4.x: Value mapping API and implementation in modules. (helidon-io#7517)

* Value mapping API and implementation in modules
* Refactored all usages

Author: tomas-langer

archetypes/helidon/src/main/archetype/se/custom/files/src/main/java/__pkg__/FileService.java.multipart.mustache

@@ -92,7 +92,7 @@ final class FileService implements HttpService {
     }
 
     private void download(ServerRequest req, ServerResponse res) {
-        Path filePath = storage.resolve(req.path().pathParameters().value("fname"));
+        Path filePath = storage.resolve(req.path().pathParameters().get("fname"));
         if (!filePath.getParent().equals(storage)) {
             res.status(BAD_REQUEST_400).send("Invalid file name");
             return;

archetypes/helidon/src/main/archetype/se/custom/files/src/main/java/__pkg__/FtService.java.mustache

@@ -57,13 +57,13 @@ public class FtService implements HttpService {
     }
 
     private void timeoutHandler(ServerRequest request, ServerResponse response) {
-        long sleep = Long.parseLong(request.path().pathParameters().value("millis"));
+        long sleep = request.path().pathParameters().first("millis").getLong();
 
         response.send(timeout.invoke(() -> sleep(sleep)));
     }
 
     private void retryHandler(ServerRequest request, ServerResponse response) {
-        int count = Integer.parseInt(request.path().pathParameters().value("count"));
+        int count = request.path().pathParameters().first("count").getInt();
 
         AtomicInteger call = new AtomicInteger(1);
         AtomicInteger failures = new AtomicInteger();
@@ -79,7 +79,7 @@ public class FtService implements HttpService {
     }
 
     private void fallbackHandler(ServerRequest request, ServerResponse response) {
-        boolean success = "true".equalsIgnoreCase(request.path().pathParameters().value("success"));
+        boolean success = request.path().pathParameters().first("success").getBoolean();
         if (success) {
             response.send(fallback.invoke(this::reactiveData));
         } else {
@@ -88,7 +88,7 @@ public class FtService implements HttpService {
     }
 
     private void circuitBreakerHandler(ServerRequest request, ServerResponse response) {
-        boolean success = "true".equalsIgnoreCase(request.path().pathParameters().value("success"));
+        boolean success = request.path().pathParameters().first("success").getBoolean();
         if (success) {
             response.send(circuitBreaker.invoke(this::reactiveData));
         } else {
@@ -97,7 +97,7 @@ public class FtService implements HttpService {
     }
 
     private void bulkheadHandler(ServerRequest request, ServerResponse response) {
-        long sleep = Long.parseLong(request.path().pathParameters().value("millis"));
+        long sleep = request.path().pathParameters().first("millis").getLong();
         CompletableFuture<String> future = async.invoke(() -> bulkhead.invoke(() -> sleep(sleep)));
         sleep(100);
         if (bulkhead.stats().callsRejected() > 0) {

archetypes/helidon/src/main/archetype/se/custom/files/src/main/java/__pkg__/GreetService.java.json.mustache

@@ -65,7 +65,7 @@ public class GreetService implements HttpService {
      */
     private void getMessageHandler(ServerRequest request,
                                    ServerResponse response) {
-        String name = request.path().pathParameters().value("name");
+        String name = request.path().pathParameters().get("name");
         sendResponse(response, name);
     }
 

archetypes/helidon/src/main/archetype/se/custom/files/src/main/java/__pkg__/GreetService.java.jsonp.mustache

@@ -86,7 +86,7 @@ class GreetService implements HttpService {
      */
     private void getMessageHandler(ServerRequest request,
                                    ServerResponse response) {
-        String name = request.path().pathParameters().value("name");
+        String name = request.path().pathParameters().get("name");
         sendResponse(response, name);
     }
 

archetypes/helidon/src/main/archetype/se/custom/files/src/main/java/__pkg__/GreetService.java.mustache

@@ -80,7 +80,7 @@ class GreetService implements HttpService {
      */
     private void getMessageHandler(ServerRequest request,
                                    ServerResponse response) {
-        String name = request.path().pathParameters().value("name");
+        String name = request.path().pathParameters().get("name");
         sendResponse(response, name);
     }
 

archetypes/helidon/src/main/archetype/se/custom/files/src/main/java/__pkg__/MetricsService.java.mustache

@@ -72,7 +72,7 @@ class MetricsService implements HttpService {
      */
     private void getMessageHandler(ServerRequest request,
                                    ServerResponse response) {
-        String name = request.path().pathParameters().value("name");
+        String name = request.path().pathParameters().get("name");
         sendResponse(response, name);
     }
 

archetypes/helidon/src/main/archetype/se/database/files/src/main/java/__pkg__/PokemonMapper.java.mustache

@@ -23,7 +23,7 @@ public class PokemonMapper implements DbMapper<Pokemon> {
         }
 
         DbColumn type = row.column("type");
-        return new Pokemon(name.as(String.class), type.as(String.class));
+        return new Pokemon(name.get(String.class), type.get(String.class));
     }
 
     @Override

archetypes/helidon/src/main/archetype/se/database/files/src/main/java/__pkg__/PokemonService.java.mustache

@@ -91,7 +91,7 @@ public class PokemonService implements HttpService {
     private void insertPokemonSimple(ServerRequest req, ServerResponse res) {
         Parameters params = req.path().pathParameters();
         // Test Pokémon POJO mapper
-        Pokemon pokemon = new Pokemon(params.value("name"), params.value("type"));
+        Pokemon pokemon = new Pokemon(params.get("name"), params.get("type"));
 
         long count = dbClient.execute().createNamedInsert("insert2")
                 .namedParam(pokemon)
@@ -106,7 +106,7 @@ public class PokemonService implements HttpService {
      * @param res server response
      */
     private void getPokemon(ServerRequest req, ServerResponse res) {
-        String pokemonName = req.path().pathParameters().value("name");
+        String pokemonName = req.path().pathParameters().get("name");
         res.send(dbClient.execute()
                 .namedGet("select-one", pokemonName)
                 .orElseThrow(() -> new NotFoundException("Pokemon " + pokemonName + " not found"))
@@ -141,8 +141,8 @@ public class PokemonService implements HttpService {
      */
     private void updatePokemonType(ServerRequest req, ServerResponse res) {
         Parameters params = req.path().pathParameters();
-        String name = params.value("name");
-        String type = params.value("type");
+        String name = params.get("name");
+        String type = params.get("type");
         long count = dbClient.execute()
                 .createNamedUpdate("update")
                 .addParam("name", name)
@@ -177,7 +177,7 @@ public class PokemonService implements HttpService {
      * @param res the server response
      */
     private void deletePokemon(ServerRequest req, ServerResponse res) {
-        String name = req.path().pathParameters().value("name");
+        String name = req.path().pathParameters().get("name");
         long count = dbClient.execute().namedDelete("delete", name);
         res.send("Deleted: " + count + " values");
     }

common/config/pom.xml

@@ -33,6 +33,10 @@
             <groupId>io.helidon.common</groupId>
             <artifactId>helidon-common</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.common</groupId>
+            <artifactId>helidon-common-mapper</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>

common/config/src/main/java/io/helidon/common/config/ConfigValue.java

@@ -17,11 +17,11 @@
 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;
+
+import io.helidon.common.GenericType;
+import io.helidon.common.mapper.OptionalValue;
 
 /**
  * A typed value of a {@link Config} node.
@@ -31,7 +31,7 @@
  *
  * @param <T> type of the value
  */
-public interface ConfigValue<T> {
+public interface ConfigValue<T> extends OptionalValue<T> {
 
     /**
      * Returns the fully-qualified key of the originating {@code Config} node.
@@ -76,213 +76,25 @@ public interface ConfigValue<T> {
      * @see #key()
      * @see io.helidon.common.config.Config.Key#name()
      */
+    @Override
     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<T> asOptional() throws ConfigException;
-
-    /**
-     * Typed value of the represented {@link Config} node.
-     * Throws {@link io.helidon.common.config.ConfigException} if the node is Type#MISSING type.
-     *
-     * @return direct value of this node converted to the expected type
-     * @throws io.helidon.common.config.ConfigException in case the value cannot be converted to the expected type
-     */
-    T get() throws ConfigException;
-
     /**
      * Convert this {@code ConfigValue} to a different type using a mapper function.
      *
      * @param mapper mapper to map the type of this {@code ConfigValue} to a type of the returned {@code ConfigValue}
      * @param <N>    type of the returned {@code ConfigValue}
      * @return a new value with the new type
      */
-    <N> ConfigValue<N> as(Function<T, N> mapper);
-
-    /**
-     * Return {@code true} if there is a value present, otherwise {@code false}.
-     * <p>
-     * 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<T> action, Runnable emptyAction) {
-        Optional<T> optional = asOptional();
-        if (optional.isPresent()) {
-            action.accept(optional.get());
-        } else {
-            emptyAction.run();
-        }
-    }
+    <N> ConfigValue<N> as(Function<? super T, ? extends N> mapper);
 
-    /**
-     * If a value is present, invoke the specified consumer with the value,
-     * otherwise do nothing.
-     * <p>
-     * 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<? super T> consumer) {
-        asOptional().ifPresent(consumer);
-    }
+    @Override
+    <N> ConfigValue<N> as(Class<N> type);
 
-    /**
-     * 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}.
-     * <p>
-     * 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<T> filter(Predicate<? super T> predicate) {
-        return asOptional().filter(predicate);
-    }
-
-    /**
-     * If a value is present, apply the provided mapping function to it,
-     * and if the result is non-null, return an {@code Optional} describing the
-     * result.  Otherwise return an empty {@code Optional}.
-     *
-     * @param <U>    The type of the result of the mapping function
-     * @param mapper a mapping function to apply to the value, if present
-     * @return an {@code Optional} describing the result of applying a 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
-     *
-     *                              <p>
-     *                              Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
-     * @see java.util.Optional#map(java.util.function.Function)
-     */
-    default <U> Optional<U> map(Function<? super T, ? extends U> 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}.
-     *
-     * <p>
-     * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
-     *
-     * @param <U>    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 <U> Optional<U> flatMap(Function<? super T, Optional<U>> mapper) {
-        return asOptional().flatMap(mapper);
-    }
-
-    /**
-     * Return the value if present, otherwise return {@code other}.
-     * <p>
-     * 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.
-     * <p>
-     * 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<? extends T> other) {
-        return asOptional().orElseGet(other);
-    }
-
-    /**
-     * Return the contained value, if present, otherwise throw an exception
-     * to be created by the provided supplier.
-     *
-     * <p>
-     * Copied from {@link java.util.Optional}. You can get real optional from {@link #asOptional()}.
-     *
-     * @param <X>               Type of the exception to be thrown
-     * @param exceptionSupplier The supplier which will return the exception to
-     *                          be thrown
-     * @return the present value
-     * @throws X                    if there is no value present
-     * @throws NullPointerException if no value is present and
-     *                              {@code exceptionSupplier} is null
-     * @see java.util.Optional#orElseThrow(java.util.function.Supplier)
-     */
-    default <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
-        return asOptional().orElseThrow(exceptionSupplier);
-    }
-
-    /**
-     * If a value is present, returns a sequential {@link java.util.stream.Stream} containing
-     * only that value, otherwise returns an empty {@code Stream}.
-     *
-     * @return the optional value as a {@code Stream}
-     */
-    default Stream<T> stream() {
-        return asOptional().stream();
-    }
+    @Override
+    <N> ConfigValue<N> as(GenericType<N> type);
 
     /**
      * Returns a supplier of a typed value. The semantics depend on implementation, this may always return the