raimund@1299: /* Copyright (C) 2013 by Bundesamt fuer Strahlenschutz
raimund@1299:  * Software engineering by Intevation GmbH
raimund@1299:  *
raimund@1299:  * This file is Free Software under the GNU GPL (v>=3)
raimund@1299:  * and comes with ABSOLUTELY NO WARRANTY! Check out
raimund@1299:  * the documentation coming with IMIS-Labordaten-Application for details.
raimund@1299:  */
raimund@1299: package de.intevation.lada.util.data;
raimund@1299: 
raimund@1299: import java.io.IOException;
raimund@1299: import java.io.Serializable;
raimund@1299: import java.sql.PreparedStatement;
raimund@1299: import java.sql.ResultSet;
raimund@1299: import java.sql.SQLException;
raimund@1299: import java.sql.Types;
raimund@1299: 
raimund@1299: import org.hibernate.HibernateException;
raimund@1299: import org.hibernate.engine.spi.SessionImplementor;
raimund@1299: import org.hibernate.usertype.UserType;
raimund@1299: 
raimund@1299: import com.fasterxml.jackson.databind.JsonNode;
raimund@1299: import com.fasterxml.jackson.databind.ObjectMapper;
raimund@1299: 
raimund@1299: /**
raimund@1299:  * Implementation for a new data type in the postgresql/postgis jdbc driver.
raimund@1299:  *
raimund@1299:  * @author <a href="mailto:rrenkert@intevation.de">Raimund Renkert</a>
raimund@1299:  */
raimund@1299: public class JsonObjectType implements UserType {
raimund@1299:     /**
raimund@1299:      * Reconstruct an object from the cacheable representation. At the very
raimund@1299:      * least this method should perform a deep copy if the type is mutable.
raimund@1299:      * (optional <span id="IL_AD5" class="IL_AD">operation</span>)
raimund@1299:      *
raimund@1299:      * @param cached
raimund@1299:      *            the object to be cached
raimund@1299:      * @param owner
raimund@1299:      *            the owner of the cached object
raimund@1299:      * @return a reconstructed object from the cachable representation
raimund@1299:      * @throws HibernateException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public Object assemble(Serializable cached, Object owner) throws HibernateException {
raimund@1299:         return this.deepCopy(cached);
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Return a deep copy of the persistent state, stopping at entities and st
raimund@1299:      * collections. It is not necessary to copy immutable objects, or null
raimund@1299:      * values, in which case it is safe to simple return the argument.
raimund@1299:      *
raimund@1299:      * @param value
raimund@1299:      *            the object to be cloned, which may be null
raimund@1299:      *
raimund@1299:      * @return object a copy
raimund@1299:      * @throws HibernateException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public Object deepCopy(Object value) throws HibernateException {
raimund@1299:         return value;
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Transform the object into its cacheable representation. At the very least
raimund@1299:      * this method should perform a deep copy if the type is mutable. That may
raimund@1299:      * not be enough for some implementations, however; for example,
raimund@1299:      * <span id="IL_AD11" class="IL_AD">associations</span> must be cached as <span id="IL_AD9" class="IL_AD">identifier</span> values. (optional operation)
raimund@1299:      *
raimund@1299:      * @param value
raimund@1299:      *            the object to be cached
raimund@1299:      * @return a cachable representation of the object
raimund@1299:      * @throws HibernateException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public Serializable disassemble(Object value) throws HibernateException {
raimund@1299:         return (String) this.deepCopy(value);
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Compare two instances of the class mapped by this type for persistence
raimund@1299:      * "equality". Equality of the persistence state.
raimund@1299:      *
raimund@1299:      * @param x
raimund@1299:      * @param y
raimund@1299:      * @return <span id="IL_AD12" class="IL_AD">boolean</span>
raimund@1299:      * @throws HibernateException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public boolean equals(Object x, Object y) throws HibernateException {
raimund@1299:         if (x == null) {
raimund@1299:             return y == null;
raimund@1299:         }
raimund@1299:         return x.equals(y);
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Get a hashcode for the instance, consistent with persistence "equality".
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public int hashCode(Object x) throws HibernateException {
raimund@1299:         return x.hashCode();
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Are objects of this type mutable?
raimund@1299:      *
raimund@1299:      * @return boolean
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public boolean isMutable() {
raimund@1299:         return true;
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Retrieve an instance of the mapped class from a JDBC resultset.
raimund@1299:      * Implementors should handle possibility of null values.
raimund@1299:      *
raimund@1299:      * @param rs
raimund@1299:      *            a JDBC result set
raimund@1299:      * @param names
raimund@1299:      *            the column names
raimund@1299:      * @param session
raimund@1299:      * @param owner
raimund@1299:      *            the containing entity
raimund@1299:      * @return
raimund@1299:      * @throws HibernateException
raimund@1299:      * @throws SQLException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public Object nullSafeGet(ResultSet rs, String[] names, SessionImplementor session, Object owner) throws HibernateException, SQLException {
raimund@1299:         ObjectMapper mapper = new ObjectMapper();
raimund@1299:         JsonNode node = null;
raimund@1299:         try {
raimund@1299:             node = mapper.readTree(rs.getString(names[0]));
raimund@1299:             return node;
raimund@1299:         } catch (IOException e) {
raimund@1299:             e.printStackTrace();
raimund@1299:         }
raimund@1299:         return mapper.createObjectNode();
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Write an instance of the mapped class to a prepared statement.
raimund@1299:      * Implementors should handle possibility of null values. A multi-column
raimund@1299:      * type should be written to parameters starting from <tt>index</tt>
raimund@1299:      *
raimund@1299:      * @param st
raimund@1299:      *            a JDBC prepared statement
raimund@1299:      * @param value
raimund@1299:      *            the object to write
raimund@1299:      * @param index
raimund@1299:      *            statement parameter index
raimund@1299:      * @param session
raimund@1299:      * @throws HibernateException
raimund@1299:      * @throws SQLException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public void nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session) throws HibernateException, SQLException {
raimund@1299:         if (value == null) {
raimund@1299:             st.setNull(index, Types.OTHER);
raimund@1299:             return;
raimund@1299:         }
raimund@1299:         st.setObject(index, value, Types.OTHER);
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * During merge, <span id="IL_AD7" class="IL_AD">replace</span> the existing (target) values in the entity we are
raimund@1299:      * merging to with a new (original) value from the detched entity we are
raimund@1299:      * merging. For immutable objects, or null values, it is safe to return a
raimund@1299:      * copy of the first parameter. For the objects with component values, it
raimund@1299:      * might make sense to recursively replace component values
raimund@1299:      *
raimund@1299:      * @param original
raimund@1299:      *            the value from the detched entity being merged
raimund@1299:      * @param target
raimund@1299:      *            the value in the managed entity
raimund@1299:      * @param owner
raimund@1299:      * @return the value to be merged
raimund@1299:      * @throws HibernateException
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public Object replace(Object original, Object target, Object owner) throws HibernateException {
raimund@1299:         return original;
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * The class returned by <tt>nullSafeGet()</tt>
raimund@1299:      *
raimund@1299:      * @return Class
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public Class returnedClass() {
raimund@1299:         return String.class;
raimund@1299:     }
raimund@1299: 
raimund@1299:     /**
raimund@1299:      * Returns the SQL type <span id="IL_AD3" class="IL_AD">codes</span> for the columns mapped by this type. The codes
raimund@1299:      * are defined on <tt>java.sql.Types</tt>
raimund@1299:      *
raimund@1299:      * @return int[] the typecodes
raimund@1299:      * @see java.sql.Types
raimund@1299:      */
raimund@1299:     @Override
raimund@1299:     public int[] sqlTypes() {
raimund@1299:         return new int[] { Types.JAVA_OBJECT };
raimund@1299:     }
raimund@1299: }