com.abubusoft.kripton.android.sqlite.internals.MigrationSQLChecker.java Source code

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Here is the source code for com.abubusoft.kripton.android.sqlite.internals.MigrationSQLChecker.java

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/*******************************************************************************
 * Copyright 2015, 2017 Francesco Benincasa (info@abubusoft.com).
 *
 * 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.abubusoft.kripton.android.sqlite.internals;

import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.tree.ParseTreeWalker;

import com.abubusoft.kripton.android.sqlite.KriptonAssert;
import com.abubusoft.kripton.common.Pair;
import com.abubusoft.kripton.processor.sqlite.grammars.jsql.JqlBaseListener;
import com.abubusoft.kripton.processor.sqlite.grammars.jsql.JqlLexer;
import com.abubusoft.kripton.processor.sqlite.grammars.jsql.JqlParser;

/**
 * The Class MigrationSQLChecker.
 */
public class MigrationSQLChecker {

    /** The instance. */
    protected static MigrationSQLChecker instance;

    /**
     * Gets the single instance of MigrationSQLChecker.
     *
     * @return single instance of MigrationSQLChecker
     */
    public static final MigrationSQLChecker getInstance() {
        if (instance == null) {
            instance = new MigrationSQLChecker();
        }

        return instance;
    }

    /** The walker. */
    ParseTreeWalker walker = new ParseTreeWalker();

    /**
     * Instantiates a new migration SQL checker.
     */
    private MigrationSQLChecker() {

    }

    /**
     * Analyze internal.
     *
     * @param <L> the generic type
     * @param jql the jql
     * @param listener the listener
     */
    protected <L extends JqlBaseListener> void analyzeInternal(final String jql, L listener) {
        walker.walk(listener, prepareParser(jql).value0);
    }

    /**
     * Analyze.
     *
     * @param <L> the generic type
     * @param sql the sql
     * @param listener the listener
     */
    public <L extends JqlBaseListener> void analyze(final String sql, L listener) {
        analyzeInternal(sql, listener);
    }

    /**
     * Prepare parser.
     *
     * @param jql the jql
     * @return the pair
     */
    protected Pair<ParserRuleContext, CommonTokenStream> prepareParser(final String jql) {
        JqlLexer lexer = new JqlLexer(CharStreams.fromString(jql));
        CommonTokenStream tokens = new CommonTokenStream(lexer);
        JqlParser parser = new JqlParser(tokens);

        parser.removeErrorListeners();
        parser.addErrorListener(new JQLBaseErrorListener() {
            @Override
            public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line,
                    int charPositionInLine, String msg, RecognitionException e) {
                KriptonAssert.assertTrue(false, "unespected char at pos %s of SQL '%s'", charPositionInLine, jql);
            }
        });

        ParserRuleContext context = parser.parse();
        return new Pair<>(context, tokens);
    }

}