com.taobao.middleware.logger.util.MessageFormatter Maven / Gradle / Ivy

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package com.taobao.middleware.logger.util;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;

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

  final public static FormattingTuple format(String messagePattern, Object arg) {
    return arrayFormat(messagePattern, new Object[] { arg });
  }

  final public static FormattingTuple format(final String messagePattern,
      Object arg1, Object arg2) {
    return arrayFormat(messagePattern, new Object[] { arg1, arg2 });
  }

  static final Throwable getThrowableCandidate(Object[] argArray) {
    if (argArray == null || argArray.length == 0) {
      return null;
    }

    final Object lastEntry = argArray[argArray.length - 1];
    if (lastEntry instanceof Throwable) {
      return (Throwable) lastEntry;
    }
    return null;
  }

  final public static FormattingTuple arrayFormat(final String messagePattern,
      final Object[] argArray) {

    Throwable throwableCandidate = getThrowableCandidate(argArray);

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

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

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

    int L;
    for (L = 0; L < argArray.length; L++) {

      j = messagePattern.indexOf(DELIM_STR, i);

      if (j == -1) {
        // no more variables
        if (i == 0) { // this is a simple string
          return new FormattingTuple(messagePattern, argArray,
              throwableCandidate);
        } else { // add the tail string which contains no variables and return
          // the result.
          sbuf.append(messagePattern.substring(i, messagePattern.length()));
          return new FormattingTuple(sbuf.toString(), argArray,
              throwableCandidate);
        }
      } else {
        if (isEscapedDelimeter(messagePattern, j)) {
          if (!isDoubleEscaped(messagePattern, j)) {
            L--; // DELIM_START was escaped, thus should not be incremented
            sbuf.append(messagePattern.substring(i, j - 1));
            sbuf.append(DELIM_START);
            i = j + 1;
          } else {
            // The escape character preceding the delimiter start is
            // itself escaped: "abc x:\\{}"
            // we have to consume one backward slash
            sbuf.append(messagePattern.substring(i, j - 1));
            deeplyAppendParameter(sbuf, argArray[L], new HashMap());
            i = j + 2;
          }
        } else {
          // normal case
          sbuf.append(messagePattern.substring(i, j));
          deeplyAppendParameter(sbuf, argArray[L], new HashMap());
          i = j + 2;
        }
      }
    }
    // append the characters following the last {} pair.
    sbuf.append(messagePattern.substring(i, messagePattern.length()));
    if (L < argArray.length - 1) {
      return new FormattingTuple(sbuf.toString(), argArray, throwableCandidate);
    } else {
      return new FormattingTuple(sbuf.toString(), argArray, null);
    }
  }

  final static boolean isEscapedDelimeter(String messagePattern,
      int delimeterStartIndex) {

    if (delimeterStartIndex == 0) {
      return false;
    }
    char potentialEscape = messagePattern.charAt(delimeterStartIndex - 1);
    if (potentialEscape == ESCAPE_CHAR) {
      return true;
    } else {
      return false;
    }
  }

  final static boolean isDoubleEscaped(String messagePattern,
      int delimeterStartIndex) {
    if (delimeterStartIndex >= 2
        && messagePattern.charAt(delimeterStartIndex - 2) == ESCAPE_CHAR) {
      return true;
    } else {
      return false;
    }
  }

  // special treatment of array values was suggested by 'lizongbo'
  private static void deeplyAppendParameter(StringBuffer sbuf, Object o,
      Map seenMap) {
    if (o == null) {
      sbuf.append("null");
      return;
    }
    if (!o.getClass().isArray()) {
      safeObjectAppend(sbuf, o);
    } else {
      // check for primitive array types because they
      // unfortunately cannot be cast to Object[]
      if (o instanceof boolean[]) {
        booleanArrayAppend(sbuf, (boolean[]) o);
      } else if (o instanceof byte[]) {
        byteArrayAppend(sbuf, (byte[]) o);
      } else if (o instanceof char[]) {
        charArrayAppend(sbuf, (char[]) o);
      } else if (o instanceof short[]) {
        shortArrayAppend(sbuf, (short[]) o);
      } else if (o instanceof int[]) {
        intArrayAppend(sbuf, (int[]) o);
      } else if (o instanceof long[]) {
        longArrayAppend(sbuf, (long[]) o);
      } else if (o instanceof float[]) {
        floatArrayAppend(sbuf, (float[]) o);
      } else if (o instanceof double[]) {
        doubleArrayAppend(sbuf, (double[]) o);
      } else {
        objectArrayAppend(sbuf, (Object[]) o, seenMap);
      }
    }
  }

  private static void safeObjectAppend(StringBuffer sbuf, Object o) {
    try {
      String oAsString = o.toString();
      sbuf.append(oAsString);
    } catch (Throwable t) {
      System.err
          .println("SLF4J: Failed toString() invocation on an object of type ["
              + o.getClass().getName() + "]");
      t.printStackTrace();
      sbuf.append("[FAILED toString()]");
    }

  }

  private static void objectArrayAppend(StringBuffer sbuf, Object[] a,
      Map seenMap) {
    sbuf.append('[');
    if (!seenMap.containsKey(a)) {
      seenMap.put(a, null);
      final int len = a.length;
      for (int i = 0; i < len; i++) {
        deeplyAppendParameter(sbuf, a[i], seenMap);
        if (i != len - 1)
          sbuf.append(", ");
      }
      // allow repeats in siblings
      seenMap.remove(a);
    } else {
      sbuf.append("...");
    }
    sbuf.append(']');
  }

  private static void booleanArrayAppend(StringBuffer sbuf, boolean[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void byteArrayAppend(StringBuffer sbuf, byte[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void charArrayAppend(StringBuffer sbuf, char[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void shortArrayAppend(StringBuffer sbuf, short[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void intArrayAppend(StringBuffer sbuf, int[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void longArrayAppend(StringBuffer sbuf, long[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void floatArrayAppend(StringBuffer sbuf, float[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void doubleArrayAppend(StringBuffer sbuf, double[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1)
        sbuf.append(", ");
    }
    sbuf.append(']');
  }
}