dev.orne.beans.converters.IdentityBeanConverter Maven / Gradle / Ivy
package dev.orne.beans.converters;
/*-
* #%L
* Orne Beans
* %%
* Copyright (C) 2020 Orne Developments
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import javax.validation.constraints.NotNull;
import org.apache.commons.beanutils.ConversionException;
import org.apache.commons.beanutils.Converter;
import org.apache.commons.beanutils.converters.AbstractConverter;
import dev.orne.beans.BaseIdentityBean;
import dev.orne.beans.Identity;
import dev.orne.beans.IdentityBean;
import dev.orne.beans.WritableIdentityBean;
/**
* Implementation of {@code Converter} that converts {@code IdentityBean}
* instances to {@code String} and {@code WritableIdentityBean} from
* {@code String} using the identity token of the bean as {@code String}
* representation.
*
* Uses a nested {@code Converter}, of type {@code IdentityConverter} by
* default, to convert bean identities.
*
* When converting from {@code String} instances of {@code TokenIdentity}
* are produced an populated on empty instances of the bean, producing valid
* {@code ValidBeanIdentity} instances.
*
* @author (w) Iker Hernaez
* @version 1.0, 2020-09
* @since 0.3
* @see IdentityBean
* @see IdentityConverter
*/
public class IdentityBeanConverter
extends AbstractConverter {
/** Message error when target type is not WritableIdentityBean. */
private static final String NOT_WRITABLE_IBEAN_ERROR =
"Can't convert value '%s' to type %s. " +
"Target type does not implement %s";
/** Message error when cannot instantiate target type. */
private static final String NEW_INSTANCE_ERROR =
"Can't convert value '%s' to type %s. " +
"Cannot create new instances of target type";
/** The default target type. */
private final Class defaultType;
/** The converter for identities. */
private final Converter identityConverter;
/**
* Creates a new instance that throws a {@code ConversionException} if an
* error occurs and uses default instance of {@code IdentityConverter} for
* identity conversions.
*/
public IdentityBeanConverter() {
super();
this.defaultType = BaseIdentityBean.class;
this.identityConverter = new IdentityConverter();
}
/**
* Creates a new instance that returns a default value if an error occurs
* and uses default instance of {@code IdentityConverter} for identity
* conversions.
*
* @param defaultValue The default value to be returned if the value to be
* converted is missing or an error occurs converting the value
*/
public IdentityBeanConverter(
final IdentityBean defaultValue) {
super(defaultValue);
this.defaultType = BaseIdentityBean.class;
this.identityConverter = new IdentityConverter();
}
/**
* Creates a new instance that throws a {@code ConversionException} if an
* error occurs.
*
* @param identityConverter The converter to use for identity conversions
*/
public IdentityBeanConverter(
final @NotNull Converter identityConverter) {
super();
this.defaultType = BaseIdentityBean.class;
this.identityConverter = identityConverter;
}
/**
* Creates a new instance that returns a default value if an error occurs.
*
* @param identityConverter The converter to use for identity conversions
* @param defaultValue The default value to be returned if the value to be
* converted is missing or an error occurs converting the value
*/
public IdentityBeanConverter(
final @NotNull Converter identityConverter,
final WritableIdentityBean defaultValue) {
super(defaultValue);
this.defaultType = BaseIdentityBean.class;
this.identityConverter = identityConverter;
}
/**
* Creates a new instance that throws a {@code ConversionException} if an
* error occurs and uses default instance of {@code IdentityConverter} for
* identity conversions.
*
* @param defaultType The default type this Converter handles.
*/
public IdentityBeanConverter(
final @NotNull Class defaultType) {
super();
this.defaultType = defaultType;
this.identityConverter = new IdentityConverter();
}
/**
* Creates a new instance that returns a default value if an error occurs
* and uses default instance of {@code IdentityConverter} for identity
* conversions.
*
* @param The default type this Converter handles.
* @param defaultType The default type this Converter handles.
* @param defaultValue The default value to be returned if the value to be
* converted is missing or an error occurs converting the value
*/
public IdentityBeanConverter(
final @NotNull Class defaultType,
final T defaultValue) {
super(defaultValue);
this.defaultType = defaultType;
this.identityConverter = new IdentityConverter();
}
/**
* Creates a new instance that throws a {@code ConversionException} if an
* error occurs.
*
* @param defaultType The default type this Converter handles.
* @param identityConverter The converter to use for identity conversions
*/
public IdentityBeanConverter(
final @NotNull Class defaultType,
final @NotNull Converter identityConverter) {
super();
this.defaultType = defaultType;
this.identityConverter = identityConverter;
}
/**
* Creates a new instance that returns a default value if an error occurs.
*
* @param The default type this Converter handles.
* @param defaultType The default type this Converter handles.
* @param identityConverter The converter to use for identity conversions
* @param defaultValue The default value to be returned if the value to be
* converted is missing or an error occurs converting the value
*/
public IdentityBeanConverter(
final @NotNull Class defaultType,
final @NotNull Converter identityConverter,
final T defaultValue) {
super(defaultValue);
this.defaultType = defaultType;
this.identityConverter = identityConverter;
}
/**
* Returns the converter for identities.
*
* @return The converter for identities
*/
protected Converter getIdentityConverter() {
return this.identityConverter;
}
/**
* {@inheritDoc}
*/
@Override
protected @NotNull Class getDefaultType() {
return this.defaultType == null ? WritableIdentityBean.class : this.defaultType;
}
/**
* {@inheritDoc}
*/
@Override
protected T convertToType(
final @NotNull Class type,
final Object value) {
if (IdentityBean.class.isAssignableFrom(type)) {
if (type.isInstance(value)) {
return type.cast(value);
} else if (WritableIdentityBean.class.isAssignableFrom(type)) {
final Identity identity = convertIdentity(value);
if (identity == null) {
return null;
}
final T bean = createInstance(type, value);
((WritableIdentityBean) bean).setIdentity(identity);
return bean;
} else {
throw new ConversionException(
String.format(
NOT_WRITABLE_IBEAN_ERROR,
value,
type,
WritableIdentityBean.class));
}
} else {
throw conversionException(type, value);
}
}
/**
* Tries to create a new instance of the target type.
*
* @param The type of bean to create
* @param type The type of bean to create
* @param value The input value to be converted. Used only when an error
* occurs
* @return The newly created instance
* @throws ConversionException If the new instance cannot be created
*/
protected T createInstance(
final @NotNull Class type,
final Object value) {
try {
return type.newInstance();
} catch (final InstantiationException | IllegalAccessException e) {
throw new ConversionException(
String.format(
NEW_INSTANCE_ERROR,
value,
type),
e);
}
}
/**
* Converts the value to a {@code Identity} instance.
*
* @param value The input value to be converted
* @return The converted value
* @throws ConversionException If an error occurs converting the value
*/
protected Identity convertIdentity(
final Object value) {
final Identity identity;
if (value instanceof Identity) {
identity = (Identity) value;
} else {
identity = this.identityConverter.convert(
Identity.class,
value);
}
return identity;
}
/**
* {@inheritDoc}
*/
@Override
protected String convertToString(
final Object value)
throws Throwable {
if (value instanceof IdentityBean) {
return this.identityConverter.convert(
String.class,
((IdentityBean) value).getIdentity());
} else if (value instanceof String) {
return value.toString();
} else {
throw conversionException(String.class, value);
}
}
}