org.springframework.core.env.PropertyResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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.core.env;
import org.springframework.lang.Nullable;
/**
* Interface for resolving properties against any underlying source.
*
* @author Chris Beams
* @author Juergen Hoeller
* @since 3.1
* @see Environment
* @see PropertySourcesPropertyResolver
*/
public interface PropertyResolver {
/**
* Return whether the given property key is available for resolution,
* i.e. if the value for the given key is not {@code null}.
*/
boolean containsProperty(String key);
/**
* Return the property value associated with the given key,
* or {@code null} if the key cannot be resolved.
* @param key the property name to resolve
* @see #getProperty(String, String)
* @see #getProperty(String, Class)
* @see #getRequiredProperty(String)
*/
@Nullable
String getProperty(String key);
/**
* Return the property value associated with the given key, or
* {@code defaultValue} if the key cannot be resolved.
* @param key the property name to resolve
* @param defaultValue the default value to return if no value is found
* @see #getRequiredProperty(String)
* @see #getProperty(String, Class)
*/
String getProperty(String key, String defaultValue);
/**
* Return the property value associated with the given key,
* or {@code null} if the key cannot be resolved.
* @param key the property name to resolve
* @param targetType the expected type of the property value
* @see #getRequiredProperty(String, Class)
*/
@Nullable
T getProperty(String key, Class targetType);
/**
* Return the property value associated with the given key,
* or {@code defaultValue} if the key cannot be resolved.
* @param key the property name to resolve
* @param targetType the expected type of the property value
* @param defaultValue the default value to return if no value is found
* @see #getRequiredProperty(String, Class)
*/
T getProperty(String key, Class targetType, T defaultValue);
/**
* Return the property value associated with the given key (never {@code null}).
* @throws IllegalStateException if the key cannot be resolved
* @see #getRequiredProperty(String, Class)
*/
String getRequiredProperty(String key) throws IllegalStateException;
/**
* Return the property value associated with the given key, converted to the given
* targetType (never {@code null}).
* @throws IllegalStateException if the given key cannot be resolved
*/
T getRequiredProperty(String key, Class targetType) throws IllegalStateException;
/**
* Resolve ${...} placeholders in the given text, replacing them with corresponding
* property values as resolved by {@link #getProperty}. Unresolvable placeholders with
* no default value are ignored and passed through unchanged.
* @param text the String to resolve
* @return the resolved String (never {@code null})
* @throws IllegalArgumentException if given text is {@code null}
* @see #resolveRequiredPlaceholders
* @see org.springframework.util.SystemPropertyUtils#resolvePlaceholders(String)
*/
String resolvePlaceholders(String text);
/**
* Resolve ${...} placeholders in the given text, replacing them with corresponding
* property values as resolved by {@link #getProperty}. Unresolvable placeholders with
* no default value will cause an IllegalArgumentException to be thrown.
* @return the resolved String (never {@code null})
* @throws IllegalArgumentException if given text is {@code null}
* or if any placeholders are unresolvable
* @see org.springframework.util.SystemPropertyUtils#resolvePlaceholders(String, boolean)
*/
String resolveRequiredPlaceholders(String text) throws IllegalArgumentException;
}