com.celum.dbplugin.sqlparser.SqlScriptParser Maven / Gradle / Ivy

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DB plugin for Maven that executes SQL scripts
There is a newer version: 1.2
/*****************************************************************************
 * Copyright 2012 celum Slovakia s r.o.
 *
 * 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 com.celum.dbplugin.sqlparser;

import org.antlr.runtime.*;

import java.io.*;
import java.util.*;

/**
 * Class parse the whole SQL script into SQL statements. This is
 * basically facade that is hiding ANTLR grammar for SQL script.
 *
 * @author Zdenko Vrabel ([email protected])
 */
public class SqlScriptParser
{

	/**
	 * Method parse SQL script and returns collection of SQL Statements
	 * @param script
	 * @return
	 */
	public Collection parseScript(String script)
	{
		try {
			return parseScript(new ANTLRStringStream(script));
		} catch (Exception e) {
			throw new IllegalStateException(e);
		}
	}


	/**
	 * Method parse SQL script and returns collection of SQL Statements
	 * @param script
	 * @return
	 * @throws IOException
	 */
	public Collection parseScript(InputStream script) throws Exception
	{
		return parseScript(new ANTLRInputStream(script));
	}


	/**
	 * Method parse SQL script and returns collection of SQL Statements
	 *
	 * @param scriptStream
	 * @return
	 */
	private Collection parseScript(CharStream scriptStream) throws IOException, RecognitionException
	{
		//parse script
		SqlGrammarLexer lexer = new SqlGrammarLexer(scriptStream);
		CommonTokenStream tokens = new CommonTokenStream(lexer);
		SqlGrammarParser parser = new SqlGrammarParser(tokens);
		parser.sqlscript();

		//process tokens
		List statements = new LinkedList();
		for(Object o : tokens.getTokens()) {
			CommonToken token = (CommonToken)o;
			String statement = token.getText();
			statement = removeMess(statement);
			if (!statement.isEmpty()) {
				statements.add(statement);
			}
		}
		return statements;
	}


	/**
	 * Method remove mess from SQL statement like comments, termination character
	 * ';' etc.
	 *
	 * @param statement
	 * @return clean statement
	 */
	private String removeMess(String statement)
	{
		StringBuffer sb = new StringBuffer();
		Scanner scanner = new Scanner(statement);
		while (scanner.hasNextLine())
		{
			String line = scanner.nextLine();
			if (line.startsWith("--")) {
				continue;
			}

			if (line.isEmpty()) {
				continue;
			}

			if (line.startsWith("")) {
				return "";
			}

			line = line.trim();
			if (line.endsWith(";")) {
				line = line.substring(0, line.length() - 1);
			}

			sb.append(line + "\n");
		}

		return sb.toString();
	}
}