com.ocadotechnology.config.SimpleConfigBuilder Maven / Gradle / Ivy
/*
* Copyright © 2017-2023 Ocado (Ocava)
*
* 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
*
* 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 com.ocadotechnology.config;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.ocadotechnology.physics.units.LengthUnit;
/**
* Utility for building a single config object from a set of {@code String:String} key:value pairs. Intended
* for use with tests and small utilities with hard-coded config.
*/
public class SimpleConfigBuilder> {
private final Class configType;
private @CheckForNull final Config initialConfig;
private final Map configMap = new HashMap<>(); // Not used ImmutableMap.Builder to allow entries to be changed
private TimeUnit timeUnit;
private LengthUnit lengthUnit;
private SimpleConfigBuilder(Class configType) {
this.configType = configType;
this.initialConfig = null;
}
private SimpleConfigBuilder(Config config) {
configType = config.cls;
initialConfig = config;
}
/**
* Create a configuration builder based on the given Enum
* @param configType Enum class reference
* @param Enum on which to base the configuration
* @return New builder to create a configuration
*/
public static > SimpleConfigBuilder create(Class configType) {
return new SimpleConfigBuilder<>(configType);
}
/**
* Create a configuration builder based on an existing configuration of the target type.
* The initial values set in the initial configuration will serve as default values in the configuration built from
* this builder
*
* @param config The initial configuration
* @param The enum type on which the configuration is based, should match the enum type of the config
* @return New builder to create a configuration
*/
public static > SimpleConfigBuilder createFromConfig(Config config) {
return new SimpleConfigBuilder<>(config);
}
/**
* Adds a config value to the builder.
* @param key A string representation of the enum key. This must be qualified from the level of the configType enum
* provided to the constructor (see {@link ConfigManager}).
* @param value A String representation of the config value. This should adhere to the appropriate syntax expected
* by the accessor. If it does not, the accessor method will throw a runtime exception.
* @param prefixes The prefixes for this config, represented as a List of Objects.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(String key, String value, Object... prefixes) {
String joinedPrefixes = Arrays.stream(prefixes)
.map(prefix -> prefix + ConfigValue.PREFIX_SEPARATOR)
.collect(Collectors.joining());
configMap.put(joinedPrefixes + key, value);
return this;
}
/**
* Adds a config value to the builder.
* @param key An enum key.
* @param value A String representation of the config value. This should adhere to the appropriate syntax expected by
* the accessor.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(Enum key, String value) {
return put(getKeyName(key), value);
}
/**
* Adds a config value to the builder.
* @param key An enum key.
* @param value A config value. This will be converted to a String using its {@code toString()} method.
* @param prefixes The prefixes for this config, represented as a List of Objects.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(Enum key, Object value, Object... prefixes) {
return put(getKeyName(key), value.toString(), prefixes);
}
/**
* Adds a config value to the builder.
* @param key An enum key.
* @param values A collection of objects to be stored as one config value. This will be converted to a String using
* the {@code toString()} method of each element and then comma-separating the elements.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(Enum key, Collection values) {
return put(getKeyName(key), Joiner.on(",").join(values));
}
/**
* Adds a time config value to the builder.
* @param key An enum key.
* @param value A numeric value to be stored as a config value.
* @param unit The time unit associated with the above value.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(Enum key, double value, TimeUnit unit) {
return put(getKeyName(key), value + "," + unit);
}
/**
* Adds a length config value to the builder.
* @param key An enum key.
* @param value A numeric value to be stored as a config value.
* @param unit The length unit associated with the above value.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(Enum key, double value, LengthUnit unit) {
return put(getKeyName(key), value + "," + unit);
}
/**
* Adds a speed or acceleration config value to the builder.
* @param key An enum key.
* @param value A numeric value to be stored as a config value.
* @param timeUnit The time unit associated with the above value.
* @param lengthUnit The length unit associated with the above value.
* @return {@code this}, to facilitate fluent call chains.
*/
public SimpleConfigBuilder put(Enum key, double value, LengthUnit lengthUnit, TimeUnit timeUnit) {
return put(getKeyName(key), value + "," + lengthUnit + "," + timeUnit);
}
/**
* Defines the TimeUnit to be used by this application as its default value. This method must be called if any of
* the supplied config is to be accessed as a Time, Speed or Acceleration value.
*/
public SimpleConfigBuilder setTimeUnit(TimeUnit timeUnit) {
this.timeUnit = timeUnit;
return this;
}
/**
* Defines the TimeUnit to be used by this application as its default value. This method must be called if any of
* the supplied config is to be accessed as a Length, Speed or Acceleration value.
*/
public SimpleConfigBuilder setLengthUnit(LengthUnit lengthUnit) {
this.lengthUnit = lengthUnit;
return this;
}
/**
* Non-destructively constructs a Config object from this {@link SimpleConfigBuilder}, leaving the internal state of
* the builder unchanged.
*
* @throws ConfigKeysNotRecognisedException if any of the config keys given in the {@code put} methods above are not
* recognised within the specified {@code configType} class.
*/
public Config build() throws ConfigKeysNotRecognisedException {
ConfigManager.Builder configManagerBuilder = (this.initialConfig == null)
? new ConfigManager.Builder(new String[]{})
: new ConfigManager.Builder(initialConfig);
configManagerBuilder.loadConfigFromMap(ImmutableMap.copyOf(configMap), ImmutableSet.of(configType));
if (timeUnit != null) {
configManagerBuilder.setTimeUnit(timeUnit);
}
if (lengthUnit != null) {
configManagerBuilder.setLengthUnit(lengthUnit);
}
return configManagerBuilder.build().getConfig(configType);
}
/**
* Non-destructively constructs a Config object from this {@link SimpleConfigBuilder}, leaving the internal state of
* the builder unchanged. This version of the build method is intended for use cases where the user is confident
* that all of the input data is valid (eg in a unit test), or otherwise wants to avoid writing handling code. It
* should be used with care.
*
* @throws RuntimeException if any of the config keys given in the {@code put} methods above are not
* recognised within the specified {@code configType} class.
*/
public Config buildWrapped() {
try {
return build();
} catch (ConfigKeysNotRecognisedException e) {
throw new RuntimeException("Error caught building Config object.", e);
}
}
private static String getKeyName(Enum key) {
Class clazz = key.getClass();
return clazz.getCanonicalName().replace(clazz.getPackage().getName() + ".", "") +
"." +
key.name();
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy