public class Util extends Object
Modifier and Type | Class and Description |
---|---|
static class |
Util.Xml
Various DOM utility functions.
|
Modifier and Type | Field and Description |
---|---|
static double |
MAX_DOUBLE
Constant
MAX_DOUBLE=Double.MAX_VALUE |
static long |
MAX_LONG
Constant
MAX_LONG=Long.MAX_VALUE |
static double |
MIN_DOUBLE
Constant
MIN_DOUBLE=-Double.MAX_VALUE |
static long |
MIN_LONG
Constant
MIN_LONG=-Long.MAX_VALUE |
Modifier and Type | Method and Description |
---|---|
static boolean |
equal(double x,
double y)
Compares two doubles but treats all NaNs as equal.
|
static boolean |
fileExists(String filename)
Checks if the file with the given file name exists
|
static String |
formatDouble(double x)
Formats double as a string using exponential notation (RRDTool like).
|
static Calendar |
getCalendar(Date date)
Returns
Calendar object for the given Date object |
static Calendar |
getCalendar(long timestamp)
Returns
Calendar object for the given timestamp
(in seconds, without milliseconds) |
static Calendar |
getCalendar(String timeStr)
Creates Calendar object from a string.
|
static String |
getCanonicalPath(String path)
Returns canonical file path for the given file path
|
static Date |
getDate(long timestamp)
Returns
Date object for the given timestamp (in seconds, without
milliseconds) |
static String |
getFileSeparator()
Returns file system separator string.
|
static String |
getLapTime()
Function used for debugging purposes and performance bottlenecks detection.
|
static long |
getLastModified(String file)
Returns last modification time for the given file.
|
static String |
getRrd4jDemoDirectory()
Returns path to directory used for placement of Rrd4j demo graphs and creates it
if necessary.
|
static String |
getRrd4jDemoPath(String filename)
Returns full path to the file stored in the demo directory of Rrd4j
|
static String |
getRrd4jHomeDirectory()
Returns the root directory of the Rrd4j distribution.
|
static long |
getTime()
Returns current timestamp in seconds (without milliseconds).
|
static long |
getTimestamp()
Just an alias for
getTime() method. |
static long |
getTimestamp(Calendar gc)
Returns timestamp (unix epoch) for the given Calendar object
|
static long |
getTimestamp(Date date)
Returns timestamp (unix epoch) for the given Date object
|
static long |
getTimestamp(int year,
int month,
int day)
Returns timestamp (unix epoch) for the given year, month and day.
|
static long |
getTimestamp(int year,
int month,
int day,
int hour,
int min)
Returns timestamp (unix epoch) for the given year, month, day, hour and minute.
|
static long |
getTimestamp(String atStyleTimeSpec)
Parses at-style time specification and returns the corresponding timestamp.
|
static long[] |
getTimestamps(String atStyleTimeSpec1,
String atStyleTimeSpec2)
Parses two related at-style time specifications and returns corresponding timestamps.
|
static String |
getUserHomeDirectory()
Returns path to user's home directory.
|
static boolean |
isDouble(String s)
Checks if a string can be parsed as double.
|
static double |
max(double[] values)
Finds max value for an array of doubles (NaNs are ignored).
|
static double |
max(double x,
double y)
Returns the greater of two double values, but treats NaN as the smallest possible
value.
|
static double |
min(double[] values)
Finds min value for an array of doubles (NaNs are ignored).
|
static double |
min(double x,
double y)
Returns the smaller of two double values, but treats NaN as the greatest possible
value.
|
static long |
normalize(long timestamp,
long step)
Rounds the given timestamp to the nearest whole "e;step"e;.
|
static boolean |
parseBoolean(String valueStr)
Parses input string as a boolean value.
|
static Paint |
parseColor(String valueStr)
Parses input string as color.
|
static double |
parseDouble(String valueStr)
Parses input string as a double value.
|
static String |
sprintf(Locale l,
String format,
Object... args)
Equivalent of the C-style sprintf function.
|
static double |
sum(double x,
double y)
Calculates sum of two doubles, but treats NaNs as zeros.
|
static double[] |
toDoubleArray(long[] array)
Converts an array of long primitives to an array of doubles.
|
public static final long MAX_LONG
MAX_LONG=Long.MAX_VALUE
public static final long MIN_LONG
MIN_LONG=-Long.MAX_VALUE
public static final double MAX_DOUBLE
MAX_DOUBLE=Double.MAX_VALUE
public static final double MIN_DOUBLE
MIN_DOUBLE=-Double.MAX_VALUE
public static double[] toDoubleArray(long[] array)
array
- an array of long.public static long getTime()
(System.currentTimeMillis() + 500L) / 1000L
public static long getTimestamp()
getTime()
method.public static long normalize(long timestamp, long step)
timestamp - timestamp % step;
timestamp
- Timestamp in secondsstep
- Step in secondspublic static double max(double x, double y)
Math.max()
behaves differently for NaN arguments.x
- an argumenty
- another argumentpublic static double min(double x, double y)
Math.min()
behaves differently for NaN arguments.x
- an argumenty
- another argumentpublic static double sum(double x, double y)
x
- First doubley
- Second doubleDouble.isNaN(x)? y: Double.isNaN(y)? x: x + y;
public static String formatDouble(double x)
x
- value to be formattedpublic static Date getDate(long timestamp)
Date
object for the given timestamp (in seconds, without
milliseconds)timestamp
- Timestamp in seconds.public static Calendar getCalendar(long timestamp)
Calendar
object for the given timestamp
(in seconds, without milliseconds)timestamp
- Timestamp in seconds.public static Calendar getCalendar(Date date)
Calendar
object for the given Date objectdate
- Date objectpublic static long getTimestamp(Date date)
date
- Date objectpublic static long getTimestamp(Calendar gc)
gc
- Calendar objectpublic static long getTimestamp(int year, int month, int day, int hour, int min)
year
- Yearmonth
- Month (zero-based)day
- Day in monthhour
- Hourmin
- Minutepublic static long getTimestamp(int year, int month, int day)
year
- Yearmonth
- Month (zero-based)day
- Day in monthpublic static long getTimestamp(String atStyleTimeSpec)
long t = Util.getTimestamp("now-1d");
atStyleTimeSpec
- at-style time specification. For the complete explanation of the syntax
allowed see RRDTool's rrdfetch
man page.public static long[] getTimestamps(String atStyleTimeSpec1, String atStyleTimeSpec2)
long[] t = Util.getTimestamps("end-1d","now");
atStyleTimeSpec1
- Starting at-style time specification. For the complete explanation of the syntax
allowed see RRDTool's rrdfetch
man page.atStyleTimeSpec2
- Ending at-style time specification. For the complete explanation of the syntax
allowed see RRDTool's rrdfetch
man page.public static double parseDouble(String valueStr)
valueStr
- String representing double valuepublic static boolean isDouble(String s)
s
- Input stringtrue
if the string can be parsed as double, false
otherwisepublic static boolean parseBoolean(String valueStr)
valueStr
- String representing boolean valuetrue
, if valueStr equals to 'true', 'on', 'yes', 'y' or '1';
false
in all other cases.public static Paint parseColor(String valueStr)
valueStr
- Input string, for example #FFAA24, #AABBCC33, 010203 or ABC13E4FIllegalArgumentException
- If the input string is not 6 or 8 characters long (without optional '#')public static String getFileSeparator()
public static String getUserHomeDirectory()
public static String getRrd4jDemoDirectory()
public static String getRrd4jDemoPath(String filename)
filename
- Partial path to the file stored in the demo directory of Rrd4j
(just name and extension, without parent directories)public static Calendar getCalendar(String timeStr)
timeStr
- Input stringpublic static String getLapTime()
getLapTime()
method call.public static String getRrd4jHomeDirectory()
The function assumes that all Rrd4j .class files are placed under the <root>/classes subdirectory and that all jars (libraries) are placed in the <root>/lib subdirectory (the original Rrd4j directory structure).
public static boolean equal(double x, double y)
false
x
- the first valuey
- the second valuetrue
if x and y are both equal to Double.NaN, or if x == y. false
otherwisepublic static String getCanonicalPath(String path) throws IOException
path
- Absolute or relative file pathIOException
- Thrown if canonical file path could not be resolvedpublic static long getLastModified(String file)
file
- File object representing file on the diskpublic static boolean fileExists(String filename)
filename
- File nametrue
if file exists, false
otherwisepublic static double max(double[] values)
values
- Array of double valuespublic static double min(double[] values)
values
- Array of double valuesCopyright © 2015. All rights reserved.