geometrytype.java

postGIS是一个能够使用postSQL数据库来管理GIS数据的小程序,充分发挥了该数据库的空间管理功能,非常有用哦

/*
 * GeometryType.java
 * 
 * PostGIS extension for PostgreSQL JDBC driver - EJB3 Tutorial
 * 
 * (C) 2006  Norman Barker <[e-mail]>
 * 
 * This library 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.
 * 
 * This library 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 library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA or visit the web at
 * http://www.gnu.org.
 * 
 * $Id: GeometryType.java 2531 2006-11-22 10:42:17Z mschaber $
 */
package org.postgis.hibernate;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.Serializable;
import java.sql.Blob;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

import org.hibernate.HibernateException;
import org.hibernate.usertype.UserType;
import java.io.InputStream;
import org.postgis.Geometry;
import org.postgis.binary.BinaryParser;
import org.postgis.binary.BinaryWriter;

/**
 * @author nbarker $date 16/8/06
 */
public class GeometryType implements UserType {
	 private static final int[] SQL_TYPES = { Types.BLOB };
	

	/**
	 * @see org.hibernate.usertype.UserType#deepCopy(java.lang.Object)
	 */
	public Object deepCopy(Object value) throws HibernateException {
		return value;
	}

	/**
	 * @see org.hibernate.usertype.UserType#equals(java.lang.Object, java.lang.Object)
	 */
	public boolean equals(Object x, Object y) throws HibernateException {
		if (x == y) {
			return true;
		} else if (x == null || y == null) {
			return false;
		} else {
			return x.equals(y);
		}
	}

	/**
	 * @see org.hibernate.usertype.UserType#hashCode(java.lang.Object)
	 */
	public int hashCode(Object arg0) throws HibernateException {
		// TODO Auto-generated method stub
		return 0;
	}

	/**
	 * @see org.hibernate.usertype.UserType#isMutable()
	 */
	public boolean isMutable() {
		return false;
	}

	/**)
	 * @see org.hibernate.usertype.UserType#nullSafeGet(java.sql.ResultSet, java.lang.String[], java.lang.Object)
	 */
	public Object nullSafeGet(ResultSet resultSet, 
		      String[] names, Object owner) throws HibernateException, SQLException {
        Geometry result = null;
        String geom = resultSet.getString(names[0]);
        if(geom != null ) {
            BinaryParser parser = new BinaryParser();
            result = parser.parse(geom);
        }
        return result;
	}

	/**
	 * @see org.hibernate.usertype.UserType#nullSafeSet(java.sql.PreparedStatement, java.lang.Object, int)
	 */
	public void nullSafeSet(PreparedStatement statement, 
		      Object value, int index) throws HibernateException, SQLException {
	    if (value == null) {
	        statement.setBytes(index, null);
	      } else {
	    	BinaryWriter bw = new BinaryWriter();
	    	
	    	byte[] bytes = bw.writeBinary((Geometry)value);
	        statement.setBytes(index, bytes);
	      }
	}

	/* (non-Javadoc)
	 * @see org.hibernate.usertype.UserType#replace(java.lang.Object, java.lang.Object, java.lang.Object)
	 */
	public Object replace(Object original, Object target, 
                              Object owner) throws HibernateException {
		return original;	
	}

	/* (non-Javadoc)
	 * @see org.hibernate.usertype.UserType#returnedClass()
	 */
	public Class returnedClass() {
		return Geometry.class;
	}

	/**
	 * @see org.hibernate.usertype.UserType#sqlTypes()
	 */
	public int[] sqlTypes() {
		return GeometryType.SQL_TYPES;
	}

	/**
	 * @see org.hibernate.usertype.UserType#assemble(java.io.Serializable, java.lang.Object)
	 */
	public Object assemble(Serializable cached, Object owner) throws HibernateException {
		return cached;
	}
	
	/**
	 * @see org.hibernate.usertype.UserType#disassemble(java.lang.Object)
	 */
	public Serializable disassemble(Object value) throws HibernateException {
		return (Serializable)value;
	}

}