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/*
* Copyright (c) 2017, 2023 Oracle and/or its affiliates.
*
* 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 io.helidon.config;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Instant;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Properties;
import java.util.function.Supplier;
import io.helidon.common.media.type.MediaType;
import io.helidon.config.spi.ConfigContent;
import io.helidon.config.spi.ConfigNode;
import io.helidon.config.spi.ConfigParser;
import io.helidon.config.spi.ConfigSource;
import io.helidon.config.spi.NodeConfigSource;
/**
* Provides access to built-in {@link ConfigSource} implementations.
*
* @see ConfigSource
*/
public final class ConfigSources {
static final String DEFAULT_MAP_NAME = "map";
static final String DEFAULT_PROPERTIES_NAME = "properties";
private ConfigSources() {
throw new AssertionError("Instantiation not allowed.");
}
/**
* Provides an empty config source.
* @return empty config source
*/
public static ConfigSource empty() {
return EmptyConfigSourceHolder.EMPTY;
}
/**
* Returns a {@link ConfigSource} that contains the same configuration model
* as the provided {@link Config
* config}.
*
* @param config the original {@code Config}
* @return {@code ConfigSource} for the same {@code Config} as the original
*/
public static ConfigSource create(Config config) {
return create(ObjectNodeImpl.create(config));
}
/**
* Returns a {@link ConfigSource} that wraps the specified {@code objectNode}.
*
* @param objectNode hierarchical configuration representation that will be
* returned by the created config source
* @return new instance of {@link ConfigSource}
* @see ConfigNode.ObjectNode
* @see ConfigNode.ListNode
* @see ConfigNode.ValueNode
* @see ConfigNode.ObjectNode.Builder
* @see ConfigNode.ListNode.Builder
*/
public static NodeConfigSource create(ConfigNode.ObjectNode objectNode) {
return InMemoryConfigSource.create("ObjectNode", ConfigContent.NodeContent.builder()
.node(objectNode)
.build());
}
/**
* Provides a {@link ConfigSource} from the provided {@link Readable readable content} and
* with the specified {@code mediaType}.
*
* {@link Instant#now()} is the {@link io.helidon.config.spi.ConfigContent#stamp() content timestamp}.
*
* @param data a {@code InputStream} providing the configuration content
* @param mediaType a configuration media type
* @return a config source
*/
public static ConfigSource create(InputStream data, MediaType mediaType) {
return InMemoryConfigSource.create("Readable", ConfigParser.Content.builder()
.data(data)
.mediaType(mediaType)
.build());
}
/**
* Provides a {@link ConfigSource} from the provided {@code String} content and
* with the specified {@code mediaType}.
*
* {@link Instant#now()} is the {@link io.helidon.config.spi.ConfigContent#stamp() content timestamp}.
*
* @param content a configuration content
* @param mediaType a configuration media type
* @return a config source
*/
public static ConfigSource create(String content, MediaType mediaType) {
return InMemoryConfigSource.create("String", ConfigParser.Content.builder()
.data(new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8)))
.mediaType(mediaType)
.build());
}
/**
* Provides a {@link MapConfigSource.Builder} for creating a {@code ConfigSource}
* for a {@code Map}.
*
* @param map a map
* @return new Builder instance
* @see #create(Properties)
*/
public static MapConfigSource.Builder create(Map map) {
return create(map, DEFAULT_MAP_NAME);
}
/**
* Provides a {@link MapConfigSource.Builder} for creating a {@code ConfigSource}
* for a {@code Map}.
*
* @param map a map
* @param name the name.
* @return new Builder instance
* @see #create(Properties)
*/
public static MapConfigSource.Builder create(Map map, String name) {
return MapConfigSource.builder()
.map(map)
.name(name);
}
/**
* Provides a {@link MapConfigSource.Builder} for creating a {@code ConfigSource} for a
* {@code Map} from a {@code Properties} object.
*
* @param properties properties
* @return new Builder instance
* @see #create(Map)
*/
public static MapConfigSource.Builder create(Properties properties) {
return create(properties, DEFAULT_PROPERTIES_NAME);
}
/**
* Provides a {@link MapConfigSource.Builder} for creating a {@code ConfigSource} for a
* {@code Map} from a {@code Properties} object.
*
* @param properties properties
* @param name the name.
* @return new Builder instance
* @see #create(Map)
*/
public static MapConfigSource.Builder create(Properties properties, String name) {
return MapConfigSource.builder()
.properties(properties)
.name(name);
}
/**
* Provides a {@link ConfigSource} from a {@link Supplier sourceSupplier}, adding the
* specified {@code prefix} to the keys in the source.
*
* @param key key prefix to be added to all keys
* @param sourceSupplier a config source supplier
* @return new @{code ConfigSource} for the newly-prefixed content
*/
public static ConfigSource prefixed(String key, Supplier sourceSupplier) {
return PrefixedConfigSource.create(key, sourceSupplier.get());
}
/**
* Provides a {@code ConfigSource} for creating a {@code Config} derived
* from system properties.
*
* @return {@code ConfigSource} for config derived from system properties
*/
public static SystemPropertiesConfigSource.Builder systemProperties() {
return new SystemPropertiesConfigSource.Builder()
.properties(System.getProperties());
}
/**
* Provides a @{code ConfigSource} for creating a {@code Config} from
* environment variables.
*
* @return {@code ConfigSource} for config derived from environment variables
*/
public static MapConfigSource environmentVariables() {
return new EnvironmentVariablesConfigSource();
}
/**
* Provides a {@code Builder} for creating a {@code ConfigSource}
* from the specified resource located on the classpath of the current
* thread's context classloader.
*
* The name of a resource is a '{@code /}'-separated full path name that
* identifies the resource. If the resource name has a leading slash then it
* is dropped before lookup.
*
* @param resource a name of the resource
* @return builder for a {@code ConfigSource} for the classpath-based resource
*/
public static ClasspathConfigSource.Builder classpath(String resource) {
return ClasspathConfigSource.builder().resource(resource);
}
/**
* Create builders for each instance of the resource on the current classpath.
* @param resource resource to look for
* @return a list of classpath config source builders
*/
public static List classpathAll(String resource) {
List result = new LinkedList<>();
try {
Enumeration resources = Thread.currentThread().getContextClassLoader().getResources(resource);
while (resources.hasMoreElements()) {
URL url = resources.nextElement();
result.add(url(url));
}
} catch (IOException e) {
throw new ConfigException("Failed to read " + resource + " from classpath", e);
}
return result;
}
/**
* Provides a {@code Builder} for creating a {@code ConfigSource} from the specified
* file path.
*
* @param path a file path
* @return builder for the file-based {@code ConfigSource}
*/
public static FileConfigSource.Builder file(String path) {
return FileConfigSource.builder().path(Paths.get(path));
}
/**
* Provides a {@code Builder} for creating a {@code ConfigSource} from the specified
* file path.
*
* @param path a file path
* @return builder for the file-based {@code ConfigSource}
*/
public static FileConfigSource.Builder file(Path path) {
return FileConfigSource.builder().path(path);
}
/**
* Provides a {@code Builder} for creating a {@code ConfigSource} from the specified
* directory path.
*
* @param path a directory path
* @return new Builder instance
*/
public static DirectoryConfigSource.Builder directory(String path) {
return DirectoryConfigSource.builder().path(Paths.get(path));
}
/**
* Provides a {@code Builder} for creating a {@code ConfigSource} from the specified
* URL.
*
* @param url a URL with configuration
* @return new Builder instance
* @see #url(URL)
*/
public static UrlConfigSource.Builder url(URL url) {
return UrlConfigSource.builder().url(url);
}
/**
* Holder of singleton instance of {@link ConfigSource}.
*
* @see ConfigSources#empty()
*/
static final class EmptyConfigSourceHolder {
private EmptyConfigSourceHolder() {
throw new AssertionError("Instantiation not allowed.");
}
/**
* EMPTY singleton instance.
*/
static final ConfigSource EMPTY = new NodeConfigSource() {
@Override
public String description() {
return "Empty";
}
@Override
public Optional load() throws ConfigException {
return Optional.empty();
}
@Override
public String toString() {
return "EmptyConfigSource";
}
@Override
public boolean optional() {
return true;
}
};
}
/**
* Environment variables config source.
*/
static final class EnvironmentVariablesConfigSource extends MapConfigSource {
/**
* Constructor.
*/
EnvironmentVariablesConfigSource() {
super(MapConfigSource.builder().map(EnvironmentVariables.expand()).name(""));
}
}
/**
* System properties config source.
*/
public static final class SystemPropertiesConfigSource extends MapConfigSource {
private SystemPropertiesConfigSource(Builder builder) {
super(builder);
}
/**
* A fluent API builder for {@link io.helidon.config.ConfigSources.SystemPropertiesConfigSource}.
*/
public static final class Builder extends MapBuilder {
private Builder() {
}
@Override
public MapConfigSource build() {
super.name("");
return new SystemPropertiesConfigSource(this);
}
@Override
public Builder name(String sourceName) {
return this;
}
}
}
}