http://micronaut.io: Natively Cloud Native
  • Graeme Rocher 
/*
 * Copyright 2017-2020 original authors
 *
 * 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
 *
 * https://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 io.micronaut.core.beans;

import io.micronaut.core.annotation.AnnotationMetadataProvider;
import io.micronaut.core.annotation.Internal;
import io.micronaut.core.naming.Named;

import edu.umd.cs.findbugs.annotations.NonNull;


A reference to a BeanIntrospection that may or may not be present on the classpath. 
This interface allows soft loading a BeanIntrospection without knowing if the class is present on the classpath or not. It also ensures that less memory is occupied as only a reference to the annotation metadata is retained and the full bean can be loaded via the load() method.


In general results of the load() do not need to be cached as object creation is cheap and no runtime analysis is performed so it is extremely fast.


Author:graemerocher
Type parameters:
  • <T> – The bean type
Since:1.1
/**
 * A reference to a {@link BeanIntrospection} that may or may not be present on the classpath.
 *
 * <p>This interface allows soft loading a {@link BeanIntrospection} without knowing if the class is present on the classpath or not. It also ensures that less memory is occupied as only a reference to the annotation metadata is retained and the full bean can be loaded via the {@link #load()} method.</p>
 *
 * <p>In general results of the {@link #load()} do not need to be cached as object creation is cheap and no runtime analysis is performed so it is extremely fast.</p>
 *
 * @param <T> The bean type
 * @author graemerocher
 * @since 1.1
 */
@Internal
public interface BeanIntrospectionReference<T> extends AnnotationMetadataProvider, Named {

    
Returns:Is the introspection present?
/**
     * @return Is the introspection present?
     */
    boolean isPresent();

    
The type. The method isPresent() should be checked first. 
Throws:
Returns:The type
/**
     * The type. The method {@link #isPresent()} should be checked first.
     * @return The type
     * @throws io.micronaut.core.beans.exceptions.IntrospectionException if the introspection cannot be loaded
     */
    @NonNull Class<T> getBeanType();

    
Loads the introspection.

Throws:
Returns:The loaded introspection.
/**
     * Loads the introspection.
     * @return The loaded introspection.
     * @throws io.micronaut.core.beans.exceptions.IntrospectionException if the introspection cannot be loaded
     */
    @NonNull BeanIntrospection<T> load();
}