Package com.tangosol.config.expression

Class ValueMacroExpression

java.lang.Object
com.tangosol.config.expression.ValueMacroExpression
All Implemented Interfaces:
Expression<String>, ExternalizableLite, PortableObject, Serializable
public class ValueMacroExpression extends Object implements Expression<String>, ExternalizableLite, PortableObject
A ValueMacroExpression is a string value potentially containing expandable macros.

Resolving the expression performs macro expansion. The macro syntax is ${macro-parameter default-value}. Thus, a value of near-${coherence.client direct} is macro expanded by default to near-direct. If property coherence.client is set to remote, then the value would be expanded to near-remote.

As of Coherence 14.1.2.0.0, the following common shell parameter expansion capabilities have been added. 

 ${macro-parameter ${macro-parameter-default default-value}}
 Supports nesting of macro parameters to enable the defaulting value to be configured as a macro-parameter.
In addition to the default delimiter of a space character, the colon character indicates a modifier for macro expansion.
Note that word referenced below is either a nested macro parameter default or the default value. 

 ${macro-parameter:-word}
 If macro-parameter is unset or null, the expansion of wordis substituted,
 otherwise, the value of macro-parameter is substituted.

 ${macro-parameter:+word}
 If macro-parameter is null or unset, nothing is substituted,
 otherwise the expansion of word is substituted.

 ${macro-parameter:offset}
 ${macro-parameter:offset:length}
 Note that length and offset are integer values.
See ValueMacroExpression.OffsetLengthSubstringExpansionProcessor.process(String, ParameterResolver, int) for substring expansion details and example usages.

Since:
Coherence 12.2.1
Author:
jf 2015.05.18
See Also:

  • Field Details

    • MAX_MACRO_EXPANSIONS

      public static int MAX_MACRO_EXPANSIONS
      Avoid recursive macro expansions that never return. No need for more than 20 macro expansions on one value.

    • PARAMETER_PREFIX

      public static final String PARAMETER_PREFIX
      Prefix indicating the start of a property macro.
      See Also:

    • PARAMETER_SUFFIX

      public static final Character PARAMETER_SUFFIX
      Suffix indicating the close of a property macro.

    • SUBSTRING_OFFSET_LENGTH_EXPANSION

      public static final String SUBSTRING_OFFSET_LENGTH_EXPANSION
      Delimiter introducing substring expansion of optional :offset and/or :length in a macro parameter.
      See Also:

  • Constructor Details

    • ValueMacroExpression

      public ValueMacroExpression()
      Default constructor needed for serialization.

    • ValueMacroExpression

      public ValueMacroExpression(String value)
      Construct a ValueMacroExpression.
      Parameters:
      value - the value that potentially contains a macro expression.

  • Method Details

    • evaluate

      public String evaluate(ParameterResolver resolver)
      Evaluates the Expression to produce a value of type T.
      Specified by:
      evaluate in interface Expression<String>
      Parameters:
      resolver - the ParameterResolver for resolving any parameters used by the Expression
      Returns:
      The result of evaluating the expression

    • substitute

      protected String substitute(String sValue, ParameterResolver resolver, int cDepth)
      Return a string value containing no outstanding macro parameters.
      Parameters:
      sValue - a value containing 0 or more macro parameters
      resolver - a macro parameter resolver
      cDepth - current number of macro parameter resolutions
      Returns:
      a string value containing no outstanding macro parameters

    • processRegisteredMacroExpansions

      protected String processRegisteredMacroExpansions(String sMacro, ParameterResolver resolver, int cDepth)
      Process macro expansion of sMacro by registered macro-expansion processors.
      Parameters:
      sMacro - macro parameter
      resolver - resolve macro parameter within sMacro
      cDepth - count of macro parameter expansions
      Returns:
      result of macro parameter expansion processing

    • containsMacro

      public boolean containsMacro()
      Check if this contains a macro.
      Returns:
      true iff this contains a macro

    • containsMacro

      public static boolean containsMacro(String sValue)
      Check if string contains a macro.
      Parameters:
      sValue - string potentially containing a macro
      Returns:
      true iff the string value contains a macro

    • containsRegisteredDelimiter

      protected static boolean containsRegisteredDelimiter(String sMacro)
      Return true if sMacro contains a registered delimiter.
      Parameters:
      sMacro - macro parameter
      Returns:
      true if sMacro string contains a registered delimiter

    • readExternal

      public void readExternal(DataInput in) throws IOException
      Restore the contents of this object by loading the object's state from the passed DataInput object.
      Specified by:
      readExternal in interface ExternalizableLite
      Parameters:
      in - the DataInput stream to read data from in order to restore the state of this object
      Throws:
      IOException - if an I/O exception occurs

    • writeExternal

      public void writeExternal(DataOutput out) throws IOException
      Save the contents of this object by storing the object's state into the passed DataOutput object.
      Specified by:
      writeExternal in interface ExternalizableLite
      Parameters:
      out - the DataOutput stream to write the state of this object to
      Throws:
      IOException - if an I/O exception occurs

    • readExternal

      public void readExternal(PofReader reader) throws IOException
      Restore the contents of a user type instance by reading its state using the specified PofReader object.
      Specified by:
      readExternal in interface PortableObject
      Parameters:
      reader - the PofReader from which to read the object's state
      Throws:
      IOException - if an I/O error occurs

    • writeExternal

      public void writeExternal(PofWriter writer) throws IOException
      Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
      Specified by:
      writeExternal in interface PortableObject
      Parameters:
      writer - the PofWriter to which to write the object's state
      Throws:
      IOException - if an I/O error occurs

    • toString

      public String toString()
      Overrides:
      toString in class Object