org.springframework.boot.context.properties.source.SystemEnvironmentPropertyMapper Maven / Gradle / Ivy
/*
* Copyright 2012-2018 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.source;
import java.util.Locale;
import org.springframework.boot.context.properties.source.ConfigurationPropertyName.Form;
/**
* {@link PropertyMapper} for system environment variables. Names are mapped by removing
* invalid characters, converting to lower case and replacing "{@code _}" with
* "{@code .}". For example, "{@code SERVER_PORT}" is mapped to "{@code server.port}". In
* addition, numeric elements are mapped to indexes (e.g. "{@code HOST_0}" is mapped to
* "{@code host[0]}").
*
* @author Phillip Webb
* @author Madhura Bhave
* @see PropertyMapper
* @see SpringConfigurationPropertySource
*/
final class SystemEnvironmentPropertyMapper implements PropertyMapper {
public static final PropertyMapper INSTANCE = new SystemEnvironmentPropertyMapper();
@Override
public PropertyMapping[] map(ConfigurationPropertyName configurationPropertyName) {
String name = convertName(configurationPropertyName);
String legacyName = convertLegacyName(configurationPropertyName);
if (name.equals(legacyName)) {
return new PropertyMapping[] {
new PropertyMapping(name, configurationPropertyName) };
}
return new PropertyMapping[] {
new PropertyMapping(name, configurationPropertyName),
new PropertyMapping(legacyName, configurationPropertyName) };
}
@Override
public PropertyMapping[] map(String propertySourceName) {
ConfigurationPropertyName name = convertName(propertySourceName);
if (name == null || name.isEmpty()) {
return NO_MAPPINGS;
}
return new PropertyMapping[] { new PropertyMapping(propertySourceName, name) };
}
private ConfigurationPropertyName convertName(String propertySourceName) {
try {
return ConfigurationPropertyName.adapt(propertySourceName, '_',
this::processElementValue);
}
catch (Exception ex) {
return null;
}
}
private String convertName(ConfigurationPropertyName name) {
return convertName(name, name.getNumberOfElements());
}
private String convertName(ConfigurationPropertyName name, int numberOfElements) {
StringBuilder result = new StringBuilder();
for (int i = 0; i < numberOfElements; i++) {
if (result.length() > 0) {
result.append("_");
}
result.append(name.getElement(i, Form.UNIFORM).toUpperCase(Locale.ENGLISH));
}
return result.toString();
}
private String convertLegacyName(ConfigurationPropertyName name) {
StringBuilder result = new StringBuilder();
for (int i = 0; i < name.getNumberOfElements(); i++) {
if (result.length() > 0) {
result.append("_");
}
result.append(convertLegacyNameElement(name.getElement(i, Form.ORIGINAL)));
}
return result.toString();
}
private Object convertLegacyNameElement(String element) {
return element.replace('-', '_').toUpperCase(Locale.ENGLISH);
}
private CharSequence processElementValue(CharSequence value) {
String result = value.toString().toLowerCase(Locale.ENGLISH);
return isNumber(result) ? "[" + result + "]" : result;
}
private static boolean isNumber(String string) {
return string.chars().allMatch(Character::isDigit);
}
}