[FLINK-18938][table-api] Throw better exception message for querying …

…sink only or source only connector

This closes apache#13214

flink-table/flink-table-common/src/main/java/org/apache/flink/table/factories/FactoryUtil.java

@@ -365,15 +365,41 @@ private static <T extends DynamicTableFactory> T getDynamicTableFactory(
  "Table options do not contain an option key '%s' for discovering a connector.",
  CONNECTOR.key()));
  }
+ final DynamicTableFactory factory;
  try {
- return discoverFactory(context.getClassLoader(), factoryClass, connectorOption);
+ factory = discoverFactory(context.getClassLoader(), DynamicTableFactory.class, connectorOption);
  } catch (ValidationException e) {
  throw new ValidationException(
  String.format(
  "Cannot discover a connector using option '%s'.",
  stringifyOption(CONNECTOR.key(), connectorOption)),
  e);
  }
+
+ if (factoryClass.isAssignableFrom(factory.getClass())) {
+ return (T) factory;
+ } else {
+ final Class<?> sourceFactoryClass = DynamicTableSourceFactory.class;
+ final Class<?> sinkFactoryClass = DynamicTableSinkFactory.class;
+ // for a better exception message
+ if (sourceFactoryClass.equals(factoryClass) && sinkFactoryClass.isAssignableFrom(factory.getClass())) {
+ // discovering source, but not found, and this is a sink connector.
+ throw new ValidationException(String.format(
+ "Connector '%s' only supports to be used as sink, can't be used as source.",
+ connectorOption));
+ } else if (sinkFactoryClass.equals(factoryClass) && sourceFactoryClass.isAssignableFrom(factory.getClass())) {
+ // discovering sink, but not found, and this is a a source connector.
+ throw new ValidationException(String.format(
+ "Connector '%s' only supports to be used as source, can't be used as sink.",
+ connectorOption));
+ } else {
+ throw new ValidationException(String.format(
+ "Connector '%s' should at least implements '%s' or '%s' interface.",
+ connectorOption,
+ sourceFactoryClass.getName(),
+ sinkFactoryClass.getName()));
+ }
+ }
  }
 
  private static List<Factory> discoverFactories(ClassLoader classLoader) {

flink-table/flink-table-common/src/test/java/org/apache/flink/table/factories/FactoryUtilTest.java

@@ -35,6 +35,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -43,6 +44,8 @@
 
 import static org.apache.flink.core.testutils.FlinkMatchers.containsCause;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
 
 /**
  * Tests for {@link FactoryUtil}.
@@ -62,9 +65,9 @@ public void testMissingConnector() {
  public void testInvalidConnector() {
  expectError(
  "Could not find any factory for identifier 'FAIL' that implements '" +
- DynamicTableSourceFactory.class.getName() + "' in the classpath.\n\n" +
+ DynamicTableFactory.class.getName() + "' in the classpath.\n\n" +
  "Available factory identifiers are:\n\n" +
- "test-connector");
+ "sink-only\nsource-only\ntest-connector");
  testError(options -> options.put("connector", "FAIL"));
  }
 
@@ -207,6 +210,25 @@ public void testAlternativeValueFormat() {
  assertEquals(expectedSink, actualSink);
  }
 
+ @Test
+ public void testAvailableFactoryTipsDependencyJarForConnector() {
+ try {
+ createTableSource(Collections.singletonMap("connector", "sink-only"));
+ fail();
+ } catch (Exception e) {
+ String errorMsg = "Connector 'sink-only' only supports to be used as sink, can't be used as source.";
+ assertThat(e, containsCause(new ValidationException(errorMsg)));
+ }
+
+ try {
+ createTableSink(Collections.singletonMap("connector", "source-only"));
+ fail();
+ } catch (Exception e) {
+ String errorMsg = "Connector 'source-only' only supports to be used as source, can't be used as sink.";
+ assertThat(e, containsCause(new ValidationException(errorMsg)));
+ }
+ }
+
  // --------------------------------------------------------------------------------------------
 
  private void expectError(String message) {

flink-table/flink-table-common/src/test/java/org/apache/flink/table/factories/TestDynamicTableSinkOnlyFactory.java

@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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:https://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 org.apache.flink.table.factories;
+
+import org.apache.flink.configuration.ConfigOption;
+import org.apache.flink.table.connector.sink.DynamicTableSink;
+
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * Test implementations for {@link DynamicTableSinkFactory} which only supports to be used as sink.
+ */
+public final class TestDynamicTableSinkOnlyFactory implements DynamicTableSinkFactory {
+
+ public static final String IDENTIFIER = "sink-only";
+
+ @Override
+ public DynamicTableSink createDynamicTableSink(Context context) {
+ return null;
+ }
+
+ @Override
+ public String factoryIdentifier() {
+ return IDENTIFIER;
+ }
+
+ @Override
+ public Set<ConfigOption<?>> requiredOptions() {
+ return Collections.emptySet();
+ }
+
+ @Override
+ public Set<ConfigOption<?>> optionalOptions() {
+ return Collections.emptySet();
+ }
+
+}

flink-table/flink-table-common/src/test/java/org/apache/flink/table/factories/TestDynamicTableSourceOnlyFactory.java

@@ -0,0 +1,53 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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:https://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 org.apache.flink.table.factories;
+
+import org.apache.flink.configuration.ConfigOption;
+import org.apache.flink.table.connector.source.DynamicTableSource;
+
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * Test implementations for {@link DynamicTableSourceFactory} which only supports to be used as source.
+ */
+public final class TestDynamicTableSourceOnlyFactory implements DynamicTableSourceFactory {
+
+ public static final String IDENTIFIER = "source-only";
+
+ @Override
+ public DynamicTableSource createDynamicTableSource(Context context) {
+ return null;
+ }
+
+ @Override
+ public String factoryIdentifier() {
+ return IDENTIFIER;
+ }
+
+ @Override
+ public Set<ConfigOption<?>> requiredOptions() {
+ return Collections.emptySet();
+ }
+
+ @Override
+ public Set<ConfigOption<?>> optionalOptions() {
+ return Collections.emptySet();
+ }
+}

flink-table/flink-table-common/src/test/resources/META-INF/services/org.apache.flink.table.factories.Factory

@@ -15,3 +15,5 @@
 
 org.apache.flink.table.factories.TestDynamicTableFactory
 org.apache.flink.table.factories.TestFormatFactory
+org.apache.flink.table.factories.TestDynamicTableSinkOnlyFactory
+org.apache.flink.table.factories.TestDynamicTableSourceOnlyFactory