package com.github.ltsopensource.core.logger.support;
import java.util.HashMap;
import java.util.Map;
/**
* 来自 slf4j
* @author Robert HG (254963746@qq.com) on 5/19/15.
*/
@SuppressWarnings("rawtypes")
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.
* <p>
* For example,
*
* <pre>
* MessageFormatter.format("Hi {}.", "there");
* </pre>
*
* will return the string "Hi there.".
* <p>
*
* @param messagePattern
* The message pattern which will be parsed and formatted
* 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.
* <p>
* For example,
*
* <pre>
* MessageFormatter.format("Hi {}. My name is {}.", "Alice", "Bob");
* </pre>
*
* 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;
}
/**
* 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
*/
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(']');
}
}