/*
*
*
* Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.j2me.global;
/**
* <code>MessageFormat</code> provides means to produce concatenated messages
* in language-neutral way. Use this to construct messages displayed for end
* users. <code>MessageFormat</code> formats message with variable number of
* parameters. Pattern string contains placeholders of the form {0} .. {nn}.
* Placeholders are replaced by parameters. Escaped "{{" can be used to get '{'
* in formatted message. <p>
*
* <code>MessageFormat</code> takes a set of strings, and inserts the them into
* the pattern at the appropriate places. <p>
*
* <pre>
* String output = MessageFormat.format("Message {1} for formatting {2}",
* new String[]{"first_arg",
* "second_arg"});
* </pre>
*
*/
public class MessageFormat {
/**
* Value for the left parenthesis char
*/
private final static char LEFT_PARENTHESIS = '{';
/**
* Value for the right parenthesis char
*/
private final static char RIGHT_PARENTHESIS = '}';
/**
* Replace placeholders in template with parameters.
*
* @param message the template with placeholders
* @param params array of parameters
* @return buffer containing formatted message
*/
public static String format(String message, String[] params) {
if (message == null || params == null) {
throw new NullPointerException("Template or parameter array is null.");
}
boolean inside = false;
boolean escaped = false;
StringBuffer result = new StringBuffer();
StringBuffer placeholder = null;
char lookingFor = LEFT_PARENTHESIS;
char c;
for (int i = 0; i < message.length(); i++) {
c = message.charAt(i);
if (c == lookingFor) {
if (escaped) {
result.append(c);
escaped = false;
continue;
}
if (c == LEFT_PARENTHESIS) {
// look ahead for escaped parenthesis
if ((i + 1) < message.length() &&
message.charAt(i + 1) == LEFT_PARENTHESIS) {
escaped = true;
} else {
inside = true;
lookingFor = RIGHT_PARENTHESIS;
placeholder = new StringBuffer();
}
} else {
inside = false;
lookingFor = LEFT_PARENTHESIS;
// placeholder finished get parameter
try {
if (placeholder.length() > 2) {
throw new IllegalArgumentException(
"Illegal placeholder.");
}
int index = Integer.parseInt(placeholder.toString());
result.append(params[index]);
} catch (ArrayIndexOutOfBoundsException ie) {
throw new IllegalArgumentException(
"Illegal number of parameters.");
}
}
} else {
if (inside) {
placeholder.append(c);
} else {
result.append(c);
}
}
}
// for
return result.toString();
}
}