONArray from a JSONTokener.
      Parameters:
      x - A JSONTokener
      Throws:
      JSONException - If there is a syntax error.

    • JSONArray

      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.

    • JSONArray

      public JSONArray(Collection collection)
      Construct a JSONArray from a Collection.
      Parameters:
      collection - A Collection.

    • JSONArray

      public JSONArray(Collection collection, boolean includeSuperClass)
      Construct a JSONArray from a collection of beans. The collection should have Java Beans.
      Throws:
      JSONException - If not an array.

    • JSONArray

      public JSONArray(Object array) throws JSONException
      Construct a JSONArray from an array
      Throws:
      JSONException - If not an array.

    • JSONArray

      public JSONArray(Object array, boolean includeSuperClass) throws JSONException
      Construct a JSONArray from an array with a bean. The array should have Java Beans.
      Throws:
      JSONException - If not an array.

  • Method Details

    • get

      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.

    • getBoolean

      public boolean getBoolean(int index) throws JSONException
      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.

    • getDouble

      public double getDouble(int index) throws JSONException
      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.

    • getInt

      public int getInt(int index) throws JSONException
      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.

    • getJSONArray

      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

    • getJSONObject

      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

    • getLong

      public long getLong(int index) throws JSONException
      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.

    • getString

      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.

    • isNull

      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.

    • join

      public String join(String separator) throws JSONException
      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.

    • length

      public int length()
      Get the number of elements in the JSONArray, included nulls.
      Returns:
      The length (or size).

    • opt

      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.

    • optBoolean

      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.

    • optBoolean

      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.

    • optDouble

      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.

    • optDouble

      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.

    • optInt

      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.

    • optInt

      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.

    • optJSONArray

      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.

    • optJSONObject

      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.

    • optLong

      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.

    • optLong

      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.

    • optString

      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.

    • optString

      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.

    • put

      public JSONArray put(boolean value)
      Append a boolean value. This increases the array's length by one.
      Parameters:
      value - A boolean value.
      Returns:
      this.

    • put

      public JSONArray put(Collection value)
      Put a value in the JSONArray, where the value will be a JSONArray which is produced from a Collection.
      Parameters:
      value - A Collection value.
      Returns:
      this.

    • put

      public JSONArray put(double value) throws JSONException
      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.

    • put

      public JSONArray put(int value)
      Append an int value. This increases the array's length by one.
      Parameters:
      value - An int value.
      Returns:
      this.

    • put

      public JSONArray put(long value)
      Append an long value. This increases the array's length by one.
      Parameters:
      value - A long value.
      Returns:
      this.

    • put

      public JSONArray put(Map value)
      Put a value in the JSONArray, where the value will be a JSONObject which is produced from a Map.
      Parameters:
      value - A Map value.
      Returns:
      this.

    • put

      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.

    • put

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

    • put

      public JSONArray put(int index, Collection value) throws JSONException
      Put a value in the JSONArray, where the value will be a JSONArray which is produced from a Collection.
      Parameters:
      index - The subscript.
      value - A Collection value.
      Returns:
      this.
      Throws:
      JSONException - If the index is negative or if the value is not finite.

    • put

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

    • put

      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.

    • put

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

    • put

      public JSONArray put(int index, Map value) throws JSONException
      Put a value in the JSONArray, where the value will be a JSONObject which is produced from a Map.
      Parameters:
      index - The subscript.
      value - The Map value.
      Returns:
      this.
      Throws:
      JSONException - If the index is negative or if the the value is an invalid number.

    • put

      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.

    • toJSONObject

      public JSONObject toJSONObject(JSONArray names) throws JSONException
      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.

    • toString

      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.

      Overrides:
      toString in class Object
      Returns:
      a printable, displayable, transmittable representation of the array.

    • toString

      public String toString(int indentFactor) throws JSONException
      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

    • write

      public Writer write(Writer writer) throws JSONException
      Write the contents of the JSONArray as JSON text to a writer. For compactness, no whitespace is added.

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

      Returns:
      The writer.
      Throws:
      JSONException