Load scenario and configuration from file

package com.toolsverse.etl.examples.embedded;

import java.util.Calendar;

import java.util.Date;

import com.toolsverse.config.SystemConfig;

import com.toolsverse.etl.core.config.EtlConfig;

import com.toolsverse.etl.core.engine.EtlProcess;

import com.toolsverse.etl.core.engine.EtlResponse;

import com.toolsverse.etl.resource.EtlResource;

import com.toolsverse.etl.util.EtlLogger;

import com.toolsverse.util.Utils;

import com.toolsverse.util.log.Logger;

/**

* This example demonstrates embedding ETL engine into application. It loads ETL configuration file and executes

* ETL process using connections and scenario specified in the configuration file.

*

* The configuration file is <code>test_etl_config.xml</code> which is expected to be under APP_HOME/config

*

* The ETL scenario is APP_HOME/data/scenario/Examples/engine/db2file.xml. It is configured to extract data from 3 tables in the java db

* database and use it to create json files. It can create files in any supported format without any scenario

* modification.

*

* Data are streamed from the source database to the destination which means the memory consumption is minimal.

*

* There are no input files. Output files are: APP_HOME/data/EMPLOYEE.json, APP_HOME/data/CONFIG_PROPERTY.json and

* APP_HOME/data/CONFIG_VALUE.json

*

* The logger is manually set to the INFO mode which increases verbosity of the etl engine.

public class LoadScenarioAndConfigurationFromFile

{

/**

* Configures ETL engine and executes ETL scenario.

* @param args the command line arguments

public static void main(String[] args)

{

LoadScenarioAndConfigurationFromFile engine = new LoadScenarioAndConfigurationFromFile();

try

{

// instantiates ETL configuration

EtlConfig etlConfig = new EtlConfig();

// set log level to INFO which increases verbosity of the etl engine

Logger.setLevel(EtlLogger.class, Logger.INFO);

// creates embedded ETL process

EtlProcess etlProcess = new EtlProcess(EtlProcess.EtlMode.EMBEDDED);

// print out framework version

System.out.println(SystemConfig.instance().getTitle(

EtlConfig.DEFAULT_TITLE)

+ " "

+ SystemConfig.instance().getSystemProperty(

SystemConfig.VERSION));

// load configuration which contains source and destination

// connections and ETL scenario name. Load and execute ETL scenario.

// If no full path

// provided the configuration file test_etl_config.xml is expected

// to be under app_home/config

EtlResponse response = engine.loadConfigAndExecute(etlConfig,

"test_etl_config.xml", etlProcess);

// print out formatted output from the ETL response

System.out.println(engine.getMessage(response,

"Exampes/Engine/db2file.xml"));

}

catch (Exception ex)

{

System.out.println(Utils.getStackTraceAsString(ex));

}

System.exit(0);

}

/**

* Creates the formatted message from the ETL response

* @param response the ETl response

* @param scenarioName the ETL scenario name

* @return formatted message from the ETL response

private String getMessage(EtlResponse response, String scenarioName)

{

String msg = "";

String start = response != null ? response.getStartTime().toString()

: new Date().toString();

String end = response != null && response.getEndTime() != null ? response

.getEndTime().toString() : new Date().toString();

String diff = response != null ? String

.valueOf(Utils.getDateDiff(response.getEndTime(),

response.getStartTime(), Calendar.SECOND)) : "0";

if (response.getRetCode() == EtlConfig.RETURN_OK)

{

msg = Utils

.format("\n"

+ EtlResource.FINISH_SUCCESS_MSG.getValue()

+ "\n"

+ "Scenario name: %1"

+ "\n"

+ "Started at %2, finished at %3, total execution time %4 seconds.",

scenarioName, start, end, diff);

if (!Utils.isNothing(response.getWarnings()))

{

msg = msg + "\n"

+ EtlResource.WARING_NOTHING_WAS_EXECUTED.getValue();

}

else if (response.getRetCode() == EtlConfig.RETURN_NO_DRIVERS)

{

msg = "\n" + EtlResource.NO_DRIVERS_MSG.getValue();

}

else

{

msg = Utils

.format("\n"

+ EtlResource.FINISH_ERROR_MSG.getValue()

+ "\n"

+ "Scenario name: %1"

+ "\n"

+ "Started at %2, finished at %3, total execution time %4 seconds.",

scenarioName, start, end, diff)

+ "\n"

+ Utils.getStackTraceAsString(response.getException());

}

return msg;

}

/**

* Loads ETL configuration file using given name. Creates connections for the ETL process

* by parsing configuration file. Executes ETL scenario specified in the ETL configuration file.

* @param config the ETl config

* @param configFileName the ETL config file name

* @param etlProcess the ETL process

* @return ETl response

* @throws Exception in case of any error

private EtlResponse loadConfigAndExecute(EtlConfig config,

String configFileName, EtlProcess etlProcess)

throws Exception

{

// loads specified configuration file

// from the default folder: APP_HOME/config. Creates connections and

// loads scenario in process.

if (!config.initConfigXml(configFileName))

{

System.out.println("Cannot read " + config.getXmlConfigFileName()

+ ". Check log for details.");

System.exit(0);

}

// executes ETL scenario specified in the configuration file

return etlProcess.execute(config);

}