Github user leskin-in commented on a diff in the pull request:
https://github.com/apache/incubator-hawq/pull/1353#discussion_r214430750
--- Diff:
pxf/pxf-jdbc/src/main/java/org/apache/hawq/pxf/plugins/jdbc/JdbcResolver.java
---
@@ -0,0 +1,364 @@
+package org.apache.hawq.pxf.plugins.jdbc;
+
+/*
+ * 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.
+ */
+
+import org.apache.hawq.pxf.api.io.DataType;
+import org.apache.hawq.pxf.api.utilities.ColumnDescriptor;
+import org.apache.hawq.pxf.api.utilities.InputData;
+import org.apache.hawq.pxf.api.OneField;
+import org.apache.hawq.pxf.api.OneRow;
+import org.apache.hawq.pxf.api.ReadResolver;
+import org.apache.hawq.pxf.api.UserDataException;
+import org.apache.hawq.pxf.api.WriteResolver;
+
+import java.util.List;
+import java.util.LinkedList;
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.sql.Date;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Timestamp;
+import java.sql.Types;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * JDBC tables resolver
+ */
+public class JdbcResolver extends JdbcPlugin implements ReadResolver,
WriteResolver {
+ /**
+ * Class constructor
+ */
+ public JdbcResolver(InputData input) throws UserDataException {
+ super(input);
+ }
+
+ /**
+ * getFields() implementation
+ *
+ * @throws SQLException if the provided {@link OneRow} object is
invalid
+ */
+ @Override
+ public List<OneField> getFields(OneRow row) throws SQLException {
+ ResultSet result = (ResultSet) row.getData();
+ LinkedList<OneField> fields = new LinkedList<>();
+
+ for (ColumnDescriptor column : columns) {
+ String colName = column.columnName();
+ Object value = null;
+
+ OneField oneField = new OneField();
+ oneField.type = column.columnTypeCode();
+
+ switch (DataType.get(oneField.type)) {
+ case INTEGER:
+ value = result.getInt(colName);
+ break;
+ case FLOAT8:
+ value = result.getDouble(colName);
+ break;
+ case REAL:
+ value = result.getFloat(colName);
+ break;
+ case BIGINT:
+ value = result.getLong(colName);
+ break;
+ case SMALLINT:
+ value = result.getShort(colName);
+ break;
+ case BOOLEAN:
+ value = result.getBoolean(colName);
+ break;
+ case BYTEA:
+ value = result.getBytes(colName);
+ break;
+ case VARCHAR:
+ case BPCHAR:
+ case TEXT:
+ case NUMERIC:
+ value = result.getString(colName);
+ break;
+ case DATE:
+ value = result.getDate(colName);
+ break;
+ case TIMESTAMP:
+ value = result.getTimestamp(colName);
+ break;
+ default:
+ throw new UnsupportedOperationException("Field type '"
+ DataType.get(oneField.type).toString() + "' (column '" + column.toString() +
"') is not supported");
+ }
+
+ oneField.val = value;
+ fields.add(oneField);
+ }
+ return fields;
+ }
+
+ /**
+ * setFields() implementation
+ *
+ * @return OneRow with the data field containing a List<OneField>
+ * OneFields are not reordered before being passed to Accessor; at the
+ * moment, there is no way to correct the order of the fields if it is
not.
+ * In practice, the 'record' provided is always ordered the right way.
+ *
+ * @throws UnsupportedOperationException if field of some type is not
supported
+ */
+ @Override
+ public OneRow setFields(List<OneField> record) throws
UnsupportedOperationException, ParseException {
+ int column_index = 0;
+ for (OneField oneField : record) {
+ ColumnDescriptor column = columns.get(column_index);
+ if (
+ LOG.isDebugEnabled() &&
+ DataType.get(column.columnTypeCode()) !=
DataType.get(oneField.type)
+ ) {
+ LOG.warn("The provided tuple of data may be disordered.
Datatype of column with descriptor '" + column.toString() + "' must be '" +
DataType.get(column.columnTypeCode()).toString() + "', but actual is '" +
DataType.get(oneField.type).toString() + "'");
+ }
+
+ // Check that data type is supported
+ switch (DataType.get(oneField.type)) {
+ case BOOLEAN:
+ case INTEGER:
+ case FLOAT8:
+ case REAL:
+ case BIGINT:
+ case SMALLINT:
+ case NUMERIC:
+ case VARCHAR:
+ case BPCHAR:
+ case TEXT:
+ case BYTEA:
+ case TIMESTAMP:
+ case DATE:
+ break;
+ default:
+ throw new UnsupportedOperationException("Field type '"
+ DataType.get(oneField.type).toString() + "' (column '" + column.toString() +
"') is not supported");
+ }
+
+ if (LOG.isDebugEnabled()) {
+ if (DataType.get(oneField.type) == DataType.BYTEA) {
+ LOG.debug("OneField content (conversion from BYTEA):
'" + new String((byte[])oneField.val) + "'");
+ }
+ }
+
+ // Convert TEXT columns into native data types
+ if ((oneField.val != null) && (DataType.get(oneField.type) ==
DataType.TEXT) && (DataType.get(column.columnTypeCode()) != DataType.TEXT)) {
+ String rawVal = (String)oneField.val;
+ if (LOG.isDebugEnabled()) {
+ LOG.debug("OneField content (conversion from TEXT): '"
+ rawVal + "'");
+ }
+ switch (DataType.get(column.columnTypeCode())) {
+ case VARCHAR:
+ case BPCHAR:
+ case TEXT:
+ case BYTEA:
+ break;
+ case BOOLEAN:
+ oneField.val =
(Object)Boolean.parseBoolean(rawVal);
+ break;
+ case INTEGER:
+ oneField.val = (Object)Integer.parseInt(rawVal);
+ break;
+ case FLOAT8:
+ oneField.val = (Object)Double.parseDouble(rawVal);
+ break;
+ case REAL:
+ oneField.val = (Object)Float.parseFloat(rawVal);
+ break;
+ case BIGINT:
+ oneField.val = (Object)Long.parseLong(rawVal);
+ break;
+ case SMALLINT:
+ oneField.val = (Object)Short.parseShort(rawVal);
+ break;
+ case NUMERIC:
+ oneField.val = (Object)new BigDecimal(rawVal);
+ break;
+ case TIMESTAMP:
+ boolean isConversionSuccessful = false;
+ for (SimpleDateFormat sdf : timestampSDFs.get()) {
+ try {
+ java.util.Date parsedTimestamp =
sdf.parse(rawVal);
+ oneField.val = (Object)new
Timestamp(parsedTimestamp.getTime());
+ isConversionSuccessful = true;
+ break;
+ }
+ catch (ParseException e) {
+ // pass
+ }
+ }
+ if (!isConversionSuccessful) {
+ throw new ParseException(rawVal, 0);
+ }
+ break;
+ case DATE:
+ oneField.val = (Object)new
Date(dateSDF.get().parse(rawVal).getTime());
+ break;
+ default:
+ throw new UnsupportedOperationException("Field
type '" + DataType.get(oneField.type).toString() + "' (column '" +
column.toString() + "') is not supported");
+ }
+ oneField.type = column.columnTypeCode();
+ }
+
+ column_index += 1;
+ }
+ return new OneRow(new LinkedList<OneField>(record));
+ }
+
+ /**
+ * Decode OneRow object and pass all its contents to a
PreparedStatement
+ *
+ * @throws IOException if data in a OneRow is corrupted
+ * @throws SQLException if the given statement is broken
+ */
+ @SuppressWarnings("unchecked")
+ public static void decodeOneRowToPreparedStatement(OneRow row,
PreparedStatement statement) throws IOException, SQLException {
+ // This is safe: OneRow comes from JdbcResolver
+ List<OneField> tuple = (List<OneField>)row.getData();
+ for (int i = 1; i <= tuple.size(); i++) {
+ OneField field = tuple.get(i - 1);
+ switch (DataType.get(field.type)) {
+ case INTEGER:
+ if (field.val == null) {
+ statement.setNull(i, Types.INTEGER);
+ }
+ else {
+ statement.setInt(i, (int)field.val);
+ }
+ break;
+ case BIGINT:
+ if (field.val == null) {
+ statement.setNull(i, Types.INTEGER);
+ }
+ else {
+ statement.setLong(i, (long)field.val);
+ }
+ break;
+ case SMALLINT:
+ if (field.val == null) {
+ statement.setNull(i, Types.INTEGER);
+ }
+ else {
+ statement.setShort(i, (short)field.val);
+ }
+ break;
+ case REAL:
+ if (field.val == null) {
+ statement.setNull(i, Types.FLOAT);
+ }
+ else {
+ statement.setFloat(i, (float)field.val);
+ }
+ break;
+ case FLOAT8:
+ if (field.val == null) {
+ statement.setNull(i, Types.DOUBLE);
+ }
+ else {
+ statement.setDouble(i, (double)field.val);
+ }
+ break;
+ case BOOLEAN:
+ if (field.val == null) {
+ statement.setNull(i, Types.BOOLEAN);
+ }
+ else {
+ statement.setBoolean(i, (boolean)field.val);
+ }
+ break;
+ case NUMERIC:
+ if (field.val == null) {
+ statement.setNull(i, Types.NUMERIC);
+ }
+ else {
+ statement.setBigDecimal(i, (BigDecimal)field.val);
+ }
+ break;
+ case VARCHAR:
+ case BPCHAR:
+ case TEXT:
+ if (field.val == null) {
+ statement.setNull(i, Types.VARCHAR);
+ }
+ else {
+ statement.setString(i, (String)field.val);
+ }
+ break;
+ case BYTEA:
+ if (field.val == null) {
+ statement.setNull(i, Types.BINARY);
+ }
+ else {
+ statement.setBytes(i, (byte[])field.val);
+ }
+ break;
+ case TIMESTAMP:
+ if (field.val == null) {
+ statement.setNull(i, Types.TIMESTAMP);
+ }
+ else {
+ statement.setTimestamp(i, (Timestamp)field.val);
+ }
+ break;
+ case DATE:
+ if (field.val == null) {
+ statement.setNull(i, Types.DATE);
+ }
+ else {
+ statement.setDate(i, (Date)field.val);
+ }
+ break;
+ default:
+ throw new IOException("The data tuple from
JdbcResolver is corrupted");
+ }
+ }
+ }
+
+ private static final Log LOG = LogFactory.getLog(JdbcResolver.class);
+
+ // SimpleDateFormat to parse TEXT into DATE
+ private static ThreadLocal<SimpleDateFormat> dateSDF = new
ThreadLocal<SimpleDateFormat>() {
--- End diff --
@denalex, I would be glad if you could tell about the details of a
`ThreadLocal`'s lifecycle in Tomcat. As far as I know (see
https://docs.oracle.com/javase/7/docs/api/java/lang/ThreadLocal.html), every
`ThreadLocal` object is a subject to garbage collection when a thread dies.
---
