eu.stratosphere.api.java.io.jdbc.JDBCInputFormat Maven / Gradle / Ivy
/***********************************************************************************************************************
*
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.api.java.io.jdbc;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import eu.stratosphere.api.common.io.InputFormat;
import eu.stratosphere.api.common.io.statistics.BaseStatistics;
import eu.stratosphere.api.java.tuple.Tuple;
import eu.stratosphere.configuration.Configuration;
import eu.stratosphere.core.io.GenericInputSplit;
import eu.stratosphere.core.io.InputSplit;
import eu.stratosphere.types.NullValue;
/**
* InputFormat to read data from a database and generate tuples.
* The InputFormat has to be configured using the supplied InputFormatBuilder.
*
* @param
* @see Tuple
* @see DriverManager
*/
public class JDBCInputFormat implements InputFormat {
private static final long serialVersionUID = 1L;
@SuppressWarnings("unused")
private static final Log LOG = LogFactory.getLog(JDBCInputFormat.class);
private String username;
private String password;
private String drivername;
private String dbURL;
private String query;
private transient Connection dbConn;
private transient Statement statement;
private transient ResultSet resultSet;
private int[] columnTypes = null;
public JDBCInputFormat() {
}
@Override
public void configure(Configuration parameters) {
}
/**
* Connects to the source database and executes the query.
*
* @param ignored
* @throws IOException
*/
@Override
public void open(InputSplit ignored) throws IOException {
try {
establishConnection();
statement = dbConn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
resultSet = statement.executeQuery(query);
} catch (SQLException se) {
close();
throw new IllegalArgumentException("open() failed." + se.getMessage(), se);
} catch (ClassNotFoundException cnfe) {
throw new IllegalArgumentException("JDBC-Class not found. - " + cnfe.getMessage(), cnfe);
}
}
private void establishConnection() throws SQLException, ClassNotFoundException {
Class.forName(drivername);
if (username == null) {
dbConn = DriverManager.getConnection(dbURL);
} else {
dbConn = DriverManager.getConnection(dbURL, username, password);
}
}
/**
* Closes all resources used.
*
* @throws IOException Indicates that a resource could not be closed.
*/
@Override
public void close() throws IOException {
try {
resultSet.close();
} catch (SQLException se) {
LOG.info("Inputformat couldn't be closed - " + se.getMessage());
} catch (NullPointerException npe) {
}
try {
statement.close();
} catch (SQLException se) {
LOG.info("Inputformat couldn't be closed - " + se.getMessage());
} catch (NullPointerException npe) {
}
try {
dbConn.close();
} catch (SQLException se) {
LOG.info("Inputformat couldn't be closed - " + se.getMessage());
} catch (NullPointerException npe) {
}
}
/**
* Checks whether all data has been read.
*
* @return boolean value indication whether all data has been read.
* @throws IOException
*/
@Override
public boolean reachedEnd() throws IOException {
try {
if (resultSet.isLast()) {
close();
return true;
}
return false;
} catch (SQLException se) {
throw new IOException("Couldn't evaluate reachedEnd() - " + se.getMessage(), se);
}
}
/**
* Stores the next resultSet row in a tuple
*
* @param tuple
* @return tuple containing next row
* @throws java.io.IOException
*/
@Override
public OUT nextRecord(OUT tuple) throws IOException {
try {
resultSet.next();
if (columnTypes == null) {
extractTypes(tuple);
}
addValue(tuple);
return tuple;
} catch (SQLException se) {
close();
throw new IOException("Couldn't read data - " + se.getMessage(), se);
} catch (NullPointerException npe) {
close();
throw new IOException("Couldn't access resultSet", npe);
}
}
private void extractTypes(OUT tuple) throws SQLException, IOException {
ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
columnTypes = new int[resultSetMetaData.getColumnCount()];
if (tuple.getArity() != columnTypes.length) {
close();
throw new IOException("Tuple size does not match columncount");
}
for (int pos = 0; pos < columnTypes.length; pos++) {
columnTypes[pos] = resultSetMetaData.getColumnType(pos + 1);
}
}
/**
* Enters data value from the current resultSet into a Record.
*
* @param pos Tuple position to be set.
* @param type SQL type of the resultSet value.
* @param reuse Target Record.
*/
private void addValue(OUT reuse) throws SQLException {
for (int pos = 0; pos < columnTypes.length; pos++) {
switch (columnTypes[pos]) {
case java.sql.Types.NULL:
reuse.setField(NullValue.getInstance(), pos);
break;
case java.sql.Types.BOOLEAN:
reuse.setField(resultSet.getBoolean(pos + 1), pos);
break;
case java.sql.Types.BIT:
reuse.setField(resultSet.getBoolean(pos + 1), pos);
break;
case java.sql.Types.CHAR:
reuse.setField(resultSet.getString(pos + 1), pos);
break;
case java.sql.Types.NCHAR:
reuse.setField(resultSet.getString(pos + 1), pos);
break;
case java.sql.Types.VARCHAR:
reuse.setField(resultSet.getString(pos + 1), pos);
break;
case java.sql.Types.LONGVARCHAR:
reuse.setField(resultSet.getString(pos + 1), pos);
break;
case java.sql.Types.LONGNVARCHAR:
reuse.setField(resultSet.getString(pos + 1), pos);
break;
case java.sql.Types.TINYINT:
reuse.setField(resultSet.getShort(pos + 1), pos);
break;
case java.sql.Types.SMALLINT:
reuse.setField(resultSet.getShort(pos + 1), pos);
break;
case java.sql.Types.BIGINT:
reuse.setField(resultSet.getLong(pos + 1), pos);
break;
case java.sql.Types.INTEGER:
reuse.setField(resultSet.getInt(pos + 1), pos);
break;
case java.sql.Types.FLOAT:
reuse.setField(resultSet.getDouble(pos + 1), pos);
break;
case java.sql.Types.REAL:
reuse.setField(resultSet.getFloat(pos + 1), pos);
break;
case java.sql.Types.DOUBLE:
reuse.setField(resultSet.getDouble(pos + 1), pos);
break;
case java.sql.Types.DECIMAL:
reuse.setField(resultSet.getBigDecimal(pos + 1).doubleValue(), pos);
break;
case java.sql.Types.NUMERIC:
reuse.setField(resultSet.getBigDecimal(pos + 1).doubleValue(), pos);
break;
case java.sql.Types.DATE:
reuse.setField(resultSet.getDate(pos + 1).toString(), pos);
break;
case java.sql.Types.TIME:
reuse.setField(resultSet.getTime(pos + 1).getTime(), pos);
break;
case java.sql.Types.TIMESTAMP:
reuse.setField(resultSet.getTimestamp(pos + 1).toString(), pos);
break;
case java.sql.Types.SQLXML:
reuse.setField(resultSet.getSQLXML(pos + 1).toString(), pos);
break;
default:
throw new SQLException("Unsupported sql-type [" + columnTypes[pos] + "] on column [" + pos + "]");
// case java.sql.Types.BINARY:
// case java.sql.Types.VARBINARY:
// case java.sql.Types.LONGVARBINARY:
// case java.sql.Types.ARRAY:
// case java.sql.Types.JAVA_OBJECT:
// case java.sql.Types.BLOB:
// case java.sql.Types.CLOB:
// case java.sql.Types.NCLOB:
// case java.sql.Types.DATALINK:
// case java.sql.Types.DISTINCT:
// case java.sql.Types.OTHER:
// case java.sql.Types.REF:
// case java.sql.Types.ROWID:
// case java.sql.Types.STRUCT:
}
}
}
@Override
public BaseStatistics getStatistics(BaseStatistics cachedStatistics) throws IOException {
return cachedStatistics;
}
@Override
public InputSplit[] createInputSplits(int minNumSplits) throws IOException {
GenericInputSplit[] split = {
new GenericInputSplit(0, 1)
};
return split;
}
@Override
public Class getInputSplitType() {
return GenericInputSplit.class;
}
/**
* A builder used to set parameters to the output format's configuration in a fluent way.
* @return builder
*/
public static JDBCInputFormatBuilder buildJDBCInputFormat() {
return new JDBCInputFormatBuilder();
}
public static class JDBCInputFormatBuilder {
private final JDBCInputFormat format;
public JDBCInputFormatBuilder() {
this.format = new JDBCInputFormat();
}
public JDBCInputFormatBuilder setUsername(String username) {
format.username = username;
return this;
}
public JDBCInputFormatBuilder setPassword(String password) {
format.password = password;
return this;
}
public JDBCInputFormatBuilder setDrivername(String drivername) {
format.drivername = drivername;
return this;
}
public JDBCInputFormatBuilder setDBUrl(String dbURL) {
format.dbURL = dbURL;
return this;
}
public JDBCInputFormatBuilder setQuery(String query) {
format.query = query;
return this;
}
public JDBCInputFormat finish() {
if (format.username == null) {
LOG.info("Username was not supplied separately.");
}
if (format.password == null) {
LOG.info("Password was not supplied separately.");
}
if (format.dbURL == null) {
throw new IllegalArgumentException("No dababase URL supplied.");
}
if (format.query == null) {
throw new IllegalArgumentException("No query suplied");
}
if (format.drivername == null) {
throw new IllegalArgumentException("No driver supplied");
}
return format;
}
}
}
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