add convert rule configuration provider for Single table.

kernel/single/distsql/handler/src/main/java/org/apache/shardingsphere/single/distsql/handler/constant/SingleDistSQLConstants.java

@@ -0,0 +1,36 @@
+/*
+ * 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://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.shardingsphere.single.distsql.handler.constant;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+/**
+ * Single DistSQL constants.
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class SingleDistSQLConstants {
+
+    public static final String COMMA = ", ";
+
+    public static final String SEMI = ";";
+
+    public static final String LOAD_SINGLE_TABLE = "LOAD SINGLE TABLE ";
+
+    public static final String DATASOURCE_AND_TABLE = "%s.%s";
+}

kernel/single/distsql/handler/src/main/java/org/apache/shardingsphere/single/distsql/handler/provider/SingleConvertRuleConfigurationProvider.java

@@ -0,0 +1,58 @@
+/*
+ * 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://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.shardingsphere.single.distsql.handler.provider;
+
+import org.apache.shardingsphere.distsql.handler.engine.query.ral.convert.ConvertRuleConfigurationProvider;
+import org.apache.shardingsphere.infra.config.rule.RuleConfiguration;
+import org.apache.shardingsphere.single.api.config.SingleRuleConfiguration;
+import org.apache.shardingsphere.single.distsql.handler.constant.SingleDistSQLConstants;
+
+import java.util.Iterator;
+
+/**
+ * Single convert rule configuration provider.
+ */
+public final class SingleConvertRuleConfigurationProvider implements ConvertRuleConfigurationProvider {
+
+    @Override
+    public String convert(final RuleConfiguration ruleConfig) {
+        return getSingleDistSQL((SingleRuleConfiguration) ruleConfig);
+    }
+
+    private String getSingleDistSQL(final SingleRuleConfiguration ruleConfig) {
+        if (ruleConfig.getTables().isEmpty()) {
+            return "";
+        }
+        StringBuilder result = new StringBuilder(SingleDistSQLConstants.LOAD_SINGLE_TABLE);
+        Iterator<String> iterator = ruleConfig.getTables().iterator();
+        while (iterator.hasNext()) {
+            String tableName = iterator.next();
+            result.append(String.format(SingleDistSQLConstants.DATASOURCE_AND_TABLE, ruleConfig.getDefaultDataSource(), tableName));
+            if (iterator.hasNext()) {
+                result.append(SingleDistSQLConstants.COMMA);
+            }
+        }
+        result.append(SingleDistSQLConstants.SEMI).append(System.lineSeparator()).append(System.lineSeparator());
+        return result.toString();
+    }
+
+    @Override
+    public Class<? extends RuleConfiguration> getType() {
+        return SingleRuleConfiguration.class;
+    }
+}

kernel/single/distsql/handler/src/main/resources/META-INF/services/org.apache.shardingsphere.distsql.handler.engine.query.ral.convert.ConvertRuleConfigurationProvider

@@ -0,0 +1,18 @@
+#
+# 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://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.
+#
+
+org.apache.shardingsphere.single.distsql.handler.provider.SingleConvertRuleConfigurationProvider