I created this library of methods, all of them static, out of my daily work on Java projects. AS I see that there is a chance to write a generic expression evaluator, I just add it to this package:
package sactosoft.common;
import java.text.CharacterIterator;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.text.StringCharacterIterator;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeSet;
//import com.raleys.dw.tlog.utils.F;
// date format could be MM/dd/yyyy, yyyy-MM-dd, ...
/**
* @author Sactosoft
*
*
* Date format reference
* y:Year, H:Hour in day (0-23):
* M:Month in year, k:Hour in day (1-24):
* w:Week in year, K:Hour in am/pm (0-11):
* W:Week in month, h:Hour in am/pm (1-12):
* D:Day in year:m, Minute in hour:
* d:Day in month, s:Second in minute:
* F:Day of week in month, S:Millisecond:
* E:Day in week, z:Time zone:
* a:Am/pm marker, Z:Time zone:
*
*/
public class Evaluate {
public static final String yyyy_MM_dd = "yyyy-MM-dd";
/**
* Convert date to string.
*
* @param date - java.util.Date
* @param format - yyyy-MM-dd, MM/dd/yy, ...
* @return
*/
public static String dateToString(Date date, String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format);
return sdf.format(date);
}
/**
* Convert string to date
*
* @param date - java.util.Date
* @param format - yyyy-MM-dd, MM/dd/yy, ...
* @return date
* @throws Exception
*/
public static Date stringToDate(String date, String format) throws Exception {
SimpleDateFormat sdf = new SimpleDateFormat(format);
return sdf.parse(date);
}
/**
*
* @param date - Date text in the format defined by the next param.
* @param format - yyyy-MM-dd, MM/dd/yy, ...
* @return Date + 7 days
* @throws Exception
*/
public static String nextWeekDate(String date, String format) throws Exception {
return addDays(date, format, 7);
}
public static String prevWeekDate(String date, String format) throws Exception {
return addDays(date, format, -7);
}
/**
*
* @param date - Date text in the format defined by the next param.
* @param format - yyyy-MM-dd, MM/dd/yy, ...
* @param days - Number of days to add or subtract (e.g. 2, -3)
* @return - Evaluated date as string.
* @throws Exception
*/
public static String addDays(String date, String format, int days) throws Exception {
Date d = Evaluate.stringToDate(date, format);
Calendar c = Calendar.getInstance();
c.setTime(d);
c.add(Calendar.DATE, days);
d = c.getTime();
return Evaluate.dateToString(d, format);
}
/**
*
* @param date - Date text in the format defined by the next param.
* @param format - yyyy-MM-dd, MM/dd/yy, ...
* @return - 1=Sunday, 2=Monday, ...
* @throws Exception
*/
public static int dayOfWeek(String date, String format) throws Exception {
SimpleDateFormat sdf = new SimpleDateFormat(format);
Date date1 = sdf.parse(date);
Calendar c = Calendar.getInstance();
c.setTime(date1);
return c.get(Calendar.DAY_OF_WEEK);
}
/**
*
* @param dayOfWeek - 1=Sunday, 2=Monday, ...
* @param format - yyyy-MM-dd, MM/dd/yy, ...
* @return The date of the provided day of week, within the current week. E.g. assume todays date is Tues Aug 26,
* 2008, then: Evaluate.thisWeekDayOfWeekDate(2,"yyyyMMdd") would return "20080825"
* @throws Exception
*/
public static String thisWeekDayOfWeekDate(int dayOfWeek, String format) throws Exception {
String date = Evaluate.dateToString(new Date(), format);
int days = dayOfWeek - Evaluate.dayOfWeek(date, format);
return Evaluate.addDays(date, format, days);
}
public static String lastDayOfWeekDate(int dayOfWeek, String dateFormat) throws Exception {
String date = Evaluate.dateToString(new Date(), dateFormat);
int days = Evaluate.dayOfWeek(date, dateFormat) - dayOfWeek + 7;
days = -1 * (days % 7);
return Evaluate.addDays(date, dateFormat, days);
}
/**
*
* @param strings
* @param stringToFind
* @return the index of str in array
*/
public static int arrayIndex(String[] strings, String stringToFind) {
int retVal = -1;
for (int i = 0; i < strings.length; i++) {
if (strings[i].equalsIgnoreCase(stringToFind)) {
return i;
}
}
return retVal;
}
public static String arrayToString(String values[], String delimiter) {
String retVal = values[0];
for (int i = 1; i < values.length; i++) {
retVal = retVal + delimiter + values[i];
}
return retVal;
}
public static int getJulianDateInt(String dateString, String format) throws Exception {
SimpleDateFormat sdf = new SimpleDateFormat(format);
Date d = sdf.parse(dateString);
Calendar c = Calendar.getInstance();
c.setTime(d);
int jDate = c.get(Calendar.DAY_OF_YEAR);
return jDate;
}
public static String getJulianDateStr(String dateString, String format) throws Exception {
int jd = Evaluate.getJulianDateInt(dateString, format);
return Evaluate.intToString(jd, "000");
}
public static String intToString(int i, String format) {
NumberFormat nf = new DecimalFormat(format);
String str = nf.format(i);
return str;
}
public static Map sortMapOnValues(Map hmap) {
HashMap map = new LinkedHashMap();
List mapKeys = new ArrayList(hmap.keySet());
List mapValues = new ArrayList(hmap.values());
TreeSet sortedSet = new TreeSet(mapValues);
Object[] sortedArray = sortedSet.toArray();
int size = sortedArray.length;
// Ascending sort
for (int i = 0; i < size; i++) {
map.put(mapKeys.get(mapValues.indexOf(sortedArray[i])), sortedArray[i]);
}
return map;
}
public static String escapeXMLSpecialChars(String input) {
final StringBuffer result = new StringBuffer();
final StringCharacterIterator iterator = new StringCharacterIterator(input);
char character = iterator.current();
while (character != CharacterIterator.DONE) {
if (character == '&') {
result.append("&");
} else if (character == '\"') {
result.append(""");
} else if (character == '<') {
result.append("<");
} else if (character == '>') {
result.append(">");
} else {
result.append(character); // char not special, just append
}
character = iterator.next();
}
return result.toString();
}
/*
* String leftPaddedWithX = stringPadding("aa", 5, "X", true); String rightPaddedWithX = stringPadding("aa", 5, "X",
* false);
*/
public static String stringPadding(String s, int n, char c, boolean paddingLeft) {
if (s == null) {
return s;
}
int add = n - s.length(); // may overflow int size... should not be a problem in real life
if (add <= 0) {
return s;
}
StringBuffer str = new StringBuffer(s);
char[] ch = new char[add];
Arrays.fill(ch, c);
if (paddingLeft) {
str.insert(0, ch);
} else {
str.append(ch);
}
return str.toString();
}
}
