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1. Core Java Programs [PAGE 1]
2. Core Java Programs [PAGE 2]
3. Core Java Programs [PAGE 3]
4. Date Utility Code Snippet
5. String Utility Code Snippet
JAVA String Utility
( This program Demonstrates the proper use of Number Formats in common java programming scenarios )
String Utility
/*
* NumberUtility.java
*
* Source: http://www.freejavaguide.com
*/
import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;
/**
* Class provides common functions on number formats.
*/
public class NumberUtility {
/**
* Method takes Object as parameter and returns decimal number.
* if argument is float or double and contains tailing zeros
* it removes them. If argument is float or double then no change in return type.
* Change the Format of the Number by changing the String Pattern
*/
public static String changeToDecimalFormat(Object number) {
BigDecimal bdNumber = new BigDecimal(number.toString());
bdNumber = bdNumber.stripTrailingZeros(); //Returns a BigDecimal with any trailing zero's removed
String pattern = "###,##0.0###########"; //To apply formatting when the number of digits in input equals the pattern
DecimalFormat newFormat = new DecimalFormat(pattern, new DecimalFormatSymbols(Locale.US));
return newFormat.format(bdNumber);
}
/* Method takes Object as parameter and removes commas from the parameter */
public static double removeCommasFromNumber(Object number) {
try {
StringBuffer inputNo = new StringBuffer(number.toString());
if (inputNo.length() > 0) {
while (inputNo.indexOf(",") != -1) {
inputNo.deleteCharAt(inputNo.indexOf(","));
}
} else {
return 0.0;
}
return Double.parseDouble(inputNo.toString());
} catch (NumberFormatException e) {
return 0.0;
}
}
/* Some times its required to have a fixed set of decimal places for a
* number. We can set that by changing the precision number for a particular
* input BigDecimal Input String
*/
public static String changeToRequiredDecimals(String bigDecimalString,
int precision) {
String newFormattedString = null;
String afterDecimal = null;
if (bigDecimalString == null || bigDecimalString.length() == 0) {
return "0.0";
}
if (bigDecimalString.contains(".")) {
afterDecimal = bigDecimalString.substring(bigDecimalString
.indexOf(".") + 1);
int length = Math.abs((afterDecimal.length() - precision));
if (afterDecimal.length() < precision) {
newFormattedString = bigDecimalString;
for (int i = 0; i < length; i++) {
newFormattedString = newFormattedString + "0";
}
} else if (afterDecimal.length() > precision) {
newFormattedString = bigDecimalString.substring(0,
bigDecimalString.length() - length);
if (precision == 0) {
newFormattedString = newFormattedString.substring(0,
newFormattedString.indexOf("."));
} else {
newFormattedString = bigDecimalString;
}
} else {
if (precision > 0)
newFormattedString = bigDecimalString + ".";
else
newFormattedString = bigDecimalString;
for (int i = 0; i < precision; i++) {
newFormattedString = newFormattedString + "0";
}
}
}
return newFormattedString;
}
public static void main(String args[]){
int intVar = 10;
double doubleVar = 10.504000;
float floatVar = 343534534348.5687654F;
String commaString = "343,534,535,000.0";
BigDecimal bdNumber = new BigDecimal("1234.8765");
System.out.println(NumberUtility.changeToDecimalFormat(new Integer(intVar)));
System.out.println(NumberUtility.changeToDecimalFormat(new Double(doubleVar)));
System.out.println(NumberUtility.changeToDecimalFormat(new Float(floatVar)));
System.out.println(NumberUtility.removeCommasFromNumber(commaString));
System.out.println(NumberUtility.changeToRequiredDecimals(bdNumber.toString(), 8));
}
}