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org.apache.tika.parser.jdbc.JDBCTableReader Maven / Gradle / Ivy
package org.apache.tika.parser.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 static java.nio.charset.StandardCharsets.UTF_8;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.LinkedList;
import java.util.List;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOExceptionWithCause;
import org.apache.commons.io.IOUtils;
import org.apache.tika.config.TikaConfig;
import org.apache.tika.detect.Detector;
import org.apache.tika.extractor.EmbeddedDocumentUtil;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.metadata.Database;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TikaMetadataKeys;
import org.apache.tika.mime.MimeTypes;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.sax.XHTMLContentHandler;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* General base class to iterate through rows of a JDBC table
*/
class JDBCTableReader {
private final static Attributes EMPTY_ATTRIBUTES = new AttributesImpl();
private final Connection connection;
private final String tableName;
int maxClobLength = 1000000;
ResultSet results = null;
int rows = 0;
private final EmbeddedDocumentUtil embeddedDocumentUtil;
public JDBCTableReader(Connection connection, String tableName, ParseContext context) {
this.connection = connection;
this.tableName = tableName;
embeddedDocumentUtil = new EmbeddedDocumentUtil(context);
}
public boolean nextRow(ContentHandler handler, ParseContext context) throws IOException, SAXException {
//lazy initialization
if (results == null) {
reset();
}
try {
if (!results.next()) {
return false;
}
} catch (SQLException e) {
throw new IOExceptionWithCause(e);
}
try {
ResultSetMetaData meta = results.getMetaData();
handler.startElement(XHTMLContentHandler.XHTML, "tr", "tr", EMPTY_ATTRIBUTES);
for (int i = 1; i <= meta.getColumnCount(); i++) {
handler.startElement(XHTMLContentHandler.XHTML, "td", "td", EMPTY_ATTRIBUTES);
handleCell(meta, i, handler, context);
handler.endElement(XHTMLContentHandler.XHTML, "td", "td");
}
handler.endElement(XHTMLContentHandler.XHTML, "tr", "tr");
} catch (SQLException e) {
throw new IOExceptionWithCause(e);
}
rows++;
return true;
}
private void handleCell(ResultSetMetaData rsmd, int i, ContentHandler handler, ParseContext context) throws SQLException, IOException, SAXException {
switch (rsmd.getColumnType(i)) {
case Types.BLOB:
handleBlob(tableName, rsmd.getColumnName(i), rows, results, i, handler, context);
break;
case Types.CLOB:
handleClob(tableName, rsmd.getColumnName(i), rows, results, i, handler, context);
break;
case Types.BOOLEAN:
handleBoolean(results, i, handler);
break;
case Types.DATE:
handleDate(results, i, handler);
break;
case Types.TIMESTAMP:
handleTimeStamp(results, i, handler);
break;
case Types.INTEGER:
handleInteger(results, i, handler);
break;
case Types.FLOAT:
//this is necessary to handle rounding issues in presentation
//Should we just use getString(i)?
float f = results.getFloat(i);
if (! results.wasNull()) {
addAllCharacters(Float.toString(f), handler);
}
break;
case Types.DOUBLE:
double d = results.getDouble(i);
if (! results.wasNull()) {
addAllCharacters(Double.toString(d), handler);
}
break;
default:
String s = results.getString(i);
if (!results.wasNull()) {
addAllCharacters(s, handler);
}
break;
}
}
public List getHeaders() throws IOException {
List headers = new LinkedList();
//lazy initialization
if (results == null) {
reset();
}
try {
ResultSetMetaData meta = results.getMetaData();
for (int i = 1; i <= meta.getColumnCount(); i++) {
headers.add(meta.getColumnName(i));
}
} catch (SQLException e) {
throw new IOExceptionWithCause(e);
}
return headers;
}
protected void handleInteger(ResultSet rs, int columnIndex, ContentHandler handler) throws SQLException, SAXException {
int i = rs.getInt(columnIndex);
if (! rs.wasNull()) {
addAllCharacters(Integer.toString(i), handler);
}
}
private void handleBoolean(ResultSet rs, int columnIndex, ContentHandler handler) throws SAXException, SQLException {
boolean b = rs.getBoolean(columnIndex);
if (! rs.wasNull()) {
addAllCharacters(Boolean.toString(b), handler);
}
}
protected void handleClob(String tableName, String columnName, int rowNum,
ResultSet resultSet, int columnIndex,
ContentHandler handler, ParseContext context) throws SQLException, IOException, SAXException {
Clob clob = resultSet.getClob(columnIndex);
if (resultSet.wasNull()) {
return;
}
boolean truncated = clob.length() > Integer.MAX_VALUE || clob.length() > maxClobLength;
int readSize = (clob.length() < maxClobLength ? (int) clob.length() : maxClobLength);
Metadata m = new Metadata();
m.set(Database.TABLE_NAME, tableName);
m.set(Database.COLUMN_NAME, columnName);
m.set(Database.PREFIX + "ROW_NUM", Integer.toString(rowNum));
m.set(Database.PREFIX + "IS_CLOB", "true");
m.set(Database.PREFIX + "CLOB_LENGTH", Long.toString(clob.length()));
m.set(Database.PREFIX + "IS_CLOB_TRUNCATED", Boolean.toString(truncated));
m.set(Metadata.CONTENT_TYPE, "text/plain; charset=UTF-8");
m.set(Metadata.CONTENT_LENGTH, Integer.toString(readSize));
m.set(TikaMetadataKeys.RESOURCE_NAME_KEY,
//just in case something screwy is going on with the column name
FilenameUtils.normalize(FilenameUtils.getName(columnName + "_" + rowNum + ".txt")));
//is there a more efficient way to go from a Reader to an InputStream?
String s = clob.getSubString(0, readSize);
if (embeddedDocumentUtil.shouldParseEmbedded(m)) {
embeddedDocumentUtil.parseEmbedded(new ByteArrayInputStream(s.getBytes(UTF_8)), handler, m, true);
}
}
protected void handleBlob(String tableName, String columnName, int rowNum, ResultSet resultSet, int columnIndex,
ContentHandler handler, ParseContext context) throws SQLException, IOException, SAXException {
Metadata m = new Metadata();
m.set(Database.TABLE_NAME, tableName);
m.set(Database.COLUMN_NAME, columnName);
m.set(Database.PREFIX + "ROW_NUM", Integer.toString(rowNum));
m.set(Database.PREFIX + "IS_BLOB", "true");
Blob blob = null;
TikaInputStream is = null;
try {
blob = getBlob(resultSet, columnIndex, m);
if (blob == null) {
return;
}
is = TikaInputStream.get(blob, m);
Attributes attrs = new AttributesImpl();
((AttributesImpl) attrs).addAttribute("", "type", "type", "CDATA", "blob");
((AttributesImpl) attrs).addAttribute("", "column_name", "column_name", "CDATA", columnName);
((AttributesImpl) attrs).addAttribute("", "row_number", "row_number", "CDATA", Integer.toString(rowNum));
handler.startElement("", "span", "span", attrs);
String extension = embeddedDocumentUtil.getExtension(is, m);
m.set(TikaMetadataKeys.RESOURCE_NAME_KEY,
//just in case something screwy is going on with the column name
FilenameUtils.normalize(FilenameUtils.getName(columnName + "_" + rowNum + extension)));
if (embeddedDocumentUtil.shouldParseEmbedded(m)) {
embeddedDocumentUtil.parseEmbedded(is, handler, m, true);
}
} finally {
if (blob != null) {
try {
blob.free();
} catch (SQLException|UnsupportedOperationException e) {
//swallow
}
}
IOUtils.closeQuietly(is);
}
handler.endElement("", "span", "span");
}
/**
*
* @param resultSet result set to grab value from
* @param columnIndex index in result set
* @param metadata metadata to populate or use for each implementation
* @return the blob or null if the value was null
* @throws SQLException
*/
protected Blob getBlob(ResultSet resultSet, int columnIndex, Metadata metadata) throws SQLException {
Blob blob = resultSet.getBlob(columnIndex);
if (! resultSet.wasNull()) {
return blob;
}
return null;
}
protected void handleDate(ResultSet resultSet, int columnIndex, ContentHandler handler) throws SAXException, SQLException {
addAllCharacters(resultSet.getString(columnIndex), handler);
}
protected void handleTimeStamp(ResultSet resultSet, int columnIndex, ContentHandler handler) throws SAXException, SQLException {
addAllCharacters(resultSet.getString(columnIndex), handler);
}
protected void addAllCharacters(String s, ContentHandler handler) throws SAXException {
if (s == null) {
return;
}
char[] chars = s.toCharArray();
handler.characters(chars, 0, chars.length);
}
void reset() throws IOException {
if (results != null) {
try {
results.close();
} catch (SQLException e) {
//swallow
}
}
String sql = "SELECT * from " + tableName;
try {
Statement st = connection.createStatement();
results = st.executeQuery(sql);
} catch (SQLException e) {
throw new IOExceptionWithCause(e);
}
rows = 0;
}
public String getTableName() {
return tableName;
}
protected TikaConfig getTikaConfig() {
return embeddedDocumentUtil.getTikaConfig();
}
protected Detector getDetector() {
return embeddedDocumentUtil.getDetector();
}
protected MimeTypes getMimeTypes() {
return embeddedDocumentUtil.getMimeTypes();
}
}
