CDI API for injection of configuration values

.gitignore

@@ -6,4 +6,4 @@ tck/.checkstyle
 tck/bin/
 .project
 build/
-.classpath
+.classpath

api/pom.xml

@@ -23,6 +23,11 @@
             <scope>provided</scope>
             <optional>true</optional>
         </dependency>
+        <dependency>
+            <groupId>javax.enterprise</groupId>
+            <artifactId>cdi-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <build>

api/src/main/java/io/microprofile/config/inject/ConfigProperty.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016-2017 Payara Services Ltd. and others
+ *
+ * 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.microprofile.config.inject;
+
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+import javax.enterprise.util.Nonbinding;
+import javax.inject.Qualifier;
+
+/**
+ * Binds the injection point with a configured value.
+ * Should annotate injection points of type ConfigValue<T>, where T can be String and all types which have appropriate converters. 
+ * <p>
+ * Example:
+ * <pre>
+ * <code>
+ *
+ *   {@literal @Inject}
+ *   {@literal @ConfigProperty("my.long.property")}
+ *   {@literal ConfigValue<Long>} longConfigValue;  
+ *            // injects a ConfigValue for the value of my.long.property property to resolve the property dynamically
+ * </code>
+ * </pre>
+ * @author Ondrej Mihalyi
+ */
+@Qualifier
+@Retention(RUNTIME)
+@Target({METHOD, FIELD, PARAMETER, TYPE})
+public @interface ConfigProperty {
+    /**
+     * The kay of the config property used to look up the configuration value. 
+     * If it is not specified, it will be derived automatically as {@code <class_name>.<injetion_point_name>}, 
+     * where {@code injection_point_name} is either a field name or a property name in case of field/property injection, 
+     * {@code class_name} is the simple name of the class being injected to. 
+     * If one of the {@code class_name} or {@code injection_point_name} cannot be determined, the value has to be provided.
+     * 
+     * @return Name (key) of the config property to inject
+     */
+    @Nonbinding
+    String value() default "";
+}

api/src/main/java/org/eclipse/microprofile/config/ConfigValue.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2016-2017 Payara Services Ltd. and others
+ *
+ * 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 org.eclipse.microprofile.config;
+
+/**
+ * Accessor to a configured value. Suitable when a configured value should be
+ * accessed dynamically or additional metadata is necessary on top of the
+ * configured value.
+ *
+ * @author Ondrej Mihalyi
+ * 
+ * @param <T_VALUE> Type of the configuration value
+ */
+public interface ConfigValue<T_VALUE> {
+
+    /**
+     * Returns the converted resolved value.
+     *
+     * @return the resolved value
+     */
+    T_VALUE getValue();
+
+    /**
+     * Whether the value is defined in one of the config sources or not.
+     * @return True if a value for the key is defined, false otherwise
+     */
+    boolean isValueAvailable();
+
+    /**
+     * Returns the key used to retrieve the configuration value.
+     *
+     * @return the original key
+     */
+    String getKey();
+}

pom.xml

@@ -15,6 +15,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
 
         <checkstyle.version>2.17</checkstyle.version>
+        <checkstyle.methodNameFormat>^_?[a-z][a-zA-Z0-9]*$</checkstyle.methodNameFormat>
     </properties>
 
     <licenses>
@@ -32,13 +33,38 @@
         <module>tck</module>
         <module>spec</module>
     </modules>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>javax.enterprise</groupId>
+                <artifactId>cdi-api</artifactId>
+                <version>1.2</version>
+            </dependency>
+            <dependency>
+                <groupId>org.jboss.arquillian</groupId>
+                <artifactId>arquillian-bom</artifactId>
+                <version>1.1.12.Final</version>
+                <scope>import</scope>
+                <type>pom</type>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
 
     <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-checkstyle-plugin</artifactId>
+                    <version>${checkstyle.version}</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-checkstyle-plugin</artifactId>
-                <version>${checkstyle.version}</version>
                 <executions>
                     <execution>
                         <id>verify-style</id>
@@ -71,7 +97,7 @@
                                 </module>
                                 <module name="LocalVariableName" />
                                 <module name="MethodName">
-                                    <property name="format" value="^_?[a-z][a-zA-Z0-9]*$" />
+                                    <property name="format" value="${checkstyle.methodNameFormat}" />
                                 </module>
                                 <module name="PackageName" />
                                 <module name="LocalFinalVariableName" />

tck/pom.xml

@@ -13,7 +13,10 @@
     <artifactId>microprofile-config-tck</artifactId>
     <version>1.0-SNAPSHOT</version>
 
-
+    <properties>
+            <checkstyle.methodNameFormat>^_?[a-z][a-zA-Z0-9_]*$</checkstyle.methodNameFormat>
+    </properties>
+
     <dependencies>
         <dependency>
             <groupId>org.eclipse.microprofile.config.api</groupId>
@@ -27,6 +30,53 @@
             <version>6.9.9</version>
             <scope>compile</scope>
         </dependency>
-    </dependencies>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>compile</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.hamcrest</groupId>
+                    <artifactId>hamcrest-core</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-all</artifactId>
+            <version>1.3</version>
+            <scope>compile</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.jboss.arquillian.junit</groupId>
+            <artifactId>arquillian-junit-container</artifactId>
+            <scope>compile</scope>
+        </dependency>
 
+        <dependency>
+            <groupId>org.jboss.arquillian.container</groupId>
+            <artifactId>arquillian-weld-embedded</artifactId>
+            <version>2.0.0.Beta4</version>
+            <scope>compile</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.jboss.weld</groupId>
+            <artifactId>weld-core</artifactId>
+            <version>2.4.1.Final</version>
+            <scope>compile</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.jboss.shrinkwrap</groupId>
+            <artifactId>shrinkwrap-api</artifactId>
+            <scope>compile</scope>
+        </dependency>
+
+    </dependencies>
+
 </project>

tck/src/main/java/org/eclipse/microprofile/config/tck/CDIPlainInjectionTest.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2016-2017 Payara Services Ltd. and others
+ *
+ * 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 org.eclipse.microprofile.config.tck;
+
+import io.microprofile.config.inject.ConfigProperty;
+import javax.enterprise.context.Dependent;
+import javax.inject.Inject;
+import org.eclipse.microprofile.config.ConfigValue;
+import static org.eclipse.microprofile.config.tck.testsupport.TestSetup.ensure_property_defined;
+import static org.eclipse.microprofile.config.tck.testsupport.TestSetup.ensure_property_undefined;
+import static org.eclipse.microprofile.config.tck.testsupport.TestSetup.get_bean_of_type;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import org.jboss.arquillian.container.test.api.Deployment;
+import org.jboss.arquillian.junit.Arquillian;
+import org.jboss.shrinkwrap.api.Archive;
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.asset.EmptyAsset;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import static org.junit.Assert.assertThat;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/**
+ * Test cases for CDI-based API that test retrieving values from the configuration. 
+ * The tests depend only on CDI 1.2. 
+ * @author Ondrej Mihalyi
+ */
+@RunWith(Arquillian.class)
+public class CDIPlainInjectionTest {
+
+    @Deployment
+    public static Archive deployment() {
+        return ShrinkWrap.create(JavaArchive.class)
+                .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml");
+    }
+
+    @Test
+    public void can_inject_dynamic_values_via_ConfigValue() {
+        clear_all_property_values();
+
+        DynamicValuesBean bean = get_bean_of_type(DynamicValuesBean.class);
+        ConfigValue<Integer> intPropertyValue = bean.getIntPropertyValue();
+
+        assertThat(intPropertyValue.isValueAvailable(), is(false));
+
+        ensure_all_property_values_are_defined();
+
+        assertThat(intPropertyValue.isValueAvailable(), is(true));
+        assertThat(intPropertyValue.getValue(), is(equalTo(5)));
+    }
+
+    private void ensure_all_property_values_are_defined() {
+        ensure_property_defined("my.string.property", "text");
+        ensure_property_defined("my.boolean.property", "true");
+        ensure_property_defined("my.int.property", "5");
+        ensure_property_defined("my.long.property", "10");
+        ensure_property_defined("my.float.property", "10.5");
+        ensure_property_defined("my.double.property", "11.5");
+        ensure_property_defined("my.date.property", "2017-01-30");
+        ensure_property_defined("my.localdate.property", "2016-01-30");
+        ensure_property_defined("my.datetime.property", "2015-01-30T10:00");
+    }
+
+    private void clear_all_property_values() {
+        ensure_property_undefined("my.string.property");
+        ensure_property_undefined("my.boolean.property");
+        ensure_property_undefined("my.int.property");
+        ensure_property_undefined("my.long.property");
+        ensure_property_undefined("my.float.property");
+        ensure_property_undefined("my.double.property");
+        ensure_property_undefined("my.date.property");
+        ensure_property_undefined("my.localdate.property");
+        ensure_property_undefined("my.datetime.property");
+    }
+
+    @Dependent
+    public static class DynamicValuesBean {
+
+        @Inject
+        @ConfigProperty("my.int.property")
+        private ConfigValue<Integer> intPropertyValue;
+
+        public ConfigValue<Integer> getIntPropertyValue() {
+            return intPropertyValue;
+        }
+
+    }
+
+}