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java.lang.Objectorg.ckkloverdos.util.Util
public final class Util
General utility methods.
Field Summary | |
---|---|
static java.lang.Object[] |
EMPTY_ARRAY
Empty object array |
static java.util.Random |
RANDOM
A utility random instance. |
static java.text.SimpleDateFormat |
STD_DATE_FMT
The default date format |
Method Summary | |
---|---|
static java.lang.Object[] |
arrayFromItem(java.lang.Object object)
Returns either an empty array or a one-item array containing the given object . |
static java.lang.Object[] |
arrayFromItem(java.lang.Object component,
java.lang.Class componentType)
Returns either an empty array or a one-item array containing the given component . |
static boolean |
emptySafe(java.util.Collection collection)
Checks if the provided collection is empty. |
static boolean |
emptySafe(IL list)
Checks if the provided list is empty. |
static boolean |
emptySafe(java.lang.Object[] array)
Checks if the provided array is empty. |
static boolean |
emptySafe(java.lang.String s)
Checks if the provided string is empty. |
static boolean |
equalSafe(java.lang.Object a,
java.lang.Object b)
Checks if the two objects are equal by also taking into account that one of them (or even both) may be null. |
static java.lang.String |
getenv(java.lang.String name)
Returns the environment variable of the given name . |
static java.lang.String |
getEnvOrProperty(java.lang.String name)
Tries to obtain name either as an environment variable or as a system property. |
static java.lang.String |
getFormattedDate()
Formats the current date by using the default date format. |
static java.lang.String |
getFormattedDate(java.text.SimpleDateFormat sdf)
Formats the current date by using the given SimpleDateFormat . |
static java.lang.String |
getLocalHost()
Returns the localhost name. |
static java.lang.String |
getProperty(java.lang.String name)
A wrapper call around System.getProperty(String) . |
static java.lang.String |
getPropertyOrEnv(java.lang.String name)
Tries to obtain name either as a system property or as an environment variable. |
static java.util.Random |
getRandom()
Creates a new Random instance, preferably of the SHA1PRNG
algorithm. |
static java.util.Random |
getRandom(java.lang.String algorithm)
Creates a new Random instance, of the algorithm
provided. |
static java.lang.String |
getStackTrace(java.lang.Throwable throwable)
Returns the string representation of the stacktrace provided by throwable . |
static boolean |
isInteger(java.lang.String s)
Returns true iff s can be parsed correctly by
Integer.parseInt(s) . |
static boolean |
isLong(java.lang.String s)
Returns true iff s can be parsed correctly by
Long.parseLong(String) . |
static java.lang.ClassLoader[] |
safe(java.lang.ClassLoader[] array)
Returns array "safe" value for array . |
static java.io.File[] |
safe(java.io.File[] array)
Returns array "safe" value for array . |
static java.lang.Object[] |
safe(java.lang.Object[] array,
java.lang.Class componentType)
Returns a "safe" value for array of the given componentType . |
static java.util.Set |
safe(java.util.Set set)
Returns a "safe" value for set . |
static java.lang.String |
safe(java.lang.String s)
Returns a "safe" value for s . |
static java.lang.String[] |
safe(java.lang.String[] array)
Returns array "safe" value for array . |
static double |
safe(java.lang.String s,
double safe)
Returns a "safe" value of the double represented by String s . |
static int |
safe(java.lang.String s,
int safe)
Returns a "safe" value of the int represented by String s . |
static long |
safe(java.lang.String s,
long safe)
Returns a "safe" value of the long represented by String s . |
static java.net.URL |
toURL(java.lang.String s)
Tries to convert s to a URL and ignores a possible MalformedURLException . |
static boolean |
trimmedEmpty(java.lang.String s)
Checks if the provided string is empty, after it is trimmed. |
static boolean |
trimmedEmptySafe(java.lang.String s)
Checks if the provided string is empty, after it is trimmed. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
---|
public static final java.lang.Object[] EMPTY_ARRAY
public static final java.util.Random RANDOM
public static final java.text.SimpleDateFormat STD_DATE_FMT
Method Detail |
---|
public static java.lang.String getFormattedDate(java.text.SimpleDateFormat sdf)
SimpleDateFormat
.
sdf
-
public static java.lang.String getFormattedDate()
default
date format.
public static java.util.Random getRandom()
Random
instance, preferably of the SHA1PRNG
algorithm. If this is not possible, then just a new Random()
is returned.
Random
.public static java.util.Random getRandom(java.lang.String algorithm)
Random
instance, of the algorithm
provided. If this is not possible, then just a new Random()
is returned.
algorithm
- the desired algorithm.
Random
.public static boolean trimmedEmpty(java.lang.String s)
null
, then you should consider using
trimmedEmptySafe(String)
.
s
- the string to be checked.
0 == s.trim().length()
public static java.lang.String getLocalHost()
localhost
name. If this cannot be determined, then
localhost
is returned.
localhost
.public static java.lang.String getStackTrace(java.lang.Throwable throwable)
throwable
.
In effect, the following algorithm is applied:
StringWriter w = new StringWriter(); PrintWriter pw = new PrintWriter(w); throwable.printStackTrace(pw); return w.toString();
throwable
-
public static java.net.URL toURL(java.lang.String s)
s
to a URL
and ignores a possible MalformedURLException
.
s
-
URL
public static java.lang.String getPropertyOrEnv(java.lang.String name)
name
either as a system property or as an environment variable.
First, it tries to obtain name
by using System.getProperty(name)
.
If this returns null
and we are under Java 1.5+, then it uses System.getenv(name)
.
name
-
name
.public static java.lang.String getEnvOrProperty(java.lang.String name)
name
either as an environment variable or as a system property.
First, if we are under Java version < 1.5, it just returns System.getProperty(name)
.
Otherwise, if we are under Java version >= 1.5, it first tries to obtain name
by using System.getenv(name)
.
If this returns null
it returns System.getProperty(name)
.
name
-
name
.public static boolean isInteger(java.lang.String s)
true
iff s
can be parsed correctly by
Integer.parseInt(s)
.
s
-
true
iff s
contains an integer.public static boolean isLong(java.lang.String s)
true
iff s
can be parsed correctly by
Long.parseLong(String)
.
s
-
true
iff s
contains a long.public static java.lang.String getenv(java.lang.String name)
name
.
Since System.getenv(String)
is deprecated for java 1.4, if we are
in a 1.4 VM then System.getProperty(String)
is called, otherwise
System.getenv(String)
is called.
name
-
public static java.lang.String getProperty(java.lang.String name)
System.getProperty(String)
.
name
-
name
.public static boolean equalSafe(java.lang.Object a, java.lang.Object b)
NullPointerException
s.
a
- b
-
true
iff a
and b
are equal.public static boolean emptySafe(java.lang.String s)
null
string is also considered empty.
s
- the string to be checked.
s == null || 0 == s.length()
public static boolean trimmedEmptySafe(java.lang.String s)
null
string is also considered empty.
s
- the string to be checked.
s == null || 0 == s.trim().length()
public static java.lang.String safe(java.lang.String s)
s
.
If s
is null
, then the empty string ""
is returned.
s
-
s
if it is not null
, otherwise ""
.public static java.lang.Object[] safe(java.lang.Object[] array, java.lang.Class componentType)
array
of the given componentType
.
If array
is null
, then an empty Object[]
array is returned.
array
- componentType
-
array
if it is not null
, otherwise an empty Object[]
array.public static java.util.Set safe(java.util.Set set)
set
.
If set
is null
, then an empty Set
is returned.
set
-
set
if it is not null
, otherwise an empty Set
.public static java.lang.Object[] arrayFromItem(java.lang.Object object)
object
.
If object
is null
, then an empty array is returned.
Otherwise, an array of type object.getJavaClass()
and length 1 is created
and filled with object
.
object
-
public static java.lang.Object[] arrayFromItem(java.lang.Object component, java.lang.Class componentType)
component
.
The array component type is determined by componentType
.
If component
is null
, then an empty array is returned.
After succesfull return, the client can safely cast the return value to the proper array type.
component
- componentType
-
java.lang.NullPointerException
- if componentType
is null
.public static boolean emptySafe(java.lang.Object[] array)
null
value for array
is also considered as an empty array.
array
- the array to be checked.
null == array ? true : 0 == array.length
public static java.lang.String[] safe(java.lang.String[] array)
array
.
If array
is null
, then an empty String[]
array is returned.
array
-
array
if it is not null
, otherwise an empty String[]
array.public static java.io.File[] safe(java.io.File[] array)
array
.
If array
is null
, then an empty File[]
array is returned.
array
-
array
if it is not null
, otherwise an empty File[]
array.public static java.lang.ClassLoader[] safe(java.lang.ClassLoader[] array)
array
.
If array
is null
, then an empty ClassLoader[]
array is returned.
array
-
array
if it is not null
, otherwise an empty ClassLoader[]
array.public static boolean emptySafe(java.util.Collection collection)
collection
is empty.
A null
value for collection
is also considered as an empty collection.
collection
- the collection to be checked.
collection
as empty.public static boolean emptySafe(IL list)
list
is empty.
A null
value for list
is also considered as an empty list.
list
-
true
iff it is safe to consider list
as empty.public static int safe(java.lang.String s, int safe)
int
represented by String s
.
If s
cannot be parsed correctly as an int
, then the value
safe
is returned.
s
- the string representation of the int
.safe
- the safe value for the int
.
int
provided in String s
.public static long safe(java.lang.String s, long safe)
long
represented by String s
.
If s
cannot be parsed correctly as an long
, then the value
safe
is returned.
s
- the string representation of the long
.safe
- the safe value for the long
.
long
provided in String s
.public static double safe(java.lang.String s, double safe)
double
represented by String s
.
If s
cannot be parsed correctly as an double
, then the value
safe
is returned.
s
- the string representation of the double
.safe
- the safe value for the double
.
double
provided in String s
.
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