com.github.peiatgithub.java.utils

Class Utils

java.lang.Object

com.github.peiatgithub.java.utils.Utils

public class Utils
extends Object

Since:

1.0

Author:

pei

Constructor Summary

Constructors

Constructor and Description
Utils()

Method Summary

Modifier and Type	Method and Description
static String	bytesToReadable(double numOfBytes) Display the number of bytes in a human readable way.
static Throwable	catchThrowable(NonArgFunction function) Simplify the codes to catch an unchecked exception, usually the RuntimeException.
static Thread	createAndStartThread(Runnable r) Simplify this common practice to one line.
static String	getSubString(String str, String delimiter, int n1, int n2) Get the sub String between the n1th and the n2th delimiter index begins from 0 E.g.
static void	ifElse(boolean flag, NonArgFunction fnc1, NonArgFunction fnc2) If flag is true, run function1, else, run function2 Simplify the usually 5 lines code to one line
static void	ifNotNull(Object obj, NonArgFunction fnc) If obj is not null, run fnc.
static void	ifThen(boolean flag, NonArgFunction fnc) If flag is true, run function.
static int	intsSum(int... numbers) get the sum value of an array of int numbers.
static String	numberToReadableString(long num) returns the human readable String of a number with proper units
static void	printlnWithThreadName(String message) println the message with the thread name prefixed.
static void	repeatRun(int times, Consumer<Integer> c) Simplify the code to repeatedly run a piece of code for N times.
static void	repeatRun(int times, NonArgFunction function) Simplifies the code to repeatedly run a piece of code for N times.
static void	threadJoin(Thread thr) Make the codes for thread.join() in one line by swallowing the InterruptedException (just call e.printStackTrace())
static void	threadSleep(long millis) Make the codes for Thread.sleep(millis) in one line by swallowing the InterruptedException (just call e.printStackTrace())

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

printlnWithThreadName

public static void printlnWithThreadName(String message)

println the message with the thread name prefixed.

catchThrowable

public static Throwable catchThrowable(NonArgFunction function)

Simplify the codes to catch an unchecked exception, usually the RuntimeException.

Parameters:

function -

Returns:

The Throwable thrown by the function. null if no throwable is thrown.

repeatRun

public static void repeatRun(int times,
                             NonArgFunction function)

Simplifies the code to repeatedly run a piece of code for N times.

Parameters:

times -

function -

repeatRun

public static void repeatRun(int times,
                             Consumer<Integer> c)

Simplify the code to repeatedly run a piece of code for N times. Takes the iteration index as arg of the to-run code.

Parameters:

times -

function -

bytesToReadable

public static String bytesToReadable(double numOfBytes)

Display the number of bytes in a human readable way. Apache Commons FileUtils.byteCountToDisplaySize() rounds down to integer numbers. This method keeps 1 digit after decimal point.

Parameters:

numOfBytes -

Returns:

the readable String

numberToReadableString

public static String numberToReadableString(long num)

returns the human readable String of a number with proper units

Parameters:

num -

Returns:

threadSleep

public static void threadSleep(long millis)

Make the codes for Thread.sleep(millis) in one line by swallowing the InterruptedException (just call e.printStackTrace())

Parameters:

millis -

createAndStartThread

public static Thread createAndStartThread(Runnable r)

Simplify this common practice to one line.

Parameters:

r - the Runnable to run in the newly created thread

Returns:

the newly created thread

threadJoin

public static void threadJoin(Thread thr)

Make the codes for thread.join() in one line by swallowing the InterruptedException (just call e.printStackTrace())

Parameters:

the - thread to join

getSubString

public static String getSubString(String str,
                                  String delimiter,
                                  int n1,
                                  int n2)

Get the sub String between the n1th and the n2th delimiter index begins from 0 E.g. getSubString("111,aaa,bbb,,ccc", ",", 1, 2) returns "bbb" getSubString("111,aaa,bbb,,ccc", ",", -1, 1) returns "111,aaa" getSubString("111,aaa,bbb,,ccc", ",", 2, 3) returns "" getSubString("111,aaa,bbb,,ccc", ",", x, x) returns "" getSubString("111,aaa,bbb,,ccc", ",", x, [a value bigger than the max occurrence number of delimiter]) returns ""

ifNotNull

public static void ifNotNull(Object obj,
                             NonArgFunction fnc)

If obj is not null, run fnc. Simplify the following code to one line: if (sth != null){ run some code; }

Parameters:

obj -

fnc -

ifThen

public static void ifThen(boolean flag,
                          NonArgFunction fnc)

If flag is true, run function. Simplify the usually 3 lines code if(...){...} to one line

Parameters:

flag -

fnc -

ifElse

public static void ifElse(boolean flag,
                          NonArgFunction fnc1,
                          NonArgFunction fnc2)

If flag is true, run function1, else, run function2 Simplify the usually 5 lines code to one line

Parameters:

flag -

fnc1 -

fnc2 -

intsSum

public static int intsSum(int... numbers)

get the sum value of an array of int numbers.

Parameters:

numbers -

Returns: