You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@openjpa.apache.org by Boblitz John <jo...@bertschi.com> on 2014/07/01 08:34:22 UTC

RE: Postgres HStore implementation

Thanks Chris!

The part I was missing was the Annotation - I had almost completed a custom implementation, but this works well now.

FWIW:  With the latest jdbc4 driver from Postgres, a lot of the legwork is no longer needed.

I'll do a write up of my solution and post it to the group - maybe it will help someone else.

Cheers,

John

> -----Original Message-----
> From: Krzysztof [mailto:yazuna@gmail.com]
> Sent: Montag, 30. Juni 2014 15:49
> To: users@openjpa.apache.org
> Subject: Re: Postgres HStore implementation
> 
> You'd need jdbc mapper for hstore (might be included in newer jdbc drivers),
> I use this one:
> 
> 
> /*-----------------------------------------------------------------------------
>  *
>  *                      Gaia CU7 variability
>  *
>  *         Copyright (C) 2005-2020 Gaia Data Processing and Analysis
> Consortium
>  *
>  *
>  * CU7 variability software is free software; you can redistribute it and/or
>  * modify it under the terms of the GNU Lesser General Public
>  * License as published by the Free Software Foundation; either
>  * version 2.1 of the License, or (at your option) any later version.
>  *
>  * CU7 variability software is distributed in the hope that it will be useful,
>  * but WITHOUT ANY WARRANTY; without even the implied warranty of
>  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>  * Lesser General Public License for more details.
>  *
>  * You should have received a copy of the GNU Lesser General Public
>  * License along with this CU7 variability software; if not, write to the
>  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
>  * MA  02110-1301  USA
>  *
> 
> *-----------------------------------------------------------------------------
>  */
> package gaia.cu7.om.dal.dictionary.PGType;
> 
> /*
> 
>  * 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 java.io.Serializable;
> import java.util.Collection;
> import java.util.Iterator;
> import java.util.LinkedHashMap;
> import java.util.Map;
> import java.util.Set;
> 
> import org.postgresql.util.PGobject;
> import org.postgresql.util.PSQLException;
> import org.postgresql.util.PSQLState;
> 
> /**
>  * Class that handles hstore contrib datatype.
>  * In PG JDBC uses non-standard PGObject interface instead of SQLData
>  *
>  * @author knienart inspired by Petr Jelinek
>  * @version $Id: PGhstore.java 319537 2013-10-08 20:49:15Z knienart $
>  * @since 10.0
>  */
> @SuppressWarnings("rawtypes")
> public class PGhstore extends PGobject implements Serializable, Cloneable,
> Map {
> 
> 	private final static long serialVersionUID = 1;
> 	private Map hashList;
> 
> 	public PGhstore() {
> 		setType("hstore");
> 	}
> 
> 	public PGhstore(String value) throws java.sql.SQLException {
> 		this();
> 		setValue(value);
> 	}
> 
> 	@SuppressWarnings("unchecked")
> 	public PGhstore(Map value) {
> 		this();
> 		hashList = new LinkedHashMap(value);
> 	}
> 
> 	@SuppressWarnings("unchecked")
> 	@Override
> 	public void setValue(String s) throws java.sql.SQLException {
> 		hashList = new LinkedHashMap();
> 
> 		if (s != null) {
> 			char[] chars = s.toCharArray();
> 			String key = null;
> 			StringBuffer buffer = new StringBuffer();
> 			boolean insideKey = true;
> 			boolean insideVal = false;
> 			boolean insideString = false;
> 
> 			for (int i = 0; i < chars.length; i++) {
> 				// escape character that we need to skip
> 				if (chars[i] == '\\') {
> 					i++;
> 				}
> 
> 				// white space
> 				else if (!insideString &&
> Character.isWhitespace(chars[i])) {
> 					continue;
> 				}
> 
> 				// the => between key and value
> 				else if (!insideString && chars[i] == '=') {
> 					i++;
> 					if (i == chars.length)
> 						throw new
> PSQLException("Unexpected end of string", PSQLState.DATA_ERROR);
> 
> 					if (!insideKey || chars[i] != '>')
> 						throw new
> PSQLException("Syntax error at position " + i, PSQLState.DATA_ERROR);
> 
> 					insideKey = false;
> 					insideVal = true;
> 
> 					key = buffer.toString();
> 					buffer.setLength(0);
> 
> 					continue;
> 				}
> 
> 				// quote, item separator or end of string
> 				else if (chars[i] == '"' || (!insideString &&
> chars[i] == ',') || i == chars.length - 1) {
> 					if (chars[i] == '"') {
> 						insideString = !insideString;
> 						if (i != chars.length - 1)
> 							continue;
> 					} else if (chars[i] != ',' && buffer !=
> null) {
> 						buffer.append(chars[i]);
> 					}
> 
> 					String b = (buffer == null) ? null :
> buffer.toString();
> 
> 					// end of element, add it to list
> 					if (b != null && (b.length() > 0 ||
> insideVal)) {
> 						hashList.put(key,
> b.equalsIgnoreCase("NULL") ? null : b);
> 					}
> 
> 					insideKey = true;
> 					insideVal = false;
> 					buffer = new StringBuffer();
> 
> 					continue;
> 				}
> 
> 				if (buffer != null)
> 					buffer.append(chars[i]);
> 			}
> 		}
> 	}
> 
> 	@Override
> 	public String getValue() {
> 		if (hashList == null)
> 			return null;
> 
> 		Iterator iter = hashList.entrySet().iterator();
> 		if (!iter.hasNext())
> 			return null;
> 
> 		Entry e = (Entry) iter.next();
> 		StringBuffer buffer = new StringBuffer();
> 		appendEntry(buffer, e);
> 
> 		while (iter.hasNext()) {
> 			e = (Entry) iter.next();
> 			buffer.append(',');
> 			appendEntry(buffer, e);
> 		}
> 
> 		return buffer.toString();
> 	}
> 
> 	private void appendEntry(StringBuffer buf, Entry e) {
> 		appendValue(buf, e.getKey(), true);
> 		buf.append("=>");
> 		appendValue(buf, e.getValue(), false);
> 	}
> 
> 	private void appendValue(StringBuffer buf, Object v, boolean isKey)
> {
> 		if (v == null) {
> 			if (isKey)
> 				buf.append("\"NULL\"");
> 			else
> 				buf.append("NULL");
> 			return;
> 		}
> 
> 		String s = v.toString();
> 
> 		buf.append('"');
> 		for (int i = 0; i < s.length(); i++) {
> 			char c = s.charAt(i);
> 			if (c == '"' || c == '\\')
> 				buf.append('\\');
> 			buf.append(c);
> 		}
> 		buf.append('"');
> 	}
> 
> 	public Collection values() {
> 		return hashList.values();
> 	}
> 
> 	public int size() {
> 		return hashList.size();
> 	}
> 
> 	public Object remove(Object key) {
> 		return hashList.remove(key);
> 	}
> 
> 	@SuppressWarnings("unchecked")
> 	public void putAll(Map m) {
> 		hashList.putAll(m);
> 	}
> 
> 	@SuppressWarnings("unchecked")
> 	public Object put(Object key, Object value) {
> 		return hashList.put(key, value);
> 	}
> 
> 	public Set keySet() {
> 		return hashList.keySet();
> 	}
> 
> 	public boolean isEmpty() {
> 		return hashList.isEmpty();
> 	}
> 
> 	public Set entrySet() {
> 		return hashList.entrySet();
> 	}
> 
> 	public boolean containsKey(Object key) {
> 		return hashList.containsKey(key);
> 	}
> 
> 	public Object get(Object key) {
> 		return hashList.get(key);
> 	}
> 
> 	public boolean containsValue(Object value) {
> 		return hashList.containsValue(value);
> 	}
> 
> 	public void clear() {
> 		hashList.clear();
> 	}
> 
> }
> 
> 
> //end of pghstore
> 
> add it to jdbc properties:
> jdbc://yourjdbcURL?datatype.hstore=gaia.cu7.om.dal.dictionary.PGType.PG
> hstore
> 
> 
> define the strategy:
> import gaia.cu7.om.dal.dictionary.PGType.PGhstore;
> 
> import java.sql.Types;
> import java.util.HashMap;
> import java.util.Map;
> 
> import org.apache.openjpa.jdbc.identifier.DBIdentifier;
> import org.apache.openjpa.jdbc.kernel.JDBCStore;
> import org.apache.openjpa.jdbc.meta.JavaSQLTypes;
> import org.apache.openjpa.jdbc.meta.ValueMapping;
> import org.apache.openjpa.jdbc.meta.strats.AbstractValueHandler;
> import org.apache.openjpa.jdbc.schema.Column;
> import org.apache.openjpa.jdbc.schema.ColumnIO;
> import org.apache.openjpa.jdbc.sql.DBDictionary;
> import org.apache.openjpa.util.InternalException;
> 
> /**
>  * Base class for PG hstore value handlers.
>  *
>  * @author knienart
>  * @version $Id: HStoreValueHandler.java 359484 2014-04-08 13:57:13Z
> knienart $
>  * @since 10.0
>  */
> @SuppressWarnings("serial")
> public class HStoreValueHandler
>     extends AbstractValueHandler {
>     private static final String dbTypeName = "hstore";
>     private static final int javaSQLType = JavaSQLTypes.PC;
>     private static final int jdbcType = Types.OTHER;
>     private static final int storeSize = -1;
> 
>     public Column[] map(ValueMapping vm, String name, ColumnIO io,
>         boolean adapt) {
>         DBDictionary dict = vm.getMappingRepository().getDBDictionary();
>         DBIdentifier colName = DBIdentifier.newColumn(name, dict != null ?
> dict.delimitAll() : false);
>         return map(vm, colName, io, adapt);
>     }
> 
>     public Column[] map(ValueMapping vm, DBIdentifier name, ColumnIO io,
>         boolean adapt) {
>         Column col = new Column();
>         col.setIdentifier(name);
>         col.setJavaType(javaSQLType);
>         col.setSize(storeSize);
>         col.setTypeIdentifier(DBIdentifier.newColumnDefinition(dbTypeName));
>         col.setType(jdbcType);
> 
>         return new Column[]{ col };
>     }
> 
>     public Object toDataStoreValue(ValueMapping vm, Object val,
>         JDBCStore store) {
>         // check for null value.
>         if (val == null)
>             return null;
>         	if(!(val instanceof Map))
>         		throw new InternalException("Wrong type - not a map but "
> + val.getClass().getCanonicalName());
>         	if(((Map)val).isEmpty())return null;
>         	PGhstore result = new PGhstore((Map)val);
>         	return result;
> 
>     }
> 
>     public Object toObjectValue(ValueMapping vm, Object val) {
>         // check for null value.
>         if (val == null)
>             return null;
>         try {
>             /**get the object/string and marshall it into the map<key,value>
>              * We could use PGObject mapping here but initialization in JPA is
> problematic
>              */
>         	if(!(val instanceof HashMap))
>         		throw new InternalException("Wrong type - not a HashMap
> but " + val.getClass().getCanonicalName());
> 
>         	return (Map) val;
>         }
>         catch (Exception e) {
>         	e.printStackTrace();
>             throw new InternalException(e);
>         }
>     }
> }
> 
> and use it like this i.e.:
> 
> 	@PersistentMap(fetch=FetchType.EAGER )
> 	@Strategy ("gaia.cu7.om.dal.dictionary.HStoreValueHandler")
> 	protected Map<String, String> otherStringParameters = new
> HashMap<String,
> String>();
> 
> cheers
> Chris
> 
> 
> 
> Boblitz John wrote
> > Hello,
> >
> > I'm trying to get the Postgres HStore type to work and play nice in
> > openJPA 2.3 and I've hit a wall ...
> >
> > Are there any examples around / has anyone done this before and would
> > be willing to share?`
> >
> > Thanks & Best Regards,
> >
> > John
> 
> 
> 
> 
> 
> --
> View this message in context:
> http://openjpa.208410.n2.nabble.com/Postgres-HStore-implementation-
> tp7586887p7586890.html
> Sent from the OpenJPA Users mailing list archive at Nabble.com.

Re: Postgres HStore implementation

Posted by Kevin Sutter <kw...@gmail.com>.
Thanks, John.  That write-up would be helpful.

Thanks,
Kevin


On Tue, Jul 1, 2014 at 1:34 AM, Boblitz John <jo...@bertschi.com>
wrote:

> Thanks Chris!
>
> The part I was missing was the Annotation - I had almost completed a
> custom implementation, but this works well now.
>
> FWIW:  With the latest jdbc4 driver from Postgres, a lot of the legwork is
> no longer needed.
>
> I'll do a write up of my solution and post it to the group - maybe it will
> help someone else.
>
> Cheers,
>
> John
>
> > -----Original Message-----
> > From: Krzysztof [mailto:yazuna@gmail.com]
> > Sent: Montag, 30. Juni 2014 15:49
> > To: users@openjpa.apache.org
> > Subject: Re: Postgres HStore implementation
> >
> > You'd need jdbc mapper for hstore (might be included in newer jdbc
> drivers),
> > I use this one:
> >
> >
> >
> /*-----------------------------------------------------------------------------
> >  *
> >  *                      Gaia CU7 variability
> >  *
> >  *         Copyright (C) 2005-2020 Gaia Data Processing and Analysis
> > Consortium
> >  *
> >  *
> >  * CU7 variability software is free software; you can redistribute it
> and/or
> >  * modify it under the terms of the GNU Lesser General Public
> >  * License as published by the Free Software Foundation; either
> >  * version 2.1 of the License, or (at your option) any later version.
> >  *
> >  * CU7 variability software is distributed in the hope that it will be
> useful,
> >  * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> >  * Lesser General Public License for more details.
> >  *
> >  * You should have received a copy of the GNU Lesser General Public
> >  * License along with this CU7 variability software; if not, write to the
> >  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
> Boston,
> >  * MA  02110-1301  USA
> >  *
> >
> >
> *-----------------------------------------------------------------------------
> >  */
> > package gaia.cu7.om.dal.dictionary.PGType;
> >
> > /*
> >
> >  * 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 java.io.Serializable;
> > import java.util.Collection;
> > import java.util.Iterator;
> > import java.util.LinkedHashMap;
> > import java.util.Map;
> > import java.util.Set;
> >
> > import org.postgresql.util.PGobject;
> > import org.postgresql.util.PSQLException;
> > import org.postgresql.util.PSQLState;
> >
> > /**
> >  * Class that handles hstore contrib datatype.
> >  * In PG JDBC uses non-standard PGObject interface instead of SQLData
> >  *
> >  * @author knienart inspired by Petr Jelinek
> >  * @version $Id: PGhstore.java 319537 2013-10-08 20:49:15Z knienart $
> >  * @since 10.0
> >  */
> > @SuppressWarnings("rawtypes")
> > public class PGhstore extends PGobject implements Serializable,
> Cloneable,
> > Map {
> >
> >       private final static long serialVersionUID = 1;
> >       private Map hashList;
> >
> >       public PGhstore() {
> >               setType("hstore");
> >       }
> >
> >       public PGhstore(String value) throws java.sql.SQLException {
> >               this();
> >               setValue(value);
> >       }
> >
> >       @SuppressWarnings("unchecked")
> >       public PGhstore(Map value) {
> >               this();
> >               hashList = new LinkedHashMap(value);
> >       }
> >
> >       @SuppressWarnings("unchecked")
> >       @Override
> >       public void setValue(String s) throws java.sql.SQLException {
> >               hashList = new LinkedHashMap();
> >
> >               if (s != null) {
> >                       char[] chars = s.toCharArray();
> >                       String key = null;
> >                       StringBuffer buffer = new StringBuffer();
> >                       boolean insideKey = true;
> >                       boolean insideVal = false;
> >                       boolean insideString = false;
> >
> >                       for (int i = 0; i < chars.length; i++) {
> >                               // escape character that we need to skip
> >                               if (chars[i] == '\\') {
> >                                       i++;
> >                               }
> >
> >                               // white space
> >                               else if (!insideString &&
> > Character.isWhitespace(chars[i])) {
> >                                       continue;
> >                               }
> >
> >                               // the => between key and value
> >                               else if (!insideString && chars[i] == '=')
> {
> >                                       i++;
> >                                       if (i == chars.length)
> >                                               throw new
> > PSQLException("Unexpected end of string", PSQLState.DATA_ERROR);
> >
> >                                       if (!insideKey || chars[i] != '>')
> >                                               throw new
> > PSQLException("Syntax error at position " + i, PSQLState.DATA_ERROR);
> >
> >                                       insideKey = false;
> >                                       insideVal = true;
> >
> >                                       key = buffer.toString();
> >                                       buffer.setLength(0);
> >
> >                                       continue;
> >                               }
> >
> >                               // quote, item separator or end of string
> >                               else if (chars[i] == '"' || (!insideString
> &&
> > chars[i] == ',') || i == chars.length - 1) {
> >                                       if (chars[i] == '"') {
> >                                               insideString =
> !insideString;
> >                                               if (i != chars.length - 1)
> >                                                       continue;
> >                                       } else if (chars[i] != ',' &&
> buffer !=
> > null) {
> >                                               buffer.append(chars[i]);
> >                                       }
> >
> >                                       String b = (buffer == null) ? null
> :
> > buffer.toString();
> >
> >                                       // end of element, add it to list
> >                                       if (b != null && (b.length() > 0 ||
> > insideVal)) {
> >                                               hashList.put(key,
> > b.equalsIgnoreCase("NULL") ? null : b);
> >                                       }
> >
> >                                       insideKey = true;
> >                                       insideVal = false;
> >                                       buffer = new StringBuffer();
> >
> >                                       continue;
> >                               }
> >
> >                               if (buffer != null)
> >                                       buffer.append(chars[i]);
> >                       }
> >               }
> >       }
> >
> >       @Override
> >       public String getValue() {
> >               if (hashList == null)
> >                       return null;
> >
> >               Iterator iter = hashList.entrySet().iterator();
> >               if (!iter.hasNext())
> >                       return null;
> >
> >               Entry e = (Entry) iter.next();
> >               StringBuffer buffer = new StringBuffer();
> >               appendEntry(buffer, e);
> >
> >               while (iter.hasNext()) {
> >                       e = (Entry) iter.next();
> >                       buffer.append(',');
> >                       appendEntry(buffer, e);
> >               }
> >
> >               return buffer.toString();
> >       }
> >
> >       private void appendEntry(StringBuffer buf, Entry e) {
> >               appendValue(buf, e.getKey(), true);
> >               buf.append("=>");
> >               appendValue(buf, e.getValue(), false);
> >       }
> >
> >       private void appendValue(StringBuffer buf, Object v, boolean isKey)
> > {
> >               if (v == null) {
> >                       if (isKey)
> >                               buf.append("\"NULL\"");
> >                       else
> >                               buf.append("NULL");
> >                       return;
> >               }
> >
> >               String s = v.toString();
> >
> >               buf.append('"');
> >               for (int i = 0; i < s.length(); i++) {
> >                       char c = s.charAt(i);
> >                       if (c == '"' || c == '\\')
> >                               buf.append('\\');
> >                       buf.append(c);
> >               }
> >               buf.append('"');
> >       }
> >
> >       public Collection values() {
> >               return hashList.values();
> >       }
> >
> >       public int size() {
> >               return hashList.size();
> >       }
> >
> >       public Object remove(Object key) {
> >               return hashList.remove(key);
> >       }
> >
> >       @SuppressWarnings("unchecked")
> >       public void putAll(Map m) {
> >               hashList.putAll(m);
> >       }
> >
> >       @SuppressWarnings("unchecked")
> >       public Object put(Object key, Object value) {
> >               return hashList.put(key, value);
> >       }
> >
> >       public Set keySet() {
> >               return hashList.keySet();
> >       }
> >
> >       public boolean isEmpty() {
> >               return hashList.isEmpty();
> >       }
> >
> >       public Set entrySet() {
> >               return hashList.entrySet();
> >       }
> >
> >       public boolean containsKey(Object key) {
> >               return hashList.containsKey(key);
> >       }
> >
> >       public Object get(Object key) {
> >               return hashList.get(key);
> >       }
> >
> >       public boolean containsValue(Object value) {
> >               return hashList.containsValue(value);
> >       }
> >
> >       public void clear() {
> >               hashList.clear();
> >       }
> >
> > }
> >
> >
> > //end of pghstore
> >
> > add it to jdbc properties:
> > jdbc://yourjdbcURL?datatype.hstore=gaia.cu7.om.dal.dictionary.PGType.PG
> > hstore
> >
> >
> > define the strategy:
> > import gaia.cu7.om.dal.dictionary.PGType.PGhstore;
> >
> > import java.sql.Types;
> > import java.util.HashMap;
> > import java.util.Map;
> >
> > import org.apache.openjpa.jdbc.identifier.DBIdentifier;
> > import org.apache.openjpa.jdbc.kernel.JDBCStore;
> > import org.apache.openjpa.jdbc.meta.JavaSQLTypes;
> > import org.apache.openjpa.jdbc.meta.ValueMapping;
> > import org.apache.openjpa.jdbc.meta.strats.AbstractValueHandler;
> > import org.apache.openjpa.jdbc.schema.Column;
> > import org.apache.openjpa.jdbc.schema.ColumnIO;
> > import org.apache.openjpa.jdbc.sql.DBDictionary;
> > import org.apache.openjpa.util.InternalException;
> >
> > /**
> >  * Base class for PG hstore value handlers.
> >  *
> >  * @author knienart
> >  * @version $Id: HStoreValueHandler.java 359484 2014-04-08 13:57:13Z
> > knienart $
> >  * @since 10.0
> >  */
> > @SuppressWarnings("serial")
> > public class HStoreValueHandler
> >     extends AbstractValueHandler {
> >     private static final String dbTypeName = "hstore";
> >     private static final int javaSQLType = JavaSQLTypes.PC;
> >     private static final int jdbcType = Types.OTHER;
> >     private static final int storeSize = -1;
> >
> >     public Column[] map(ValueMapping vm, String name, ColumnIO io,
> >         boolean adapt) {
> >         DBDictionary dict = vm.getMappingRepository().getDBDictionary();
> >         DBIdentifier colName = DBIdentifier.newColumn(name, dict != null
> ?
> > dict.delimitAll() : false);
> >         return map(vm, colName, io, adapt);
> >     }
> >
> >     public Column[] map(ValueMapping vm, DBIdentifier name, ColumnIO io,
> >         boolean adapt) {
> >         Column col = new Column();
> >         col.setIdentifier(name);
> >         col.setJavaType(javaSQLType);
> >         col.setSize(storeSize);
> >
> col.setTypeIdentifier(DBIdentifier.newColumnDefinition(dbTypeName));
> >         col.setType(jdbcType);
> >
> >         return new Column[]{ col };
> >     }
> >
> >     public Object toDataStoreValue(ValueMapping vm, Object val,
> >         JDBCStore store) {
> >         // check for null value.
> >         if (val == null)
> >             return null;
> >               if(!(val instanceof Map))
> >                       throw new InternalException("Wrong type - not a
> map but "
> > + val.getClass().getCanonicalName());
> >               if(((Map)val).isEmpty())return null;
> >               PGhstore result = new PGhstore((Map)val);
> >               return result;
> >
> >     }
> >
> >     public Object toObjectValue(ValueMapping vm, Object val) {
> >         // check for null value.
> >         if (val == null)
> >             return null;
> >         try {
> >             /**get the object/string and marshall it into the
> map<key,value>
> >              * We could use PGObject mapping here but initialization in
> JPA is
> > problematic
> >              */
> >               if(!(val instanceof HashMap))
> >                       throw new InternalException("Wrong type - not a
> HashMap
> > but " + val.getClass().getCanonicalName());
> >
> >               return (Map) val;
> >         }
> >         catch (Exception e) {
> >               e.printStackTrace();
> >             throw new InternalException(e);
> >         }
> >     }
> > }
> >
> > and use it like this i.e.:
> >
> >       @PersistentMap(fetch=FetchType.EAGER )
> >       @Strategy ("gaia.cu7.om.dal.dictionary.HStoreValueHandler")
> >       protected Map<String, String> otherStringParameters = new
> > HashMap<String,
> > String>();
> >
> > cheers
> > Chris
> >
> >
> >
> > Boblitz John wrote
> > > Hello,
> > >
> > > I'm trying to get the Postgres HStore type to work and play nice in
> > > openJPA 2.3 and I've hit a wall ...
> > >
> > > Are there any examples around / has anyone done this before and would
> > > be willing to share?`
> > >
> > > Thanks & Best Regards,
> > >
> > > John
> >
> >
> >
> >
> >
> > --
> > View this message in context:
> > http://openjpa.208410.n2.nabble.com/Postgres-HStore-implementation-
> > tp7586887p7586890.html
> > Sent from the OpenJPA Users mailing list archive at Nabble.com.
>