Utils (JOSM)

java.lang.Object
- org.openstreetmap.josm.tools.Utils

```
public final class Utils
extends java.lang.Object
```
Basic utils, that can be useful in different parts of the program.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface Utils.Function<A,B>
Represents a function that can be applied to objects of A and returns objects of B.

Nested Classes
Modifier and Type	Class and Description
`static interface`	`Utils.Function<A,B>` Represents a function that can be applied to objects of `A` and returns objects of `B`.

Field Summary

Fields
Modifier and Type	Field and Description
`private static double`	`EPSILON`
`private static char[]`	`HEX_ARRAY`
`private static java.util.regex.Pattern`	`HTTP_PREFFIX_PATTERN`
`private static int`	`MILLIS_OF_DAY`
`private static int`	`MILLIS_OF_HOUR`
`private static int`	`MILLIS_OF_MINUTE`
`private static int`	`MILLIS_OF_SECOND`
`static java.lang.String`	`URL_CHARS`
`static java.util.regex.Pattern`	`WHITE_SPACES_PATTERN`

Constructor Summary

Constructors
Modifier Constructor and Description

private Utils()

Constructors
Modifier	Constructor and Description
`private`	`Utils()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static <T> T[]`	`addInArrayCopy(T[] array, T item)` Adds the given item at the end of a new copy of given array.
`static <T> T`	`cast(java.lang.Object o, java.lang.Class<T> klass)` Cast an object savely.
`static void`	`close(java.io.Closeable c)` Utility method for closing a `Closeable` object.
`static void`	`close(java.util.zip.ZipFile zip)` Utility method for closing a `ZipFile`.
`static java.lang.Integer`	`color_float2int(java.lang.Float val)` convert float range 0 <= x <= 1 to integer range 0..255 when dealing with colors and color alpha value
`static java.lang.Float`	`color_int2float(java.lang.Integer val)` convert integer range 0..255 to float range 0 <= x <= 1 when dealing with colors and color alpha value
`static java.awt.Color`	`complement(java.awt.Color clr)`
`static char[]`	`copyArray(char[] array)` Copies the given array.
`static int[]`	`copyArray(int[] array)` Copies the given array.
`static <T> T[]`	`copyArray(T[] array)` Copies the given array.
`static void`	`copyDirectory(java.io.File in, java.io.File out)` Recursive directory copy function
`static java.nio.file.Path`	`copyFile(java.io.File in, java.io.File out)` Simple file copy function that will overwrite the target file.
`static int`	`copyStream(java.io.InputStream source, java.io.OutputStream destination)` Copy data from source stream to output stream.
`static boolean`	`copyToClipboard(java.lang.String s)` Copies the string `s` to system clipboard.
`static boolean`	`deleteDirectory(java.io.File path)` Deletes a directory recursively.
`static void`	`ensure(boolean condition, java.lang.String message, java.lang.Object... data)` Ensures a logical condition is met.
`static boolean`	`equalsEpsilon(double a, double b)` Determines if the two given double values are equal (their delta being smaller than a fixed epsilon)
`static java.lang.String`	`execOutput(java.util.List<java.lang.String> command)` Runs an external command and returns the standard output.
`static <T> boolean`	`exists(java.lang.Iterable<? extends T> collection, Predicate<? super T> predicate)` Tests whether `predicate` applies to at least one elements from `collection`.
`static <T> boolean`	`exists(java.lang.Iterable<T> collection, java.lang.Class<? extends T> klass)`
`static java.net.URL`	`fileToURL(java.io.File f)` Converts the given file to its URL.
`static <T> java.util.Collection<T>`	`filter(java.util.Collection<? extends T> collection, Predicate<? super T> predicate)`
`static <S,T extends S> SubclassFilteredCollection<S,T>`	`filteredCollection(java.util.Collection<S> collection, java.lang.Class<T> klass)` Filter a collection by (sub)class.
`static <T> T`	`find(java.lang.Iterable<? extends T> collection, Predicate<? super T> predicate)`
`static <T> T`	`find(java.lang.Iterable<? super T> collection, java.lang.Class<? extends T> klass)`
`static <T> T`	`firstNonNull(T... items)` Returns the first element from `items` which is non-null, or null if all elements are null.
`static java.lang.String`	`fixURLQuery(java.lang.String url)` Fixes URL with illegal characters in the query (and fragment) part by percent encoding those characters.
`static <T> boolean`	`forAll(java.lang.Iterable<? extends T> collection, Predicate<? super T> predicate)` Tests whether `predicate` applies to all elements from `collection`.
`static BZip2CompressorInputStream`	`getBZip2InputStream(java.io.InputStream in)` Returns a Bzip2 input stream wrapping given input stream.
`static java.lang.String`	`getClipboardContent()` Extracts clipboard content as string.
`static java.lang.String`	`getDurationString(long elapsedTime)` Returns a simple human readable (hours, minutes, seconds) string for a given duration in milliseconds.
`static java.util.zip.GZIPInputStream`	`getGZipInputStream(java.io.InputStream in)` Returns a Gzip input stream wrapping given input stream.
`static java.io.File`	`getJosmTempDir()` Returns the JOSM temp directory.
`static java.util.List<java.lang.String>`	`getMatches(java.util.regex.Matcher m)` Returns a list of capture groups if `Matcher.matches()`, or `null`.
`static java.lang.String`	`getPositionListString(java.util.List<java.lang.Integer> positionList)` Returns a human readable representation of a list of positions.
`static java.lang.Throwable`	`getRootCause(java.lang.Throwable t)` Returns the root cause of a throwable object.
`static java.util.zip.ZipInputStream`	`getZipInputStream(java.io.InputStream in)` Returns a Zip input stream wrapping given input stream.
`static <T> int`	`indexOf(java.lang.Iterable<? extends T> collection, Predicate<? super T> predicate)`
`static boolean`	`isLocalUrl(java.lang.String url)` Determines if the given URL denotes a file on a local filesystem.
`static java.lang.String`	`join(java.lang.String sep, java.util.Collection<?> values)` Joins a list of strings (or objects that can be converted to string via Object.toString()) into a single string with fields separated by sep.
`static java.lang.String`	`joinAsHtmlUnorderedList(java.lang.Iterable<?> values)` Converts the given iterable collection as an unordered HTML list.
`static int`	`max(int a, int b, int c, int d)` Returns the greater of four `int` values.
`static java.lang.String`	`md5Hex(java.lang.String data)` Calculate MD5 hash of a string and output in hexadecimal format.
`static int`	`min(int a, int b, int c)` Returns the minimum of three values.
`static int`	`mod(int a, int n)` return the modulus in the range [0, n)
`static Pair<java.lang.Integer,java.util.concurrent.ExecutorService>`	`newThreadPool(java.lang.String pref)` Returns a pair containing the number of threads (n), and a thread pool (if n > 1) to perform multi-thread computation in the context of the given preference key.
`static java.net.HttpURLConnection`	`openHttpConnection(java.net.URL httpURL)` Opens a HTTP connection to the given URL and sets the User-Agent property to JOSM's one.
`static java.net.HttpURLConnection`	`openHttpConnection(java.net.URL httpURL, boolean keepAlive)` Opens a HTTP connection to the given URL, sets the User-Agent property to JOSM's one and optionnaly disables Keep-Alive.
`static java.io.InputStream`	`openURL(java.net.URL url)` Opens a connection to the given URL and sets the User-Agent property to JOSM's one.
`static java.io.InputStream`	`openURLAndDecompress(java.net.URL url, boolean decompress)` Opens a connection to the given URL, sets the User-Agent property to JOSM's one, and decompresses stream if necessary.
`static java.io.BufferedReader`	`openURLReader(java.net.URL url)` Opens a connection to the given URL and sets the User-Agent property to JOSM's one.
`static java.io.BufferedReader`	`openURLReaderAndDecompress(java.net.URL url, boolean decompress)` Opens a connection to the given URL and sets the User-Agent property to JOSM's one.
`static java.net.URLConnection`	`setupURLConnection(java.net.URLConnection connection)` Setups the given URL connection to match JOSM needs by setting its User-Agent and timeout properties.
`static java.lang.String`	`shortenString(java.lang.String s, int maxLength)` If the string `s` is longer than `maxLength`, the string is cut and "..." is appended.
`static java.lang.String`	`strip(java.lang.String str)` An alternative to `String.trim()` to effectively remove all leading and trailing white characters, including Unicode ones.
`static java.lang.String`	`toHexString(byte[] bytes)` Converts a byte array to a string of hexadecimal characters.
`static <T> java.util.List<T>`	`topologicalSort(MultiMap<T,T> dependencies)` Topological sort.
`static java.lang.String`	`toString(java.awt.Color c)` convert Color to String (Color.toString() omits alpha value)
`static <A,B> java.util.Collection<B>`	`transform(java.util.Collection<? extends A> c, Utils.Function<A,B> f)` Transforms the collection `c` into an unmodifiable collection and applies the `Utils.Function` `f` on each element upon access.
`static <A,B> java.util.List<B>`	`transform(java.util.List<? extends A> l, Utils.Function<A,B> f)` Transforms the list `l` into an unmodifiable list and applies the `Utils.Function` `f` on each element upon access.
`static java.lang.String`	`updateSystemProperty(java.lang.String key, java.lang.String value)` Updates a given system property.

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

- Field Detail
  - WHITE_SPACES_PATTERN
```
public static final java.util.regex.Pattern WHITE_SPACES_PATTERN
```
  - MILLIS_OF_SECOND
```
private static final int MILLIS_OF_SECOND
```
    See Also:
    
    Constant Field Values
  - MILLIS_OF_MINUTE
```
private static final int MILLIS_OF_MINUTE
```
    See Also:
    
    Constant Field Values
  - MILLIS_OF_HOUR
```
private static final int MILLIS_OF_HOUR
```
    See Also:
    
    Constant Field Values
  - MILLIS_OF_DAY
```
private static final int MILLIS_OF_DAY
```
    See Also:
    
    Constant Field Values
  - URL_CHARS
```
public static final java.lang.String URL_CHARS
```
    See Also:
    
    Constant Field Values
  - EPSILON
```
private static final double EPSILON
```
    See Also:
    
    Constant Field Values
  - HEX_ARRAY
```
private static final char[] HEX_ARRAY
```
  - HTTP_PREFFIX_PATTERN
```
private static final java.util.regex.Pattern HTTP_PREFFIX_PATTERN
```
- Constructor Detail
  - Utils
```
private Utils()
```
- Method Detail
  - exists
```
public static <T> boolean exists(java.lang.Iterable<? extends T> collection,
                                 Predicate<? super T> predicate)
```
    Tests whether predicate applies to at least one elements from collection.
  - forAll
```
public static <T> boolean forAll(java.lang.Iterable<? extends T> collection,
                                 Predicate<? super T> predicate)
```
    Tests whether predicate applies to all elements from collection.
  - exists
```
public static <T> boolean exists(java.lang.Iterable<T> collection,
                                 java.lang.Class<? extends T> klass)
```
  - find
```
public static <T> T find(java.lang.Iterable<? extends T> collection,
                         Predicate<? super T> predicate)
```
  - find
```
public static <T> T find(java.lang.Iterable<? super T> collection,
                         java.lang.Class<? extends T> klass)
```
  - filter
```
public static <T> java.util.Collection<T> filter(java.util.Collection<? extends T> collection,
                                                 Predicate<? super T> predicate)
```
  - firstNonNull
```
@SafeVarargs
public static <T> T firstNonNull(T... items)
```
    Returns the first element from items which is non-null, or null if all elements are null.
    
    Parameters:
    
    items - the items to look for
    
    Returns:
    
    first non-null item if there is one
  - filteredCollection
```
public static <S,T extends S> SubclassFilteredCollection<S,T> filteredCollection(java.util.Collection<S> collection,
                                                                                 java.lang.Class<T> klass)
```
    Filter a collection by (sub)class. This is an efficient read-only implementation.
  - indexOf
```
public static <T> int indexOf(java.lang.Iterable<? extends T> collection,
                              Predicate<? super T> predicate)
```
  - min
```
public static int min(int a,
                      int b,
                      int c)
```
    Returns the minimum of three values.
    
    Parameters:
    
    a - an argument.
    
    b - another argument.
    
    c - another argument.
    
    Returns:
    
    the smaller of a, b and c.
  - max
```
public static int max(int a,
                      int b,
                      int c,
                      int d)
```
    Returns the greater of four int values. That is, the result is the argument closer to the value of Integer.MAX_VALUE. If the arguments have the same value, the result is that same value.
    
    Parameters:
    
    a - an argument.
    
    b - another argument.
    
    c - another argument.
    
    d - another argument.
    
    Returns:
    
    the larger of a, b, c and d.
  - ensure
```
public static void ensure(boolean condition,
                          java.lang.String message,
                          java.lang.Object... data)
```
    Ensures a logical condition is met. Otherwise throws an assertion error.
    
    Parameters:
    
    condition - the condition to be met
    
    message - Formatted error message to raise if condition is not met
    
    data - Message parameters, optional
    
    Throws:
    
    java.lang.AssertionError - if the condition is not met
  - mod
```
public static int mod(int a,
                      int n)
```
    return the modulus in the range [0, n)
  - join
```
public static java.lang.String join(java.lang.String sep,
                                    java.util.Collection<?> values)
```
    Joins a list of strings (or objects that can be converted to string via Object.toString()) into a single string with fields separated by sep.
    
    Parameters:
    
    sep - the separator
    
    values - collection of objects, null is converted to the empty string
    
    Returns:
    
    null if values is null. The joined string otherwise.
  - joinAsHtmlUnorderedList
```
public static java.lang.String joinAsHtmlUnorderedList(java.lang.Iterable<?> values)
```
    Converts the given iterable collection as an unordered HTML list.
    
    Parameters:
    
    values - The iterable collection
    
    Returns:
    
    An unordered HTML list
  - toString
```
public static java.lang.String toString(java.awt.Color c)
```
    convert Color to String (Color.toString() omits alpha value)
  - color_float2int
```
public static java.lang.Integer color_float2int(java.lang.Float val)
```
    convert float range 0 <= x <= 1 to integer range 0..255 when dealing with colors and color alpha value
    
    Returns:
    
    null if val is null, the corresponding int if val is in the range 0...1. If val is outside that range, return 255
  - color_int2float
```
public static java.lang.Float color_int2float(java.lang.Integer val)
```
    convert integer range 0..255 to float range 0 <= x <= 1 when dealing with colors and color alpha value
  - complement
```
public static java.awt.Color complement(java.awt.Color clr)
```
  - copyArray
```
public static <T> T[] copyArray(T[] array)
```
    Copies the given array. Unlike Arrays.copyOf(T[], int), this method is null-safe.
    
    Parameters:
    
    array - The array to copy
    
    Returns:
    
    A copy of the original array, or null if array is null
    
    Since:
    
    6221
  - copyArray
```
public static char[] copyArray(char[] array)
```
    Copies the given array. Unlike Arrays.copyOf(T[], int), this method is null-safe.
    
    Parameters:
    
    array - The array to copy
    
    Returns:
    
    A copy of the original array, or null if array is null
    
    Since:
    
    6222
  - copyArray
```
public static int[] copyArray(int[] array)
```
    Copies the given array. Unlike Arrays.copyOf(T[], int), this method is null-safe.
    
    Parameters:
    
    array - The array to copy
    
    Returns:
    
    A copy of the original array, or null if array is null
    
    Since:
    
    7436
  - copyFile
```
public static java.nio.file.Path copyFile(java.io.File in,
                                          java.io.File out)
                                   throws java.io.IOException
```
    Simple file copy function that will overwrite the target file.
    
    Parameters:
    
    in - The source file
    
    out - The destination file
    
    Returns:
    
    the path to the target file
    
    Throws:
    
    java.io.IOException - If any I/O error occurs
    
    java.lang.IllegalArgumentException - If in or out is null
    
    Since:
    
    7003
  - copyDirectory
```
public static void copyDirectory(java.io.File in,
                                 java.io.File out)
                          throws java.io.IOException
```
    Recursive directory copy function
    
    Parameters:
    
    in - The source directory
    
    out - The destination directory
    
    Throws:
    
    java.io.IOException - If any I/O error ooccurs
    
    java.lang.IllegalArgumentException - If in or out is null
    
    Since:
    
    7835
  - copyStream
```
public static int copyStream(java.io.InputStream source,
                             java.io.OutputStream destination)
                      throws java.io.IOException
```
    Copy data from source stream to output stream.
    
    Parameters:
    
    source - source stream
    
    destination - target stream
    
    Returns:
    
    number of bytes copied
    
    Throws:
    
    java.io.IOException - if any I/O error occurs
  - deleteDirectory
```
public static boolean deleteDirectory(java.io.File path)
```
    Deletes a directory recursively.
    
    Parameters:
    
    path - The directory to delete
    
    Returns:
    
    true if and only if the file or directory is successfully deleted; false otherwise
  - close
```
public static void close(java.io.Closeable c)
```
    Utility method for closing a Closeable object.
    
    Parameters:
    
    c - the closeable object. May be null.
  - close
```
public static void close(java.util.zip.ZipFile zip)
```
    Utility method for closing a ZipFile.
    
    Parameters:
    
    zip - the zip file. May be null.
  - fileToURL
```
public static java.net.URL fileToURL(java.io.File f)
```
    Converts the given file to its URL.
    
    Parameters:
    
    f - The file to get URL from
    
    Returns:
    
    The URL of the given file, or null if not possible.
    
    Since:
    
    6615
  - equalsEpsilon
```
public static boolean equalsEpsilon(double a,
                                    double b)
```
    Determines if the two given double values are equal (their delta being smaller than a fixed epsilon)
    
    Parameters:
    
    a - The first double value to compare
    
    b - The second double value to compare
    
    Returns:
    
    true if abs(a - b) <= 1e-11, false otherwise
  - copyToClipboard
```
public static boolean copyToClipboard(java.lang.String s)
```
    Copies the string s to system clipboard.
    
    Parameters:
    
    s - string to be copied to clipboard.
    
    Returns:
    
    true if succeeded, false otherwise.
  - getClipboardContent
```
public static java.lang.String getClipboardContent()
```
    Extracts clipboard content as string.
    
    Returns:
    
    string clipboard contents if available, null otherwise.
  - md5Hex
```
public static java.lang.String md5Hex(java.lang.String data)
```
    Calculate MD5 hash of a string and output in hexadecimal format.
    
    Parameters:
    
    data - arbitrary String
    
    Returns:
    
    MD5 hash of data, string of length 32 with characters in range [0-9a-f]
  - toHexString
```
public static java.lang.String toHexString(byte[] bytes)
```
    Converts a byte array to a string of hexadecimal characters. Preserves leading zeros, so the size of the output string is always twice the number of input bytes.
    
    Parameters:
    
    bytes - the byte array
    
    Returns:
    
    hexadecimal representation
  - topologicalSort
```
public static <T> java.util.List<T> topologicalSort(MultiMap<T,T> dependencies)
```
    Topological sort.
    
    Parameters:
    
    dependencies - contains mappings (key -> value). In the final list of sorted objects, the key will come after the value. (In other words, the key depends on the value(s).) There must not be cyclic dependencies.
    
    Returns:
    
    the list of sorted objects
  - transform
```
public static <A,B> java.util.Collection<B> transform(java.util.Collection<? extends A> c,
                                                      Utils.Function<A,B> f)
```
    Transforms the collection c into an unmodifiable collection and applies the Utils.Function f on each element upon access.
    
    Type Parameters:
    
    A - class of input collection
    
    B - class of transformed collection
    
    Parameters:
    
    c - a collection
    
    f - a function that transforms objects of A to objects of B
    
    Returns:
    
    the transformed unmodifiable collection
  - transform
```
public static <A,B> java.util.List<B> transform(java.util.List<? extends A> l,
                                                Utils.Function<A,B> f)
```
    Transforms the list l into an unmodifiable list and applies the Utils.Function f on each element upon access.
    
    Type Parameters:
    
    A - class of input collection
    
    B - class of transformed collection
    
    Parameters:
    
    l - a collection
    
    f - a function that transforms objects of A to objects of B
    
    Returns:
    
    the transformed unmodifiable list
  - openHttpConnection
```
public static java.net.HttpURLConnection openHttpConnection(java.net.URL httpURL)
                                                     throws java.io.IOException
```
    Opens a HTTP connection to the given URL and sets the User-Agent property to JOSM's one.
    
    Parameters:
    
    httpURL - The HTTP url to open (must use http:// or https://)
    
    Returns:
    
    An open HTTP connection to the given URL
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
    
    Since:
    
    5587
  - openURL
```
public static java.io.InputStream openURL(java.net.URL url)
                                   throws java.io.IOException
```
    Opens a connection to the given URL and sets the User-Agent property to JOSM's one.
    
    Parameters:
    
    url - The url to open
    
    Returns:
    
    An stream for the given URL
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
    
    Since:
    
    5867
  - openURLAndDecompress
```
public static java.io.InputStream openURLAndDecompress(java.net.URL url,
                                                       boolean decompress)
                                                throws java.io.IOException
```
    Opens a connection to the given URL, sets the User-Agent property to JOSM's one, and decompresses stream if necessary.
    
    Parameters:
    
    url - The url to open
    
    decompress - whether to wrap steam in a GZIPInputStream or BZip2CompressorInputStream if the Content-Type header is set accordingly.
    
    Returns:
    
    An stream for the given URL
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
    
    Since:
    
    6421
  - getBZip2InputStream
```
public static BZip2CompressorInputStream getBZip2InputStream(java.io.InputStream in)
                                                      throws java.io.IOException
```
    Returns a Bzip2 input stream wrapping given input stream.
    
    Parameters:
    
    in - The raw input stream
    
    Returns:
    
    a Bzip2 input stream wrapping given input stream, or null if in is null
    
    Throws:
    
    java.io.IOException - if the given input stream does not contain valid BZ2 header
    
    Since:
    
    7867
  - getGZipInputStream
```
public static java.util.zip.GZIPInputStream getGZipInputStream(java.io.InputStream in)
                                                        throws java.io.IOException
```
    Returns a Gzip input stream wrapping given input stream.
    
    Parameters:
    
    in - The raw input stream
    
    Returns:
    
    a Gzip input stream wrapping given input stream, or null if in is null
    
    Throws:
    
    java.io.IOException - if an I/O error has occurred
    
    Since:
    
    7119
  - getZipInputStream
```
public static java.util.zip.ZipInputStream getZipInputStream(java.io.InputStream in)
                                                      throws java.io.IOException
```
    Returns a Zip input stream wrapping given input stream.
    
    Parameters:
    
    in - The raw input stream
    
    Returns:
    
    a Zip input stream wrapping given input stream, or null if in is null
    
    Throws:
    
    java.io.IOException - if an I/O error has occurred
    
    Since:
    
    7119
  - setupURLConnection
```
public static java.net.URLConnection setupURLConnection(java.net.URLConnection connection)
```
    Setups the given URL connection to match JOSM needs by setting its User-Agent and timeout properties.
    
    Parameters:
    
    connection - The connection to setup
    
    Returns:
    
    connection, with updated properties
    
    Since:
    
    5887
  - openURLReader
```
public static java.io.BufferedReader openURLReader(java.net.URL url)
                                            throws java.io.IOException
```
    Opens a connection to the given URL and sets the User-Agent property to JOSM's one.
    
    Parameters:
    
    url - The url to open
    
    Returns:
    
    An buffered stream reader for the given URL (using UTF-8)
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
    
    Since:
    
    5868
  - openURLReaderAndDecompress
```
public static java.io.BufferedReader openURLReaderAndDecompress(java.net.URL url,
                                                                boolean decompress)
                                                         throws java.io.IOException
```
    Opens a connection to the given URL and sets the User-Agent property to JOSM's one.
    
    Parameters:
    
    url - The url to open
    
    decompress - whether to wrap steam in a GZIPInputStream or BZip2CompressorInputStream if the Content-Type header is set accordingly.
    
    Returns:
    
    An buffered stream reader for the given URL (using UTF-8)
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
    
    Since:
    
    6421
  - openHttpConnection
```
public static java.net.HttpURLConnection openHttpConnection(java.net.URL httpURL,
                                                            boolean keepAlive)
                                                     throws java.io.IOException
```
    Opens a HTTP connection to the given URL, sets the User-Agent property to JOSM's one and optionnaly disables Keep-Alive.
    
    Parameters:
    
    httpURL - The HTTP url to open (must use http:// or https://)
    
    keepAlive - whether not to set header Connection=close
    
    Returns:
    
    An open HTTP connection to the given URL
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
    
    Since:
    
    5587
  - strip
```
public static java.lang.String strip(java.lang.String str)
```
    An alternative to String.trim() to effectively remove all leading and trailing white characters, including Unicode ones.
    
    Parameters:
    
    str - The string to strip
    
    Returns:
    
    str, without leading and trailing characters, according to Character.isWhitespace(char) and Character.isSpaceChar(char).
    
    Since:
    
    5772
    
    See Also:
    
    Java’s String.trim has a strange idea of whitespace, JDK bug 4080617
  - execOutput
```
public static java.lang.String execOutput(java.util.List<java.lang.String> command)
                                   throws java.io.IOException
```
    Runs an external command and returns the standard output. The program is expected to execute fast.
    
    Parameters:
    
    command - the command with arguments
    
    Returns:
    
    the output
    
    Throws:
    
    java.io.IOException - when there was an error, e.g. command does not exist
  - getJosmTempDir
```
public static java.io.File getJosmTempDir()
```
    Returns the JOSM temp directory.
    
    Returns:
    
    The JOSM temp directory (<java.io.tmpdir>/JOSM), or null if java.io.tmpdir is not defined
    
    Since:
    
    6245
  - getDurationString
```
public static java.lang.String getDurationString(long elapsedTime)
```
    Returns a simple human readable (hours, minutes, seconds) string for a given duration in milliseconds.
    
    Parameters:
    
    elapsedTime - The duration in milliseconds
    
    Returns:
    
    A human readable string for the given duration
    
    Throws:
    
    java.lang.IllegalArgumentException - if elapsedTime is < 0
    
    Since:
    
    6354
  - getPositionListString
```
public static java.lang.String getPositionListString(java.util.List<java.lang.Integer> positionList)
```
    Returns a human readable representation of a list of positions.
    For instance, [1,5,2,6,7 yields "1-2,5-7
    
    Parameters:
    
    positionList - a list of positions
    
    Returns:
    
    a human readable representation
  - getMatches
```
public static java.util.List<java.lang.String> getMatches(java.util.regex.Matcher m)
```
    Returns a list of capture groups if Matcher.matches(), or null. The first element (index 0) is the complete match. Further elements correspond to the parts in parentheses of the regular expression.
    
    Parameters:
    
    m - the matcher
    
    Returns:
    
    a list of capture groups if Matcher.matches(), or null.
  - cast
```
public static <T> T cast(java.lang.Object o,
                         java.lang.Class<T> klass)
```
    Cast an object savely.
    
    Type Parameters:
    
    T - the target type
    
    Parameters:
    
    o - the object to cast
    
    klass - the target class (same as T)
    
    Returns:
    
    null if o is null or the type o is not a subclass of klass. The casted value otherwise.
  - getRootCause
```
public static java.lang.Throwable getRootCause(java.lang.Throwable t)
```
    Returns the root cause of a throwable object.
    
    Parameters:
    
    t - The object to get root cause for
    
    Returns:
    
    the root cause of t
    
    Since:
    
    6639
  - addInArrayCopy
```
public static <T> T[] addInArrayCopy(T[] array,
                                     T item)
```
    Adds the given item at the end of a new copy of given array.
    
    Parameters:
    
    array - The source array
    
    item - The item to add
    
    Returns:
    
    An extended copy of array containing item as additional last element
    
    Since:
    
    6717
  - shortenString
```
public static java.lang.String shortenString(java.lang.String s,
                                             int maxLength)
```
    If the string s is longer than maxLength, the string is cut and "..." is appended.
    
    Parameters:
    
    s - String to shorten
    
    maxLength - maximum number of characters to keep (not including the "...")
    
    Returns:
    
    the shortened string
  - fixURLQuery
```
public static java.lang.String fixURLQuery(java.lang.String url)
```
    Fixes URL with illegal characters in the query (and fragment) part by percent encoding those characters. special characters like & and # are not encoded
    
    Parameters:
    
    url - the URL that should be fixed
    
    Returns:
    
    the repaired URL
  - isLocalUrl
```
public static boolean isLocalUrl(java.lang.String url)
```
    Determines if the given URL denotes a file on a local filesystem.
    
    Parameters:
    
    url - The URL to test
    
    Returns:
    
    true if the url points to a local file
    
    Since:
    
    7356
  - newThreadPool
```
public static Pair<java.lang.Integer,java.util.concurrent.ExecutorService> newThreadPool(java.lang.String pref)
```
    Returns a pair containing the number of threads (n), and a thread pool (if n > 1) to perform multi-thread computation in the context of the given preference key.
    
    Parameters:
    
    pref - The preference key
    
    Returns:
    
    a pair containing the number of threads (n), and a thread pool (if n > 1, null otherwise)
    
    Since:
    
    7423
  - updateSystemProperty
```
public static java.lang.String updateSystemProperty(java.lang.String key,
                                                    java.lang.String value)
```
    Updates a given system property.
    
    Parameters:
    
    key - The property key
    
    value - The property value
    
    Returns:
    
    the previous value of the system property, or null if it did not have one.
    
    Since:
    
    7894

Class Utils

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

WHITE_SPACES_PATTERN

MILLIS_OF_SECOND

MILLIS_OF_MINUTE

MILLIS_OF_HOUR

MILLIS_OF_DAY

URL_CHARS

EPSILON

HEX_ARRAY

HTTP_PREFFIX_PATTERN

Constructor Detail

Utils

Method Detail

exists

forAll

exists

find

find

filter

firstNonNull

filteredCollection

indexOf

min

max

ensure

mod

join

joinAsHtmlUnorderedList

toString

color_float2int

color_int2float

complement

copyArray

copyArray

copyArray

copyFile

copyDirectory

copyStream

deleteDirectory

close

close

fileToURL

equalsEpsilon

copyToClipboard

getClipboardContent

md5Hex

toHexString

topologicalSort

transform

transform

openHttpConnection

openURL

openURLAndDecompress

getBZip2InputStream

getGZipInputStream

getZipInputStream

setupURLConnection

openURLReader

openURLReaderAndDecompress

openHttpConnection

strip

execOutput

getJosmTempDir

getDurationString

getPositionListString

getMatches

cast

getRootCause

addInArrayCopy

shortenString

fixURLQuery

isLocalUrl

newThreadPool

updateSystemProperty