export.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.impl.load.Export

   Copyright 1998, 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.impl.load;

import java.sql.Connection;
import java.sql.ResultSet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.*;    

/**
 * This class provides ways to export data from
 * a table or a view into a file. Export functions provided 
 * in this  class are called through Systement Procedures.  
 */
public class Export extends ExportAbstract{

	private String outputFileName;


	private void doExport() throws SQLException
	{
		try {
			if (entityName == null && selectStatement == null)
				throw LoadError.entityNameMissing();
			
			if (outputFileName == null)
				throw LoadError.dataFileNull();
			try {
				doAllTheWork();
			} catch (IOException iex) {
				//in case of ioexception, catch it and throw it as our own exception
				throw LoadError.errorWritingData();
			}
		} catch (Exception ex) {
			throw LoadError.unexpectedError(ex);
		}

	}
	
	private Export(Connection con, String schemaName , 
					   String tableName, String selectStatement ,
					   String outputFileName, String characterDelimeter,
					   String columnDelimeter, String codeset)
		throws SQLException{
		this.con = con;
		this.schemaName = schemaName;
		this.entityName = tableName;
		this.selectStatement = selectStatement;
		this.outputFileName = outputFileName;
		try{
			controlFileReader = new ControlInfo();
			controlFileReader.setControlProperties(characterDelimeter,
												   columnDelimeter, codeset);
		}catch(Exception ex)
		{
			throw LoadError.unexpectedError(ex);
		}
	}

	/**
	 * SYSCS_EXPORT_TABLE  system Procedure from ij or from a Java application
	 * invokes  this method to perform export of  a table data to a file.
	 * @param con	 The Cloudscape database connection URL for the database containing the table
	 * @param schemaName	schema name of the table data is being exported from
	 * @param tableName     Name of the Table from which  data has to be exported.
	 * @param outputFileName Name of the file to  which data has to be exported.
	 * @param colDelimiter  Delimiter that seperates columns in the output file
	 * @param characterDelimiter  Delimiter that is used to quoate non-numeric types
	 * @param codeset           Codeset that should be used to write  the data to  the file
 	 * @exception SQL Exception on errors
	 */

	public static void exportTable(Connection con, String schemaName, 
                              String tableName, String outputFileName,  
							  String columnDelimeter, String characterDelimeter,
							  String codeset)
		throws SQLException {
		
		Export fex = new Export(con, schemaName, tableName, null,
										outputFileName,	characterDelimeter,   
										columnDelimeter, codeset);

		fex.doExport();
	}

	
	/**
	 * SYSCS_EXPORT_QUERY  system Procedure from ij or from a Java application
	 * invokes  this method to perform export of the data retrieved by select statement to a file.
	 * @param con	 The Cloudscape database connection URL for the database containing the table
	 * @param selectStatement    select query that is used to export the data
	 * @param outputFileName Name of the file to  which data has to be exported.
	 * @param colDelimiter  Delimiter that seperates columns in the output file
	 * @param characterDelimiter  Delimiter that is used to quiote non-numeric types
	 * @param codeset           Codeset that should be used to write  the data to  the file
 	 * @exception SQL Exception on errors
	 */
	public static void exportQuery(Connection con, String selectStatement,
							  String outputFileName, String columnDelimeter, 
							  String characterDelimeter, String codeset)
		throws SQLException {
		
		Export fex = new Export(con, null, null, selectStatement,
										outputFileName,characterDelimeter,
										columnDelimeter, codeset);
		fex.doExport();
	}


	/**
	 * For internal use only
	 * @exception	Exception if there is an error
	 */
	//returns the control file reader corresponding to the control file passed
	protected ExportWriteDataAbstract getExportWriteData() throws Exception {
		return new ExportWriteData(outputFileName, controlFileReader);
	}
}