Github user sandeepdeshmukh commented on a diff in the pull request:
https://github.com/apache/incubator-apex-malhar/pull/235#discussion_r60868038
--- Diff:
contrib/src/main/java/com/datatorrent/contrib/enrich/JDBCLoader.java ---
@@ -0,0 +1,201 @@
+/**
+ * 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 com.datatorrent.contrib.enrich;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.collections.CollectionUtils;
+import org.apache.hadoop.classification.InterfaceStability;
+
+import com.google.common.collect.Lists;
+import com.datatorrent.lib.db.jdbc.JdbcStore;
+import com.datatorrent.lib.util.FieldInfo;
+
+/**
+ * <p>HBaseLoader extends from {@link JdbcStore} uses JDBC to connect and
implements BackendLoaders interface.</p> <br/>
+ * <p>
+ * Properties:<br>
+ * <b>queryStmt</b>: Sql Prepared Statement which needs to be executed<br>
+ * <b>tableName</b>: JDBC table name<br>
+ * <br>
+ */
[email protected]
+public class JDBCLoader extends JdbcStore implements BackendLoader
+{
+ protected String queryStmt;
+
+ protected String tableName;
+
+ protected transient List<FieldInfo> includeFieldInfo;
+ protected transient List<FieldInfo> lookupFieldInfo;
+
+ protected Object getQueryResult(Object key)
+ {
+ try {
+ PreparedStatement getStatement =
getConnection().prepareStatement(queryStmt);
+ ArrayList<Object> keys = (ArrayList<Object>)key;
+ for (int i = 0; i < keys.size(); i++) {
+ getStatement.setObject(i + 1, keys.get(i));
+ }
+ return getStatement.executeQuery();
+ } catch (SQLException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ protected ArrayList<Object> getDataFrmResult(Object result) throws
RuntimeException
+ {
+ try {
+ ResultSet resultSet = (ResultSet)result;
+ if (resultSet.next()) {
+ ResultSetMetaData rsdata = resultSet.getMetaData();
+ // If the includefields is empty, populate it from
ResultSetMetaData
+ if (CollectionUtils.isEmpty(includeFieldInfo)) {
+ if (includeFieldInfo == null) {
+ includeFieldInfo = new ArrayList<>();
+ }
+ for (int i = 1; i <= rsdata.getColumnCount(); i++) {
+ String columnName = rsdata.getColumnName(i);
+ // TODO: Take care of type conversion.
+ includeFieldInfo.add(new FieldInfo(columnName, columnName,
FieldInfo.SupportType.OBJECT));
+ }
+ }
+
+ ArrayList<Object> res = new ArrayList<Object>();
+ for (FieldInfo f : includeFieldInfo) {
+ res.add(getConvertedData(resultSet.getObject(f.getColumnName()),
f));
+ }
+ return res;
+ } else {
+ return null;
+ }
+ } catch (SQLException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ private Object getConvertedData(Object object, FieldInfo f)
+ {
+ if (f.getType().getJavaType() == object.getClass()) {
+ return object;
+ } else {
+ logger.warn("Type mismatch seen for field {}, returning as it is",
f.getColumnName());
+ return null;
+ }
+ }
+
+ private String generateQueryStmt()
+ {
+ String stmt = "select * from " + tableName + " where ";
+ boolean first = true;
+ for (FieldInfo fieldInfo : lookupFieldInfo) {
+ if (first) {
+ first = false;
+ } else {
+ stmt += " and ";
+ }
+ stmt += fieldInfo.getColumnName() + " = ?";
+ }
+
+ logger.info("generateQueryStmt: {}", stmt);
+ return stmt;
+ }
+
+ public String getQueryStmt()
+ {
+ return queryStmt;
+ }
+
+ /**
+ * Set the sql Prepared Statement if the enrichment mechanism is query
based.
+ */
+ public void setQueryStmt(String queryStmt)
+ {
+ this.queryStmt = queryStmt;
+ }
+
+ public String getTableName()
+ {
+ return tableName;
+ }
+
+ /**
+ * Set the table name.
+ */
+ public void setTableName(String tableName)
+ {
+ this.tableName = tableName;
+ }
+
+ @Override
+ public void setFieldInfo(List<FieldInfo> lookupFieldInfo,
List<FieldInfo> includeFieldInfo)
+ {
+ this.lookupFieldInfo = lookupFieldInfo;
+ this.includeFieldInfo = includeFieldInfo;
+ if (queryStmt == null) {
+ queryStmt = generateQueryStmt();
+ }
+ }
+
+ @Override
+ public Map<Object, Object> loadInitialData()
+ {
+ return null;
+ }
+
+ @Override
+ public Object get(Object key)
+ {
+ return getDataFrmResult(getQueryResult(key));
+ }
+
+ @Override
+ public List<Object> getAll(List<Object> keys)
+ {
+ List<Object> values = Lists.newArrayList();
+ for (Object key : keys) {
+ values.add(get(key));
+ }
+ return values;
+ }
+
+ @Override
+ public void put(Object key, Object value)
+ {
+ throw new RuntimeException("Not supported operation");
--- End diff --
UnsupportedOperationException ?
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
