Safe load for query handlers

Author: daneeldeveloper

src/main/java/org/fugerit/java/query/export/facade/QueryExportFacade.java

@@ -1,59 +1,68 @@
-package org.fugerit.java.query.export.facade;
-
-import java.sql.ResultSet;
-import java.sql.Statement;
-
-import org.fugerit.java.core.util.collection.ListMapStringKey;
-import org.fugerit.java.query.export.facade.format.QueryExportHandlerCSV;
-import org.fugerit.java.query.export.facade.format.QueryExportHandlerXLS;
-import org.fugerit.java.query.export.facade.format.QueryExportHandlerXLSX;
-import org.fugerit.java.query.export.meta.BasicMetaRSE;
-import org.fugerit.java.query.export.meta.BasicMetaResult;
-import org.fugerit.java.query.export.meta.MetaResult;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class QueryExportFacade {
-
-	public static final String FORMAT_XLS = "xls";
-	public static final String FORMAT_XLSX = "xlsx";
-	
-	public static final String FORMAT_CSV = "csv";
-	public static final String FORMAT_DEFAULT = FORMAT_CSV;
-	public static final char CSV_SEPARATOR_DEF = ',';
-	
-	protected static final Logger logger = LoggerFactory.getLogger(QueryExportFacade.class);
-	
-	private static ListMapStringKey<QueryExportHandler> HANDLERS = new ListMapStringKey<QueryExportHandler>();
-	static {
-		HANDLERS.add( new QueryExportHandlerCSV() );
-		HANDLERS.add( new QueryExportHandlerXLS() );
-		HANDLERS.add( new QueryExportHandlerXLSX() );
-	}
-	
-	public static int export( QueryExportConfig config ) throws Exception {
-		int res = 0;
-		Statement stm = config.getConn().createStatement();
-		logger.info( "sql : "+config.getQuery() );
-		ResultSet rs = stm.executeQuery( config.getQuery() );
-		MetaResult meta = new BasicMetaResult( BasicMetaRSE.newInstanceAllToString( rs.getMetaData(), config.getObjectFormat() ) , rs );
-		export( config, meta );
-		int count = meta.close();
-		stm.close();
-		logger.info( "record count "+count );
-		return res;
-	}
-	
-	public static int export( QueryExportConfig config, MetaResult meta ) throws Exception {
-		int res = 0;
-		String format = config.getFormat().toLowerCase();
-		QueryExportHandler handler = HANDLERS.get( format );
-		if ( handler != null ) {
-			res = handler.export(config, meta);
-		} else {
-			throw new Exception( "Unsupported export format "+format );
-		}
-		return res;
-	}
-	
-}
+package org.fugerit.java.query.export.facade;
+
+import java.sql.ResultSet;
+import java.sql.Statement;
+
+import org.fugerit.java.core.lang.helpers.ClassHelper;
+import org.fugerit.java.core.util.collection.ListMapStringKey;
+import org.fugerit.java.query.export.meta.BasicMetaRSE;
+import org.fugerit.java.query.export.meta.BasicMetaResult;
+import org.fugerit.java.query.export.meta.MetaResult;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class QueryExportFacade {
+
+	public static final String FORMAT_XLS = "xls";
+	public static final String FORMAT_XLSX = "xlsx";
+	
+	public static final String FORMAT_CSV = "csv";
+	public static final String FORMAT_DEFAULT = FORMAT_CSV;
+	public static final char CSV_SEPARATOR_DEF = ',';
+	
+	protected static final Logger logger = LoggerFactory.getLogger(QueryExportFacade.class);
+	
+	private static void registerHandler( String type, ListMapStringKey<QueryExportHandler> handlers ) {
+		try {
+			QueryExportHandler handler = (QueryExportHandler)ClassHelper.newInstance( type );
+			handlers.add( handler );
+		} catch (Throwable e) {
+			String message = "Failed to register handler : "+type+" "+e;
+			logger.warn( message+" [set log level to debug for full stack trace]" );
+			logger.debug( message, e );
+		}
+	}
+	
+	private static ListMapStringKey<QueryExportHandler> HANDLERS = new ListMapStringKey<QueryExportHandler>();
+	static {
+		registerHandler( "org.fugerit.java.query.export.facade.format.QueryExportHandlerCSV" , HANDLERS );
+		registerHandler( "org.fugerit.java.query.export.facade.format.QueryExportHandlerXLS" , HANDLERS );
+		registerHandler( "org.fugerit.java.query.export.facade.format.QueryExportHandlerXLSX" , HANDLERS );
+	}
+	
+	public static int export( QueryExportConfig config ) throws Exception {
+		int res = 0;
+		Statement stm = config.getConn().createStatement();
+		logger.info( "sql : "+config.getQuery() );
+		ResultSet rs = stm.executeQuery( config.getQuery() );
+		MetaResult meta = new BasicMetaResult( BasicMetaRSE.newInstanceAllToString( rs.getMetaData(), config.getObjectFormat() ) , rs );
+		export( config, meta );
+		int count = meta.close();
+		stm.close();
+		logger.info( "record count "+count );
+		return res;
+	}
+	
+	public static int export( QueryExportConfig config, MetaResult meta ) throws Exception {
+		int res = 0;
+		String format = config.getFormat().toLowerCase();
+		QueryExportHandler handler = HANDLERS.get( format );
+		if ( handler != null ) {
+			res = handler.export(config, meta);
+		} else {
+			throw new Exception( "Unsupported export format "+format );
+		}
+		return res;
+	}
+	
+}