Migration.java

package org.javalite.db_migrator;

import org.javalite.common.Util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

import static org.javalite.common.Util.blank;
import static org.javalite.db_migrator.DbUtils.exec;


public class Migration implements Comparable {
    private static final Logger LOGGER = LoggerFactory.getLogger(Migration.class);
    private static final String DEFAULT_DELIMITER = ";";
    private static final String DELIMITER_KEYWORD = "DELIMITER";
    private static final String[] COMMENT_CHARS = new String[]{"--", "#", "//"};

    private File migrationFile;
    private String version;

    public Migration(String version, File migrationFile) {
        this.migrationFile = migrationFile;
        this.version = version;
    }

    public String getVersion() {
        return version;
    }

    public String getName() {
        return migrationFile.getName();
    }

    public void migrate(String encoding) throws Exception {
        List<String> lines = Files.readAllLines(Paths.get(migrationFile.getCanonicalPath()), encoding != null ? Charset.forName(encoding) : Charset.defaultCharset());
        String delimiter = DEFAULT_DELIMITER;
        List<String> statements = new ArrayList<>();
        try {
            String currentStatement = "";
            for (String line : lines) {
                if (!commentLine(line) && !blank(line)) {
                    if (line.startsWith(DELIMITER_KEYWORD)) {
                        delimiter = line.substring(10).trim();
                    } else if (line.contains(delimiter)) {
                        currentStatement += line.substring(0, line.indexOf(delimiter)) ;
                        if(!blank(currentStatement)){
                            statements.add(currentStatement);
                        }
                        currentStatement = line.substring(line.indexOf(delimiter) + delimiter.length());
                    }else {
                        currentStatement += line + System.getProperty("line.separator");
                    }
                }
            }

            if(!blank(currentStatement)){
                statements.add(currentStatement);
            }

            for (String statement : statements) {
                exec(statement);
            }
        } catch (Exception e) {
            LOGGER.error("Error executing migration file: {}", migrationFile.getCanonicalPath(), e);
            throw e;
        }
    }

    private boolean commentLine(String line) {
        for (String cc : COMMENT_CHARS) {
            if (line.trim().startsWith(cc)) {
                return true;
            }
        }
        return false;
    }

    public int compareTo(Object o) {
        Migration other = (Migration) o;
        return this.getVersion().compareTo(other.getVersion());
    }
}