Class MessageFormatter

java.lang.Object
io.netty.util.internal.logging.MessageFormatter
public final class MessageFormatter extends java.lang.Object
Formats messages according to very simple substitution rules. Substitutions can be made 1, 2 or more arguments.

For example, 

MessageFormatter.format("Hi {}.", "there")

will return the string "Hi there.".

The {} pair is called the formatting anchor. It serves to designate the location where arguments need to be substituted within the message pattern.

In case your message contains the '{' or the '}' character, you do not have to do anything special unless the '}' character immediately follows '{'. For example, 

MessageFormatter.format("Set {1,2,3} is not equal to {}.", "1,2");

will return the string "Set {1,2,3} is not equal to 1,2.".

If for whatever reason you need to place the string "{}" in the message without its formatting anchor meaning, then you need to escape the '{' character with '\', that is the backslash character. Only the '{' character should be escaped. There is no need to escape the '}' character. For example, 

MessageFormatter.format("Set \\{} is not equal to {}.", "1,2");

will return the string "Set {} is not equal to 1,2.".

The escaping behavior just described can be overridden by escaping the escape character '\'. Calling 

MessageFormatter.format("File name is C:\\\\{}.", "file.zip");

will return the string "File name is C:\file.zip".

The formatting conventions are different than those of MessageFormat which ships with the Java platform. This is justified by the fact that SLF4J's implementation is 10 times faster than that of MessageFormat. This local performance difference is both measurable and significant in the larger context of the complete logging processing chain.

See also format(String, Object), format(String, Object, Object) and arrayFormat(String, Object[]) methods for more details.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private static final java.lang.String
    DELIM_STR
     
    private static final char
    ESCAPE_CHAR
     

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    private
    MessageFormatter()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static FormattingTuple
    arrayFormat(java.lang.String messagePattern, java.lang.Object[] argArray)
    Same principle as the format(String, Object) and format(String, Object, Object) methods except that any number of arguments can be passed in an array.
    private static void
    booleanArrayAppend(java.lang.StringBuilder sbuf, boolean[] a)
     
    private static void
    byteArrayAppend(java.lang.StringBuilder sbuf, byte[] a)
     
    private static void
    charArrayAppend(java.lang.StringBuilder sbuf, char[] a)
     
    private static void
    deeplyAppendParameter(java.lang.StringBuilder sbuf, java.lang.Object o, java.util.Set<java.lang.Object[]> seenSet)
     
    private static void
    doubleArrayAppend(java.lang.StringBuilder sbuf, double[] a)
     
    private static void
    floatArrayAppend(java.lang.StringBuilder sbuf, float[] a)
     
    static FormattingTuple
    format(java.lang.String messagePattern, java.lang.Object arg)
    Performs single argument substitution for the 'messagePattern' passed as parameter.
    static FormattingTuple
    format(java.lang.String messagePattern, java.lang.Object argA, java.lang.Object argB)
    Performs a two argument substitution for the 'messagePattern' passed as parameter.
    private static void
    intArrayAppend(java.lang.StringBuilder sbuf, int[] a)
     
    private static void
    longArrayAppend(java.lang.StringBuilder sbuf, long[] a)
     
    private static void
    objectArrayAppend(java.lang.StringBuilder sbuf, java.lang.Object[] a, java.util.Set<java.lang.Object[]> seenSet)
     
    private static void
    safeObjectAppend(java.lang.StringBuilder sbuf, java.lang.Object o)
     
    private static void
    shortArrayAppend(java.lang.StringBuilder sbuf, short[] a)
     

    Methods inherited from class java.lang.Object

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

  • Field Details

  • Constructor Details

    • MessageFormatter

      private MessageFormatter()

  • Method Details

    • format

      public static FormattingTuple format(java.lang.String messagePattern, java.lang.Object arg)
      Performs single argument substitution for the 'messagePattern' passed as parameter.

      For example, 

      MessageFormatter.format("Hi {}.", "there");

      will return the string "Hi there.".

      Parameters:
      messagePattern - The message pattern which will be parsed and formatted
      arg - The argument to be substituted in place of the formatting anchor
      Returns:
      The formatted message

    • format

      public static FormattingTuple format(java.lang.String messagePattern, java.lang.Object argA, java.lang.Object argB)
      Performs a two argument substitution for the 'messagePattern' passed as parameter.

      For example, 

      MessageFormatter.format("Hi {}. My name is {}.", "Alice", "Bob");

      will return the string "Hi Alice. My name is Bob.".

      Parameters:
      messagePattern - The message pattern which will be parsed and formatted
      argA - The argument to be substituted in place of the first formatting anchor
      argB - The argument to be substituted in place of the second formatting anchor
      Returns:
      The formatted message

    • arrayFormat

      public static FormattingTuple arrayFormat(java.lang.String messagePattern, java.lang.Object[] argArray)
      Same principle as the format(String, Object) and format(String, Object, Object) methods except that any number of arguments can be passed in an array.
      Parameters:
      messagePattern - The message pattern which will be parsed and formatted
      argArray - An array of arguments to be substituted in place of formatting anchors
      Returns:
      The formatted message

    • deeplyAppendParameter

      private static void deeplyAppendParameter(java.lang.StringBuilder sbuf, java.lang.Object o, java.util.Set<java.lang.Object[]> seenSet)

    • safeObjectAppend

      private static void safeObjectAppend(java.lang.StringBuilder sbuf, java.lang.Object o)

    • objectArrayAppend

      private static void objectArrayAppend(java.lang.StringBuilder sbuf, java.lang.Object[] a, java.util.Set<java.lang.Object[]> seenSet)

    • booleanArrayAppend

      private static void booleanArrayAppend(java.lang.StringBuilder sbuf, boolean[] a)

    • byteArrayAppend

      private static void byteArrayAppend(java.lang.StringBuilder sbuf, byte[] a)

    • charArrayAppend

      private static void charArrayAppend(java.lang.StringBuilder sbuf, char[] a)

    • shortArrayAppend

      private static void shortArrayAppend(java.lang.StringBuilder sbuf, short[] a)

    • intArrayAppend

      private static void intArrayAppend(java.lang.StringBuilder sbuf, int[] a)

    • longArrayAppend

      private static void longArrayAppend(java.lang.StringBuilder sbuf, long[] a)

    • floatArrayAppend

      private static void floatArrayAppend(java.lang.StringBuilder sbuf, float[] a)

    • doubleArrayAppend

      private static void doubleArrayAppend(java.lang.StringBuilder sbuf, double[] a)