Class TypeUtil

java.lang.Object

org.eclipse.jetty.util.TypeUtil

public class TypeUtil
extends Object

TYPE Utilities. Provides various static utility methods for manipulating types and their string representations.

Since:

Jetty 4.1

Field Summary

Fields

Modifier and Type	Field	Description
static final int	CR
static final int	LF
static final Class<?>[]	NO_ARGS

Method Summary

Modifier and Type	Method	Description
static <T> List<T>	asList(T[] a)	Array to List.
static <T> Iterator<T>	concat(Iterator<T> i1, Iterator<T> i2)
static byte	convertHexDigit(byte c)
static int	convertHexDigit(char c)
static int	convertHexDigit(int c)
static void	dump(Class<?> c)
static void	dump(ClassLoader cl)
static <T> Predicate<T>	falsePredicate()	A Predicate that is always false, with optimized and/or/not methods.
static Class<?>	fromName(String name)	Class from a canonical name for a type.
static URI	getClassLoaderLocation(Class<?> clazz)
static URI	getClassLoaderLocation(Class<?> clazz, ClassLoader loader)
static URI	getCodeSourceLocation(Class<?> clazz)
static URI	getLocationOfClass(Class<?> clazz)	Attempt to find the Location of a loaded Class.
static URI	getModuleLocation(Class<?> clazz)
static URI	getSystemClassLoaderLocation(Class<?> clazz)
static boolean	isDeclaredMethodOn(Object object, String methodName, Class<?>... args)	Test is a method has been declared on the class of an instance
static boolean	isFalse(Object o)
static boolean	isHex(String str, int offset, int len)
static boolean	isTrue(Object o)
static <T> ListIterator<T>	listIteratorAtEnd(List<T> list)	Returns a ListIterator positioned at the last item in a list.
static int	parseInt(byte[] b, int offset, int length, int base)	Parse an int from a byte array of ascii characters.
static int	parseInt(String s, int offset, int length, int base)	Parse an int from a substring.
static <T> Stream<ServiceLoader.Provider<T>>	serviceProviderStream(ServiceLoader<T> serviceLoader)	Utility to create a stream which provides the same functionality as ServiceLoader.stream().
static <T> Stream<T>	serviceStream(ServiceLoader<T> serviceLoader)	Utility method to provide a stream of the service type from a ServiceLoader.
static String	toClassReference(Class<?> clazz)	Return the Classpath / Classloader reference for the provided class file.
static String	toClassReference(String className)	Return the Classpath / Classloader reference for the provided class file.
static void	toHex(byte b, Appendable buf)
static void	toHex(int value, Appendable buf)
static void	toHex(long value, Appendable buf)
static String	toShortName(Class<?> type)
static String	toString(byte[] bytes, int base)
static String	toString(Map<?,?> map)	Pretty print a map.
static <T> Predicate<T>	truePredicate()	A Predicate that is always true, with optimized and/or/not methods.
static Object	valueOf(Class<?> type, String value)	Convert String value to instance.
static Object	valueOf(String type, String value)	Convert String value to instance.

Methods inherited from class Object

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

Field Details

NO_ARGS

public static final Class<?>[] NO_ARGS

CR

public static final int CR

See Also:

• Constant Field Values

LF

public static final int LF

See Also:

• Constant Field Values

Method Details

asList

public static <T> List<T> asList(T[] a)

Array to List.

Works like Arrays.asList(Object...), but handles null arrays.

Type Parameters:

T - the array and list entry type

Parameters:

a - the array to convert to a list

Returns:

a list backed by the array.

listIteratorAtEnd

public static <T> ListIterator<T> listIteratorAtEnd(List<T> list)

Returns a ListIterator positioned at the last item in a list.

Type Parameters:

T - the element type

Parameters:

list - the list

Returns:

A ListIterator positioned at the last item of the list.

fromName

public static Class<?> fromName(String name)

Class from a canonical name for a type.

Parameters:

name - A class or type name.

Returns:

A class , which may be a primitive TYPE field..

toShortName

public static String toShortName(Class<?> type)

toClassReference

public static String toClassReference(Class<?> clazz)

Return the Classpath / Classloader reference for the provided class file.

Convenience method for the code

String ref = myObject.getClass().getName().replace('.','/') + ".class";

Parameters:

clazz - the class to reference

Returns:

the classpath reference syntax for the class file

toClassReference

public static String toClassReference(String className)

Return the Classpath / Classloader reference for the provided class file.

Convenience method for the code

String ref = myClassName.replace('.','/') + ".class";

Parameters:

className - the class to reference

Returns:

the classpath reference syntax for the class file

valueOf

public static Object valueOf(Class<?> type,
 String value)

Convert String value to instance.

Parameters:

type - The class of the instance, which may be a primitive TYPE field.

value - The value as a string.

Returns:

The value as an Object.

valueOf

public static Object valueOf(String type,
 String value)

Convert String value to instance.

Parameters:

type - classname or type (eg int)

value - The value as a string.

Returns:

The value as an Object.

parseInt

public static int parseInt(String s,
 int offset,
 int length,
 int base)
                    throws NumberFormatException

Parse an int from a substring. Negative numbers are not handled.

Parameters:

s - String

offset - Offset within string

length - Length of integer or -1 for remainder of string

base - base of the integer

Returns:

the parsed integer

Throws:

NumberFormatException - if the string cannot be parsed

parseInt

public static int parseInt(byte[] b,
 int offset,
 int length,
 int base)
                    throws NumberFormatException

Parse an int from a byte array of ascii characters. Negative numbers are not handled.

Parameters:

b - byte array

offset - Offset within string

length - Length of integer or -1 for remainder of string

base - base of the integer

Returns:

the parsed integer

Throws:

NumberFormatException - if the array cannot be parsed into an integer

toString

public static String toString(byte[] bytes,
 int base)

convertHexDigit

public static byte convertHexDigit(byte c)

Parameters:

c - An ASCII encoded character 0-9 a-f A-F

Returns:

The byte value of the character 0-16.

convertHexDigit

public static int convertHexDigit(char c)

Parameters:

c - An ASCII encoded character 0-9 a-f A-F

Returns:

The byte value of the character 0-16.

convertHexDigit

public static int convertHexDigit(int c)

Parameters:

c - An ASCII encoded character 0-9 a-f A-F

Returns:

The byte value of the character 0-16.

isHex

public static boolean isHex(String str,
 int offset,
 int len)

toHex

public static void toHex(byte b,
 Appendable buf)

toHex

public static void toHex(int value,
 Appendable buf)
                  throws IOException

Throws:

IOException

toHex

public static void toHex(long value,
 Appendable buf)
                  throws IOException

Throws:

IOException

dump

public static void dump(Class<?> c)

dump

public static void dump(ClassLoader cl)

isTrue

public static boolean isTrue(Object o)

Parameters:

o - Object to test for true

Returns:

True if passed object is not null and is either a Boolean with value true or evaluates to a string that evaluates to true.

isFalse

public static boolean isFalse(Object o)

Parameters:

o - Object to test for false

Returns:

True if passed object is not null and is either a Boolean with value false or evaluates to a string that evaluates to false.

getLocationOfClass

public static URI getLocationOfClass(Class<?> clazz)

Attempt to find the Location of a loaded Class.

This can be null for primitives, void, and in-memory classes.

Parameters:

clazz - the loaded class to find a location for.

Returns:

the location as a URI (this is a URI pointing to a holder of the class: a directory, a jar file, a jrt:// resource, etc), or null of no location available.

getSystemClassLoaderLocation

public static URI getSystemClassLoaderLocation(Class<?> clazz)

getClassLoaderLocation

public static URI getClassLoaderLocation(Class<?> clazz)

getClassLoaderLocation

public static URI getClassLoaderLocation(Class<?> clazz,
 ClassLoader loader)

getCodeSourceLocation

public static URI getCodeSourceLocation(Class<?> clazz)

getModuleLocation

public static URI getModuleLocation(Class<?> clazz)

concat

public static <T> Iterator<T> concat(Iterator<T> i1,
 Iterator<T> i2)

serviceStream

public static <T> Stream<T> serviceStream(ServiceLoader<T> serviceLoader)

Utility method to provide a stream of the service type from a ServiceLoader. ServiceConfigurationErrors thrown when loading or instantiating the service instances are logged at DEBUG level and ignored, so that the stream can proceed with the next service provider.

Consider using serviceProviderStream(ServiceLoader) if you want to explicitly handle ServiceConfigurationErrors thrown when loading or instantiating the service instances.

Type Parameters:

T - the type of the service to load.

Parameters:

serviceLoader - the ServiceLoader instance to use.

Returns:

a stream of the service type which will not throw ServiceConfigurationError.

serviceProviderStream

public static <T> Stream<ServiceLoader.Provider<T>> serviceProviderStream(ServiceLoader<T> serviceLoader)

Utility to create a stream which provides the same functionality as ServiceLoader.stream().

However, this also guards the case in which Iterator.hasNext() throws. Any exceptions from the underlying iterator will be cached until the ServiceLoader.Provider.get() is called.

Consider using serviceStream(ServiceLoader) to ignore exceptions and continue the iteration.

Type Parameters:

T - the type of the service to load.

Parameters:

serviceLoader - the ServiceLoader instance to use.

Returns:

A stream that lazily loads providers for this loader's service

truePredicate

public static <T> Predicate<T> truePredicate()

A Predicate that is always true, with optimized and/or/not methods.

Type Parameters:

T - The type of the predicate test

Returns:

true

falsePredicate

public static <T> Predicate<T> falsePredicate()

A Predicate that is always false, with optimized and/or/not methods.

Type Parameters:

T - The type of the predicate test

Returns:

true

isDeclaredMethodOn

public static boolean isDeclaredMethodOn(Object object,
 String methodName,
 Class<?>... args)

Test is a method has been declared on the class of an instance

Parameters:

object - The object to check

methodName - The method name

args - The arguments to the method

Returns:

true iff Class.getDeclaredMethod(String, Class[]) can be called on the Class of the object, without throwing NoSuchMethodException.

toString

public static String toString(Map<?,?> map)

Pretty print a map. Specifically expanding Array values.

Parameters:

map - The map to render as a String

Returns:

A String representation of the map