/*
* Copyright 2013 The Netty Project
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
/**
* Copyright (c) 2004-2011 QOS.ch
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
package org.waarp.common.logging;
import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;
// contributors: lizongbo: proposed special treatment of array parameter values
// Joern Huxhorn: pointed out double[] omission, suggested deep array copy
/**
* Formats messages according to very simple substitution rules. Substitutions
* can be made 1, 2 or more arguments.
* <p/>
* <p/>
* For example,
* <p/>
*
* <pre>
* MessageFormatter.format("Hi {}.", "there")
* </pre>
* <p/>
* will return the string "Hi there.".
* <p/>
* The {} pair is called the <em>formatting anchor</em>. It serves to designate the location where arguments need to be
* substituted within the message pattern.
* <p/>
* In case your message contains the '{' or the '}' character, you do not have to do anything special unless the '}' character
* immediately follows '{'. For example,
* <p/>
*
* <pre>
* MessageFormatter.format("Set {1,2,3} is not equal to {}.", "1,2");
* </pre>
* <p/>
* will return the string "Set {1,2,3} is not equal to 1,2.".
* <p/>
* <p/>
* If for whatever reason you need to place the string "{}" in the message without its <em>formatting anchor</em> 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,
* <p/>
*
* <pre>
* MessageFormatter.format("Set \\{} is not equal to {}.", "1,2");
* </pre>
* <p/>
* will return the string "Set {} is not equal to 1,2.".
* <p/>
* <p/>
* The escaping behavior just described can be overridden by escaping the escape character '\'. Calling
* <p/>
*
* <pre>
* MessageFormatter.format("File name is C:\\\\{}.", "file.zip");
* </pre>
* <p/>
* will return the string "File name is C:\file.zip".
* <p/>
* <p/>
* The formatting conventions are different than those of {@link MessageFormat} which ships with the Java platform. This is
* justified by the fact that SLF4J's implementation is 10 times faster than that of {@link MessageFormat}. This local performance
* difference is both measurable and significant in the larger context of the complete logging processing chain.
* <p/>
* <p/>
* See also {@link #format(String, Object)}, {@link #format(String, Object, Object)} and {@link #arrayFormat(String, Object[])}
* methods for more details.
*/
final class MessageFormatter {
private static final WaarpLogger LOGGER = WaarpLoggerFactory.getInstance(MessageFormatter.class);
static final char DELIM_START = '{';
static final char DELIM_STOP = '}';
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("Hi {}.", "there");
* </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
*/
static FormattingTuple format(final String messagePattern, final 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("Hi {}. My name is {}.", "Alice", "Bob");
* </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
*/
static FormattingTuple format(final String messagePattern, final Object argA, final Object argB) {
return arrayFormat(messagePattern, new Object[] { argA, argB });
}
static Throwable getThrowableCandidate(final 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;
}
/**
* 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
*/
static FormattingTuple arrayFormat(final String messagePattern, final Object[] argArray) {
final 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;
final 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<Object[], Void>());
i = j + 2;
}
} else {
// normal case
sbuf.append(messagePattern.substring(i, j));
deeplyAppendParameter(sbuf, argArray[l], new HashMap<Object[], Void>());
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);
}
}
static boolean isEscapedDelimeter(final String messagePattern, final int delimeterStartIndex) {
if (delimeterStartIndex == 0) {
return false;
}
return messagePattern.charAt(delimeterStartIndex - 1) == ESCAPE_CHAR;
}
static boolean isDoubleEscaped(final String messagePattern, final int delimeterStartIndex) {
return delimeterStartIndex >= 2 && messagePattern.charAt(delimeterStartIndex - 2) == ESCAPE_CHAR;
}
// special treatment of array values was suggested by 'lizongbo'
private static void deeplyAppendParameter(final StringBuffer sbuf, final Object o, final Map<Object[], Void> 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(final StringBuffer sbuf, final Object o) {
try {
final String oAsString = o.toString();
sbuf.append(oAsString);
} catch (final Throwable t) {
LOGGER.error("SLF4J: Failed toString() invocation on an object of type [" + o.getClass().getName() + ']', t);
sbuf.append("[FAILED toString()]");
}
}
private static void objectArrayAppend(final StringBuffer sbuf, final Object[] a, final Map<Object[], Void> 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(final StringBuffer sbuf, final 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(']');
}
private MessageFormatter() {
}
}