Android String Format format(String message, Object[] params)

Description

Apply printf() like formatting to a string.

License

Apache License

Parameter

Parameter	Description
message	the string with embedded formatting info eg. "This is a test %2.2"
params	array of values to format into the string

Return

The formatted string

Declaration

public static String format(String message, Object[] params) 

Method Source Code

//package com.java2s;
/* ====================================================================
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 this work for additional information regarding copyright ownership.
 The ASF 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.// w  ww.j av  a 2  s.  c om
 ==================================================================== */

import java.text.FieldPosition;
import java.text.NumberFormat;

public class Main {
    /**
     *  Apply printf() like formatting to a string.
     *  Primarily used for logging.
     * @param  message  the string with embedded formatting info
     *                 eg. "This is a test %2.2"
     * @param  params   array of values to format into the string
     * @return          The formatted string
     */
    public static String format(String message, Object[] params) {
        int currentParamNumber = 0;
        StringBuffer formattedMessage = new StringBuffer();
        for (int i = 0; i < message.length(); i++) {
            if (message.charAt(i) == '%') {
                if (currentParamNumber >= params.length) {
                    formattedMessage.append("?missing data?");
                } else if ((params[currentParamNumber] instanceof Number)
                        && (i + 1 < message.length())) {
                    i += matchOptionalFormatting(
                            (Number) params[currentParamNumber++],
                            message.substring(i + 1), formattedMessage);
                } else {
                    formattedMessage.append(params[currentParamNumber++]
                            .toString());
                }
            } else {
                if ((message.charAt(i) == '\\')
                        && (i + 1 < message.length())
                        && (message.charAt(i + 1) == '%')) {
                    formattedMessage.append('%');
                    i++;
                } else {
                    formattedMessage.append(message.charAt(i));
                }
            }
        }
        return formattedMessage.toString();
    }

    private static int matchOptionalFormatting(Number number,
            String formatting, StringBuffer outputTo) {
        NumberFormat numberFormat = NumberFormat.getInstance();
        if ((0 < formatting.length())
                && Character.isDigit(formatting.charAt(0))) {
            numberFormat.setMinimumIntegerDigits(Integer
                    .parseInt(formatting.charAt(0) + ""));
            if ((2 < formatting.length()) && (formatting.charAt(1) == '.')
                    && Character.isDigit(formatting.charAt(2))) {
                numberFormat.setMaximumFractionDigits(Integer
                        .parseInt(formatting.charAt(2) + ""));
                numberFormat.format(number, outputTo, new FieldPosition(0));
                return 3;
            }
            numberFormat.format(number, outputTo, new FieldPosition(0));
            return 1;
        } else if ((0 < formatting.length())
                && (formatting.charAt(0) == '.')) {
            if ((1 < formatting.length())
                    && Character.isDigit(formatting.charAt(1))) {
                numberFormat.setMaximumFractionDigits(Integer
                        .parseInt(formatting.charAt(1) + ""));
                numberFormat.format(number, outputTo, new FieldPosition(0));
                return 2;
            }
        }
        numberFormat.format(number, outputTo, new FieldPosition(0));
        return 1;
    }
}

Related

1. formatPriceWithTwoDecimals(Locale locale, String stringToFormat)
2. format(String formatString, Object... args)
3. fillSpace(String formatString, int length)
4. fillString(String formatString, int length, char fillChar, boolean leftFillFlag)
5. fillZero(String formatString, int length)
6. centerString(String input, int size)