add caching to graph inventory client

add caching to graph inventory client
updated properties files to read cache properties

Issue-ID: SO-3398
Signed-off-by: Benjamin, Max (mb388a) <mb388a@att.com>
Change-Id: Ib3e67ae014b6668c9b004aae1e8b5d49b9ce6b06

6 files changed, 88 insertions, 4 deletions

diff --git a/common/src/main/java/org/onap/so/client/AddCacheHeaders.java b/common/src/main/java/org/onap/so/client/AddCacheHeaders.java
new file mode 100644
index 0000000000..1a41be1233
--- /dev/null
+++ b/common/src/main/java/org/onap/so/client/AddCacheHeaders.java
@@ -0,0 +1,28 @@
+package org.onap.so.client;
+
+import java.io.IOException;
+import java.util.Collections;
+import javax.annotation.Priority;
+import javax.ws.rs.client.ClientRequestContext;
+import javax.ws.rs.client.ClientResponseContext;
+import javax.ws.rs.client.ClientResponseFilter;
+import javax.ws.rs.ext.Provider;
+
+@Provider
+@Priority(1)
+public class AddCacheHeaders implements ClientResponseFilter {
+
+    private final CacheProperties props;
+
+    public AddCacheHeaders(CacheProperties props) {
+        this.props = props;
+    }
+
+    public void filter(ClientRequestContext request, ClientResponseContext response) throws IOException {
+        if (request.getMethod().equalsIgnoreCase("GET")) {
+            response.getHeaders().putIfAbsent("Cache-Control",
+                    Collections.singletonList("public, max-age=" + (props.getMaxAge() / 1000)));
+        }
+
+    }
+}
diff --git a/common/src/main/java/org/onap/so/client/CacheFactory.java b/common/src/main/java/org/onap/so/client/CacheFactory.java
new file mode 100644
index 0000000000..6bc4858463
--- /dev/null
+++ b/common/src/main/java/org/onap/so/client/CacheFactory.java
@@ -0,0 +1,25 @@
+package org.onap.so.client;
+
+
+import java.util.concurrent.TimeUnit;
+import javax.cache.configuration.Factory;
+import javax.cache.expiry.Duration;
+import javax.cache.expiry.ExpiryPolicy;
+import javax.cache.expiry.TouchedExpiryPolicy;
+
+public class CacheFactory implements Factory<ExpiryPolicy> {
+
+    private static final long serialVersionUID = 8948728679233836929L;
+
+    private final CacheProperties props;
+
+    public CacheFactory(CacheProperties props) {
+        this.props = props;
+    }
+
+    @Override
+    public ExpiryPolicy create() {
+        return TouchedExpiryPolicy.factoryOf(new Duration(TimeUnit.MILLISECONDS, props.getMaxAge())).create();
+    }
+
+}
diff --git a/common/src/main/java/org/onap/so/client/CacheProperties.java b/common/src/main/java/org/onap/so/client/CacheProperties.java
new file mode 100644
index 0000000000..4fb2a87a5b
--- /dev/null
+++ b/common/src/main/java/org/onap/so/client/CacheProperties.java
@@ -0,0 +1,13 @@
+package org.onap.so.client;
+
+public interface CacheProperties {
+
+
+    default Long getMaxAge() {
+        return 60000L;
+    }
+
+    default String getCacheName() {
+        return "default-http-cache";
+    }
+}
diff --git a/common/src/main/java/org/onap/so/client/RestClient.java b/common/src/main/java/org/onap/so/client/RestClient.java
index 9fce328b1d..be0a0f3f9e 100644
--- a/common/src/main/java/org/onap/so/client/RestClient.java
+++ b/common/src/main/java/org/onap/so/client/RestClient.java
@@ -188,8 +188,20 @@ public abstract class RestClient {
         return APPLICATION_MERGE_PATCH_JSON;
     }
 
+    protected ClientBuilder getClientBuilder() {
+        ClientBuilder builder = ClientBuilder.newBuilder();
+        if (props.isCachingEnabled()) {
+            enableCaching(builder);
+        }
+        return builder.readTimeout(props.getReadTimeout(), TimeUnit.MILLISECONDS);
+    }
+
+    protected ClientBuilder enableCaching(ClientBuilder builder) {
+        return builder;
+    }
+
     protected Client getClient() {
-        return ClientBuilder.newBuilder().readTimeout(props.getReadTimeout(), TimeUnit.MILLISECONDS).build();
+        return getClientBuilder().build();
     }
 
     protected abstract ONAPComponentsList getTargetEntity();
diff --git a/common/src/main/java/org/onap/so/client/RestClientSSL.java b/common/src/main/java/org/onap/so/client/RestClientSSL.java
index 8956e20a5a..c6252e4652 100644
--- a/common/src/main/java/org/onap/so/client/RestClientSSL.java
+++ b/common/src/main/java/org/onap/so/client/RestClientSSL.java
@@ -24,7 +24,6 @@ import java.net.URI;
 import java.security.KeyStore;
 import java.security.NoSuchAlgorithmException;
 import java.util.Optional;
-import java.util.concurrent.TimeUnit;
 import javax.net.ssl.SSLContext;
 import javax.ws.rs.client.Client;
 import javax.ws.rs.client.ClientBuilder;
@@ -57,8 +56,7 @@ public abstract class RestClientSSL extends RestClient {
                 }
             }
             // Use default SSL context
-            client = ClientBuilder.newBuilder().sslContext(SSLContext.getDefault())
-                    .readTimeout(props.getReadTimeout(), TimeUnit.MILLISECONDS).build();
+            client = getClientBuilder().sslContext(SSLContext.getDefault()).build();
             logger.info("RestClientSSL using default SSL context!");
         } catch (NoSuchAlgorithmException e) {
             throw new RuntimeException(e);
diff --git a/common/src/main/java/org/onap/so/client/RestProperties.java b/common/src/main/java/org/onap/so/client/RestProperties.java
index 36da424f93..a7a0ef614c 100644
--- a/common/src/main/java/org/onap/so/client/RestProperties.java
+++ b/common/src/main/java/org/onap/so/client/RestProperties.java
@@ -49,4 +49,12 @@ public interface RestProperties {
     public default Long getReadTimeout() {
         return Long.valueOf(60000);
     }
+
+    public default boolean isCachingEnabled() {
+        return false;
+    }
+
+    public default CacheProperties getCacheProperties() {
+        return new CacheProperties() {};
+    }
 }