+ * The fully-qualified key is a sequence of tokens derived from the name of + * each node along the path from the config root to the current node. Tokens + * are separated by {@code .} (the dot character). See {@link #name()} for + * more information on the format of each token. + * + * @return current config node key + * @see #name() + */ + Key key(); + + /** + * Returns the last token of the fully-qualified key for the {@code Config} + * node. + *
+ * The name of a node is the last token in its fully-qualified key. + *
+ * The exact format of the name depends on the {@code Type} of the + * containing node: + *
+ * The ABNF syntax of config key is: + *
{@code
+ * config-key = *1( key-token *( "." key-token ) )
+ * key-token = *( unescaped / escaped )
+ * unescaped = %x00-2D / %x2F-7D / %x7F-10FFFF
+ * ; %x2E ('.') and %x7E ('~') are excluded from 'unescaped'
+ * escaped = "~" ( "0" / "1" )
+ * ; representing '~' and '.', respectively
+ * }
+ *
+ * @return current config node key
+ * @see #key()
+ * @see io.helidon.common.config.Config.Key#name()
+ */
+ default String name() {
+ return key().name();
+ }
+
+ /**
+ * Returns the single sub-node for the specified sub-key.
+ * + * The format of the key is described on {@link #key()} method. + * + * @param key sub-key of requested sub-node + * @return config node for specified sub-key, never returns {@code null}. + * @see #get(io.helidon.common.config.Config.Key) + * @throws io.helidon.common.config.ConfigException if not defined + */ + Config get(String key) throws ConfigException; + + /** + * Returns the single sub-node for the specified sub-key. + * + * @param key sub-key of requested sub-node + * @return config node for specified sub-key, never returns {@code null}. + * @see #get(String) + */ + default Config get(Key key) { + return get(key.name()); + } + + /** + * Returns a copy of the {@code Config} node with no parent. + *
+ * The returned node acts as a root node for the subtree below it. Its key + * is the empty string; {@code ""}. The original config node is unchanged, + * and the original and the copy point to the same children. + *
+ * Consider the following configuration: + *
+ * app: + * name: Example 1 + * page-size: 20 + * logging: + * app.level = INFO + * level = WARNING + *+ * The {@code Config} instances {@code name1} and {@code name2} represents same data and + * in fact refer to the same object: + *
+ * Config name1 = config
+ * .get("app")
+ * .get("name");
+ * Config name2 = config
+ * .get("app")
+ * .detach() //DETACHED node
+ * .get("name");
+ *
+ * assert name1.asString() == "Example 1";
+ * assert name2.asString() == "Example 1"; //DETACHED node
+ *
+ * The only difference is the key each node returns:
+ * + * assert name1.key() == "app.name"; + * assert name2.key() == "name"; //DETACHED node + *+ *
+ * See asMap() for example of config detaching. + * + * @return returns detached Config instance of same config node + * @throws io.helidon.common.config.ConfigException if not defined + */ + Config detach() throws ConfigException; + + /** + * Returns {@code true} if the node exists, whether an object, a list, a + * value node, etc. + * + * @return {@code true} if the node exists + */ + boolean exists(); + + /** + * Returns {@code true} if this node exists and is a leaf node (has no + * children). + *
+ * A leaf node has no nested configuration subtree and has a single value. + * + * @return {@code true} if the node is existing leaf node, {@code false} + * otherwise. + */ + boolean isLeaf(); + + /** + * Returns {@code true} if this node exists and is Type#Object. + * + * @return {@code true} if the node exists and is Type#Object, {@code false} + * otherwise. + */ + boolean isObject(); + + /** + * Returns {@code true} if this node exists and is Type#List. + * + * @return {@code true} if the node exists and is Type#List, {@code false} + * otherwise. + */ + boolean isList(); + + /** + * Returns {@code true} if this configuration node has a direct value. + *
+ * This may be a value node (e.g. a leaf) or object node or a list node
+ * (e.g. a branch with value). The application can invoke methods such as
+ * {@link #as(Class)} on nodes that have value.
+ *
+ * @return {@code true} if the node has direct value, {@code false} otherwise.
+ */
+ boolean hasValue();
+
+ //
+ // accessors
+ //
+
+ /**
+ * Typed value as a {@link ConfigValue}.
+ *
+ * @param type type class
+ * @param
+ * Fully-qualified key is list of key tokens separated by {@code .} (dot character).
+ * Depending on context the key token is evaluated one by one:
+ *
+ * The ABNF syntax of config key is:
+ *
+ * If the key represents root config node it throws an exception.
+ *
+ * @return key that represents key of parent config node.
+ * @see #isRoot()
+ * @throws IllegalStateException in case you attempt to call this method on a root node
+ * @throws io.helidon.common.config.ConfigException if not defined
+ */
+ Key parent() throws ConfigException;
+
+ /**
+ * Returns {@code true} in case the key represents root config node,
+ * otherwise it returns {@code false}.
+ *
+ * @return {@code true} in case the key represents root node, otherwise {@code false}.
+ * @see #parent()
+ * @throws io.helidon.common.config.ConfigException if not defined
+ */
+ boolean isRoot();
+
+ /**
+ * Returns the name of Config node.
+ *
+ * The name of a node is the last token in fully-qualified key.
+ * Depending on context the name is evaluated one by one:
+ *
+ * You can use accessor methods on {@link Config} to obtain this value, such as {@link Config#as(Class)}.
+ * A typed value that has all the methods of {@link java.util.Optional} - including the ones added in JDK9 and newer.
+ *
+ * @param
+ * The fully-qualified key is a sequence of tokens derived from the name of
+ * each node along the path from the config root to the current node. Tokens
+ * are separated by {@code .} (the dot character). See {@link #name()} for
+ * more information on the format of each token.
+ *
+ * @return current config node key
+ * @see #name()
+ */
+ Config.Key key();
+
+ /**
+ * Returns the last token of the fully-qualified key for the originating {@code Config}
+ * node.
+ *
+ * The name of a node is the last token in its fully-qualified key.
+ *
+ * The exact format of the name depends on the {@code Type} of the
+ * containing node:
+ *
+ * The ABNF syntax of config key is:
+ *
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @return {@code true} if there is a value present, otherwise {@code false}
+ * @see java.util.Optional#isPresent()
+ */
+ default boolean isPresent() {
+ return asOptional().isPresent();
+ }
+
+ /**
+ * If a value is present, performs the given action with the value,
+ * otherwise performs the given empty-based action.
+ *
+ * @param action the action to be performed, if a value is present
+ * @param emptyAction the empty-based action to be performed, if no value is
+ * present
+ * @throws NullPointerException if a value is present and the given action
+ * is {@code null}, or no value is present and the given empty-based
+ * action is {@code null}.
+ */
+ default void ifPresentOrElse(Consumer
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @param consumer block to be executed if a value is present
+ * @throws NullPointerException if value is present and {@code consumer} is
+ * null
+ * @see java.util.Optional#ifPresent(java.util.function.Consumer)
+ */
+ default void ifPresent(Consumer consumer) {
+ asOptional().ifPresent(consumer);
+ }
+
+ /**
+ * If a value is present, and the value matches the given predicate,
+ * return an {@code Optional} describing the value, otherwise return an
+ * empty {@code Optional}.
+ *
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @param predicate a predicate to apply to the value, if present
+ * @return an {@code Optional} describing the value of this {@code Optional}
+ * if a value is present and the value matches the given predicate,
+ * otherwise an empty {@code Optional}
+ * @throws NullPointerException if the predicate is null
+ * @see java.util.Optional#filter(java.util.function.Predicate)
+ */
+ default Optional
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ * @see java.util.Optional#map(java.util.function.Function)
+ */
+ default Optional map(Function mapper) {
+ return asOptional().map(mapper);
+ }
+
+ /**
+ * If a value is present, apply the provided {@code Optional}-bearing
+ * mapping function to it, return that result, otherwise return an empty
+ * {@code Optional}. This method is similar to {@link #map(java.util.function.Function)},
+ * but the provided mapper is one whose result is already an {@code Optional},
+ * and if invoked, {@code flatMap} does not wrap it with an additional
+ * {@code Optional}.
+ *
+ *
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @param The type parameter to the {@code Optional} returned by
+ * @param mapper a mapping function to apply to the value, if present
+ * the mapping function
+ * @return the result of applying an {@code Optional}-bearing mapping
+ * function to the value of this {@code Optional}, if a value is present,
+ * otherwise an empty {@code Optional}
+ * @throws NullPointerException if the mapping function is null or returns
+ * a null result
+ * @see java.util.Optional#flatMap(java.util.function.Function)
+ */
+ default Optional flatMap(Function> mapper) {
+ return asOptional().flatMap(mapper);
+ }
+
+ /**
+ * Return the value if present, otherwise return {@code other}.
+ *
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @param other the value to be returned if there is no value present, may
+ * be null
+ * @return the value, if present, otherwise {@code other}
+ * @see java.util.Optional#orElse(Object)
+ */
+ default T orElse(T other) {
+ return asOptional().orElse(other);
+ }
+
+ /**
+ * Return the value if present, otherwise invoke {@code other} and return
+ * the result of that invocation.
+ *
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @param other a {@code Supplier} whose result is returned if no value
+ * is present
+ * @return the value if present otherwise the result of {@code other.get()}
+ * @throws NullPointerException if value is not present and {@code other} is
+ * null
+ * @see java.util.Optional#orElseGet(java.util.function.Supplier)
+ */
+ default T orElseGet(Supplier other) {
+ return asOptional().orElseGet(other);
+ }
+
+ /**
+ * Return the contained value, if present, otherwise throw an exception
+ * to be created by the provided supplier.
+ *
+ *
+ * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
+ *
+ * @param
+ *
+ * {@code
+ * config-key = *1( key-token *( "." key-token ) )
+ * key-token = *( unescaped / escaped )
+ * unescaped = %x00-2D / %x2F-7D / %x7F-10FFFF
+ * ; %x2E ('.') and %x7E ('~') are excluded from 'unescaped'
+ * escaped = "~" ( "0" / "1" )
+ * ; representing '~' and '.', respectively
+ * }
+ *
+ * @see Config#key()
+ */
+ interface Key extends Comparable
+ *
+ *
+ * @return name of config node
+ * @see Config#name()
+ */
+ String name();
+
+ /**
+ * Returns formatted fully-qualified key.
+ *
+ * @return formatted fully-qualified key.
+ */
+ @Override
+ String toString();
+
+ /**
+ * Create a child key to the current key.
+ *
+ * @param key child key (relative to current key)
+ * @return a new resolved key
+ * @throws io.helidon.common.config.ConfigException if not defined
+ */
+ Key child(Key key);
+
+ }
+
+}
diff --git a/common/config/src/main/java/io/helidon/common/config/ConfigException.java b/common/config/src/main/java/io/helidon/common/config/ConfigException.java
new file mode 100644
index 00000000000..fcdb4deb617
--- /dev/null
+++ b/common/config/src/main/java/io/helidon/common/config/ConfigException.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2017, 2022 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.common.config;
+
+/**
+ * Exception is thrown by {@link Config} implementations.
+ */
+public class ConfigException extends RuntimeException {
+
+ private static final long serialVersionUID = 1L;
+
+ /**
+ * Constructor with the detailed message.
+ *
+ * @param message the message
+ */
+ public ConfigException(String message) {
+ super(message);
+ }
+
+ /**
+ * Constructor with the detailed message.
+ *
+ * @param message the message
+ * @param cause the cause
+ */
+ public ConfigException(String message, Throwable cause) {
+ super(message, cause);
+ }
+
+}
diff --git a/common/config/src/main/java/io/helidon/common/config/ConfigValue.java b/common/config/src/main/java/io/helidon/common/config/ConfigValue.java
new file mode 100644
index 00000000000..1faa622723f
--- /dev/null
+++ b/common/config/src/main/java/io/helidon/common/config/ConfigValue.java
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) 2018, 2022 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.common.config;
+
+import java.util.Optional;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+import java.util.stream.Stream;
+
+/**
+ * A typed value of a {@link Config} node.
+ *
+ *
+ * {@code
+ * config-key = *1( key-token *( "." key-token ) )
+ * key-token = *( unescaped / escaped )
+ * unescaped = %x00-2D / %x2F-7D / %x7F-10FFFF
+ * ; %x2E ('.') and %x7E ('~') are excluded from 'unescaped'
+ * escaped = "~" ( "0" / "1" )
+ * ; representing '~' and '.', respectively
+ * }
+ *
+ * @return current config node key
+ * @see #key()
+ * @see io.helidon.common.config.Config.Key#name()
+ */
+ default String name() {
+ return key().name();
+ }
+
+ /**
+ * Returns a typed value as {@link java.util.Optional}.
+ * Returns a {@link java.util.Optional#empty() empty} for nodes without a value.
+ * As this class implements all methods of {@link java.util.Optional}, this is only a utility method if an actual
+ * {@link java.util.Optional}
+ * instance is needed.
+ *
+ * @return value as type instance as {@link java.util.Optional}, {@link java.util.Optional#empty() empty} in case the node
+ * does not have
+ * a direct value
+ * @throws io.helidon.common.config.ConfigException in case the value cannot be converted to the expected type
+ * @see #get()
+ */
+ Optional
@@ -587,6 +615,7 @@ default boolean isLeaf() {
*
* @return {@code true} if the node has direct value, {@code false} otherwise.
*/
+ @Override
boolean hasValue();
/**
@@ -698,6 +727,7 @@ default Stream
@@ -892,40 +924,8 @@ interface Key extends Comparable
- * The name of a node is the last token in fully-qualified key.
- * Depending on context the name is evaluated one by one:
- *
diff --git a/config/config/src/main/java/module-info.java b/config/config/src/main/java/module-info.java
index 65f0efe11b3..da42f7919f1 100644
--- a/config/config/src/main/java/module-info.java
+++ b/config/config/src/main/java/module-info.java
@@ -27,6 +27,7 @@
requires transitive jakarta.annotation;
+ requires transitive io.helidon.common.config;
requires transitive io.helidon.common;
requires transitive io.helidon.common.media.type;
diff --git a/integrations/cdi/datasource/pom.xml b/integrations/cdi/datasource/pom.xml
index 7add1ca9942..e34812db07b 100644
--- a/integrations/cdi/datasource/pom.xml
+++ b/integrations/cdi/datasource/pom.xml
@@ -47,6 +47,11 @@
- *
- *
- * @return name of config node
- * @see Config#name()
- */
- String name();
-
- /**
- * Returns formatted fully-qualified key.
- *
- * @return formatted fully-qualified key.
- */
@Override
- String toString();
+ Key parent();
/**
* Create a child key to the current key.
@@ -933,7 +933,8 @@ interface Key extends Comparable