PL-10565 Default methods in config interfaces

modules/core/test/spec/cuba/core/config/ConfigInterfaceTest.groovy

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2008-2018 Haulmont.
+ *
+ * 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 spec.cuba.core.config
+
+import com.haulmont.cuba.core.global.AppBeans
+import com.haulmont.cuba.core.global.Configuration
+import com.haulmont.cuba.testsupport.TestContainer
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
+
+class ConfigInterfaceTest extends Specification {
+
+    @Shared @ClassRule
+    public TestContainer cont = TestContainer.Common.INSTANCE
+
+    private Configuration configuration
+
+    void setup() {
+        configuration = AppBeans.get(Configuration)
+    }
+
+    def "default method in configuration interface"() {
+
+        def config = configuration.getConfig(TestConfig)
+
+        when: "no value provided for 'foo' property"
+
+        def foo = config.getFooOrDefault()
+
+        then: "default method returns value of 'bar' property"
+
+        foo == 'bar-value'
+
+        when: "after setting own value"
+
+        config.setFoo('foo-value')
+        foo = config.getFooOrDefault()
+
+        then: "the own value is returned"
+
+        foo == 'foo-value'
+
+        cleanup:
+
+        config.setFoo(null)
+    }
+}

modules/core/test/spec/cuba/core/config/TestConfig.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2008-2018 Haulmont.
+ *
+ * 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 spec.cuba.core.config;
+
+import com.haulmont.cuba.core.config.Config;
+import com.haulmont.cuba.core.config.Property;
+import com.haulmont.cuba.core.config.Source;
+import com.haulmont.cuba.core.config.SourceType;
+import com.haulmont.cuba.core.config.defaults.Default;
+
+public interface TestConfig extends Config {
+
+    @Property("test.bar")
+    @Source(type = SourceType.APP)
+    @Default("bar-value")
+    String getBar();
+
+    @Property("test.foo")
+    @Source(type = SourceType.DATABASE)
+    String getFoo();
+    void setFoo(String value);
+
+    default String getFooOrDefault() {
+        String foo = getFoo();
+        return foo != null ? foo : getBar();
+    }
+}

modules/global/src/com/haulmont/cuba/core/config/ConfigDefaultMethod.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2008-2018 Haulmont.
+ *
+ * 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.haulmont.cuba.core.config;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+
+/**
+ * Invokes default method of configuration interfaces.
+ */
+public class ConfigDefaultMethod extends ConfigMethod {
+
+    private final Class<?> configInterface;
+    private final Method configMethod;
+
+    public ConfigDefaultMethod(Class<?> configInterface, Method configMethod) {
+        this.configInterface = configInterface;
+        this.configMethod = configMethod;
+    }
+
+    @Override
+    public Object invoke(ConfigHandler handler, Object[] args, Object proxy) {
+        try {
+            // hack to invoke default method of an interface reflectively
+            Constructor<MethodHandles.Lookup> lookupConstructor =
+                    MethodHandles.Lookup.class.getDeclaredConstructor(Class.class, Integer.TYPE);
+            if (!lookupConstructor.isAccessible()) {
+                lookupConstructor.setAccessible(true);
+            }
+            return lookupConstructor.newInstance(configInterface, MethodHandles.Lookup.PRIVATE)
+                    .unreflectSpecial(configMethod, configInterface)
+                    .bindTo(proxy)
+                    .invokeWithArguments(args);
+        } catch (Throwable throwable) {
+            throw new RuntimeException("Error invoking default method of config interface", throwable);
+        }
+    }
+
+    /**
+     * The ConfigDefaultMethod factory.
+     */
+    public static final Factory FACTORY = new Factory() {
+
+        /**
+         * The method is default and has a non-void return type.
+         */
+        @Override
+        public boolean canHandle(Method method) {
+            return method.isDefault() && !Void.TYPE.equals(method.getReturnType());
+        }
+
+        @Override
+        public ConfigMethod newInstance(Class<?> configInterface, Method configMethod) {
+            return new ConfigDefaultMethod(configInterface, configMethod);
+        }
+    };
+
+}

modules/global/src/com/haulmont/cuba/core/config/ConfigGetter.java

@@ -60,7 +60,7 @@ public class ConfigGetter extends ConfigAccessorMethod {
      * run-time default value was specified.
      */
     @Override
-    public Object invoke(ConfigHandler handler, Object[] args) {
+    public Object invoke(ConfigHandler handler, Object[] args, Object proxy) {
         ConfigPersister configuration = handler.getPersister();
         String str;
         if ((args == null) || (args.length == 0)) {
@@ -134,6 +134,7 @@ public class ConfigGetter extends ConfigAccessorMethod {
             Class returnType = method.getReturnType();
             Class[] parameterTypes = method.getParameterTypes();
             return ConfigUtil.GET_RE.matcher(methodName).matches() &&
+                    !method.isDefault() &&
                     !Void.TYPE.equals(returnType) &&
                     (Boolean.TYPE.equals(returnType) || methodName.startsWith("get")) &&
                     ((parameterTypes.length == 0) ||

modules/global/src/com/haulmont/cuba/core/config/ConfigHandler.java

@@ -76,6 +76,6 @@ public class ConfigHandler implements InvocationHandler {
     @Override
     public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
         ConfigMethod configMethod = ConfigMethods.getInstance(configInterface, method);
-        return configMethod.invoke(this, args);
+        return configMethod.invoke(this, args, proxy);
   }
 }

modules/global/src/com/haulmont/cuba/core/config/ConfigMethod.java

@@ -36,9 +36,10 @@ public abstract class ConfigMethod {
      *
      * @param handler The handler.
      * @param args    The method arguments.
+     * @param proxy   The dynamic proxy created for the configuration interface.
      * @return The method result.
      */
-    public abstract Object invoke(ConfigHandler handler, Object[] args);
+    public abstract Object invoke(ConfigHandler handler, Object[] args, Object proxy);
 
     /**
      * Interface describing a configuration method factory.

modules/global/src/com/haulmont/cuba/core/config/ConfigMethods.java

@@ -45,7 +45,7 @@ public class ConfigMethods {
      * Supported configuration method factories.
      */
     private static final ConfigMethod.Factory[] CONFIG_METHOD_FACTORIES = {
-            ConfigGetter.FACTORY, ConfigSetter.FACTORY
+            ConfigGetter.FACTORY, ConfigSetter.FACTORY, ConfigDefaultMethod.FACTORY
     };
 
     /**

modules/global/src/com/haulmont/cuba/core/config/ConfigSetter.java

@@ -55,7 +55,7 @@ public class ConfigSetter extends ConfigAccessorMethod {
      * filed value.
      */
     @Override
-    public Object invoke(ConfigHandler handler, Object[] args) {
+    public Object invoke(ConfigHandler handler, Object[] args, Object proxy) {
         setProperty(handler.getPersister(), args[0]);
         return null;
     }
@@ -90,6 +90,7 @@ public class ConfigSetter extends ConfigAccessorMethod {
             Class returnType = method.getReturnType();
             Class[] parameterTypes = method.getParameterTypes();
             return ConfigUtil.SET_RE.matcher(methodName).matches() &&
+                    !method.isDefault() &&
                     Void.TYPE.equals(returnType) &&
                     (parameterTypes.length == 1);
         }