StringConvert.java
/*
* Copyright 2010-present Stephen Colebourne
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.joda.convert;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.SimpleTimeZone;
import java.util.TimeZone;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CopyOnWriteArrayList;
import org.joda.convert.factory.BooleanArrayStringConverterFactory;
import org.joda.convert.factory.BooleanObjectArrayStringConverterFactory;
import org.joda.convert.factory.ByteObjectArrayStringConverterFactory;
import org.joda.convert.factory.CharObjectArrayStringConverterFactory;
import org.joda.convert.factory.NumericArrayStringConverterFactory;
import org.joda.convert.factory.NumericObjectArrayStringConverterFactory;
/**
* Manager for conversion to and from a {@code String}, acting as the main client interface.
* <p>
* Support is provided for conversions based on the {@link StringConverter} interface
* or the {@link ToString} and {@link FromString} annotations.
* <p>
* StringConvert is thread-safe with concurrent caches.
*/
public final class StringConvert {
// NOTE!
// There must be no references (direct or indirect) to RenameHandler
// This class must be loaded first to avoid horrid loops in class initialization
/**
* Errors in class initialization are hard to debug.
* Set -Dorg.joda.convert.debug=true on the command line to add extra logging to System.err
*/
static final boolean LOG;
static {
String log = null;
try {
log = System.getProperty("org.joda.convert.debug");
} catch (SecurityException ex) {
// ignore
}
LOG = "true".equalsIgnoreCase(log);
}
/**
* The cached null object. Ensure this is above public constants.
*/
private static final TypedStringConverter<?> CACHED_NULL = new TypedStringConverter<Object>() {
@Override
public String convertToString(Object object) {
return null;
}
@Override
public Object convertFromString(Class<? extends Object> cls, String str) {
return null;
}
@Override
public Class<?> getEffectiveType() {
return null;
}
};
/**
* An immutable global instance.
* <p>
* This instance cannot be added to using {@link #register}, however annotated classes
* are picked up. To register your own converters, simply create an instance of this class.
*/
public static final StringConvert INSTANCE = new StringConvert();
/**
* The list of factories.
*/
private final CopyOnWriteArrayList<StringConverterFactory> factories = new CopyOnWriteArrayList<StringConverterFactory>();
/**
* The cache of converters.
*/
private final ConcurrentMap<Class<?>, TypedStringConverter<?>> registered = new ConcurrentHashMap<Class<?>, TypedStringConverter<?>>();
/**
* The cache of from-strings.
*/
private final ConcurrentMap<Class<?>, FromStringConverter<?>> fromStrings = new ConcurrentHashMap<Class<?>, FromStringConverter<?>>();
//-----------------------------------------------------------------------
/**
* Creates a new conversion manager including the extended standard set of converters.
* <p>
* The returned converter is a new instance that includes additional converters:
* <ul>
* <li>JDK converters
* <li>{@link NumericArrayStringConverterFactory}
* <li>{@link NumericObjectArrayStringConverterFactory}
* <li>{@link CharObjectArrayStringConverterFactory}
* <li>{@link ByteObjectArrayStringConverterFactory}
* <li>{@link BooleanArrayStringConverterFactory}
* <li>{@link BooleanObjectArrayStringConverterFactory}
* </ul>
* <p>
* The convert instance is mutable in a thread-safe manner.
* Converters may be altered at any time, including the JDK converters.
* It is strongly recommended to only alter the converters before performing
* actual conversions.
*
* @return the new converter, not null
* @since 1.5
*/
public static StringConvert create() {
return new StringConvert(true,
NumericArrayStringConverterFactory.INSTANCE,
NumericObjectArrayStringConverterFactory.INSTANCE,
CharObjectArrayStringConverterFactory.INSTANCE,
ByteObjectArrayStringConverterFactory.INSTANCE,
BooleanArrayStringConverterFactory.INSTANCE,
BooleanObjectArrayStringConverterFactory.INSTANCE);
}
//-----------------------------------------------------------------------
/**
* Creates a new conversion manager including the JDK converters.
* <p>
* The convert instance is mutable in a thread-safe manner.
* Converters may be altered at any time, including the JDK converters.
* It is strongly recommended to only alter the converters before performing
* actual conversions.
*/
public StringConvert() {
this(true);
}
/**
* Creates a new conversion manager.
* <p>
* The convert instance is mutable in a thread-safe manner.
* Converters may be altered at any time, including the JDK converters.
* It is strongly recommended to only alter the converters before performing
* actual conversions.
* <p>
* If specified, the factories will be queried in the order specified.
*
* @param includeJdkConverters true to include the JDK converters
* @param factories optional array of factories to use, not null
*/
public StringConvert(boolean includeJdkConverters, StringConverterFactory... factories) {
if (factories == null) {
throw new IllegalArgumentException("StringConverterFactory array must not be null");
}
for (int i = 0; i < factories.length; i++) {
if (factories[i] == null) {
throw new IllegalArgumentException("StringConverterFactory array must not contain a null element");
}
}
if (includeJdkConverters) {
for (JDKStringConverter conv : JDKStringConverter.values()) {
registered.put(conv.getType(), conv);
}
registered.put(Boolean.TYPE, JDKStringConverter.BOOLEAN);
registered.put(Byte.TYPE, JDKStringConverter.BYTE);
registered.put(Short.TYPE, JDKStringConverter.SHORT);
registered.put(Integer.TYPE, JDKStringConverter.INTEGER);
registered.put(Long.TYPE, JDKStringConverter.LONG);
registered.put(Float.TYPE, JDKStringConverter.FLOAT);
registered.put(Double.TYPE, JDKStringConverter.DOUBLE);
registered.put(Character.TYPE, JDKStringConverter.CHARACTER);
tryRegisterGuava();
tryRegisterJava8Optionals();
tryRegisterTimeZone();
tryRegisterJava8();
tryRegisterThreeTenBackport();
tryRegisterThreeTenOld();
}
if (factories.length > 0) {
this.factories.addAll(Arrays.asList(factories));
}
this.factories.add(AnnotationStringConverterFactory.INSTANCE);
if (includeJdkConverters) {
this.factories.add(EnumStringConverterFactory.INSTANCE);
this.factories.add(TypeStringConverterFactory.INSTANCE);
}
}
/**
* Tries to register the Guava converters class.
*/
private void tryRegisterGuava() {
try {
// Guava is not a direct dependency, which is significant in the Java 9 module system
// to access Guava this module must add a read edge to the module graph
// but since this code is written for Java 6, we have to do this by reflection
// yuck
Class<?> moduleClass = Class.class.getMethod("getModule").getReturnType();
Object convertModule = Class.class.getMethod("getModule").invoke(StringConvert.class);
Object layer = convertModule.getClass().getMethod("getLayer").invoke(convertModule);
if (layer != null) {
Object optGuava = layer.getClass().getMethod("findModule", String.class).invoke(layer, "com.google.common");
boolean found = (Boolean) optGuava.getClass().getMethod("isPresent").invoke(optGuava);
if (found) {
Object guavaModule = optGuava.getClass().getMethod("get").invoke(optGuava);
moduleClass.getMethod("addReads", moduleClass).invoke(convertModule, guavaModule);
}
}
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterGuava1: " + ex);
}
}
try {
// can now check for Guava
// if we have created a read edge, or if we are on the classpath, this will succeed
loadType("com.google.common.reflect.TypeToken");
@SuppressWarnings("unchecked")
Class<?> cls = loadType("org.joda.convert.TypeTokenStringConverter");
TypedStringConverter<?> conv = (TypedStringConverter<?>) cls.getDeclaredConstructor().newInstance();
registered.put(conv.getEffectiveType(), conv);
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterGuava2: " + ex);
}
}
}
/**
* Tries to register the Java 8 optional classes.
*/
private void tryRegisterJava8Optionals() {
try {
loadType("java.util.OptionalInt");
@SuppressWarnings("unchecked")
Class<?> cls1 = loadType("org.joda.convert.OptionalIntStringConverter");
TypedStringConverter<?> conv1 = (TypedStringConverter<?>) cls1.getDeclaredConstructor().newInstance();
registered.put(conv1.getEffectiveType(), conv1);
@SuppressWarnings("unchecked")
Class<?> cls2 = loadType("org.joda.convert.OptionalLongStringConverter");
TypedStringConverter<?> conv2 = (TypedStringConverter<?>) cls2.getDeclaredConstructor().newInstance();
registered.put(conv2.getEffectiveType(), conv2);
@SuppressWarnings("unchecked")
Class<?> cls3 = loadType("org.joda.convert.OptionalDoubleStringConverter");
TypedStringConverter<?> conv3 = (TypedStringConverter<?>) cls3.getDeclaredConstructor().newInstance();
registered.put(conv3.getEffectiveType(), conv3);
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterOptionals: " + ex);
}
}
}
/**
* Tries to register the subclasses of TimeZone.
* Try various things, doesn't matter if the map entry gets overwritten.
*/
private void tryRegisterTimeZone() {
try {
registered.put(SimpleTimeZone.class, JDKStringConverter.TIME_ZONE);
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterTimeZone1: " + ex);
}
}
try {
TimeZone zone = TimeZone.getDefault();
registered.put(zone.getClass(), JDKStringConverter.TIME_ZONE);
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterTimeZone2: " + ex);
}
}
try {
TimeZone zone = TimeZone.getTimeZone("Europe/London");
registered.put(zone.getClass(), JDKStringConverter.TIME_ZONE);
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterTimeZone3: " + ex);
}
}
}
/**
* Tries to register Java 8 classes.
*/
private void tryRegisterJava8() {
try {
tryRegister("java.time.Instant", "parse");
tryRegister("java.time.Duration", "parse");
tryRegister("java.time.LocalDate", "parse");
tryRegister("java.time.LocalTime", "parse");
tryRegister("java.time.LocalDateTime", "parse");
tryRegister("java.time.OffsetTime", "parse");
tryRegister("java.time.OffsetDateTime", "parse");
tryRegister("java.time.ZonedDateTime", "parse");
tryRegister("java.time.Year", "parse");
tryRegister("java.time.YearMonth", "parse");
tryRegister("java.time.MonthDay", "parse");
tryRegister("java.time.Period", "parse");
tryRegister("java.time.ZoneOffset", "of");
tryRegister("java.time.ZoneId", "of");
tryRegister("java.time.ZoneRegion", "of");
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterJava8: " + ex);
}
}
}
/**
* Tries to register ThreeTen backport classes.
*/
private void tryRegisterThreeTenBackport() {
try {
tryRegister("org.threeten.bp.Instant", "parse");
tryRegister("org.threeten.bp.Duration", "parse");
tryRegister("org.threeten.bp.LocalDate", "parse");
tryRegister("org.threeten.bp.LocalTime", "parse");
tryRegister("org.threeten.bp.LocalDateTime", "parse");
tryRegister("org.threeten.bp.OffsetTime", "parse");
tryRegister("org.threeten.bp.OffsetDateTime", "parse");
tryRegister("org.threeten.bp.ZonedDateTime", "parse");
tryRegister("org.threeten.bp.Year", "parse");
tryRegister("org.threeten.bp.YearMonth", "parse");
tryRegister("org.threeten.bp.MonthDay", "parse");
tryRegister("org.threeten.bp.Period", "parse");
tryRegister("org.threeten.bp.ZoneOffset", "of");
tryRegister("org.threeten.bp.ZoneId", "of");
tryRegister("org.threeten.bp.ZoneRegion", "of");
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterThreeTenBackport: " + ex);
}
}
}
/**
* Tries to register ThreeTen ThreeTen/JSR-310 classes v0.6.3 and beyond.
*/
private void tryRegisterThreeTenOld() {
try {
tryRegister("javax.time.Instant", "parse");
tryRegister("javax.time.Duration", "parse");
tryRegister("javax.time.calendar.LocalDate", "parse");
tryRegister("javax.time.calendar.LocalTime", "parse");
tryRegister("javax.time.calendar.LocalDateTime", "parse");
tryRegister("javax.time.calendar.OffsetDate", "parse");
tryRegister("javax.time.calendar.OffsetTime", "parse");
tryRegister("javax.time.calendar.OffsetDateTime", "parse");
tryRegister("javax.time.calendar.ZonedDateTime", "parse");
tryRegister("javax.time.calendar.Year", "parse");
tryRegister("javax.time.calendar.YearMonth", "parse");
tryRegister("javax.time.calendar.MonthDay", "parse");
tryRegister("javax.time.calendar.Period", "parse");
tryRegister("javax.time.calendar.ZoneOffset", "of");
tryRegister("javax.time.calendar.ZoneId", "of");
tryRegister("javax.time.calendar.TimeZone", "of");
} catch (Throwable ex) {
if (LOG) {
System.err.println("tryRegisterThreeTenOld: " + ex);
}
}
}
/**
* Tries to register a class using the standard toString/parse pattern.
*
* @param className the class name, not null
* @throws ClassNotFoundException if the class does not exist
*/
private void tryRegister(String className, String fromStringMethodName) throws ClassNotFoundException {
Class<?> cls = loadType(className);
registerMethods(cls, "toString", fromStringMethodName);
}
//-----------------------------------------------------------------------
/**
* Converts the specified object to a {@code String}.
* <p>
* This uses {@link #findConverter} to provide the converter.
*
* @param object the object to convert, null returns null
* @return the converted string, may be null
* @throws RuntimeException (or subclass) if unable to convert
*/
public String convertToString(Object object) {
if (object == null) {
return null;
}
Class<?> cls = object.getClass();
StringConverter<Object> conv = findConverterNoGenerics(cls);
return conv.convertToString(object);
}
/**
* Converts the specified object to a {@code String}.
* <p>
* This uses {@link #findConverter} to provide the converter.
* The class can be provided to select a more specific converter.
*
* @param cls the class to convert from, not null
* @param object the object to convert, null returns null
* @return the converted string, may be null
* @throws RuntimeException (or subclass) if unable to convert
*/
public String convertToString(Class<?> cls, Object object) {
if (object == null) {
return null;
}
StringConverter<Object> conv = findConverterNoGenerics(cls);
return conv.convertToString(object);
}
/**
* Converts the specified object from a {@code String}.
* <p>
* This uses {@link #findFromStringConverter} to provide the converter.
*
* @param <T> the type to convert to
* @param cls the class to convert to, not null
* @param str the string to convert, null returns null
* @return the converted object, may be null
* @throws RuntimeException (or subclass) if unable to convert
*/
public <T> T convertFromString(Class<T> cls, String str) {
if (str == null) {
return null;
}
FromStringConverter<T> conv = findFromStringConverter(cls);
return conv.convertFromString(cls, str);
}
//-----------------------------------------------------------------------
/**
* Checks if a suitable converter exists for the type.
* <p>
* This performs the same checks as the {@code findConverter} methods.
* Calling this before {@code findConverter} will cache the converter.
* <p>
* Note that all exceptions, including developer errors are caught and hidden.
*
* @param cls the class to find a converter for, null returns false
* @return true if convertible
* @since 1.5
*/
public boolean isConvertible(final Class<?> cls) {
try {
return cls != null && findConverterQuiet(cls) != null;
} catch (RuntimeException ex) {
return false;
}
}
/**
* Finds a suitable converter for the type.
* <p>
* This returns an instance of {@code StringConverter} for the specified class.
* This is designed for user code where the {@code Class} object generics is known.
* <p>
* The search algorithm first searches the registered converters.
* It then searches for {@code ToString} and {@code FromString} annotations on the
* specified class, class hierarchy or immediate parent interfaces.
* Finally, it handles {@code Enum} instances.
*
* @param <T> the type of the converter
* @param cls the class to find a converter for, not null
* @return the converter, not null
* @throws RuntimeException (or subclass) if no converter found
*/
public <T> StringConverter<T> findConverter(final Class<T> cls) {
return findTypedConverter(cls);
}
/**
* Finds a suitable converter for the type with open generics.
* <p>
* This returns an instance of {@code StringConverter} for the specified class.
* This is designed for framework usage where the {@code Class} object generics are unknown'?'.
* The returned type is declared with {@code Object} instead of '?' to
* allow the {@link ToStringConverter} to be invoked.
* <p>
* The search algorithm first searches the registered converters.
* It then searches for {@code ToString} and {@code FromString} annotations on the
* specified class, class hierarchy or immediate parent interfaces.
* Finally, it handles {@code Enum} instances.
*
* @param cls the class to find a converter for, not null
* @return the converter, using {@code Object} to avoid generics, not null
* @throws RuntimeException (or subclass) if no converter found
* @since 1.5
*/
public StringConverter<Object> findConverterNoGenerics(final Class<?> cls) {
return findTypedConverterNoGenerics(cls);
}
/**
* Finds a suitable converter for the type.
* <p>
* This returns an instance of {@code TypedStringConverter} for the specified class.
* This is designed for user code where the {@code Class} object generics is known.
* <p>
* The search algorithm first searches the registered converters.
* It then searches for {@code ToString} and {@code FromString} annotations on the
* specified class, class hierarchy or immediate parent interfaces.
* Finally, it handles {@code Enum} instances.
* <p>
* The returned converter may be queried for the effective type of the conversion.
* This can be used to find the best type to send in a serialized form.
* <p>
* NOTE: Changing the method return type of {@link #findConverter(Class)}
* would be source compatible but not binary compatible. As this is a low-level
* library, binary compatibility is important, hence the addition of this method.
*
* @param <T> the type of the converter
* @param cls the class to find a converter for, not null
* @return the converter, not null
* @throws RuntimeException (or subclass) if no converter found
* @since 1.7
*/
public <T> TypedStringConverter<T> findTypedConverter(final Class<T> cls) {
TypedStringConverter<T> conv = findConverterQuiet(cls);
if (conv == null) {
throw new IllegalStateException("No registered converter found: " + cls);
}
return conv;
}
/**
* Finds a suitable converter for the type with open generics.
* <p>
* This returns an instance of {@code TypedStringConverter} for the specified class.
* This is designed for framework usage where the {@code Class} object generics are unknown'?'.
* The returned type is declared with {@code Object} instead of '?' to
* allow the {@link ToStringConverter} to be invoked.
* <p>
* The search algorithm first searches the registered converters.
* It then searches for {@code ToString} and {@code FromString} annotations on the
* specified class, class hierarchy or immediate parent interfaces.
* Finally, it handles {@code Enum} instances.
* <p>
* The returned converter may be queried for the effective type of the conversion.
* This can be used to find the best type to send in a serialized form.
* <p>
* NOTE: Changing the method return type of {@link #findConverterNoGenerics(Class)}
* would be source compatible but not binary compatible. As this is a low-level
* library, binary compatibility is important, hence the addition of this method.
*
* @param cls the class to find a converter for, not null
* @return the converter, using {@code Object} to avoid generics, not null
* @throws RuntimeException (or subclass) if no converter found
* @since 1.7
*/
@SuppressWarnings("unchecked")
public TypedStringConverter<Object> findTypedConverterNoGenerics(final Class<?> cls) {
TypedStringConverter<Object> conv = (TypedStringConverter<Object>) findConverterQuiet(cls);
if (conv == null) {
throw new IllegalStateException("No registered converter found: " + cls);
}
return conv;
}
/**
* Finds a suitable from-string converter for the type.
* <p>
* This returns an instance of {@code FromStringConverter} for the specified class.
* In most cases this is identical to {@link #findConverter(Class)}.
* However, it is permitted to have a {@code FromString} annotation without a {@code ToString} annotation,
* and this method catches that use case.
*
* @param <T> the type of the converter
* @param cls the class to find a converter for, not null
* @return the converter, not null
* @throws RuntimeException (or subclass) if no converter found
*/
@SuppressWarnings("unchecked")
public <T> FromStringConverter<T> findFromStringConverter(final Class<T> cls) {
TypedStringConverter<T> converter = findConverterQuiet(cls);
if (converter == null) {
FromStringConverter<T> fromStringConverter = (FromStringConverter<T>) fromStrings.get(cls);
if (fromStringConverter == null) {
throw new IllegalStateException("No registered converter found: " + cls);
}
return fromStringConverter;
}
return converter;
}
@SuppressWarnings("unchecked")
private <T> TypedStringConverter<T> findConverterQuiet(final Class<T> cls) {
if (cls == null) {
throw new IllegalArgumentException("Class must not be null");
}
TypedStringConverter<T> conv = (TypedStringConverter<T>) registered.get(cls);
if (conv == CACHED_NULL) {
return null;
}
if (conv == null) {
try {
conv = lookupConverter(cls);
} catch (RuntimeException ex) {
registered.putIfAbsent(cls, CACHED_NULL);
throw ex;
}
if (conv == null) {
registered.putIfAbsent(cls, CACHED_NULL);
// search for from-string only converters now, so that our cache is accurate for all kinds of converter
TypedFromStringConverter<T> fromString = AnnotationStringConverterFactory.INSTANCE.findFromStringConverter(cls);
if (fromString != null) {
fromStrings.put(cls, fromString);
}
return null;
}
registered.putIfAbsent(cls, conv);
}
return conv;
}
/**
* Lookup a converter searching registered and annotated.
*
* @param <T> the type of the converter
* @param cls the class to find a method for, not null
* @return the converter, not null
* @throws RuntimeException if invalid
*/
@SuppressWarnings("unchecked")
private <T> TypedStringConverter<T> lookupConverter(final Class<T> cls) {
// check factories
for (StringConverterFactory factory : factories) {
StringConverter<T> factoryConv = (StringConverter<T>) factory.findConverter(cls);
if (factoryConv != null) {
return TypedAdapter.adapt(cls, factoryConv);
}
}
return null;
}
//-----------------------------------------------------------------------
/**
* Registers a converter factory.
* <p>
* This will be registered ahead of all existing factories.
* <p>
* No new factories may be registered for the global singleton.
*
* @param factory the converter factory, not null
* @throws IllegalStateException if trying to alter the global singleton
* @since 1.5
*/
public void registerFactory(final StringConverterFactory factory) {
if (factory == null) {
throw new IllegalArgumentException("Factory must not be null");
}
if (this == INSTANCE) {
throw new IllegalStateException("Global singleton cannot be extended");
}
factories.add(0, factory);
}
//-----------------------------------------------------------------------
/**
* Registers a converter for a specific type.
* <p>
* The converter will be used for subclasses unless overidden.
* <p>
* No new converters may be registered for the global singleton.
*
* @param <T> the type of the converter
* @param cls the class to register a converter for, not null
* @param converter the String converter, not null
* @throws IllegalArgumentException if the class or converter are null
* @throws IllegalStateException if trying to alter the global singleton
*/
public <T> void register(final Class<T> cls, StringConverter<T> converter) {
if (cls == null) {
throw new IllegalArgumentException("Class must not be null");
}
if (converter == null) {
throw new IllegalArgumentException("StringConverter must not be null");
}
if (this == INSTANCE) {
throw new IllegalStateException("Global singleton cannot be extended");
}
registered.put(cls, TypedAdapter.adapt(cls, converter));
}
/**
* Registers a converter for a specific type using two separate converters.
* <p>
* This method registers a converter for the specified class.
* It is primarily intended for use with JDK 1.8 method references or lambdas:
* <pre>
* sc.register(Distance.class, Distance::toString, Distance::parse);
* </pre>
* The converter will be used for subclasses unless overidden.
* <p>
* No new converters may be registered for the global singleton.
*
* @param <T> the type of the converter
* @param cls the class to register a converter for, not null
* @param toString the to String converter, typically a method reference, not null
* @param fromString the from String converter, typically a method reference, not null
* @throws IllegalArgumentException if the class or converter are null
* @throws IllegalStateException if trying to alter the global singleton
* @since 1.3
*/
public <T> void register(final Class<T> cls, final ToStringConverter<T> toString, final FromStringConverter<T> fromString) {
if (fromString == null || toString == null) {
throw new IllegalArgumentException("Converters must not be null");
}
register(cls, new TypedStringConverter<T>() {
@Override
public String convertToString(T object) {
return toString.convertToString(object);
}
@Override
public T convertFromString(Class<? extends T> cls, String str) {
return fromString.convertFromString(cls, str);
}
@Override
public Class<?> getEffectiveType() {
return cls;
}
});
}
/**
* Registers a converter for a specific type by method names.
* <p>
* This method allows the converter to be used when the target class cannot have annotations added.
* The two method names must obey the same rules as defined by the annotations
* {@link ToString} and {@link FromString}.
* The converter will be used for subclasses unless overidden.
* <p>
* No new converters may be registered for the global singleton.
* <p>
* For example, {@code convert.registerMethods(Distance.class, "toString", "parse");}
*
* @param <T> the type of the converter
* @param cls the class to register a converter for, not null
* @param toStringMethodName the name of the method converting to a string, not null
* @param fromStringMethodName the name of the method converting from a string, not null
* @throws IllegalArgumentException if the class or method name are null or invalid
* @throws IllegalStateException if trying to alter the global singleton
*/
public <T> void registerMethods(final Class<T> cls, String toStringMethodName, String fromStringMethodName) {
if (cls == null) {
throw new IllegalArgumentException("Class must not be null");
}
if (toStringMethodName == null || fromStringMethodName == null) {
throw new IllegalArgumentException("Method names must not be null");
}
if (this == INSTANCE) {
throw new IllegalStateException("Global singleton cannot be extended");
}
Method toString = findToStringMethod(cls, toStringMethodName);
Method fromString = findFromStringMethod(cls, fromStringMethodName);
TypedFromStringConverter<T> fromStringConverter = new MethodFromStringConverter<T>(cls, fromString, cls);
ReflectionStringConverter<T> converter = new ReflectionStringConverter<T>(cls, toString, fromStringConverter);
registered.putIfAbsent(cls, converter);
}
/**
* Registers a converter for a specific type by method and constructor.
* <p>
* This method allows the converter to be used when the target class cannot have annotations added.
* The two method name and constructor must obey the same rules as defined by the annotations
* {@link ToString} and {@link FromString}.
* The converter will be used for subclasses unless overidden.
* <p>
* No new converters may be registered for the global singleton.
* <p>
* For example, {@code convert.registerMethodConstructor(Distance.class, "toString");}
*
* @param <T> the type of the converter
* @param cls the class to register a converter for, not null
* @param toStringMethodName the name of the method converting to a string, not null
* @throws IllegalArgumentException if the class or method name are null or invalid
* @throws IllegalStateException if trying to alter the global singleton
*/
public <T> void registerMethodConstructor(final Class<T> cls, String toStringMethodName) {
if (cls == null) {
throw new IllegalArgumentException("Class must not be null");
}
if (toStringMethodName == null) {
throw new IllegalArgumentException("Method name must not be null");
}
if (this == INSTANCE) {
throw new IllegalStateException("Global singleton cannot be extended");
}
Method toString = findToStringMethod(cls, toStringMethodName);
Constructor<T> fromString = findFromStringConstructorByType(cls);
TypedFromStringConverter<T> fromStringConverter = new ConstructorFromStringConverter<T>(cls, fromString);
ReflectionStringConverter<T> converter = new ReflectionStringConverter<T>(cls, toString, fromStringConverter);
registered.putIfAbsent(cls, converter);
}
/**
* Finds the conversion method.
*
* @param cls the class to find a method for, not null
* @param methodName the name of the method to find, not null
* @return the method to call, null means use {@code toString}
*/
private Method findToStringMethod(Class<?> cls, String methodName) {
Method m;
try {
m = cls.getMethod(methodName);
} catch (NoSuchMethodException ex) {
throw new IllegalArgumentException(ex);
}
if (Modifier.isStatic(m.getModifiers())) {
throw new IllegalArgumentException("Method must not be static: " + methodName);
}
return m;
}
/**
* Finds the conversion method.
*
* @param cls the class to find a method for, not null
* @param methodName the name of the method to find, not null
* @return the method to call, null means use {@code toString}
*/
private Method findFromStringMethod(Class<?> cls, String methodName) {
Method m;
try {
m = cls.getMethod(methodName, String.class);
} catch (NoSuchMethodException ex) {
try {
m = cls.getMethod(methodName, CharSequence.class);
} catch (NoSuchMethodException ex2) {
throw new IllegalArgumentException("Method not found", ex2);
}
}
if (Modifier.isStatic(m.getModifiers()) == false) {
throw new IllegalArgumentException("Method must be static: " + methodName);
}
return m;
}
/**
* Finds the conversion method.
*
* @param <T> the type of the converter
* @param cls the class to find a method for, not null
* @return the method to call, null means use {@code toString}
*/
private <T> Constructor<T> findFromStringConstructorByType(Class<T> cls) {
try {
return cls.getDeclaredConstructor(String.class);
} catch (NoSuchMethodException ex) {
try {
return cls.getDeclaredConstructor(CharSequence.class);
} catch (NoSuchMethodException ex2) {
throw new IllegalArgumentException("Constructor not found", ex2);
}
}
}
//-----------------------------------------------------------------------
// loads a type avoiding nulls, context class loader if available
static Class<?> loadType(String fullName) throws ClassNotFoundException {
try {
ClassLoader loader = Thread.currentThread().getContextClassLoader();
return loader != null && !fullName.startsWith("[") ? loader.loadClass(fullName) : Class.forName(fullName);
} catch (ClassNotFoundException ex) {
return loadPrimitiveType(fullName, ex);
}
}
// handle primitive types
private static Class<?> loadPrimitiveType(String fullName, ClassNotFoundException ex) throws ClassNotFoundException {
if (fullName.equals("int")) {
return int.class;
} else if (fullName.equals("long")) {
return long.class;
} else if (fullName.equals("double")) {
return double.class;
} else if (fullName.equals("boolean")) {
return boolean.class;
} else if (fullName.equals("short")) {
return short.class;
} else if (fullName.equals("byte")) {
return byte.class;
} else if (fullName.equals("char")) {
return char.class;
} else if (fullName.equals("float")) {
return float.class;
} else if (fullName.equals("void")) {
return void.class;
}
throw ex;
}
//-----------------------------------------------------------------------
/**
* Returns a simple string representation of the object.
*
* @return the string representation, never null
*/
@Override
public String toString() {
return getClass().getSimpleName();
}
}