Package: groovy.lang

## [Java] Class GString

- groovy.lang.GString

- All Implemented Interfaces and Traits:
    Buildable, Comparable, CharSequence, Writable, Serializable

      public abstract class GString
      extends GroovyObjectSupport
      implements Buildable, Comparable, CharSequence, Writable, Serializable

  Represents a String which contains embedded values such as "hello there ${user} how are you?" which can be evaluated lazily. Advanced users can iterate over the text and values to perform special processing, such as for performing SQL operations, the values can be substituted for ? and the actual value objects can be bound to a JDBC statement.

  James Strachan: The lovely name of this class was suggested by Jules Gosnell and was such a good idea, I couldn't resist :)

- - ### Field Summary

    Fields
    Modifiers | Name | Description
    --- | --- | ---
    `static GString` | `EMPTY` | A GString containing a single empty String and no values.
    `static Object[]` | `EMPTY_OBJECT_ARRAY` | Shared empty object array.
    `static String[]` | `EMPTY_STRING_ARRAY` | Shared empty string array.

  - ### Constructor Summary

    Constructors
    Constructor and description
    `GString(Object values)` Creates a GString from the supplied values array reference.
    `GString(Object[] values)` Creates a GString from the supplied values.

  - ### Methods Summary

    Methods
    Type Params | Return Type | Name and description
    --- | --- | ---
    `` | `public void` | `build(GroovyObject builder)` Builds this object into the supplied builder. Parameters: `builder` - the target builder
    `` | `protected int` | `calcInitialCapacity()` Calculates the initial buffer capacity for rendering this GString.
    `` | `public char` | `charAt(int index)` {@inheritDoc}
    `` | `public int` | `compareTo(Object that)` {@inheritDoc}
    `` | `public boolean` | `equals(Object that)` {@inheritDoc}
    `` | `public boolean` | `equals(GString that)` Compares this GString with another GString by rendered content.
    `` | `public byte[]` | `getBytes()` Returns the rendered string as a byte array using the platform default charset.
    `` | `public byte[]` | `getBytes(String charset)` Returns the rendered string as a byte array using the supplied charset.
    `` | `public abstract String[]` | `getStrings()` Returns the string segments surrounding the interpolated values.
    `` | `public Object` | `getValue(int idx)` Returns the interpolated value at the supplied index.
    `` | `public int` | `getValueCount()` Returns the number of interpolated values.
    `` | `public Object[]` | `getValues()` Returns the interpolated values.
    `` | `public int` | `hashCode()` {@inheritDoc}
    `` | `public Object` | `invokeMethod(String name, Object args)` Overloaded to implement duck typing for Strings so that any method that can't be evaluated on this object will be forwarded to the toString() object instead.
    `` | `public int` | `length()` {@inheritDoc}
    `` | `public Pattern` | `negate()` Turns a String into a regular expression pattern
    `` | `public GString` | `plus(GString that)` Concatenates this GString with another GString.
    `` | `public GString` | `plus(String that)` Concatenates this GString with a String.
    `` | `public CharSequence` | `subSequence(int start, int end)` {@inheritDoc}
    `` | `public String` | `toString()` {@inheritDoc}
    `` | `public Writer` | `writeTo(Writer out)` Writes this object to the given writer. This is used to defer content creation until the point when it is streamed to the output destination. Oftentimes, content will be defined but not necessarily created (as it may be the case with a Closure definition.) In that case, the output is then 'deferred' to the point when it is serialized to the writer. This class may be used whenever an object should be responsible for creating its own textual representation, but creating the entire output as a single String would be inefficient (such as outputting a multi-gigabyte XML document.) throws: IOException if an error occurred while outputting data to the writer Parameters: `out` - the Writer to which this Writable should output its data. Returns: the Writer that was passed

  - ### Inherited Methods Summary

    Inherited Methods
    Methods inherited from class | Name
    --- | ---
    `class GroovyObjectSupport` | `getMetaClass, setMetaClass`

- - ### Field Detail

    - #### public static final GString EMPTY

      A GString containing a single empty String and no values.

    - #### public static final Object[] EMPTY_OBJECT_ARRAY

      Shared empty object array.

    - #### public static final String[] EMPTY_STRING_ARRAY

      Shared empty string array.

  - ### Constructor Detail

    - #### public GString(Object values)

      Creates a GString from the supplied values array reference.

      Parameters:
        `values` - the interpolated values

    - #### public GString(Object[] values)

      Creates a GString from the supplied values.

      Parameters:
        `values` - the interpolated values

  - ### Method Detail

    - #### public void build(GroovyObject builder)

      Builds this object into the supplied builder.

      Parameters:
        `builder` - the target builder

    - #### protected int calcInitialCapacity()

      Calculates the initial buffer capacity for rendering this GString.

      Returns:
        the initial capacity

    - #### public char charAt(int index)

      {@inheritDoc}

    - #### public int compareTo(Object that)

      {@inheritDoc}

    - #### public boolean equals(Object that)

      {@inheritDoc}

    - #### public boolean equals(GString that)

      Compares this GString with another GString by rendered content.

      Parameters:
        `that` - the other GString
      Returns:
        `true` if the rendered strings are equal

    - #### public byte[] getBytes()

      Returns the rendered string as a byte array using the platform default charset.

      Returns:
        the rendered bytes

    - #### public byte[] getBytes(String charset)

      Returns the rendered string as a byte array using the supplied charset.

      throws:
        UnsupportedEncodingException if the charset is unsupported
      Parameters:
        `charset` - the charset name
      Returns:
        the rendered bytes

    - #### public abstract String[] getStrings()

      Returns the string segments surrounding the interpolated values.

      Returns:
        the string segments

    - #### public Object getValue(int idx)

      Returns the interpolated value at the supplied index.

      Parameters:
        `idx` - the value index
      Returns:
        the interpolated value

    - #### public int getValueCount()

      Returns the number of interpolated values.

      Returns:
        the value count

    - #### public Object[] getValues()

      Returns the interpolated values.

      Returns:
        the interpolated values

    - #### public int hashCode()

      {@inheritDoc}

    - #### public Object invokeMethod(String name, Object args)

      Overloaded to implement duck typing for Strings so that any method that can't be evaluated on this object will be forwarded to the toString() object instead.

    - #### public int length()

      {@inheritDoc}

    - #### public Pattern negate()

      Turns a String into a regular expression pattern

      Returns:
        the regular expression pattern

    - #### public GString plus(GString that)

      Concatenates this GString with another GString.

      Parameters:
        `that` - the other GString
      Returns:
        the concatenated GString

    - #### public GString plus(String that)

      Concatenates this GString with a String.

      Parameters:
        `that` - the string to append
      Returns:
        the concatenated GString

    - #### public CharSequence subSequence(int start, int end)

      {@inheritDoc}

    - #### public String toString()

      {@inheritDoc}

    - #### public Writer writeTo(Writer out)

      Writes this object to the given writer.

      This is used to defer content creation until the point when it is streamed to the output destination. Oftentimes, content will be defined but not necessarily created (as it may be the case with a Closure definition.) In that case, the output is then 'deferred' to the point when it is serialized to the writer. This class may be used whenever an object should be responsible for creating its own textual representation, but creating the entire output as a single String would be inefficient (such as outputting a multi-gigabyte XML document.)

      throws:
        IOException if an error occurred while outputting data to the writer
      Parameters:
        `out` - the Writer to which this Writable should output its data.
      Returns:
        the Writer that was passed