Stu (org.gonn:gava 0.0.14 API)

java.lang.Object
- org.gonn.gava.Stu

```
public class Stu
extends Object
```
`[St]atic [U]tils` is a collection of static methods that are very frequently used.

Version:

1.4.1

Author:

Gon Yi

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`DAY`
`static String[]`	`EMPTY_STRING_ARRAY`
`static String`	`ENV_VAR_VERBOSE` Default params set when any of the method was first used.
`static long`	`EPOCH_STARTED`
`static int`	`HOUR`
`static int`	`MINUTE`
`static int`	`SECOND`
`static boolean`	`VERBOSE_MODE`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`byteSizeToString(long sizeInByte)` Get bytes in long, and returns human-readable format with 2 digit decimal.
`static int`	`count(String[] s, String key)` How many times String key was in the String array s.
`static int`	`count(String haystack, char needle)` Count char c from String s, returns int of how many times char c was used.
`static int`	`count(String haystack, String needle)` Count how many times the needle is in haystack.
`static void`	`debug(Fx01<String> s)`
`static String`	`epochToString()` Time since EPOCH_STARTED in string format
`static String`	`epochToString(long epochMillis)` Returns UTC time from epochMillis.
`static String`	`epochToString(long epoch, int offsetHr)` Return epoch time with offset.
`static String`	`epochToString(long epoch, int offsetHr, boolean signed)` Converts epoch milliseconds to human-readable time format.
`static void`	`error(Fx01<String> s)`
`static <R> R`	`eval(Fx01<R> evalFn)` Evaluate the function without a param (This is just to reduce code.)
`static <T1,T2,R> R`	`eval(T1 t1, T2 t2, Fx21<T1,T2,R> evalFn)` Evaluate the function with a param.
`static <T,R> R`	`eval(T t, Fx11<T,R> evalFn)` Evaluate the function with a param.
`static <T,R> R`	`evalX(T t, FxThrow<T,R> evalXFn, Fx11<Exception,R> fallbackFn)` Evaluate a given function with a param.
`static char`	`first(String s)`
`static <T> T`	`first(T[] t)`
`static <T> void`	`forEach(T[] src, Fx10<T> fx)` Evaluate each T in T[].
`static <T> void`	`forEachSet(T[] src, FxUnary<T> fx)` Modify array using fx
`static String`	`getBetween(String s, String prefix, String suffix)` Get a String between String prefix and String suffix from String s.
`static String`	`getCaller()` Returns caller information in "filename:lineNumber" format.
`static StackTraceElement`	`getCaller(int skip)` Get a StackTraceElement of the caller to find out who called this function.
`static String`	`getConfig(String key)`
`static boolean`	`getConfig(String key, boolean fallback)` Check (1) system properties, and then (2) environmental variables.
`static String`	`getConfig(String key, String fallback)`
`static int`	`getDigits(int n)`
`static int`	`getDigits(long n)` Get an integer and calculate number of digits.
`static long`	`getEpoch()` Returns current epoch milliseconds.
`static int`	`getHash(String s)` Get hash from the input string
`static String`	`getNth(String s, char delim, int index)` Returns index element from the String s when separated by char delim.
`static long`	`getTimed(Runnable r, int count)` Run lambda function Runnable r for count times.
`static void`	`info(Fx01<String> s)`
`static boolean`	`isBetween(String s, String prefix, String suffix)` Check if the input has the prefix AND the suffix.
`static String`	`join(String delimiter, Object... objs)`
`static char`	`last(String s)`
`static <T> T`	`last(T[] t)`
`static void`	`log(String prefix, String msg)` Whenever static method log() is called, it will print to System.out.
`static String`	`ltrim(String s)` Left trim the string
`static void`	`main(String[] args)`
`static <T> T`	`mustGet(T t, T fallback)` If t is null, return fallback value.
`static <X extends Throwable,T> T`	`mustGet(T t, X exception)` If t is null, throw an exception
`static void`	`parseArgs(String[] args, Fx20<String,String> f)` Handles args such as `--name="Gon"`
`static void`	`println(Object... any)`
`static void`	`prints(String name, Object... objs)` Prints any objects in a line per item.
`static String`	`removePrefix(String s, char prefix)` Remove prefix from the String s
`static String`	`removePrefix(String s, String prefix)` Remove prefix from the String s
`static String`	`removeSuffix(String s, char suffix)` Remove the suffix from the String s
`static String`	`removeSuffix(String s, String suffix)` Remove the suffix from the String s
`static String`	`repeat(char c, int n)` Take a char c and repeat it n times.
`static String`	`repeat(String s, int n)` Repeat the input string for n times.
`static String`	`rtrim(String s)` Right trim the string
`static boolean`	`sleep(long ms)` Shortcut function that calls Thread.sleep() but does not require try/catch.
`static String[]`	`subset(String[] src, int start, int end)` Creates a subset of String array.
`static String`	`substring(String s, int idx)` Return the string until index idx.
`static String`	`substring(String s, int idxFrom, int idxTo)` A static alternative substring method.
`static void`	`warn(Fx01<String> s)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ENV_VAR_VERBOSE
```
public static final String ENV_VAR_VERBOSE
```
    Default params set when any of the method was first used. EPOCH_STARTED -- record the time first library was used VERBOSE_MODE -- whether to log
    
    See Also:
    
    Constant Field Values
  - EPOCH_STARTED
```
public static final long EPOCH_STARTED
```
  - VERBOSE_MODE
```
public static final boolean VERBOSE_MODE
```
  - SECOND
```
public static final int SECOND
```
    See Also:
    
    Constant Field Values
  - MINUTE
```
public static final int MINUTE
```
    See Also:
    
    Constant Field Values
  - HOUR
```
public static final int HOUR
```
    See Also:
    
    Constant Field Values
  - DAY
```
public static final int DAY
```
    See Also:
    
    Constant Field Values
  - EMPTY_STRING_ARRAY
```
public static final String[] EMPTY_STRING_ARRAY
```
- Method Detail
  - subset
```
public static String[] subset(String[] src,
                              int start,
                              int end)
```
    Creates a subset of String array. Take a source array, index to start, and index to end.
    E.g. subset(src, 0, -3) creates a subset from the beggining of array EXCEPT last 3. subset(src, -3, 0) creates a subset of last 3. subset(src, 1, 3) creates a subset of 2nd and 3rd (idx 2 and 3) item.
    
    Parameters:
    
    src - Source String array
    
    start - Index from
    
    end - Index end
    
    Returns:
    
    New subset of the array
  - repeat
```
public static String repeat(char c,
                            int n)
```
    Take a char c and repeat it n times.
    
    Parameters:
    
    c - char to repeat
    
    n - number of repeats
    
    Returns:
    
    String of the result
  - repeat
```
public static String repeat(String s,
                            int n)
```
    Repeat the input string for n times.
    
    Parameters:
    
    s - A string to be repeated
    
    n - Number of repeats
    
    Returns:
    
    Repeated string s
  - count
```
public static int count(String haystack,
                        char needle)
```
    Count char c from String s, returns int of how many times char c was used.
    
    Parameters:
    
    haystack - String s to be checked for char c
    
    needle - char c to lookup
    
    Returns:
    
    number of char c found in String s
  - count
```
public static int count(String haystack,
                        String needle)
```
    Count how many times the needle is in haystack.
    
    Parameters:
    
    haystack - A string to be evaluated.
    
    needle - A string to be found.
    
    Returns:
    
    Number of times the string "search" was in s.
  - count
```
public static int count(String[] s,
                        String key)
```
    How many times String key was in the String array s.
    
    Parameters:
    
    s - String array
    
    key - String to search from the array
    
    Returns:
    
    number of key in s.
  - rtrim
```
public static String rtrim(String s)
```
    Right trim the string
    
    Parameters:
    
    s - Input string
    
    Returns:
    
    Trimmed string
  - ltrim
```
public static String ltrim(String s)
```
    Left trim the string
    
    Parameters:
    
    s - Input string
    
    Returns:
    
    Trimmed string
  - substring
```
public static String substring(String s,
                               int idxFrom,
                               int idxTo)
```
    A static alternative substring method. This method supports negative index.
    String s = "hello Gon"; substring(s, -3, 0); // returns Gon substring(s, -3, -1); // returns Go
    
    Parameters:
    
    s - input string
    
    idxFrom - index of substring from
    
    idxTo - index of substring to; when its value is 0, it means until end of the string.
    
    Returns:
    
    String value
  - substring
```
public static String substring(String s,
                               int idx)
```
    Return the string until index idx.
    
    Parameters:
    
    s - Input string
    
    idx - Index of the string. This can be negative number as well.
    
    Returns:
    
    Subset of string
  - getBetween
```
public static String getBetween(String s,
                                String prefix,
                                String suffix)
```
    Get a String between String prefix and String suffix from String s.
    String s = "https://gonn.org/test"; getStringBetween(s, "https://", "/test"); // returns gonn.org
    
    Parameters:
    
    s - Input string
    
    prefix - A prefix to search
    
    suffix - A suffix to search
    
    Returns:
    
    String value within prefix and suffix. If not matched, returns null.
  - isBetween
```
public static boolean isBetween(String s,
                                String prefix,
                                String suffix)
```
    Check if the input has the prefix AND the suffix.
    
    Parameters:
    
    s - Input string
    
    prefix - A prefix string
    
    suffix - A suffix string
    
    Returns:
    
    true if the input has the prefix and suffix.
  - getNth
```
public static String getNth(String s,
                            char delim,
                            int index)
```
    Returns index element from the String s when separated by char delim. String s = "Gon|Yi|41|Conway|AR|72034"; getNth(s, '|', 3); // returns Conway
    
    Parameters:
    
    s - An input string
    
    delim - A delimiter char to separate
    
    index - An index to search from the separated input.
    
    Returns:
    
    Returns the Nth String
  - first
```
public static <T> T first(T[] t)
```
  - first
```
public static char first(String s)
```
  - last
```
public static <T> T last(T[] t)
```
  - last
```
public static char last(String s)
```
  - removePrefix
```
public static String removePrefix(String s,
                                  String prefix)
```
    Remove prefix from the String s
    
    Parameters:
    
    s - Input string
    
    prefix - A prefix string to remove
    
    Returns:
    
    A string without the suffix
  - removePrefix
```
public static String removePrefix(String s,
                                  char prefix)
```
    Remove prefix from the String s
    
    Parameters:
    
    s - Input string
    
    prefix - A prefix char to remove
    
    Returns:
    
    A string without the suffix
  - removeSuffix
```
public static String removeSuffix(String s,
                                  String suffix)
```
    Remove the suffix from the String s
    
    Parameters:
    
    s - Input string
    
    suffix - A suffix string to remove
    
    Returns:
    
    A string without the suffix
  - removeSuffix
```
public static String removeSuffix(String s,
                                  char suffix)
```
    Remove the suffix from the String s
    
    Parameters:
    
    s - Input string
    
    suffix - A suffix char to remove
    
    Returns:
    
    A string without the suffix
  - getEpoch
```
public static long getEpoch()
```
    Returns current epoch milliseconds.
    
    Returns:
    
    epochMillis
  - epochToString
```
public static String epochToString(long epoch,
                                   int offsetHr,
                                   boolean signed)
```
    Converts epoch milliseconds to human-readable time format. Note: Date is not considered here, and returns only time part (hour, minute, second, and millisecond)
    
    Parameters:
    
    epoch - Epoch at milliseconds level
    
    offsetHr - Any offset in hour. (i.g. -6 for CST) If 0 is given, this will return UTC.
    
    signed - Whether to show +/- sign.
    
    Returns:
    
    Human-readable epoch time. i.g. "15:04:05.000"
  - epochToString
```
public static String epochToString(long epoch,
                                   int offsetHr)
```
    Return epoch time with offset.
    
    Parameters:
    
    epoch - epoch time
    
    offsetHr - UTC offset in hour (e.g. -6 for CST)
    
    Returns:
    
    String value
  - epochToString
```
public static String epochToString(long epochMillis)
```
    Returns UTC time from epochMillis.
    
    Parameters:
    
    epochMillis - epoch millisecond
    
    Returns:
    
    String format such as 15:04:05.000
  - epochToString
```
public static String epochToString()
```
    Time since EPOCH_STARTED in string format
    
    Returns:
    
    formatted epoch since
  - prints
```
public static void prints(String name,
                          Object... objs)
```
    Prints any objects in a line per item. This can be used during quick debugging.
    
    Parameters:
    
    name - Name of the group
    
    objs - Any object(s)
  - println
```
public static void println(Object... any)
```
  - join
```
public static String join(String delimiter,
                          Object... objs)
```
  - getDigits
```
public static int getDigits(long n)
```
    Get an integer and calculate number of digits. Note that this uses long type even when int or short type is given.
    
    Parameters:
    
    n - A number to evaluate
    
    Returns:
    
    Number of digits in n.
  - getDigits
```
public static int getDigits(int n)
```
  - byteSizeToString
```
public static String byteSizeToString(long sizeInByte)
```
    Get bytes in long, and returns human-readable format with 2 digit decimal. If the size is negative, it will have "-" (minus sign). This is the simplest and only handles from B to GB. (e.g. 1TB will be 1024GB)
    
    Parameters:
    
    sizeInByte - Size of a file or memory in bytes (B).
    
    Returns:
    
    Size in string with the unit such as "12.00KB" with two decimals points.
  - getConfig
```
public static boolean getConfig(String key,
                                boolean fallback)
```
    Check (1) system properties, and then (2) environmental variables. IF "false" is to be noticed, set fallback as "true." IF "true" is to be noticed, set fallback as "false."
    
    Parameters:
    
    key - property/variable name
    
    fallback - default fallback value
    
    Returns:
    
    boolean value
  - getConfig
```
public static String getConfig(String key,
                               String fallback)
```
  - getConfig
```
public static String getConfig(String key)
```
  - parseArgs
```
public static void parseArgs(String[] args,
                             Fx20<String,String> f)
```
    Handles args such as `--name="Gon"`
    
    Parameters:
    
    args - String[] as main args
    
    f - BiConsumer function, when single param such as `--disable` is given, 2nd argument for the BiConsumer will be null.
  - getCaller
```
public static StackTraceElement getCaller(int skip)
```
    Get a StackTraceElement of the caller to find out who called this function.
    
    Parameters:
    
    skip - how many skips required
    
    Returns:
    
    Caller's StackTraceElement.
  - getCaller
```
public static String getCaller()
```
    Returns caller information in "filename:lineNumber" format. (e.g. "Gava.java:123")
    
    Returns:
    
    String value file-line
  - getTimed
```
public static long getTimed(Runnable r,
                            int count)
```
    Run lambda function Runnable r for count times.
    
    Parameters:
    
    r - lambda to run
    
    count - how many times to run
    
    Returns:
    
    duration of the run in milliseconds.
  - sleep
```
public static boolean sleep(long ms)
```
    Shortcut function that calls Thread.sleep() but does not require try/catch. This returns true, when sleep ended normally, otherwise false. Note that this method does not throw any exception, but will log if verbose mode.
    
    Parameters:
    
    ms - milliseconds
    
    Returns:
    
    true if okay, otherwise false.
  - log
```
public static void log(String prefix,
                       String msg)
```
    Whenever static method log() is called, it will print to System.out. To control, one can use a static method isVerbose() to check if the mode is verbose if(isVerbose()) log(" [DEBUG] ", "debug!"); // Usage 1 -- completely manually, not recommended. if(isVerbose()) info("some info here"); // Usage 2 -- recommended when the message isn't static.
    
    Parameters:
    
    prefix - to be added right after the timestamp.
    
    msg - message to print.
  - debug
```
public static void debug(Fx01<String> s)
```
  - info
```
public static void info(Fx01<String> s)
```
  - warn
```
public static void warn(Fx01<String> s)
```
  - error
```
public static void error(Fx01<String> s)
```
  - eval
```
public static <R> R eval(Fx01<R> evalFn)
```
    Evaluate the function without a param (This is just to reduce code.)
    
    Type Parameters:
    
    R - Output type
    
    Parameters:
    
    evalFn - A lambda function returns R
    
    Returns:
    
    Result from evalFn
  - eval
```
public static <T,R> R eval(T t,
                           Fx11<T,R> evalFn)
```
    Evaluate the function with a param. (This is just to reduce code.)
    
    Type Parameters:
    
    T - Input type
    
    R - Output type
    
    Parameters:
    
    t - An input value to be evaluated
    
    evalFn - A lambda function takes T and returns R.
    
    Returns:
    
    Result from evalFn
  - eval
```
public static <T1,T2,R> R eval(T1 t1,
                               T2 t2,
                               Fx21<T1,T2,R> evalFn)
```
    Evaluate the function with a param. (This is just to reduce code.)
    
    Type Parameters:
    
    T1 - Type of first param
    
    T2 - Type of second param
    
    R - Type of the result.
    
    Parameters:
    
    t1 - First param to the lambda
    
    t2 - Second param to the lambda
    
    evalFn - A lambda eval function
    
    Returns:
    
    Result from the lambda
  - evalX
```
public static <T,R> R evalX(T t,
                            FxThrow<T,R> evalXFn,
                            Fx11<Exception,R> fallbackFn)
```
    Evaluate a given function with a param. (This is to reduce code. This also catches exception.)
    
    Type Parameters:
    
    T - Input type
    
    R - Output type
    
    Parameters:
    
    t - An input value to be evaluated
    
    evalXFn - A lambda takes T and returns R, also can throw an exception.
    
    fallbackFn - A lambda takes an exception, and returns R.
    
    Returns:
    
    Result from evalXFn if successfully ran, otherwise result from fallbackFn.
  - mustGet
```
public static <T> T mustGet(T t,
                            T fallback)
```
    If t is null, return fallback value.
    
    Type Parameters:
    
    T - output type
    
    Parameters:
    
    t - value to exam
    
    fallback - value to return if t is null
    
    Returns:
    
    t if t is not null otherwise fallback.
  - mustGet
```
public static <X extends Throwable,T> T mustGet(T t,
                                                X exception)
                                         throws X extends Throwable
```
    If t is null, throw an exception
    
    Type Parameters:
    
    X - throwable type'
    
    T - input type
    
    Parameters:
    
    t - value to exam
    
    exception - exception to throw if t is null
    
    Returns:
    
    t if t is not null
    
    Throws:
    
    X - if t is null
    
    X extends Throwable
  - forEachSet
```
public static <T> void forEachSet(T[] src,
                                  FxUnary<T> fx)
```
    Modify array using fx
    
    Type Parameters:
    
    T - type of the array
    
    Parameters:
    
    src - source array
    
    fx - lambda which modifies the src
  - forEach
```
public static <T> void forEach(T[] src,
                               Fx10<T> fx)
```
    Evaluate each T in T[].
    
    Type Parameters:
    
    T - type of the array
    
    Parameters:
    
    src - source array
    
    fx - lambda takes each T.
  - getHash
```
public static int getHash(String s)
```
    Get hash from the input string
    
    Parameters:
    
    s - Input string
    
    Returns:
    
    Hashed integer
  - main
```
public static void main(String[] args)
```

Class Stu

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ENV_VAR_VERBOSE

EPOCH_STARTED

VERBOSE_MODE

SECOND

MINUTE

HOUR

DAY

EMPTY_STRING_ARRAY

Method Detail

subset

repeat

repeat

count

count

count

rtrim

ltrim

substring

substring

getBetween

isBetween

getNth

first

first

last

last

removePrefix

removePrefix

removeSuffix

removeSuffix

getEpoch

epochToString

epochToString

epochToString

epochToString

prints

println

join

getDigits

getDigits

byteSizeToString

getConfig

getConfig

getConfig

parseArgs

getCaller

getCaller

getTimed

sleep

log

debug

info

warn

error

eval

eval

eval

evalX

mustGet

mustGet

forEachSet

forEach

getHash

main