Java Number Format Pattern format(String str_number, int digits)

Description

relation fuction to Currency format
String formatted = Util.format("1234.67789", 2);
formatted ==> "1234.68"

License

Apache License

Parameter

Parameter	Description

Return

formatted double

Declaration

public static double format(String str_number, int digits) 

Method Source Code

//package com.java2s;
/**/*from  w  w w  . ja  v a2 s  . c  om*/
 * Copyright 2014 tgrape Inc.
 * 
 * Licensed 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.
 */

import java.text.DecimalFormat;

public class Main {
    /**
    * relation fuction to Currency format<br>
    * <font color="#0000ff">String formatted = Util.format("1234.67789", 2);<br>
    * formatted ==> "1234.68"
    * </font>
    * @param String<br>
    * @param int<br>
    * @return formatted double
    */
    public static double format(String str_number, int digits) {
        String pattern = "###.";
        double value = -1.;
        for (int i = 0; i < digits; i++) {
            pattern += "#";
        }
        try {
            value = Double.parseDouble(str_number);
        } catch (NumberFormatException e) {
            System.err.println("[Util] Bad Number String!!");
        }
        return customFormat(pattern, value);
    }

    /**
    * Use this method like this:<br>
    * <font color="#0000ff">String formatted = Util.format(1234.67789, 2);<br>
    * formatted ==> "1234.68"
    * </font>
    * @param numer<br>
    * @param digits<br>
    * @return formatted double
    */
    public static double format(double number, int digits) {
        return format("" + number, digits);
    }

    /**
    * This method actually does all for number formatting...<br>
    * @param pattern pattern to apply to the given double value<br>
    * @param value number to be formatted<br>
    * @return formatted double
    */
    private static double customFormat(String pattern, double value) {
        DecimalFormat myFormatter = new DecimalFormat(pattern);
        try {
            String output = myFormatter.format(value);
            return Double.parseDouble(output);
        } catch (NumberFormatException e) {
            System.err.println("[Util] at customFormat(..): NumberFormatException");
            return -1.0;
        }
    }
}

Related

1. format(long value)
2. format(Number value)
3. format(Number value)
4. format(Object num, int dev, String valueIfZero)
5. format(Object price)
6. format(String value)
7. formatAmtByComma(String amt, int len)
8. formatBigNumber(long value)
9. formatBitRate(long bytes)