Move common classes to policy/common

Moving YamlHttpMessageConverter & CustomImplicitNamingStrategy
classes to policy/common (spring-utils sub-module).
So that the same can be used by multiple components without
duplicating it.
These classes are already covered by tests at each component.

Issue-ID: POLICY-3931
Change-Id: I8fc6978b585bfcd930e0916f67961d05946d207c
Signed-off-by: Ram Krishna Verma <ram_krishna.verma@bell.ca>

4 files changed, 198 insertions, 0 deletions

diff --git a/pom.xml b/pom.xml
index 2e544bcf..af783c80 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,6 +62,7 @@
         <module>integrity-audit</module>
         <module>integrity-monitor</module>
         <module>policy-endpoints</module>
+        <module>spring-utils</module>
     </modules>
 
     <dependencyManagement>
diff --git a/spring-utils/pom.xml b/spring-utils/pom.xml
new file mode 100644
index 00000000..a770b14e
--- /dev/null
+++ b/spring-utils/pom.xml
@@ -0,0 +1,54 @@
+<!--
+  ============LICENSE_START=======================================================
+  ONAP policy
+  ================================================================================
+  Copyright (C) 2022 Bell Canada. All rights reserved.
+  ================================================================================
+  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.
+  ============LICENSE_END=========================================================
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onap.policy.common</groupId>
+        <artifactId>common-modules</artifactId>
+        <version>1.10.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>spring-utils</artifactId>
+    <name>spring-utils</name>
+    <description>This artifact contains the common spring related utilitiy classes to be used by multiple policy framework components.</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onap.policy.common</groupId>
+            <artifactId>utils</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-core</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>
\ No newline at end of file
diff --git a/spring-utils/src/main/java/org/onap/policy/common/spring/utils/CustomImplicitNamingStrategy.java b/spring-utils/src/main/java/org/onap/policy/common/spring/utils/CustomImplicitNamingStrategy.java
new file mode 100644
index 00000000..1a747a3c
--- /dev/null
+++ b/spring-utils/src/main/java/org/onap/policy/common/spring/utils/CustomImplicitNamingStrategy.java
@@ -0,0 +1,36 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.spring.utils;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.boot.model.naming.ImplicitJoinColumnNameSource;
+import org.hibernate.boot.model.naming.ImplicitNamingStrategyJpaCompliantImpl;
+
+public class CustomImplicitNamingStrategy extends ImplicitNamingStrategyJpaCompliantImpl {
+
+    private static final long serialVersionUID = 8666774028328486896L;
+
+    @Override
+    public Identifier determineJoinColumnName(ImplicitJoinColumnNameSource source) {
+        String name = source.getReferencedColumnName().getText();
+        return toIdentifier(name, source.getBuildingContext());
+    }
+}
diff --git a/spring-utils/src/main/java/org/onap/policy/common/spring/utils/YamlHttpMessageConverter.java b/spring-utils/src/main/java/org/onap/policy/common/spring/utils/YamlHttpMessageConverter.java
new file mode 100644
index 00000000..d7dc96a9
--- /dev/null
+++ b/spring-utils/src/main/java/org/onap/policy/common/spring/utils/YamlHttpMessageConverter.java
@@ -0,0 +1,107 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.spring.utils;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.io.Reader;
+import java.io.Writer;
+import java.lang.reflect.Type;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import org.onap.policy.common.utils.coder.YamlJsonTranslator;
+import org.springframework.core.GenericTypeResolver;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpInputMessage;
+import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.AbstractGenericHttpMessageConverter;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.http.converter.HttpMessageNotWritableException;
+import org.springframework.lang.Nullable;
+
+/**
+ * Custom converter to marshal/unmarshall data structured with YAML media type.
+ */
+public class YamlHttpMessageConverter extends AbstractGenericHttpMessageConverter<Object> {
+
+    public static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
+
+    private static final YamlJsonTranslator TRANSLATOR = new YamlJsonTranslator();
+
+    public YamlHttpMessageConverter() {
+        super(new MediaType("application", "yaml"));
+        setDefaultCharset(DEFAULT_CHARSET);
+    }
+
+    @Override
+    public final Object read(Type type, @Nullable Class<?> contextClass, HttpInputMessage inputMessage)
+        throws IOException {
+        return readResolved(GenericTypeResolver.resolveType(type, contextClass), inputMessage);
+    }
+
+    @Override
+    protected final Object readInternal(Class<?> clazz, HttpInputMessage inputMessage) throws IOException {
+        return readResolved(clazz, inputMessage);
+    }
+
+    private Object readInternal(Type resolvedType, Reader reader) {
+        Class<?> clazz = (Class<?>) resolvedType;
+        return TRANSLATOR.fromYaml(reader, clazz);
+    }
+
+    @Override
+    protected final void writeInternal(Object object, @Nullable Type type, HttpOutputMessage outputMessage)
+        throws IOException {
+        try (var writer = getWriter(outputMessage)) {
+            writeInternal(object, type, writer);
+            writer.flush();
+        } catch (Exception ex) {
+            throw new HttpMessageNotWritableException("Could not write YAML: " + ex.getMessage(), ex);
+        }
+    }
+
+    private void writeInternal(Object object, @Nullable Type type, Writer writer) {
+        TRANSLATOR.toYaml(writer, object);
+    }
+
+    private Object readResolved(Type resolvedType, HttpInputMessage inputMessage) throws IOException {
+        try (var reader = getReader(inputMessage)) {
+            return readInternal(resolvedType, reader);
+        } catch (Exception ex) {
+            throw new HttpMessageNotReadableException("Could not read YAML: " + ex.getMessage(), ex, inputMessage);
+        }
+    }
+
+    private static Reader getReader(HttpInputMessage inputMessage) throws IOException {
+        return new InputStreamReader(inputMessage.getBody(), getCharset(inputMessage.getHeaders()));
+    }
+
+    private static Writer getWriter(HttpOutputMessage outputMessage) throws IOException {
+        return new OutputStreamWriter(outputMessage.getBody(), getCharset(outputMessage.getHeaders()));
+    }
+
+    private static Charset getCharset(HttpHeaders headers) {
+        Charset charset = (headers.getContentType() == null ? null : headers.getContentType().getCharset());
+        return (charset != null ? charset : DEFAULT_CHARSET);
+    }
+}
\ No newline at end of file