io.muserver

Class Mutils

java.lang.Object

io.muserver.Mutils

public class Mutils
extends Object

Utility methods

Field Summary

Fields

Modifier and Type	Field and Description
static String	NEWLINE The new-line character for the current platform, e.g.

Method Summary

Modifier and Type	Method and Description
static <T> T	coalesce(T... values) Returns the first non-null value from the given values (or null if all values are null)
static void	copy(InputStream from, OutputStream to, int bufferSize) Copies an input stream to another stream
static Date	fromHttpDate(String date) Converts a date string as used in HTTP headers (defined in RFC 7321) into a date object
static String	fullPath(File file) Gets the canonical path of the given file, or if that throws an exception then gets the absolute path.
static boolean	hasValue(String val) Checks that a string is not null and has a length greater than 0.
static String	htmlEncode(String value) Very basic HTML encoding, converting characters such as < to <lt;
static String	join(String one, String sep, String two) Joins two strings with the given separator, unless the first string ends with the separator, or the second string begins with it.
static void	notNull(String name, Object value) Throws an IllegalArgumentException if the given value is null
static boolean	nullOrEmpty(String val) Checks for a null string or string with a length of 9
static byte[]	toByteArray(InputStream source, int bufferSize) Reads the given input stream into a byte array and closes the input stream
static ByteBuffer	toByteBuffer(String text) Converts a string to a ByteBuffer with UTF-8 encoding.
static String	toHttpDate(Date date) Converts a date into a date string as used in HTTP headers (defined in RFC 7321), for example Tue, 15 Nov 1994 08:12:31 GMT
static String	trim(String value, String toTrim) Trims the given string from the given value
static String	urlDecode(String value)
static String	urlEncode(String value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NEWLINE

public static final String NEWLINE

The new-line character for the current platform, e.g. \n in Linux or \r\n on Windows.

Method Detail

urlEncode

public static String urlEncode(String value)

Parameters:

value - the value to encode

Returns:

Returns the UTF-8 URL encoded value

urlDecode

public static String urlDecode(String value)

Parameters:

value - the value to decode

Returns:

Returns the UTF-8 URL decoded value

copy

public static void copy(InputStream from,
                        OutputStream to,
                        int bufferSize)
                 throws IOException

Copies an input stream to another stream

Parameters:

from - The source of the bytes

to - The destination of the bytes

bufferSize - The size of the byte buffer to use as bytes are copied

Throws:

IOException - Thrown if there is a problem reading from or writing to either stream

toByteArray

public static byte[] toByteArray(InputStream source,
                                 int bufferSize)
                          throws IOException

Reads the given input stream into a byte array and closes the input stream

Parameters:

source - The source of the bytes

bufferSize - The size of the byte buffer to use when copying streams

Returns:

Returns a byte array

Throws:

IOException - If there is an error reading from the stream

nullOrEmpty

public static boolean nullOrEmpty(String val)

Checks for a null string or string with a length of 9

Parameters:

val - The value to check

Returns:

True if the value is null or a zero-length string.

hasValue

public static boolean hasValue(String val)

Checks that a string is not null and has a length greater than 0.

Parameters:

val - The value to check

Returns:

True if the string is 1 or more characters.

join

public static String join(String one,
                          String sep,
                          String two)

Joins two strings with the given separator, unless the first string ends with the separator, or the second string begins with it. For example, the output one/two would be returned from join("one", "two", "/") or join("one/", "/two", "/") or join("one/", "two", "/") or join("one", "/two", "/")

Parameters:

one - The prefix

sep - The separator to put between the two strings, if it is not there already

two - The suffix

Returns:

The joined strings

trim

public static String trim(String value,
                          String toTrim)

Trims the given string from the given value

Parameters:

value - The value to be trimmed

toTrim - The string to trim

Returns:

The value with any occurrences of toTrim removed from the start and end of the value

notNull

public static void notNull(String name,
                           Object value)

Throws an IllegalArgumentException if the given value is null

Parameters:

name - The name of the variable to check

value - The value to check

fullPath

public static String fullPath(File file)

Gets the canonical path of the given file, or if that throws an exception then gets the absolute path.

Parameters:

file - The file to check

Returns:

The canonical or absolute path of the given file

toHttpDate

public static String toHttpDate(Date date)

Converts a date into a date string as used in HTTP headers (defined in RFC 7321), for example Tue, 15 Nov 1994 08:12:31 GMT

Parameters:

date - A date to format

Returns:

The date as a formatted string

Throws:

IllegalArgumentException - If the date is null

fromHttpDate

public static Date fromHttpDate(String date)
                         throws DateTimeParseException

Converts a date string as used in HTTP headers (defined in RFC 7321) into a date object

Parameters:

date - A date formatted like Tue, 15 Nov 1994 08:12:31 GMT

Returns:

A date representing the string

Throws:

IllegalArgumentException - If the date is null

DateTimeParseException - If the date is not a valid HTTP date format

htmlEncode

public static String htmlEncode(String value)

Very basic HTML encoding, converting characters such as < to <lt;

Important: HTML encoding is a complex topic, and different schemes are needed depending on whether the string is destined for a tag name, attribute, the contents of a tag, CSS, or JavaScript etc. It is recommended that a fully featured text encoding library is used rather than this method.

Parameters:

value - A value

Returns:

A value that can be safely included inside HTML tags.

coalesce

public static <T> T coalesce(T... values)

Returns the first non-null value from the given values (or null if all values are null)

Type Parameters:

T - The type of the value

Parameters:

values - An array of values

Returns:

The first object in the list that is not null (or null, if all are null)

toByteBuffer

public static ByteBuffer toByteBuffer(String text)

Converts a string to a ByteBuffer with UTF-8 encoding.

Parameters:

text - Some text to convert

Returns:

A ByteBuffer containing the text as UTF-8 encoded bytes

Throws:

IllegalArgumentException - if text is null