Java tutorial
/* * Copyright 2012-2019 the original author or 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 org.springframework.boot.context.properties; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.springframework.core.annotation.AliasFor; /** * Annotation for externalized configuration. Add this to a class definition or a * {@code @Bean} method in a {@code @Configuration} class if you want to bind and validate * some external Properties (e.g. from a .properties file). * <p> * Note that contrary to {@code @Value}, SpEL expressions are not evaluated since property * values are externalized. * * @author Dave Syer * @since 1.0.0 * @see ConfigurationPropertiesBindingPostProcessor * @see EnableConfigurationProperties */ @Target({ ElementType.TYPE, ElementType.METHOD }) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface ConfigurationProperties { /** * The name prefix of the properties that are valid to bind to this object. Synonym * for {@link #prefix()}. A valid prefix is defined by one or more words separated * with dots (e.g. {@code "acme.system.feature"}). * @return the name prefix of the properties to bind */ @AliasFor("prefix") String value() default ""; /** * The name prefix of the properties that are valid to bind to this object. Synonym * for {@link #value()}. A valid prefix is defined by one or more words separated with * dots (e.g. {@code "acme.system.feature"}). * @return the name prefix of the properties to bind */ @AliasFor("value") String prefix() default ""; /** * Flag to indicate that when binding to this object invalid fields should be ignored. * Invalid means invalid according to the binder that is used, and usually this means * fields of the wrong type (or that cannot be coerced into the correct type). * @return the flag value (default false) */ boolean ignoreInvalidFields() default false; /** * Flag to indicate that when binding to this object unknown fields should be ignored. * An unknown field could be a sign of a mistake in the Properties. * @return the flag value (default true) */ boolean ignoreUnknownFields() default true; }