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/**
 * 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.slf4j.helpers;

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.
 *
 * 

* 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 {@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. * *

* See also {@link #format(String, Object)}, * {@link #format(String, Object, Object)} and * {@link #arrayFormat(String, Object[])} methods for more details. * * @author Ceki Gülcü * @author Joern Huxhorn */ 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 = '\\'; /** * Performs single argument substitution for the 'messagePattern' passed as * parameter. *

* For example, * *

     * MessageFormatter.format("Hi {}.", "there");
     * 
* * will return the string "Hi there.". *

* * @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 */ final 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. *

* For example, * *

     * MessageFormatter.format("Hi {}. My name is {}.", "Alice", "Bob");
     * 
* * will return the string "Hi Alice. My name is Bob.". * * @param messagePattern * The message pattern which will be parsed and formatted * @param arg1 * The argument to be substituted in place of the first formatting * anchor * @param arg2 * The argument to be substituted in place of the second formatting * anchor * @return The formatted message */ 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); Object[] args = argArray; if (throwableCandidate != null) { args = trimmedCopy(argArray); } return arrayFormat(messagePattern, args, throwableCandidate); } private static Object[] trimmedCopy(Object[] argArray) { if (argArray == null || argArray.length == 0) { throw new IllegalStateException("non-sensical empty or null argument array"); } final int trimemdLen = argArray.length - 1; Object[] trimmed = new Object[trimemdLen]; System.arraycopy(argArray, 0, trimmed, 0, trimemdLen); return trimmed; } final public static FormattingTuple arrayFormat(final String messagePattern, final Object[] argArray, Throwable throwable) { if (messagePattern == null) { return new FormattingTuple(null, argArray, throwable); } if (argArray == null) { return new FormattingTuple(messagePattern); } int i = 0; int j; // use string builder for better multicore performance StringBuilder sbuf = new StringBuilder(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, throwable); } else { // add the tail string which contains no variables and return // the result. sbuf.append(messagePattern, i, messagePattern.length()); return new FormattingTuple(sbuf.toString(), argArray, throwable); } } else { if (isEscapedDelimeter(messagePattern, j)) { if (!isDoubleEscaped(messagePattern, j)) { L--; // DELIM_START was escaped, thus should not be incremented sbuf.append(messagePattern, 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, i, j - 1); deeplyAppendParameter(sbuf, argArray[L], new HashMap()); i = j + 2; } } else { // normal case sbuf.append(messagePattern, i, j); deeplyAppendParameter(sbuf, argArray[L], new HashMap()); i = j + 2; } } } // append the characters following the last {} pair. sbuf.append(messagePattern, i, messagePattern.length()); return new FormattingTuple(sbuf.toString(), argArray, throwable); } 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(StringBuilder 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(StringBuilder sbuf, Object o) { try { String oAsString = o.toString(); sbuf.append(oAsString); } catch (Throwable t) { Util.report("SLF4J: Failed toString() invocation on an object of type [" + o.getClass().getName() + "]", t); sbuf.append("[FAILED toString()]"); } } private static void objectArrayAppend(StringBuilder 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(StringBuilder 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(StringBuilder 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(StringBuilder 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(StringBuilder 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(StringBuilder 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(StringBuilder 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(StringBuilder 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(StringBuilder 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(']'); } }




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