/**
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2012, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package ch.qos.logback.core.subst;
import ch.qos.logback.core.CoreConstants;
import ch.qos.logback.core.spi.ScanException;
import java.util.ArrayList;
import java.util.List;
public class Tokenizer {
enum TokenizerState {LITERAL_STATE, START_STATE, DEFAULT_VAL_STATE}
final String pattern;
final int patternLength;
public Tokenizer(String pattern) {
this.pattern = pattern;
patternLength = pattern.length();
}
TokenizerState state = TokenizerState.LITERAL_STATE;
int pointer = 0;
List tokenize() throws ScanException {
List<Token> tokenList = new ArrayList<Token>();
StringBuilder buf = new StringBuilder();
while (pointer < patternLength) {
char c = pattern.charAt(pointer);
pointer++;
switch (state) {
case LITERAL_STATE:
handleLiteralState(c, tokenList, buf);
break;
case START_STATE:
handleStartState(c, tokenList, buf);
break;
case DEFAULT_VAL_STATE:
handleDefaultValueState(c, tokenList, buf);
default:
}
}
// EOS
switch (state) {
case LITERAL_STATE:
addLiteralToken(tokenList, buf);
break;
case START_STATE:
throw new ScanException("Unexpected end of pattern string");
}
return tokenList;
}
private void handleDefaultValueState(char c, List<Token> tokenList, StringBuilder stringBuilder) {
switch(c) {
case CoreConstants.DASH_CHAR:
tokenList.add(Token.DEFAULT_SEP_TOKEN);
state = TokenizerState.LITERAL_STATE;
break;
case CoreConstants.DOLLAR:
stringBuilder.append(CoreConstants.COLON_CHAR);
addLiteralToken(tokenList, stringBuilder);
stringBuilder.setLength(0);
state = TokenizerState.START_STATE;
break;
default:
stringBuilder.append(CoreConstants.COLON_CHAR).append(c);
state = TokenizerState.LITERAL_STATE;
break;
}
}
private void handleStartState(char c, List<Token> tokenList, StringBuilder stringBuilder) {
if (c == CoreConstants.CURLY_LEFT) {
tokenList.add(Token.START_TOKEN);
} else {
stringBuilder.append(CoreConstants.DOLLAR).append(c);
}
state = TokenizerState.LITERAL_STATE;
}
private void handleLiteralState(char c, List<Token> tokenList, StringBuilder stringBuilder) {
if (c == CoreConstants.DOLLAR) {
addLiteralToken(tokenList, stringBuilder);
stringBuilder.setLength(0);
state = TokenizerState.START_STATE;
} else if (c == CoreConstants.COLON_CHAR) {
addLiteralToken(tokenList, stringBuilder);
stringBuilder.setLength(0);
state = TokenizerState.DEFAULT_VAL_STATE;
} else if (c == CoreConstants.CURLY_LEFT) {
addLiteralToken(tokenList, stringBuilder);
tokenList.add(Token.CURLY_LEFT_TOKEN);
stringBuilder.setLength(0);
} else if (c == CoreConstants.CURLY_RIGHT) {
addLiteralToken(tokenList, stringBuilder);
tokenList.add(Token.CURLY_RIGHT_TOKEN);
stringBuilder.setLength(0);
} else {
stringBuilder.append(c);
}
}
private void addLiteralToken(List<Token> tokenList, StringBuilder stringBuilder) {
if (stringBuilder.length() == 0)
return;
tokenList.add(new Token(Token.Type.LITERAL, stringBuilder.toString()));
}
}