Close module URL stream as soon as possible

This refactors LibraryModulesSchemas.createFromURLConnection()
to close the stream before doing any further processing. This
lowers resource needs as well as makes for simpler code.

Change-Id: I08f242005185637f6dcbd37fe4ba86051624e56d
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>

diff --git a/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/LibraryModulesSchemas.java b/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/LibraryModulesSchemas.java
index bb181ad4ca4879a37aacb3eb78e9aa5331dce098..8b0c3ebf804a05278d4f6141454fc3e9a9807e39 100644 (file)
--- a/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/LibraryModulesSchemas.java
+++ b/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/LibraryModulesSchemas.java
@@ -221,20 +221,18 @@ public final class LibraryModulesSchemas implements NetconfDeviceSchemas {
      * @return Resolved URLs with YANG schema resources for all yang modules from yang library
      */
     public static LibraryModulesSchemas create(final String url) {
+        final URLConnection connection;
         try {
-            final URL urlConnection = new URL(requireNonNull(url));
-            final URLConnection connection = urlConnection.openConnection();
-
-            if (connection instanceof HttpURLConnection) {
-                connection.setRequestProperty("Accept", "application/xml");
-            }
-
-            return createFromURLConnection(connection);
-
+            connection = new URL(requireNonNull(url)).openConnection();
         } catch (final IOException e) {
             LOG.warn("Unable to download yang library from {}", url, e);
             return new LibraryModulesSchemas(ImmutableMap.of());
         }
+
+        if (connection instanceof HttpURLConnection) {
+            connection.setRequestProperty("Accept", "application/xml");
+        }
+        return createFromURLConnection(connection);
     }
 
     private static Optional<? extends NormalizedNode<?, ?>> findModulesStateNode(final NormalizedNode<?, ?> result) {
@@ -262,27 +260,26 @@ public final class LibraryModulesSchemas implements NetconfDeviceSchemas {
         requireNonNull(contentType, "Content type unknown");
         checkState(contentType.equals("application/json") || contentType.equals("application/xml"),
                 "Only XML and JSON types are supported.");
-        try (InputStream in = connection.getInputStream()) {
-            final Optional<NormalizedNode<?, ?>> optionalModulesStateNode =
-                    contentType.equals("application/json") ? readJson(in) : readXml(in);
-
-            if (!optionalModulesStateNode.isPresent()) {
-                return new LibraryModulesSchemas(ImmutableMap.of());
-            }
-
-            final NormalizedNode<?, ?> modulesStateNode = optionalModulesStateNode.get();
-            checkState(modulesStateNode instanceof ContainerNode,
-                "Expecting container containing module list, but was %s", modulesStateNode);
-            final ContainerNode modulesState = (ContainerNode) modulesStateNode;
-
-            final NodeIdentifier nodeName = modulesState.getIdentifier();
-            checkState(MODULES_STATE_NID.equals(nodeName), "Wrong container identifier %s", nodeName);
 
-            return create((ContainerNode) modulesStateNode);
+        Optional<NormalizedNode<?, ?>> optionalModulesStateNode = Optional.empty();
+        try (InputStream in = connection.getInputStream()) {
+            optionalModulesStateNode = contentType.equals("application/json") ? readJson(in) : readXml(in);
         } catch (final IOException e) {
             LOG.warn("Unable to download yang library from {}", connection.getURL(), e);
+        }
+
+        if (!optionalModulesStateNode.isPresent()) {
             return new LibraryModulesSchemas(ImmutableMap.of());
         }
+
+        final NormalizedNode<?, ?> modulesStateNode = optionalModulesStateNode.get();
+        checkState(modulesStateNode instanceof ContainerNode, "Expecting container containing module list, but was %s",
+            modulesStateNode);
+        final ContainerNode modulesState = (ContainerNode) modulesStateNode;
+        final NodeIdentifier nodeName = modulesState.getIdentifier();
+        checkState(MODULES_STATE_NID.equals(nodeName), "Wrong container identifier %s", nodeName);
+
+        return create((ContainerNode) modulesStateNode);
     }
 
     private static boolean guessJsonFromFileName(final String fileName) {