org.fugerit.java.tool.ToolHandlerHelper Maven / Gradle / Ivy

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Fugerit Java Tool Library for JDK 1.8 and up
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package org.fugerit.java.tool;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Properties;

import org.fugerit.java.core.function.SafeFunction;
import org.fugerit.java.core.io.StreamIO;
import org.fugerit.java.core.lang.helpers.ClassHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Basic class for the tool handler interface.
 * 
 * @author Fugerit
 *
 */
public abstract class ToolHandlerHelper implements ToolHandler {

	protected static final Logger logger = LoggerFactory.getLogger(ToolHandlerHelper.class);
	
	protected static final String LOG_PARAM_LITERAL = "{} -> {}";
	
	public static final String ARG_EXTRA_JAR = "extra-jar";
	
	public static final int EXIT_KO_DEFAULT = 1;
	
	/**
	 * Handler worker method.
	 * 
	 * @param params			ths params for the tool
	 * @return					exit code (0 is all ok)
	 * @throws RunToolException		issues if problems arise
	 */
	public abstract int handleWorker( Properties params ) throws RunToolException;
	
	@Override
	public int handle( Properties params ) {
		int exit = EXIT_OK;
		try {
			exit = handleWorker( params );
		} catch ( Exception e ) {
			exit = EXIT_KO_DEFAULT;
			logger.error( "Exception during handleWorker()", e );
		}
		return exit;
	}
	
	protected ClassLoader getClassLoader( Properties params ) {
		final ClassLoader cl = ClassHelper.getDefaultClassLoader();
		return SafeFunction.get( () -> {
			ClassLoader res = cl;
			String extraJar = params.getProperty( ARG_EXTRA_JAR );
			if ( extraJar != null ) {
				File jarFile = new File( extraJar );
				URL[] u = { jarFile.toURI().toURL() };
				res = new URLClassLoader( u , res );
			}
			return res;
		});
	}
	
	/**
	 * 
	 * Generate the heklp for current Tool
	 * 
	 * @return	Help text
	 */
	public String getHelp() {
		String help = "";
		String resName = "tool/handler/help/"+this.getClass().getSimpleName()+".txt";
		try {
			InputStream is = ClassHelper.getDefaultClassLoader().getResourceAsStream( resName );
			ByteArrayOutputStream os = new ByteArrayOutputStream();
			StreamIO.pipeStream( is , os , StreamIO.MODE_CLOSE_BOTH );
			help = os.toString();
		} catch (Exception e) {
			logger.info( "Failed to load help : {}", resName );
		}
		return help;
	}
	
}