Package org.apache.logging.log4j.message

Class ParameterizedMessage

  • All Implemented Interfaces:
    java.io.Serializable, Message, org.apache.logging.log4j.util.StringBuilderFormattable
    public class ParameterizedMessage
extends java.lang.Object
implements Message, org.apache.logging.log4j.util.StringBuilderFormattable
    Handles messages that consist of a format string containing '{}' to represent each replaceable token, and the parameters.

    This class was originally written for Lilith by Joern Huxhorn where it is licensed under the LGPL. It has been relicensed here with his permission providing that this attribution remain.

    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      ParameterizedMessage​(java.lang.String messagePattern, java.lang.Object arg)
      Constructor with a pattern and a single parameter.
      ParameterizedMessage​(java.lang.String messagePattern, java.lang.Object... arguments)
      Constructs a ParameterizedMessage which contains the arguments converted to String as well as an optional Throwable.
      ParameterizedMessage​(java.lang.String messagePattern, java.lang.Object[] arguments, java.lang.Throwable throwable)
      Creates a parameterized message.
      ParameterizedMessage​(java.lang.String messagePattern, java.lang.Object arg0, java.lang.Object arg1)
      Constructor with a pattern and two parameters.
      ParameterizedMessage​(java.lang.String messagePattern, java.lang.String[] arguments, java.lang.Throwable throwable)
      Deprecated.
      Use constructor ParameterizedMessage(String, Object[], Throwable) instead

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static int countArgumentPlaceholders​(java.lang.String messagePattern)
      Counts the number of unescaped placeholders in the given messagePattern.
      static java.lang.String deepToString​(java.lang.Object o)
      This method performs a deep toString of the given Object.
      boolean equals​(java.lang.Object o)  
      static java.lang.String format​(java.lang.String messagePattern, java.lang.Object[] arguments)
      Replace placeholders in the given messagePattern with arguments.
      void formatTo​(java.lang.StringBuilder buffer)  
      java.lang.String getFormat()
      Returns the message pattern.
      java.lang.String getFormattedMessage()
      Returns the formatted message.
      java.lang.Object[] getParameters()
      Returns the message parameters.
      java.lang.Throwable getThrowable()
      Returns the Throwable that was given as the last argument, if any.
      int hashCode()  
      static java.lang.String identityToString​(java.lang.Object obj)
      This method returns the same as if Object.toString() would not have been overridden in obj.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait

    • Field Detail

      • RECURSION_PREFIX

        public static final java.lang.String RECURSION_PREFIX
        Prefix for recursion.
        See Also:
        Constant Field Values

      • RECURSION_SUFFIX

        public static final java.lang.String RECURSION_SUFFIX
        Suffix for recursion.
        See Also:
        Constant Field Values

      • ERROR_PREFIX

        public static final java.lang.String ERROR_PREFIX
        Prefix for errors.
        See Also:
        Constant Field Values

      • ERROR_SEPARATOR

        public static final java.lang.String ERROR_SEPARATOR
        Separator for errors.
        See Also:
        Constant Field Values

      • ERROR_MSG_SEPARATOR

        public static final java.lang.String ERROR_MSG_SEPARATOR
        Separator for error messages.
        See Also:
        Constant Field Values

      • ERROR_SUFFIX

        public static final java.lang.String ERROR_SUFFIX
        Suffix for errors.
        See Also:
        Constant Field Values

    • Constructor Detail

      • ParameterizedMessage

        @Deprecated
public ParameterizedMessage​(java.lang.String messagePattern,
                            java.lang.String[] arguments,
                            java.lang.Throwable throwable)
        Deprecated.
        Use constructor ParameterizedMessage(String, Object[], Throwable) instead
        Creates a parameterized message.
        Parameters:
        messagePattern - The message "format" string. This will be a String containing "{}" placeholders where parameters should be substituted.
        arguments - The arguments for substitution.
        throwable - A Throwable.

      • ParameterizedMessage

        public ParameterizedMessage​(java.lang.String messagePattern,
                            java.lang.Object[] arguments,
                            java.lang.Throwable throwable)
        Creates a parameterized message.
        Parameters:
        messagePattern - The message "format" string. This will be a String containing "{}" placeholders where parameters should be substituted.
        arguments - The arguments for substitution.
        throwable - A Throwable.

      • ParameterizedMessage

        public ParameterizedMessage​(java.lang.String messagePattern,
                            java.lang.Object... arguments)
        Constructs a ParameterizedMessage which contains the arguments converted to String as well as an optional Throwable.

        If the last argument is a Throwable and is NOT used up by a placeholder in the message pattern it is returned in getThrowable() and won't be contained in the created String[]. If it is used up getThrowable() will return null even if the last argument was a Throwable!

        Parameters:
        messagePattern - the message pattern that to be checked for placeholders.
        arguments - the argument array to be converted.

      • ParameterizedMessage

        public ParameterizedMessage​(java.lang.String messagePattern,
                            java.lang.Object arg)
        Constructor with a pattern and a single parameter.
        Parameters:
        messagePattern - The message pattern.
        arg - The parameter.

      • ParameterizedMessage

        public ParameterizedMessage​(java.lang.String messagePattern,
                            java.lang.Object arg0,
                            java.lang.Object arg1)
        Constructor with a pattern and two parameters.
        Parameters:
        messagePattern - The message pattern.
        arg0 - The first parameter.
        arg1 - The second parameter.

    • Method Detail

      • getFormat

        public java.lang.String getFormat()
        Returns the message pattern.
        Specified by:
        getFormat in interface Message
        Returns:
        the message pattern.

      • getParameters

        public java.lang.Object[] getParameters()
        Returns the message parameters.
        Specified by:
        getParameters in interface Message
        Returns:
        the message parameters.

      • getThrowable

        public java.lang.Throwable getThrowable()
        Returns the Throwable that was given as the last argument, if any. It will not survive serialization. The Throwable exists as part of the message primarily so that it can be extracted from the end of the list of parameters and then be added to the LogEvent. As such, the Throwable in the event should not be used once the LogEvent has been constructed.
        Specified by:
        getThrowable in interface Message
        Returns:
        the Throwable, if any.

      • getFormattedMessage

        public java.lang.String getFormattedMessage()
        Returns the formatted message.
        Specified by:
        getFormattedMessage in interface Message
        Returns:
        the formatted message.

      • formatTo

        public void formatTo​(java.lang.StringBuilder buffer)
        Specified by:
        formatTo in interface org.apache.logging.log4j.util.StringBuilderFormattable

      • format

        public static java.lang.String format​(java.lang.String messagePattern,
                                      java.lang.Object[] arguments)
        Replace placeholders in the given messagePattern with arguments.
        Parameters:
        messagePattern - the message pattern containing placeholders.
        arguments - the arguments to be used to replace placeholders.
        Returns:
        the formatted message.

      • 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

      • countArgumentPlaceholders

        public static int countArgumentPlaceholders​(java.lang.String messagePattern)
        Counts the number of unescaped placeholders in the given messagePattern.
        Parameters:
        messagePattern - the message pattern to be analyzed.
        Returns:
        the number of unescaped placeholders.

      • deepToString

        public static java.lang.String deepToString​(java.lang.Object o)
        This method performs a deep toString of the given Object. Primitive arrays are converted using their respective Arrays.toString methods while special handling is implemented for "container types", i.e. Object[], Map and Collection because those could contain themselves.

        It should be noted that neither AbstractMap.toString() nor AbstractCollection.toString() implement such a behavior. They only check if the container is directly contained in itself, but not if a contained container contains the original one. Because of that, Arrays.toString(Object[]) isn't safe either. Confusing? Just read the last paragraph again and check the respective toString() implementation.

        This means, in effect, that logging would produce a usable output even if an ordinary System.out.println(o) would produce a relatively hard-to-debug StackOverflowError.

        Parameters:
        o - The object.
        Returns:
        The String representation.

      • identityToString

        public static java.lang.String identityToString​(java.lang.Object obj)
        This method returns the same as if Object.toString() would not have been overridden in obj.

        Note that this isn't 100% secure as collisions can always happen with hash codes.

        Copied from Object.hashCode():

        As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)
        Parameters:
        obj - the Object that is to be converted into an identity string.
        Returns:
        the identity string as also defined in Object.toString()

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object