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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.deltaspike.core.spi.config;
import javax.enterprise.inject.spi.InjectionPoint;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import org.apache.deltaspike.core.api.config.ConfigResolver;
import org.apache.deltaspike.core.api.config.ConfigProperty;
import org.apache.deltaspike.core.api.provider.BeanProvider;
import org.apache.deltaspike.core.util.BeanUtils;
/**
* <p>This contains the fundamental parts for implementing own
* ConfigProperty producers.</p>
*
* <h2>Providing own Converters and Type injection</h2>
* <p>DeltaSpikes own configuration system natively supports only Strings.
* If you'd like to apply own Converters or extract other types from those Strings,
* you can simply do this by providing an own Qualifier and a simple
* CDI producer method for it.</p>
*
* <p>First we write a simple Qualifier:
* <pre>
* @Target({ PARAMETER, FIELD, METHOD, CONSTRUCTOR, ANNOTATION_TYPE })
* @Retention(RUNTIME)
* @ConfigProperty(named="unused") // the name
* @Qualifier
* public @interface NumberConfig
* {
* @Nonbinding
* boolean name(); // the name of the configuration-key to lookup the value
*
* @Nonbinding
* String defaultValue() default ConfigProperty.NULL;
*
* @Nonbinding
* boolean pattern(); // the pattern for NumberFormatter
* }
* </pre>
* </p>
*
* <p>The producer method implementation is pretty easy as well:
* <pre>
* @ApplicationScoped
* public class NumberConfigProducer extends BaseConfigPropertyProducer
* {
* @Produces
* @Dependent
* @NumberConfig
* public Float produceNumberConfig(InjectionPoint injectionPoint)
* {
* // resolve the annotation
* NumberConfig metaData = getAnnotation(injectionPoint, NumberConfig.class);
* // get the configured value from the underlying configuration system
* String configuredValue = getPropertyValue(metaData.name(), metaData.defaultValue());
* if (configuredValue == null)
* {
* return null;
* }
*
* // format according to the given pattern
* DecimalFormat df = new DecimalFormat(metaData.pattern(), new DecimalFormatSymbols(Locale.US));
* return df.parse(configuredValue).floatValue();
* }
* }
* </pre>
* </p>
*/
public abstract class BaseConfigPropertyProducer
{
/**
* <p>Inspects the given InjectionPoint and search for a {@link ConfigProperty}
* annotation or an Annotation with a {@link ConfigProperty} meta-Annotation.
* The name and defaultValue information will be used to resolve the
* configured value.</p>
*
* @param injectionPoint current injection point
* @return the configured value for the given InjectionPoint
*/
protected String getStringPropertyValue(InjectionPoint injectionPoint)
{
ConfigProperty configProperty = getAnnotation(injectionPoint, ConfigProperty.class);
if (configProperty == null)
{
throw new IllegalStateException("producer method called without @ConfigProperty being present!");
}
return getPropertyValue(injectionPoint, String.class);
}
protected <T> T getPropertyValue(InjectionPoint injectionPoint, Class<T> ipCls)
{
return getUntypedPropertyValue(injectionPoint, ipCls);
}
protected <T> T getUntypedPropertyValue(InjectionPoint injectionPoint, Type ipCls)
{
ConfigProperty configProperty = getAnnotation(injectionPoint, ConfigProperty.class);
if (configProperty == null)
{
throw new IllegalStateException("producer method called without @ConfigProperty being present!");
}
return readEntry(configProperty.name(), configProperty.defaultValue(), ipCls,
configProperty.converter(), configProperty.parameterizedBy(),
configProperty.projectStageAware(), configProperty.evaluateVariables());
}
/**
* @param propertyName the name of the property key
* @param defaultValue the default value to return if no configured property is found or
* {@link ConfigProperty#NULL} if no default value should be returned.
* @return the configured value or the defaultValue according to the NULL logic.
*/
protected String getPropertyValue(String propertyName, String defaultValue)
{
String configuredValue;
if (ConfigProperty.NULL.equals(defaultValue))
{
// no special defaultValue has been configured
configuredValue = ConfigResolver.getProjectStageAwarePropertyValue(propertyName);
}
else
{
configuredValue = ConfigResolver.getProjectStageAwarePropertyValue(propertyName, defaultValue);
}
return configuredValue;
}
/**
* @param injectionPoint current injection point
* @param targetType target type
* @param <T> type
* @return annotation instance extracted from the injection point which matches the given type
*/
protected <T extends Annotation> T getAnnotation(InjectionPoint injectionPoint, Class<T> targetType)
{
return BeanUtils.extractAnnotation(injectionPoint.getAnnotated(), targetType);
}
public <T> T readEntry(final String key, final String stringDefault, final Type ipCls,
final Class<? extends ConfigResolver.Converter> converterType,
final String parameterizedBy, final boolean projectStageAware, final boolean evaluate)
{
final ConfigResolver.TypedResolver<T> resolver = asResolver(
key, stringDefault, ipCls, converterType, parameterizedBy, projectStageAware, evaluate);
return resolver.getValue();
}
public <T> ConfigResolver.TypedResolver<T> asResolver(final String key, final String stringDefault,
final Type ipCls,
final Class<? extends ConfigResolver.Converter> converterType,
final String parameterizedBy,
final boolean projectStageAware, final boolean evaluate)
{
final ConfigResolver.UntypedResolver<String> untypedResolver = ConfigResolver.resolve(key);
final ConfigResolver.TypedResolver<T> resolver =
(ConfigResolver.Converter.class == converterType ?
untypedResolver.as(Class.class.cast(ipCls)) :
untypedResolver.as(ipCls, BeanProvider.getContextualReference(converterType)))
.withCurrentProjectStage(projectStageAware);
if (!ConfigProperty.NULL.equals(stringDefault))
{
resolver.withStringDefault(stringDefault);
}
if (!ConfigProperty.NULL.equals(parameterizedBy))
{
resolver.parameterizedBy(parameterizedBy);
}
return resolver.evaluateVariables(evaluate);
}
}