Load scenario from jar in the classpath

package com.toolsverse.etl.examples.embedded;

import java.util.Calendar;

import java.util.Date;

import com.toolsverse.config.SystemConfig;

import com.toolsverse.etl.common.Alias;

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

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

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

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

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

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

import com.toolsverse.etl.resource.EtlResource;

import com.toolsverse.util.Utils;

import com.toolsverse.util.log.Logger;

/**

* This example demonstrates embedding ETL engine into application. It programmatically creates ETL configuration with a source

* and destination connections, loads ETL scenario from the toolsverse-test-etl.jar and executes ETL process.

*

* The fully qualified path of the ETL scenario is com/toolsverse/data/scenario/db2file.xml. It is located in the

* toolsverse-test-etl.jar under APP_HOME/lib folder. Jars under APP_HOME/lib are atomically added to the classpath but it

* can be any jar, anywhere, as long as it is in the classpath.

*

* ETL scenario 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 LoadScenarioFromJarInTheClasspath

{

/**

* Configures ETL engine and executes ETL scenario.

* @param args the command line arguments

public static void main(String[] args)

{

LoadScenarioFromJarInTheClasspath engine = new LoadScenarioFromJarInTheClasspath();

try

{

// instantiates ETL configuration

EtlConfig etlConfig = new EtlConfig();

// 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));

// creates configuration which contains source and destination

// loads ETL scenario from the resource and executes ETL process.

EtlResponse response = engine.createConfigAndExecute(etlConfig,

"com/toolsverse/data/scenario/db2file.xml", etlProcess);

// print out formatted output from the ETL response

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

"com/toolsverse/data/scenario/db2file.xml"));

}

catch (Exception ex)

{

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

}

System.exit(0);

}

/**

* Manually creates connection aliases for the ETL process, loads given ETL scenario from the jar file.

* Executes ETl scenario.

* @param config the ETL config

* @param scenariFileName the ETL scenario file name

* @param etlProcess the ETl process

* @return ETL response

* @throws Exception in case of any error

private EtlResponse createConfigAndExecute(EtlConfig config,

String scenariFileName, EtlProcess etlProcess)

throws Exception

{

// initializes ETl config

config.init();

// creates source alias

Alias source = new Alias();

source.setName("Java DB");

source.setUrl("jdbc:derby:{app.root.data}/demo/javadb");

source.setJdbcDriverClass("org.apache.derby.jdbc.EmbeddedDriver");

// creates destination alias

Alias destination = new Alias();

destination.setName("JSON files");

destination

.setConnectorClassName("com.toolsverse.etl.connector.json.JsonConnector");

destination.setUrl("{app.root.data}/*.json");

// adds aliases. ETL process will create connections from these aliases

config.addAliasToMap(EtlConfig.SOURCE_CONNECTION_NAME, source);

config.addAliasToMap(EtlConfig.DEST_CONNECTION_NAME, destination);

// instantiates ETL factory

EtlFactory etlFactory = new EtlFactory();

// loads ETL scenario from the resource, sets ETL action

Scenario scenario = etlFactory.getScenario(config, scenariFileName);

if (scenario == null)

{

System.exit(0);

}

scenario.setAction(EtlConfig.EXTRACT_LOAD);

// creates ETl request using given config, scenario and log level

EtlRequest request = new EtlRequest(config, scenario, Logger.INFO);

// executes ETL process

return etlProcess.execute(request);

}

/**

* 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;

}