MessageFormatter Class — netty Architecture

Source Code

common/src/main/java/io/netty/util/internal/logging/MessageFormatter.java lines 111–397

public final class MessageFormatter {
    private static final String DELIM_STR = "{}";
    private static final char ESCAPE_CHAR = '\\';

    /**
     * Performs single argument substitution for the 'messagePattern' passed as
     * parameter.
     * <p/>
     * For example,
     * <p/>
     * <pre>
     * MessageFormatter.format(&quot;Hi {}.&quot;, &quot;there&quot;);
     * </pre>
     * <p/>
     * will return the string "Hi there.".
     * <p/>
     *
     * @param messagePattern The message pattern which will be parsed and formatted
     * @param arg            The argument to be substituted in place of the formatting anchor
     * @return The formatted message
     */
    public static FormattingTuple format(String messagePattern, Object arg) {
        return arrayFormat(messagePattern, new Object[]{arg});
    }

    /**
     * Performs a two argument substitution for the 'messagePattern' passed as
     * parameter.
     * <p/>
     * For example,
     * <p/>
     * <pre>
     * MessageFormatter.format(&quot;Hi {}. My name is {}.&quot;, &quot;Alice&quot;, &quot;Bob&quot;);
     * </pre>
     * <p/>
     * will return the string "Hi Alice. My name is Bob.".
     *
     * @param messagePattern The message pattern which will be parsed and formatted
     * @param argA           The argument to be substituted in place of the first formatting
     *                       anchor
     * @param argB           The argument to be substituted in place of the second formatting
     *                       anchor
     * @return The formatted message
     */
    public static FormattingTuple format(final String messagePattern,
                                  Object argA, Object argB) {
        return arrayFormat(messagePattern, new Object[]{argA, argB});
    }

    /**
     * Same principle as the {@link #format(String, Object)} and
     * {@link #format(String, Object, Object)} methods except that any number of
     * arguments can be passed in an array.
     *
     * @param messagePattern The message pattern which will be parsed and formatted
     * @param argArray       An array of arguments to be substituted in place of formatting
     *                       anchors
     * @return The formatted message
     */
    public static FormattingTuple arrayFormat(final String messagePattern,
                                       final Object[] argArray) {
        if (argArray == null || argArray.length == 0) {
            return new FormattingTuple(messagePattern, null);
        }

        int lastArrIdx = argArray.length - 1;
        Object lastEntry = argArray[lastArrIdx];
        Throwable throwable = lastEntry instanceof Throwable? (Throwable) lastEntry : null;

        if (messagePattern == null) {
            return new FormattingTuple(null, throwable);
        }

        int j = messagePattern.indexOf(DELIM_STR);
        if (j == -1) {
            // this is a simple string
            return new FormattingTuple(messagePattern, throwable);
        }

        StringBuilder sbuf = new StringBuilder(messagePattern.length() + 50);
        int i = 0;