RELEASE_2_1_13/src/blocks/databases/java/org/apache/cocoon/components/source/impl/BlobSource.java - cocoon - Git at Google

 /*
  * 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 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.excalibur.datasource.DataSourceComponent;
 import org.apache.avalon.framework.logger.AbstractLogEnabled;
 import org.apache.avalon.framework.service.ServiceManager;
 import org.apache.avalon.framework.service.ServiceSelector;
 import org.apache.avalon.framework.service.Serviceable;
 import org.apache.excalibur.source.Source;
 import org.apache.excalibur.source.SourceException;
 import org.apache.excalibur.source.SourceNotFoundException;
 import org.apache.excalibur.source.SourceValidity;

 import org.apache.cocoon.CascadingIOException;

 /**
  * 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 $Id$
  */
 public class BlobSource extends AbstractLogEnabled
                         implements Source, Serviceable {

     private static final String URL_PREFIX = "blob:/";
     private static final int URL_PREFIX_LEN = URL_PREFIX.length();

     /** The ServiceManager instance */
     private ServiceManager manager;

     /** The system ID for this source */
     private String systemId;

     private String datasourceName;

     private String tableName;

     private String columnName;

     private String condition;

     /**
      * 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;

         // Datasource
         int 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 conn = null;
         Statement stmt = null;
         try {
             conn = getConnection();
             stmt = conn.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);
             if (!rs.next()) {
                 throw new SourceNotFoundException("Source not found.");
             }

             int colType = rs.getMetaData().getColumnType(1);
             switch(colType) {
                 case Types.BLOB :
                     Blob blob = rs.getBlob(1);
                     if (blob != null) {
                         return new JDBCInputStream(blob.getBinaryStream(), conn);
                     }
                     break;

                 case Types.CLOB :
                     Clob clob = rs.getClob(1);
                     if (clob != null) {
                         return new JDBCInputStream(clob.getAsciiStream(), conn);
                     }
                     break;

                 default :
                     String value = rs.getString(1);
                     if (value != null) {
                         return new ByteArrayInputStream(value.getBytes());
                     }
             }

             return new ByteArrayInputStream(new byte[0]);
         } catch (SQLException e) {
             String msg = "Cannot retrieve content from " + this.systemId;
             getLogger().error(msg, e);
             // IOException would be more adequate, but SourceException is cascaded...
             throw new SourceException(msg, e);
         } finally {
             try {
                 if (stmt != null) {
                     stmt.close();
                 }
             } catch (SQLException e) { /* ignored */ }
             try {
                 if (conn != null) {
                     conn.close();
                 }
             } catch (SQLException e) { /* ignored */ }
         }
     }

     /**
      *  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();
     }

     static class EmptyIterator implements Iterator {
         public boolean hasNext() { return false; }
         public Object next() { return null; }
         public void remove() {}
     }

     private Connection getConnection() throws SourceException {

         ServiceSelector selector = null;
         DataSourceComponent datasource = null;

         try {
             try {
                 selector = (ServiceSelector)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 {

         private Connection cnx;

         private void closeCnx() throws IOException {
             if (this.cnx != null) {
                 try {
                     cnx.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);
                 } finally {
                     cnx = null;
                 }
             }
         }

         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();
         }
     }
 }
	/*
	* 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 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.excalibur.datasource.DataSourceComponent;
	import org.apache.avalon.framework.logger.AbstractLogEnabled;
	import org.apache.avalon.framework.service.ServiceManager;
	import org.apache.avalon.framework.service.ServiceSelector;
	import org.apache.avalon.framework.service.Serviceable;
	import org.apache.excalibur.source.Source;
	import org.apache.excalibur.source.SourceException;
	import org.apache.excalibur.source.SourceNotFoundException;
	import org.apache.excalibur.source.SourceValidity;

	import org.apache.cocoon.CascadingIOException;

	/**
	* 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 $Id$
	*/
	public class BlobSource extends AbstractLogEnabled
	implements Source, Serviceable {

	private static final String URL_PREFIX = "blob:/";
	private static final int URL_PREFIX_LEN = URL_PREFIX.length();

	/** The ServiceManager instance */
	private ServiceManager manager;

	/** The system ID for this source */
	private String systemId;

	private String datasourceName;

	private String tableName;

	private String columnName;

	private String condition;

	/**
	* 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;

	// Datasource
	int 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 conn = null;
	Statement stmt = null;
	try {
	conn = getConnection();
	stmt = conn.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);
	if (!rs.next()) {
	throw new SourceNotFoundException("Source not found.");
	}

	int colType = rs.getMetaData().getColumnType(1);
	switch(colType) {
	case Types.BLOB :
	Blob blob = rs.getBlob(1);
	if (blob != null) {
	return new JDBCInputStream(blob.getBinaryStream(), conn);
	}
	break;

	case Types.CLOB :
	Clob clob = rs.getClob(1);
	if (clob != null) {
	return new JDBCInputStream(clob.getAsciiStream(), conn);
	}
	break;

	default :
	String value = rs.getString(1);
	if (value != null) {
	return new ByteArrayInputStream(value.getBytes());
	}
	}

	return new ByteArrayInputStream(new byte[0]);
	} catch (SQLException e) {
	String msg = "Cannot retrieve content from " + this.systemId;
	getLogger().error(msg, e);
	// IOException would be more adequate, but SourceException is cascaded...
	throw new SourceException(msg, e);
	} finally {
	try {
	if (stmt != null) {
	stmt.close();
	}
	} catch (SQLException e) { /* ignored */ }
	try {
	if (conn != null) {
	conn.close();
	}
	} catch (SQLException e) { /* ignored */ }
	}
	}

	/**
	* 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();
	}

	static class EmptyIterator implements Iterator {
	public boolean hasNext() { return false; }
	public Object next() { return null; }
	public void remove() {}
	}

	private Connection getConnection() throws SourceException {

	ServiceSelector selector = null;
	DataSourceComponent datasource = null;

	try {
	try {
	selector = (ServiceSelector)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 {

	private Connection cnx;

	private void closeCnx() throws IOException {
	if (this.cnx != null) {
	try {
	cnx.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);
	} finally {
	cnx = null;
	}
	}
	}

	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();
	}
	}
	}