/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Apache Cocoon" and "Apache Software Foundation" must not be
used to endorse or promote products derived from this software without
prior written permission. For written permission, please contact
apache@apache.org.
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software consists of voluntary contributions made by many individuals
on behalf of the Apache Software Foundation and was originally created by
Stefano Mazzocchi <stefano@apache.org>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.components.source.impl;
import java.io.ByteArrayInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.Iterator;
import org.apache.avalon.framework.component.ComponentSelector;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.excalibur.datasource.DataSourceComponent;
import org.apache.cocoon.CascadingIOException;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceException;
import org.apache.excalibur.source.SourceValidity;
/**
* A <code>Source</code> that takes its content in a single JDBC column. Any
* kind of column can be used (clob, blob, varchar, etc), but "Blob" means
* that the whole content is contained in a single column.
* <p>The URL syntax is "blob:/datasource/table/column[cond]", where :
* <ul>
* <li>"datasource" is the jdbc datasource to use (defined in cocoon.xonf)
* <li>"table" is the database table,
* <li>"column" is (you can guess, now :) the column in "table",
* <li>"cond" is the boolean condition used to select a particular record in
* the table.
* </ul>
* <p>For example, "<code>blob:/personel/people/photo[userid='foo']</code>"
* will fetch the first column returned by the statement "<code>SELECT photo
* from people where userid='foo'</code>" in the datasource "<code>personel</code>"
*
* @author <a href="mailto:sylvain@apache.org">Sylvain Wallez</a>
* @author <a href="mailto:stephan@apache.org">Stephan Michels</a>
* @version CVS $Id: BlobSource.java,v 1.4 2003/10/25 18:06:20 joerg Exp $
*/
public class BlobSource extends AbstractLogEnabled implements Source, Serviceable {
/** The ServiceManager instance */
private ServiceManager manager = null;
/**
* The system ID for this source
*/
private String systemId;
private String datasourceName;
private String tableName;
private String columnName;
private String condition;
private final static String URL_PREFIX = "blob:/";
private final static int URL_PREFIX_LEN = URL_PREFIX.length();
/**
* Create a file source from a 'blob:' url and a component manager.
* <p>The url is of the form "blob:/datasource/table/column[condition]
*/
public BlobSource(String url) throws MalformedURLException {
this.systemId = url;
// Parse the url
int start = URL_PREFIX_LEN;
int end;
// Datasource
end = url.indexOf('/', start);
if (end == -1) {
throw new MalformedURLException("Malformed blob source (cannot find datasource) : " + url);
}
this.datasourceName = url.substring(start, end);
// Table
start = end + 1;
end = url.indexOf('/', start);
if (end == -1) {
throw new MalformedURLException("Malformed blob source (cannot find table name) : " + url);
}
this.tableName = url.substring(start, end);
// Column
start = end + 1;
end = url.indexOf('[', start);
if (end == -1) {
this.columnName = url.substring(start);
} else {
this.columnName = url.substring(start, end);
// Condition
start = end + 1;
end = url.length() - 1;
if (url.charAt(end) != ']') {
throw new MalformedURLException("Malformed url for a blob source (cannot find condition) : " + url);
} else {
this.condition = url.substring(start, end);
}
}
}
/**
* Set the current <code>ServiceManager</code> instance used by this
* <code>Serviceable</code>.
*/
public void service(ServiceManager manager) {
this.manager = manager;
}
/**
* Return the protocol
*/
public String getScheme() {
return URL_PREFIX;
}
/**
* Return the unique identifer for this source
*/
public String getURI() {
return this.systemId;
}
/**
* Get the input stream for this source.
*/
public InputStream getInputStream() throws IOException, SourceException {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Opening stream for datasource " + this.datasourceName +
", table " + this.tableName + ", column " + this.columnName +
(this.condition == null ? ", no condition" : ", condition " + this.condition)
);
}
Connection cnx = null;
Statement stmt = null;
try {
cnx = getConnection();
stmt = cnx.createStatement();
StringBuffer selectBuf = new StringBuffer("SELECT ").append(this.columnName).
append(" FROM ").append(this.tableName);
if (this.condition != null) {
selectBuf.append(" WHERE ").append(this.condition);
}
String select = selectBuf.toString();
if (getLogger().isDebugEnabled()) {
getLogger().debug("Executing statement " + select);
}
ResultSet rs = stmt.executeQuery(select);
rs.next();
int colType = rs.getMetaData().getColumnType(1);
switch(colType) {
case Types.BLOB :
Blob blob = rs.getBlob(1);
return new JDBCInputStream(blob.getBinaryStream(), cnx);
//break;
case Types.CLOB :
Clob clob = rs.getClob(1);
return new JDBCInputStream(clob.getAsciiStream(), cnx);
//break;
default :
String value = rs.getString(1);
stmt.close();
rs.close();
cnx.close();
return new ByteArrayInputStream(value.getBytes());
}
} catch(SQLException sqle) {
String msg = "Cannot retrieve content from " + this.systemId;
getLogger().error(msg, sqle);
try {
if (cnx != null) {
cnx.close();
}
} catch(SQLException sqle2) {
// PITA
throw new SourceException("Cannot close connection", sqle2);
}
// IOException would be more adequate, but ProcessingException is cascaded...
throw new SourceException(msg, sqle);
}
}
/**
* Get the Validity object. This can either wrap the last modification
* date or the expires information or...
* If it is currently not possible to calculate such an information
* <code>null</code> is returned.
*/
public SourceValidity getValidity() {
return null;
}
/**
* Refresh the content of this object after the underlying data
* content has changed.
*/
public void refresh() {
}
/**
*
* @see org.apache.excalibur.source.Source#exists()
*/
public boolean exists() {
// FIXME
return true;
}
/**
* The mime-type of the content described by this object.
* If the source is not able to determine the mime-type by itself
* this can be <code>null</code>.
*/
public String getMimeType() {
return null;
}
/**
* Return the content length of the content or -1 if the length is
* unknown
*/
public long getContentLength() {
return -1;
}
/**
* Get the last modification date.
* @return The last modification in milliseconds since January 1, 1970 GMT
* or 0 if it is unknown
*/
public long getLastModified() {
return 0;
}
/**
* Get the value of a parameter.
* Using this it is possible to get custom information provided by the
* source implementation, like an expires date, HTTP headers etc.
*/
public String getParameter(String name) {
return null;
}
/**
* Get the value of a parameter.
* Using this it is possible to get custom information provided by the
* source implementation, like an expires date, HTTP headers etc.
*/
public long getParameterAsLong(String name) {
return 0;
}
/**
* Get parameter names
* Using this it is possible to get custom information provided by the
* source implementation, like an expires date, HTTP headers etc.
*/
public Iterator getParameterNames() {
return new EmptyIterator();
}
class EmptyIterator implements Iterator {
public boolean hasNext() { return false; }
public Object next() { return null; }
public void remove() {}
}
private Connection getConnection() throws SourceException {
ComponentSelector selector = null;
DataSourceComponent datasource = null;
try {
try {
selector = (ComponentSelector)this.manager.lookup(DataSourceComponent.ROLE + "Selector");
datasource = (DataSourceComponent)selector.select(this.datasourceName);
} catch(Exception e) {
String msg = "Cannot get datasource '" + this.datasourceName + "'";
getLogger().error(msg);
throw new SourceException(msg, e);
}
try {
return datasource.getConnection();
} catch(Exception e) {
String msg = "Cannot get connection for datasource '" + this .datasourceName + "'";
getLogger().error(msg);
throw new SourceException(msg, e);
}
} finally {
if (datasource != null) {
selector.release(datasource);
}
}
}
/**
* An OutputStream that will close the connection that created it on
* close.
*/
private class JDBCInputStream extends FilterInputStream {
Connection cnx;
private final void closeCnx() throws IOException {
if (this.cnx != null) {
try {
Connection tmp = cnx;
cnx = null;
tmp.close();
} catch(Exception e) {
String msg = "Error closing the connection for " + BlobSource.this.getURI();
BlobSource.this.getLogger().warn(msg, e);
throw new CascadingIOException(msg + " : " + e.getMessage(), e);
}
}
}
public JDBCInputStream(InputStream stream, Connection cnx) {
super(stream);
this.cnx = cnx;
}
public int read() throws IOException {
try {
int result = in.read();
if (result == -1) {
closeCnx();
}
return result;
} catch(IOException e) {
closeCnx();
throw e;
}
}
public int read(byte[] b) throws IOException {
try {
int result = in.read(b);
if (result == -1) {
closeCnx();
}
return result;
} catch(IOException e) {
closeCnx();
throw e;
}
}
public int read(byte[] b, int off, int len) throws IOException {
try {
int result = in.read(b, off, len);
if (result == -1) {
closeCnx();
}
return result;
} catch(IOException e) {
closeCnx();
throw e;
}
}
public void close() throws IOException {
super.close();
closeCnx();
}
}
}