de.julielab.xmlData.config.DBConfig Maven / Gradle / Ivy

Go to download
package de.julielab.xmlData.config;

import java.io.IOException;

import org.apache.commons.lang3.StringUtils;

import com.ximpleware.AutoPilot;
import com.ximpleware.EOFException;
import com.ximpleware.EncodingException;
import com.ximpleware.EntityException;
import com.ximpleware.NavException;
import com.ximpleware.ParseException;
import com.ximpleware.PilotException;
import com.ximpleware.VTDException;
import com.ximpleware.VTDGen;
import com.ximpleware.VTDNav;
import com.ximpleware.XPathEvalException;
import com.ximpleware.XPathParseException;

public class DBConfig extends ConfigBase {

	private static final String XPATH_CONF_DB_INFO = "//DBConnectionInformation";
	private static final String XPATH_CONF_ACTIVE_DB_NAME = "//activeDBConnection";
	private static final String XPATH_CONF_ACTIVE_PG_SCHEMA = "//activePostgresSchema";
	private static final String XPATH_CONF_ACTIVE_DATA_PG_SCHEMA = "//activeDataPostgresSchema";

	private static final String XPATH_CONF_DBs = XPATH_CONF_DB_INFO + "/DBConnections";
	private static final String XPATH_CONF_DB = XPATH_CONF_DBs + "/DBConnection";
	private static final String XPATH_CONF_MAX_CON = XPATH_CONF_DB_INFO + "/maxActiveDBConnections";
	private static final String XPATH_CONF_TEMPLATE = XPATH_CONF_DB + "[@name='%s']";
	private static final String XPATH_CONF_URL_TEMPLATE = XPATH_CONF_TEMPLATE;
	private static final String ATTRIBUTE_URL = "url";

	private String url;
	private String activePGSchema;
	private int maxConnections = 5;
	private String activeDatabase;
	private String activeDataPGSchema;

	public DBConfig(byte[] configData) throws VTDException {
		try {
			// Convert the schema name to lower case as Postgres does so.
			activePGSchema = getActiveConfig(configData, XPATH_CONF_ACTIVE_PG_SCHEMA).toLowerCase();
			activeDataPGSchema = getActiveConfig(configData, XPATH_CONF_ACTIVE_DATA_PG_SCHEMA).toLowerCase();
			activeDatabase = getActiveConfig(configData, XPATH_CONF_ACTIVE_DB_NAME);
			buildDatabaseValues(activeDatabase, configData);

			VTDGen vg = new VTDGen();
			vg.setDoc(configData);
			vg.parse(true);
			VTDNav vn = vg.getNav();
			AutoPilot ap = new AutoPilot(vn);
			String maxConnString = stringFromXpath(ap, XPATH_CONF_MAX_CON);
			if (!StringUtils.isBlank(maxConnString))
				maxConnections = Integer.parseInt(maxConnString);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private void buildDatabaseValues(String activeDatabase, byte[] mergedConfData)
			throws EncodingException, EOFException, EntityException, ParseException, XPathParseException,
			XPathEvalException, NavException, PilotException {
		VTDGen vg = new VTDGen();
		vg.setDoc(mergedConfData);
		vg.parse(true);
		VTDNav vn = vg.getNav();
		AutoPilot ap = new AutoPilot(vn);

		ap.selectXPath(String.format(XPATH_CONF_URL_TEMPLATE, activeDatabase));
		if (ap.evalXPath() != -1) {
			int attrIndex = vn.getAttrVal(ATTRIBUTE_URL);
			if (attrIndex != -1)
				url = vn.toString(attrIndex);
		} else {
			throw new IllegalArgumentException(
					"There is no database connection named \"" + activeDatabase + "\" defined in the configuration.");
		}
	}

	/**
	 * @return - url of the database
	 */
	public String getUrl() {
		return url;
	}

	/**
	 * 
	 * @return The active Postgres Schema.
	 */
	public String getActivePGSchema() {
		return activePGSchema;
	}

	/**
	 * 
	 * @return The active data Postgres Schema.
	 */
	public String getActiveDataPGSchema() {
		return activeDataPGSchema;
	}

	/**
	 * @param pgSchema
	 */
	public void setActivePGSchema(String pgSchema) {
		activePGSchema = pgSchema;
	}

	public String getActiveDatabase() {
		return activeDatabase;
	}

	public int getMaxConnections() {
		return maxConnections;
	}

	@Override
	public String toString() {
		String str;
		str = "Database URL: " + url + "\n";
		str += "Active Postgres schema: " + activePGSchema + "\n";
		str += "Max open connections: " + maxConnections;
		return str;
	}

}