decimaltypeidimpl.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.catalog.types.DecimalTypeIdImpl

   Copyright 2000, 2004 The Apache Software Foundation or its licensors, as applicable.

   Licensed 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.derby.catalog.types;
import org.apache.derby.iapi.services.io.StoredFormatIds;
import java.io.ObjectOutput;
import java.io.ObjectInput;
import java.io.IOException;
import java.sql.Types;

public class DecimalTypeIdImpl extends BaseTypeIdImpl
{
	/* this class is needed because writeexternal for this class stores
	   extra information; when the object is sent over the wire the niladic
	   constructor is first called and then we call the readExternal method. 
	   the readExternal needs to know the formatId atleast for decimal types
	   to read the extra information.
	*/
	public DecimalTypeIdImpl() 
	{
		super(StoredFormatIds.DECIMAL_TYPE_ID_IMPL);
	}
	
	/**
	 * Read this object from a stream of stored objects.
	 *
	 * @param in read this.
	 *
	 * @exception IOException					thrown on error
	 * @exception ClassNotFoundException		thrown on error
	 */
	public void readExternal( ObjectInput in )
		 throws IOException, ClassNotFoundException
	{
		boolean isNumeric = in.readBoolean();

		super.readExternal(in);

		if (isNumeric)
		{
			setNumericType();
		}

	}

	/**
	 * Write this object to a stream of stored objects.
	 *
	 * @param out write bytes here.
	 *
	 * @exception IOException		thrown on error
	 */
	public void writeExternal( ObjectOutput out )
		 throws IOException
	{
		out.writeBoolean(JDBCTypeId == Types.NUMERIC);

		super.writeExternal(out);
	}

	public void setNumericType()
	{
		SQLTypeName = "NUMERIC";
		JDBCTypeId = Types.NUMERIC;
	}
}