NIFI-4839 - Support both public URLs and local files as inputs for import actions.

- The handling of empty canvas got lost in the merge, causing errors with a new NiFi instance.
- Broaden support for input, now supportes both local files _and_ any public URL with a schema recognized by Java runtime.

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/CLICompleter.java

@@ -48,7 +48,7 @@ public class CLICompleter implements Completer {
     static {
         final Set<String> args = new HashSet<>();
         args.add("-" + CommandOption.PROPERTIES.getShortName());
-        args.add("-" + CommandOption.INPUT_FILE.getShortName());
+        args.add("-" + CommandOption.INPUT_SOURCE.getShortName());
         args.add("-" + CommandOption.OUTPUT_FILE.getShortName());
         FILE_COMPLETION_ARGS = Collections.unmodifiableSet(args);
     }

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/client/nifi/ProcessGroupBox.java

@@ -58,7 +58,7 @@ public class ProcessGroupBox implements Comparable<ProcessGroupBox> {
 
 
     public boolean intersects(ProcessGroupBox other) {
-        // adapted for java.awt Rectangle, we don't want to import it
+        // adapted from java.awt Rectangle, we don't want to import it
         // assume everything to be of the PG size for simplicity
         int tw = PG_SIZE_WIDTH;
         int th = PG_SIZE_HEIGHT;

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/client/nifi/impl/JerseyFlowClient.java

@@ -108,9 +108,13 @@ public class JerseyFlowClient extends AbstractJerseyClient implements FlowClient
         pgComponents.addAll(flowDTO.getLabels());
 
         final Set<PositionDTO> positions = pgComponents.stream()
-                .map(c -> c.getPosition())
+                .map(ComponentEntity::getPosition)
                 .collect(Collectors.toSet());
 
+        if (positions.isEmpty()) {
+            return ProcessGroupBox.CANVAS_CENTER;
+        }
+
         final List<ProcessGroupBox> coords = positions.stream()
                 .map(p -> new ProcessGroupBox(p.getX().intValue(), p.getY().intValue()))
                 .collect(Collectors.toList());

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/CommandOption.java

@@ -25,7 +25,7 @@ public enum CommandOption {
 
     // General
     URL("u", "baseUrl", "The URL to execute the command against", true),
-    INPUT_FILE("i", "inputFile", "A file to read as input, must contain full path and filename", true),
+    INPUT_SOURCE("i", "input", "A local file to read as input contents, or a public URL to fetch", true),
     OUTPUT_FILE("o", "outputFile", "A file to write output to, must contain full path and filename", true),
     PROPERTIES("p", "properties", "A properties file to load arguments from, " +
             "command line values will override anything in the properties file, must contain full path to file", true),

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/registry/flow/ImportFlowVersion.java

@@ -18,6 +18,7 @@ package org.apache.nifi.toolkit.cli.impl.command.registry.flow;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.commons.cli.ParseException;
+import org.apache.commons.io.IOUtils;
 import org.apache.nifi.registry.client.FlowSnapshotClient;
 import org.apache.nifi.registry.client.NiFiRegistryClient;
 import org.apache.nifi.registry.client.NiFiRegistryException;
@@ -28,8 +29,12 @@ import org.apache.nifi.toolkit.cli.impl.command.CommandOption;
 import org.apache.nifi.toolkit.cli.impl.command.registry.AbstractNiFiRegistryCommand;
 import org.apache.nifi.toolkit.cli.impl.util.JacksonUtils;
 
-import java.io.FileInputStream;
 import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Paths;
 import java.util.Properties;
 
 /**
@@ -50,20 +55,30 @@ public class ImportFlowVersion extends AbstractNiFiRegistryCommand {
     @Override
     public void doInitialize(final Context context) {
         addOption(CommandOption.FLOW_ID.createOption());
-        addOption(CommandOption.INPUT_FILE.createOption());
+        addOption(CommandOption.INPUT_SOURCE.createOption());
     }
 
     @Override
     protected void doExecute(final NiFiRegistryClient client, final Properties properties)
             throws ParseException, IOException, NiFiRegistryException {
         final String flowId = getRequiredArg(properties, CommandOption.FLOW_ID);
-        final String inputFile = getRequiredArg(properties, CommandOption.INPUT_FILE);
+        final String inputFile = getRequiredArg(properties, CommandOption.INPUT_SOURCE);
+
+        String contents;
+        try {
+            // try a public resource URL
+            URL url = new URL(inputFile);
+            contents = IOUtils.toString(url, StandardCharsets.UTF_8);
+        } catch (MalformedURLException e) {
+            // assume a local file then
+            URI uri = Paths.get(inputFile).toAbsolutePath().toUri();
+            contents = IOUtils.toString(uri, StandardCharsets.UTF_8);
+        }
 
-        try (final FileInputStream in = new FileInputStream(inputFile)) {
         final FlowSnapshotClient snapshotClient = client.getFlowSnapshotClient();
 
         final ObjectMapper objectMapper = JacksonUtils.getObjectMapper();
-            final VersionedFlowSnapshot deserializedSnapshot = objectMapper.readValue(in, VersionedFlowSnapshot.class);
+        final VersionedFlowSnapshot deserializedSnapshot = objectMapper.readValue(contents, VersionedFlowSnapshot.class);
         if (deserializedSnapshot == null) {
             throw new IOException("Unable to deserialize flow version from " + inputFile);
         }
@@ -78,7 +93,7 @@ public class ImportFlowVersion extends AbstractNiFiRegistryCommand {
             version = latestMetadata.getVersion() + 1;
         } catch (NiFiRegistryException e) {
             // when there are no versions it produces a 404 not found
-                version = new Integer(1);
+            version = 1;
         }
 
         // create new metadata using the passed in bucket and flow in the target registry, keep comments
@@ -98,7 +113,6 @@ public class ImportFlowVersion extends AbstractNiFiRegistryCommand {
         final VersionedFlowSnapshotMetadata createdMetadata = createdSnapshot.getSnapshotMetadata();
 
         println(String.valueOf(createdMetadata.getVersion()));
-        }
+}
-    }
 
 }