ddfloader.java

联合国农粮署牵头开发的geonetwork源代码最新版

//==============================================================================
//===
//===   DdfLoader (adapted class from druid project http://druid.sf.net)
//===
//===   Copyright (C) by Andrea Carboni.
//===   This file may be distributed under the terms of the GPL license.
//==============================================================================

package org.fao.gast.lib.druid;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.dlib.tools.FullTokenizer;

//==============================================================================

public class DdfLoader
{
	public static interface Handler
	{
		public void handleFields(List<ImportField> fields) throws Exception;
		public void handleRow(List<String> values) throws Exception;
		public void cleanUp();
	}

	//---------------------------------------------------------------------------
	//---
	//--- API methods
	//---
	//---------------------------------------------------------------------------

	public void setHandler(Handler h)
	{
		handler = h;
	}

	//---------------------------------------------------------------------------

	public void load(String fileName) throws FileNotFoundException, IOException, Exception
	{
		BufferedReader	rdr = new BufferedReader(new FileReader(fileName));

		String line;

		int status = START;

		ArrayList<ImportField> alFields = new ArrayList<ImportField>();

		try
		{
			while ((line = rdr.readLine()) != null)
			{
				//--- skip comments or blank lines

				if (line.equals("") || line.startsWith("#"))
					continue;

				//--- start [FIELDS] section

				if (line.equals("[FIELDS]"))
					status = FIELDS;

				//--- start [DATA] section and build prepared statement

				else if (line.equals("[DATA]"))
				{
					status = DATA;
					handler.handleFields(alFields);
				}
				else
				{
					if (status == FIELDS)
						alFields.add(new ImportField(line));

					else if (status == DATA)
						handleRow(line);

					else
						throw new IllegalArgumentException("Data not allowed before [FIELDS] section");
				}
			}

			if (status != DATA)
				throw new IllegalArgumentException("Unexpected EOF encountered");
		}
		finally
		{
			handler.cleanUp();
			rdr.close();
		}
	}

	//---------------------------------------------------------------------------
	//---
	//--- Private methods
	//---
	//---------------------------------------------------------------------------

	private void handleRow(String line) throws Exception
	{
		FullTokenizer ft = new FullTokenizer(line, "\t");

		String token;

		ArrayList<String> al = new ArrayList<String>();

		for(int i=0; i<ft.countTokens(); i++)
		{
			token = ft.nextToken();
			al.add(token);
		}

		handler.handleRow(al);
	}

	//---------------------------------------------------------------------------
	//---
	//--- Variables
	//---
	//---------------------------------------------------------------------------

	private Handler handler;

	//---------------------------------------------------------------------------

	private static final int START  = 0;
	private static final int FIELDS = 1;
	private static final int DATA   = 2;
}

//==============================================================================