org.dlese.dpc.util
Class Utils

java.lang.Object
  org.dlese.dpc.util.Utils

public class Utils
extends Object

This class holds a number of handy static methods for generating unique ids, random numbers within a given range, parsing dates, executing command-line processes, and others.

Author:

John Weatherley

Constructor Summary

Utils()

Method Summary

static boolean	contains(Object target, Object subject) Returns true if the object in the first parameter contains the Object in the second parameter according to the Objects equals method.
static String	convertDateToString(Date date, String dateFormat) Converts a Java Date that into a formatted String.
static Date	convertLongToDate(long milliseconds) Converts a long representation of time to a Date.
static String	convertMillisecondsToTime(long milliseconds) Converts a long that represents time in milliseconds to a String that displays the time in minutes and seconds.
static Date	convertStringToDate(String dateString, String dateFormat) Converts a String that contains a recognizable date/time to a Java Date object.
static String	encodeToSearchTerm(String string) Encodes a String to a single term for searching over fields that have been indexed encoded.
static String	encodeToSearchTerms(String string) Encodes a String to a String for searching over fields that have been indexed encoded.
static String	getDayOfWeekString(int dayOfWeek) Gets a String representation of the Calendar.DAY_OF_WEEK field.
static String	getLexicalDateString(String dateString) Converts a date String of the form YYYY-mm-dd, YYYY-mm, YYYY or yyyy-MM-ddTHH:mm:ssZ to a searchable Lucene (v2.x) lexical date String of the form 'yyyyMMddHHmmss', or null if unable to parse the date String.
static Map	getPropertiesMap(String propertiesString) Gets the Map from a String in the Java properties format of the form property=value one per line.
static ResourceBundle	getPropertiesResourceBundle(String propsFileName) Gets a ResourceBundle from a properties file that is in a Jar file or class path within this application's runtime environment.
static String	getRandomAlphaString(int length) Generates a random alpha string of the given length.
static String	getRandomCharsString(int length) Generates a random string containing extended chars of the given length
static int	getRandomIntBetween(int low, int high) Generates a random integer greater-than or equal to low and less-than high.
static long	getUniqueID() Gets a global system unique ID.
static Date	luceneStringToDate(String dateString) Converts a Lucene String-encoded date to a Date Object.
static Map	map(Map myMap, String key, String value) Puts items in a Map, creating a new TreeMap if null is passed in for the myMap argument, otherwise updating the Map with the key/value pair.
static Map	mapSortByValue(Map myMap, String key, String value, String ascending) Puts items in a Map, creating a new Map if null is passed in for the myMap argument, otherwise updating the Map with the key/value pair.
static boolean	matches(String source, String regEx) Tells whether or not the source string matches the given regular expression.
static String	ObjectInspector(Object o) Inspects an objects type and methods to standard out.
static void	print_char_values() Prints the char values of all chars in range 0 to 256.
static void	printElapsedTime(String msg, Date start, Date end) Print the elapsed time that occured beween two points of time as recorded in java Date objects.
static void	printToSystemErr(String s) Sends the string to System-err-println.
static void	printToSystemOut(String s) * Sends the string to System-out-println.
static String	RedirectEncoder(String text) Encodes a string used in the URL sent to the redirect server and ensures it does not contain problematic characters for the Apache 1 mod_redirect rules (the character sequence %2F is replaced with /).
static String	replaceAll(String source, String regEx, String replacement) Replaces each substring of this string that matches the given regular expression with the given replacement.
static String	replaceFirst(String source, String regEx, String replacement) Replaces the first substring of this string that matches the given regular expression with the given replacement.
static int	runCommand(String command, StringBuffer standardOutput, StringBuffer errorOutput) Runs the given command-line command.
static String[]	split(String source, String regEx) Splits this string around matches of the given regular expression.
static String	URLEncoder(String text) Encodes a String for use in a URL using UTF-8 character encoding.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Utils

public Utils()

Method Detail

convertStringToDate

public static final Date convertStringToDate(String dateString,
                                             String dateFormat)
                                      throws ParseException

Converts a String that contains a recognizable date/time to a Java Date object. See SimpleDateFormat for syntax information for the format String. For example a valid date String might look like '2003-04-27MST' with a date format specifier of 'yyyy-MM-ddz' where yyyy indicates the year, MM the month, dd the day and z the general time zone (GMT, MST, PST, etc).

Parameters:

dateString - A String that contains a recognizable date/time in it, for example '2003-04-27MST'.

dateFormat - The format of the date String as specified in SimpleDateFormat, for example 'yyyy-MM-ddz'.

Returns:

The Date object.

Throws:

ParseException - If unable to interpret the date String using the given format specifier.

convertDateToString

public static final String convertDateToString(Date date,
                                               String dateFormat)
                                        throws ParseException

Converts a Java Date that into a formatted String. See SimpleDateFormat for syntax information for the format String. For example a valid date format specifier might be '"MMM' 'dd', 'yyyy' 'z"' where yyyy indicates the year, MMM the month, dd the day and z the time zone (GMT, MST, PST, etc).

Parameters:

date - A Java Date object.

dateFormat - The format of the date String to be output as specified in SimpleDateFormat, for example 'yyyy-MM-ddz'.

Returns:

The formatted String.

Throws:

ParseException - If unable to interpret the date Date using the given format specifier.

convertLongToDate

public static final Date convertLongToDate(long milliseconds)

Converts a long representation of time to a Date.

Parameters:

milliseconds - Time in milliseconds

Returns:

A Date object

printElapsedTime

public static void printElapsedTime(String msg,
                                    Date start,
                                    Date end)

Print the elapsed time that occured beween two points of time as recorded in java Date objects.

Parameters:

start - The start Date.

end - The end Date.

msg - A message inserted in front of the elapsed time string.

convertMillisecondsToTime

public static String convertMillisecondsToTime(long milliseconds)

Converts a long that represents time in milliseconds to a String that displays the time in minutes and seconds.

Parameters:

milliseconds - Time in millisoconds.

Returns:

A String that displays the time in minutes and seconds.

getRandomAlphaString

public static String getRandomAlphaString(int length)

Generates a random alpha string of the given length.

Parameters:

length - The length of the String to generate

Returns:

The randomAlphaString value

getRandomIntBetween

public static int getRandomIntBetween(int low,
                                      int high)

Generates a random integer greater-than or equal to low and less-than high.

Parameters:

low - Smallest possible value

high - Highest possible value

Returns:

A random number greater-than or equal to low and less-than high

getRandomCharsString

public static String getRandomCharsString(int length)

Generates a random string containing extended chars of the given length

Parameters:

length - The length of the String

Returns:

The randomCharsString value

contains

public static final boolean contains(Object target,
                                     Object subject)

Returns true if the object in the first parameter contains the Object in the second parameter according to the Objects equals method. The first parameter can be an Array, Collection (List, Set, etc.), Map or String. If the Object in the first parameter is a String, returns true if the Object in the second parameter is a subString of the first. If the Object in the first parameter is a Map, returns true if one of it's keys is equal to the Object in the second parameter.

Implements a more versitile version of the regular JSTL contains function.

Parameters:

target - The target Object

subject - The subject Object for comparison

Returns:

True if the target Object contains the subject Object

map

public static Map map(Map myMap,
                      String key,
                      String value)

Puts items in a Map, creating a new TreeMap if null is passed in for the myMap argument, otherwise updating the Map with the key/value pair. TreeMap keeps its keys sorted lexagraphically.

Parameters:

myMap - A Map or null

key - A key for insertion in the Map

value - A value for insertion in the Map, or null to insert empty String

Returns:

The existing Map or a new TreeMap with the key/value pair inserted

mapSortByValue

public static Map mapSortByValue(Map myMap,
                                 String key,
                                 String value,
                                 String ascending)

Puts items in a Map, creating a new Map if null is passed in for the myMap argument, otherwise updating the Map with the key/value pair. Keys remain sorted by the *values* in the Map.

Parameters:

myMap - A Map or null

key - A key for insertion in the Map

value - A value for insertion in the Map, or null to insert empty String

ascending - 'ascending' or 'descending' (defaults to ascending if other value is passed)

Returns:

The existing Map or a new TreeMap with the key/value pair inserted

getPropertiesMap

public static Map getPropertiesMap(String propertiesString)

Gets the Map from a String in the Java properties format of the form property=value one per line.

Parameters:

propertiesString - A Java Properties String

Returns:

A Map of properties, or null if unable to parse

runCommand

public static int runCommand(String command,
                             StringBuffer standardOutput,
                             StringBuffer errorOutput)

Runs the given command-line command.

Parameters:

command - The full command string including arguments

errorOutput - A StringBuffer that will be pupulated with the normal output after execution, if any, or null not to use it

standardOutput - A StringBuffer that will be pupulated with the error output after execution, if any, or null not to use it

Returns:

0 if normal completion, non-zero if abnormal

print_char_values

public static void print_char_values()

Prints the char values of all chars in range 0 to 256.

URLEncoder

public static final String URLEncoder(String text)
                               throws UnsupportedEncodingException

Encodes a String for use in a URL using UTF-8 character encoding.

Parameters:

text - Unencoded text

Returns:

Text that is encoded for use in a URL

Throws:

UnsupportedEncodingException - If unable to encode using UTF-8.

RedirectEncoder

public static final String RedirectEncoder(String text)
                                    throws UnsupportedEncodingException

Encodes a string used in the URL sent to the redirect server and ensures it does not contain problematic characters for the Apache 1 mod_redirect rules (the character sequence %2F is replaced with /).

Parameters:

text - Unencoded text

Returns:

Text that is encoded for use in a URL

Throws:

UnsupportedEncodingException - If unable to encode using UTF-8.

ObjectInspector

public static final String ObjectInspector(Object o)

Inspects an objects type and methods to standard out.

Parameters:

o - The Object to inspect

Returns:

The objects class name

matches

public static final boolean matches(String source,
                                    String regEx)

Tells whether or not the source string matches the given regular expression.

Parameters:

source - The source String

regEx - A regular expression

Returns:

True if the source String matches the regular expression

See Also:

String.matches(String regEx)

replaceAll

public static final String replaceAll(String source,
                                      String regEx,
                                      String replacement)

Replaces each substring of this string that matches the given regular expression with the given replacement. If replacement is empty or null, all matches are removed from the source String.

Parameters:

source - The source String

regEx - A regular expression

replacement - The replacement String

Returns:

The resulting String

See Also:

String.replaceAll(String regex, String replacement)

replaceFirst

public static final String replaceFirst(String source,
                                        String regEx,
                                        String replacement)

Replaces the first substring of this string that matches the given regular expression with the given replacement. If replacement is empty or null, all matches are removed from the source String.

Parameters:

source - The source String

regEx - A regular expression

replacement - The replacement String

Returns:

The resulting String

See Also:

String.replaceFirst(String regex, String replacement)

luceneStringToDate

public static final Date luceneStringToDate(String dateString)

Converts a Lucene String-encoded date to a Date Object. If the String can not be converted, returns null.

Parameters:

dateString - A Lucene String-encoded date

Returns:

A Date Object, or null

getLexicalDateString

public static final String getLexicalDateString(String dateString)

Converts a date String of the form YYYY-mm-dd, YYYY-mm, YYYY or yyyy-MM-ddTHH:mm:ssZ to a searchable Lucene (v2.x) lexical date String of the form 'yyyyMMddHHmmss', or null if unable to parse the date String.

Parameters:

dateString - A date String

Returns:

The corresponding lexicalDateString value

getPropertiesResourceBundle

public static final ResourceBundle getPropertiesResourceBundle(String propsFileName)

Gets a ResourceBundle from a properties file that is in a Jar file or class path within this application's runtime environment.

Parameters:

propsFileName - The name of the properties file

Returns:

The ResourceBundle, or null if not found

getDayOfWeekString

public static String getDayOfWeekString(int dayOfWeek)
                                 throws ArrayIndexOutOfBoundsException

Gets a String representation of the Calendar.DAY_OF_WEEK field.

Parameters:

dayOfWeek - A Calenday.DAY_OF_WEEK field value

Returns:

A String representation of the day

Throws:

ArrayIndexOutOfBoundsException - If the specified field is out of range (field < 0 || field >= 7)

split

public static final String[] split(String source,
                                   String regEx)

Splits this string around matches of the given regular expression.

Parameters:

source - The source String

regEx - A regular expression

Returns:

The resulting String tokens

See Also:

String.split(String regex)

encodeToSearchTerm

public static final String encodeToSearchTerm(String string)

Encodes a String to a single term for searching over fields that have been indexed encoded. Encodes spaces but leaves the wild card '*' un-encoded for searching.

Parameters:

string - A String to encode

Returns:

An encoded String that may be used for searches

See Also:

SimpleLuceneIndex.encodeToTerm(String, boolean, boolean)

encodeToSearchTerms

public static final String encodeToSearchTerms(String string)

Encodes a String to a String for searching over fields that have been indexed encoded. Preserves the wild card '*' and spaces ' '.

Parameters:

string - The String to encode

Returns:

An encoded String that may be used for searches

See Also:

SimpleLuceneIndex.encodeToTerm(String, boolean, boolean)

printToSystemErr

public static final void printToSystemErr(String s)

Sends the string to System-err-println.

Parameters:

s - String to ouptut.

printToSystemOut

public static final void printToSystemOut(String s)

* Sends the string to System-out-println.

Parameters:

s - String to ouptut.

getUniqueID

public static long getUniqueID()

Gets a global system unique ID. This algorithm is reasonably guaranteed to be correct within a single running JVM.

Returns:

A number guaranteed to be unique throughout this JVM.