org.microbean.microprofile.config

Class ConversionHub

java.lang.Object

org.microbean.microprofile.config.ConversionHub

All Implemented Interfaces:

Closeable, Serializable, AutoCloseable, TypeConverter

public class ConversionHub
extends Object
implements Closeable, Serializable, TypeConverter

A Serializable, Closeable TypeConverter implementation that is based on a collection of Converters.

Author:

Laird Nelson

See Also:

convert(String, Type), Serialized Form

Constructor Summary

Constructors

Constructor and Description
ConversionHub() Creates a new ConversionHub.
ConversionHub(Map<? extends Type,? extends Converter<?>> converters) Creates a new ConversionHub.

Method Summary

Modifier and Type	Method and Description
void	close() Closes this ConversionHub using a best-effort strategy.
<T> T	convert(String value, Type type) Attempts to convert the supplied String value to an object assignable to the supplied Type, throwing an IllegalArgumentException if such conversion is impossible.
boolean	isClosed() Returns true if this ConversionHub has been closed.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConversionHub

public ConversionHub()

Creates a new ConversionHub.

ConversionHub

public ConversionHub(Map<? extends Type,? extends Converter<?>> converters)

Creates a new ConversionHub.

Thread Safety

converters will be synchronized on and iterated over by this constructor, which may have implications on the type of Map supplied.

Parameters:

converters - a Map of Converter instances, indexed by the Type describing the type of the return value of their respective Converter.convert(String) methods; may be null; will be synchronized on and iterated over; copied by value; no reference is kept to this object

Method Detail

close

public void close()
           throws IOException

Closes this ConversionHub using a best-effort strategy.

This method attempts to close each of this ConversionHub's associated Closeable Converters. Any IOException thrown during such an attempt does not abort the closing process.

Once this method has been invoked:

• All future invocations of the convert(String, Type) method will throw an IllegalStateException
• All future invocations of the isClosed() method will return true

ConversionHub instances are often supplied to Config instances at construction time, and so may be closed by them.

Thread Safety

This method is safe for concurrent use by multiple threads.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException - if at least one underlying Closeable Converter could not be closed

isClosed

public final boolean isClosed()

Returns true if this ConversionHub has been closed.

All invocations of the convert(String, Type) method will always throw an IllegalStateException once this ConversionHub has been closed.

Thread Safety

This method is idempotent and safe for concurrent use by multiple threads.

Returns:

true if this ConversionHub has been closed; false otherwise

See Also:

close()

convert

public final <T> T convert(String value,
                           Type type)

Attempts to convert the supplied String value to an object assignable to the supplied Type, throwing an IllegalArgumentException if such conversion is impossible.

This method may return null.

Thread Safety

This method is safe for concurrent use by multiple threads.

Specified by:

convert in interface TypeConverter

Type Parameters:

T - the type of the return value, assumed to be assignable to references of the supplied type

Parameters:

value - the value to convert; may be null

type - the Type to which the value should be converted; must not be null; the type of the return value resulting from invocations this method should be assignable to references of this type

Returns:

the converted object, which may be null

Throws:

IllegalArgumentException - if conversion could not occur for any reason

IllegalStateException - if this ConversionHub was closed