common EGIZ code-style refactoring

6 files changed, 607 insertions, 613 deletions

diff --git a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractGUIFormBuilderConfiguration.java b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractGUIFormBuilderConfiguration.java
deleted file mode 100644
index dde5ab70..00000000
--- a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractGUIFormBuilderConfiguration.java
+++ /dev/null
@@ -1,179 +0,0 @@
-/*******************************************************************************
- * Copyright 2017 Graz University of Technology
- * EAAF-Core Components has been developed in a cooperation between EGIZ,  
- * A-SIT Plus, A-SIT, and Graz University of Technology.
- *
- * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by
- * the European Commission - subsequent versions of the EUPL (the "Licence");
- * You may not use this work except in compliance with the Licence.
- * You may obtain a copy of the Licence at:
- * https://joinup.ec.europa.eu/news/understanding-eupl-v12
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the Licence is distributed on an "AS IS" basis,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the Licence for the specific language governing permissions and
- * limitations under the Licence.
- *  
- * This product combines work with different licenses. See the "NOTICE" text
- * file for details on the various modules and licenses.
- * The "NOTICE" text file is part of the distribution. Any derivative works
- * that you distribute must include a readable copy of the "NOTICE" text file.
- *******************************************************************************/
-/*******************************************************************************
- *******************************************************************************/
-/*******************************************************************************
- *******************************************************************************/
-package at.gv.egiz.eaaf.core.impl.gui;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import org.apache.commons.lang3.StringUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import at.gv.egiz.eaaf.core.api.gui.GroupDefinition;
-import at.gv.egiz.eaaf.core.api.gui.GroupDefinition.TYPE;
-import at.gv.egiz.eaaf.core.api.gui.IGUIBuilderConfiguration;
-
-/**
- * @author tlenz
- *
- */
-public abstract class AbstractGUIFormBuilderConfiguration implements IGUIBuilderConfiguration {
-	private static final Logger log = LoggerFactory.getLogger(AbstractGUIFormBuilderConfiguration.class);
-	
-	public static final GroupDefinition PARAM_GROUP_FORM = GroupDefinition.getInstance("form", TYPE.MAP);
-	public static final GroupDefinition PARAM_GROUP_ACTIONS = GroupDefinition.getInstance("actions", TYPE.LIST);
-	public static final GroupDefinition PARAM_GROUP_PARAMS = GroupDefinition.getInstance("params", TYPE.MAP);
-	public static final GroupDefinition PARAM_GROUP_UIOPTIONS = GroupDefinition.getInstance("uiOptions", TYPE.MAP);
-	public static final GroupDefinition PARAM_GROUP_MSG = GroupDefinition.getInstance("msg", TYPE.MAP);
-	
-	
-	public static final String PARAM_VIEWNAME = "viewName";
-	public static final String PARAM_AUTHCONTEXT = "contextPath";
-	public static final String PARAM_FORMSUBMITENDPOINT = "submitEndpoint";	
-	@Deprecated public static final String PARAM_PENDINGREQUESTID_DEPRECATED = "pendingReqID";
-	public static final String PARAM_PENDINGREQUESTID = "pendingid";
-	
-	private String authURL = null;
-	private String viewName = null;
-	private String formSubmitEndpoint = null;
-	
-	private final Map<String, Object> params =  new HashMap<String, Object>();
-	
-	/**
-	 * @param authURL IDP PublicURL-Prefix which should be used, but never null
-	 * @param viewName Name of the template (with suffix) but never null
-	 * @param formSubmitEndpoint EndPoint on which the form should be submitted, 
-	 * or null if the form must not submitted
-	 * 
-	 */
-	public AbstractGUIFormBuilderConfiguration(String authURL, String viewName, String formSubmitEndpoint) {
-		if (viewName.startsWith("/"))
-			this.viewName = viewName.substring(1);
-		else
-			this.viewName = viewName;
-		
-		if (authURL.endsWith("/"))
-			this.authURL = authURL.substring(0, authURL.length() - 1);
-		else
-			this.authURL = authURL;
-		
-		if (StringUtils.isNotEmpty(formSubmitEndpoint)) {
-			if (formSubmitEndpoint.startsWith("/"))
-				this.formSubmitEndpoint = formSubmitEndpoint;
-			else		
-				this.formSubmitEndpoint = "/" + formSubmitEndpoint;
-		}
-	}
-			
-	/* (non-Javadoc)
-	 * @see at.gv.egovernment.moa.id.auth.frontend.builder.IGUIBuilderConfiguration#getViewName()
-	 */
-	@Override
-	public final String getViewName() {
-		return this.viewName;
-		
-	}
-	
-
-	/* (non-Javadoc)
-	 * @see at.gv.egovernment.moa.id.auth.frontend.builder.IGUIBuilderConfiguration#getViewParameters()
-	 */
-	@Override
-	public final Map<String, Object> getViewParameters() {		
-		//set generic parameters
-		setViewParameter(getFromGroup(), PARAM_AUTHCONTEXT, this.authURL);
-		setViewParameter(getFromGroup(), PARAM_FORMSUBMITENDPOINT, this.formSubmitEndpoint);
-		setViewParameter(getFromGroup(), PARAM_VIEWNAME, this.viewName);
-				
-		//get parameters from detail implementation
-		putSpecificViewParameters();
-				
-		try {
-			log.trace("Full view parameters: {}", StringUtils.join(params, ","));			
-		} catch (final Exception e) {
-			log.info("Can NOT trace view parameters. Reason: {}", e.getMessage() );
-		}
-		
-		return params;
-		
-	}
-	
-	/**
-	 * Define the parameters, which should be evaluated in the template <br>
-	 * <b>IMPORTANT:</b> external HTML escapetion is required, because it is NOT done internally during the building process
-	 * 
-	 */
-	abstract protected void putSpecificViewParameters();
-	
-	/**
-	 * Get the Group for generic form elements
-	 * 
-	 * @return {@link GroupDefinition} or <code>null</code> if no groups are used
-	 */
-	abstract protected GroupDefinition getFromGroup();
-
-	@SuppressWarnings("unchecked")
-	protected void setViewParameter(GroupDefinition groupDefinition, String key, Object value) {
-		
-		if (groupDefinition != null) {
-			log.trace("Adding group object ... ");
-			Object groupMap = params.get(groupDefinition.getName());
-			if (groupMap == null) {
-				if (groupDefinition.getType().equals(TYPE.MAP)) {
-					groupMap = new HashMap<String, Object>();; 
-					log.trace("Build new MAP based group element");
-					
-				} else if (groupDefinition.getType().equals(TYPE.LIST)) {
-					groupMap = new ArrayList<Object>(); 
-					log.trace("Build new List based group element");
-					
-				} else
-					log.warn("GroupDefinition contains an unknown type: {}", groupDefinition.getType().name());
-				
-			}
-						
-			params.put(groupDefinition.getName(), groupMap);
-			if (groupMap instanceof Map<?,?>)
-				((Map<String, Object>) groupMap).put(key, value);
-				
-			else if (groupMap instanceof List<?>)
-				((List<Object>)groupMap).add(value);
-			
-			else
-				log.warn("Can NOT add element: {} to group: {}, because group is of type: {}",
-						key, groupDefinition.getName(), groupMap.getClass().getName());
-						
-		} else {
-			log.trace("Add root object ... ");
-			params.put(key, value);
-			
-		}
-				
-	}
-}
diff --git a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractGuiFormBuilderConfiguration.java b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractGuiFormBuilderConfiguration.java
new file mode 100644
index 00000000..efb8c713
--- /dev/null
+++ b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractGuiFormBuilderConfiguration.java
@@ -0,0 +1,195 @@
+/*
+ * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
+ * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
+ *
+ * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by the European
+ * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
+ * compliance with the Licence. You may obtain a copy of the Licence at:
+ * https://joinup.ec.europa.eu/news/understanding-eupl-v12
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the Licence
+ * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the Licence for the specific language governing permissions and limitations under
+ * the Licence.
+ *
+ * This product combines work with different licenses. See the "NOTICE" text file for details on the
+ * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
+ * works that you distribute must include a readable copy of the "NOTICE" text file.
+*/
+
+package at.gv.egiz.eaaf.core.impl.gui;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import at.gv.egiz.eaaf.core.api.gui.GroupDefinition;
+import at.gv.egiz.eaaf.core.api.gui.GroupDefinition.Type;
+import at.gv.egiz.eaaf.core.api.gui.IGuiBuilderConfiguration;
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Abstract Configuration implementation for GUI Builders.
+ *
+ * @author tlenz
+ *
+ */
+public abstract class AbstractGuiFormBuilderConfiguration implements IGuiBuilderConfiguration {
+  private static final Logger log =
+      LoggerFactory.getLogger(AbstractGuiFormBuilderConfiguration.class);
+
+  public static final GroupDefinition PARAM_GROUP_FORM =
+      GroupDefinition.getInstance("form", Type.MAP);
+  public static final GroupDefinition PARAM_GROUP_ACTIONS =
+      GroupDefinition.getInstance("actions", Type.LIST);
+  public static final GroupDefinition PARAM_GROUP_PARAMS =
+      GroupDefinition.getInstance("params", Type.MAP);
+  public static final GroupDefinition PARAM_GROUP_UIOPTIONS =
+      GroupDefinition.getInstance("uiOptions", Type.MAP);
+  public static final GroupDefinition PARAM_GROUP_MSG =
+      GroupDefinition.getInstance("msg", Type.MAP);
+
+
+  public static final String PARAM_VIEWNAME = "viewName";
+  public static final String PARAM_AUTHCONTEXT = "contextPath";
+  public static final String PARAM_FORMSUBMITENDPOINT = "submitEndpoint";
+  @Deprecated
+  public static final String PARAM_PENDINGREQUESTID_DEPRECATED = "pendingReqID";
+  public static final String PARAM_PENDINGREQUESTID = "pendingid";
+
+  private String authUrl = null;
+  private String viewName = null;
+  private String formSubmitEndpoint = null;
+
+  private final Map<String, Object> params = new HashMap<>();
+
+  /**
+   * Abstract GUI Builder config.
+   *
+   * @param authUrl IDP PublicURL-Prefix which should be used, but never null
+   * @param viewName Name of the template (with suffix) but never null
+   * @param formSubmitEndpoint EndPoint on which the form should be submitted, or null if the form
+   *        must not submitted
+   *
+   */
+  public AbstractGuiFormBuilderConfiguration(final String authUrl, final String viewName,
+      final String formSubmitEndpoint) {
+    if (viewName.startsWith("/")) {
+      this.viewName = viewName.substring(1);
+    } else {
+      this.viewName = viewName;
+    }
+
+    if (authUrl.endsWith("/")) {
+      this.authUrl = authUrl.substring(0, authUrl.length() - 1);
+    } else {
+      this.authUrl = authUrl;
+    }
+
+    if (StringUtils.isNotEmpty(formSubmitEndpoint)) {
+      if (formSubmitEndpoint.startsWith("/")) {
+        this.formSubmitEndpoint = formSubmitEndpoint;
+      } else {
+        this.formSubmitEndpoint = "/" + formSubmitEndpoint;
+      }
+    }
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see at.gv.egovernment.moa.id.auth.frontend.builder.IGUIBuilderConfiguration#getViewName()
+   */
+  @Override
+  public final String getViewName() {
+    return this.viewName;
+
+  }
+
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * at.gv.egovernment.moa.id.auth.frontend.builder.IGUIBuilderConfiguration#getViewParameters()
+   */
+  @Override
+  public final Map<String, Object> getViewParameters() {
+    // set generic parameters
+    setViewParameter(getFromGroup(), PARAM_AUTHCONTEXT, this.authUrl);
+    setViewParameter(getFromGroup(), PARAM_FORMSUBMITENDPOINT, this.formSubmitEndpoint);
+    setViewParameter(getFromGroup(), PARAM_VIEWNAME, this.viewName);
+
+    // get parameters from detail implementation
+    putSpecificViewParameters();
+
+    try {
+      log.trace("Full view parameters: {}", StringUtils.join(params, ","));
+    } catch (final Exception e) {
+      log.info("Can NOT trace view parameters. Reason: {}", e.getMessage());
+    }
+
+    return params;
+
+  }
+
+  /**
+   * Define the parameters, which should be evaluated in the template. <br>
+   * <b>IMPORTANT:</b> external HTML escapetion is required, because it is NOT done internally
+   * during the building process
+   *
+   */
+  protected abstract void putSpecificViewParameters();
+
+  /**
+   * Get the Group for generic form elements.
+   *
+   * @return {@link GroupDefinition} or <code>null</code> if no groups are used
+   */
+  protected abstract GroupDefinition getFromGroup();
+
+  @SuppressWarnings("unchecked")
+  protected void setViewParameter(final GroupDefinition groupDefinition, final String key,
+      final Object value) {
+
+    if (groupDefinition != null) {
+      log.trace("Adding group object ... ");
+      Object groupMap = params.get(groupDefinition.getName());
+      if (groupMap == null) {
+        if (groupDefinition.getType().equals(Type.MAP)) {
+          groupMap = new HashMap<String, Object>();
+          log.trace("Build new MAP based group element");
+
+        } else if (groupDefinition.getType().equals(Type.LIST)) {
+          groupMap = new ArrayList<>();
+          log.trace("Build new List based group element");
+
+        } else {
+          log.warn("GroupDefinition contains an unknown type: {}",
+              groupDefinition.getType().name());
+          groupMap = StringUtils.EMPTY;
+
+        }
+
+      }
+
+      params.put(groupDefinition.getName(), groupMap);
+      if (groupMap instanceof Map<?, ?>) {
+        ((Map<String, Object>) groupMap).put(key, value);
+      } else if (groupMap instanceof List<?>) {
+        ((List<Object>) groupMap).add(value);
+      } else {
+        log.warn("Can NOT add element: {} to group: {}, because group is of type: {}", key,
+            groupDefinition.getName(), groupMap.getClass().getName());
+      }
+
+    } else {
+      log.trace("Add root object ... ");
+      params.put(key, value);
+
+    }
+
+  }
+}
diff --git a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractVelocityGUIFormBuilderImpl.java b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractVelocityGUIFormBuilderImpl.java
deleted file mode 100644
index b9c16538..00000000
--- a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractVelocityGUIFormBuilderImpl.java
+++ /dev/null
@@ -1,242 +0,0 @@
-/*******************************************************************************
- * Copyright 2017 Graz University of Technology
- * EAAF-Core Components has been developed in a cooperation between EGIZ,  
- * A-SIT Plus, A-SIT, and Graz University of Technology.
- *
- * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by
- * the European Commission - subsequent versions of the EUPL (the "Licence");
- * You may not use this work except in compliance with the Licence.
- * You may obtain a copy of the Licence at:
- * https://joinup.ec.europa.eu/news/understanding-eupl-v12
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the Licence is distributed on an "AS IS" basis,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the Licence for the specific language governing permissions and
- * limitations under the Licence.
- *  
- * This product combines work with different licenses. See the "NOTICE" text
- * file for details on the various modules and licenses.
- * The "NOTICE" text file is part of the distribution. Any derivative works
- * that you distribute must include a readable copy of the "NOTICE" text file.
- *******************************************************************************/
-/*******************************************************************************
- *******************************************************************************/
-/*******************************************************************************
- *******************************************************************************/
-package at.gv.egiz.eaaf.core.impl.gui;
-
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.StringWriter;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Map.Entry;
-
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
-import org.apache.commons.lang3.StringUtils;
-import org.apache.velocity.VelocityContext;
-import org.apache.velocity.app.VelocityEngine;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import at.gv.egiz.eaaf.core.api.data.EAAFConstants;
-import at.gv.egiz.eaaf.core.api.gui.IGUIBuilderConfiguration;
-import at.gv.egiz.eaaf.core.api.gui.IVelocityGUIBuilderConfiguration;
-import at.gv.egiz.eaaf.core.api.gui.IVelocityGuiFormBuilder;
-import at.gv.egiz.eaaf.core.exceptions.GUIBuildException;
-import at.gv.egiz.eaaf.core.impl.gui.velocity.VelocityProvider;
-
-/**
- * @author tlenz 
- *
- */
-public abstract class AbstractVelocityGUIFormBuilderImpl implements IVelocityGuiFormBuilder {
-	private static final Logger log = LoggerFactory.getLogger(AbstractVelocityGUIFormBuilderImpl.class);
-	private static final String DEFAULT_CONTENT_TYPE = EAAFConstants.CONTENTTYPE_HTML_UTF8;
-			
-	private VelocityEngine engine;
-		
-	public AbstractVelocityGUIFormBuilderImpl() throws GUIBuildException {
-		try {
-			engine = VelocityProvider.getClassPathVelocityEngine();
-			
-		} catch (final Exception e) {
-			log.error("Initialization of Velocity-Engine to render GUI components FAILED.", e);
-			throw new GUIBuildException("Initialization of Velocity-Engine to render GUI components FAILED.", e);
-			
-		}
-		
-	}
-
-	@Override
-	public final void build(HttpServletRequest httpReq, HttpServletResponse httpResp, IGUIBuilderConfiguration config,
-			String loggerName) throws GUIBuildException {
-		if (config instanceof IVelocityGUIBuilderConfiguration)
-			build(httpReq, httpResp, (IVelocityGUIBuilderConfiguration)config, loggerName);
-		else
-			throw new IllegalStateException(this.getClass().getName() + " needs a " + IVelocityGUIBuilderConfiguration.class.getName());
-		
-		
-	}
-
-	@Override
-	public final void build(HttpServletRequest httpReq, HttpServletResponse httpResp, IGUIBuilderConfiguration config,
-			String contentType, String loggerName) throws GUIBuildException {
-		if (config instanceof IVelocityGUIBuilderConfiguration)
-			build(httpReq, httpResp, (IVelocityGUIBuilderConfiguration)config, contentType, loggerName);
-		else
-			throw new IllegalStateException(this.getClass().getName() + " needs a " + IVelocityGUIBuilderConfiguration.class.getName());
-		
-	}
-	
-	@Override
-	public void build(HttpServletRequest httpReq, HttpServletResponse httpResp, IVelocityGUIBuilderConfiguration config, String loggerName) throws GUIBuildException {
-		build(httpReq, httpResp, config, getInternalContentType(config), loggerName);
-		
-	}
-	
-	@Override
-	public void build(HttpServletRequest httpReq, HttpServletResponse httpResp, IVelocityGUIBuilderConfiguration config, 
-			String contentType, String loggerName) throws GUIBuildException {
-		
-		InputStream is = null;
-		try {
-			final String viewName = config.getViewName();			
-			is = getTemplateInputStream(config);
-			
-			//build Velocity Context from input paramters
-			final VelocityContext context = buildContextFromViewParams(config.getViewParameters());
-
-			//evaluate template
-			final StringWriter writer = new StringWriter();
-			engine.evaluate(context, writer, loggerName, new BufferedReader(new InputStreamReader(is)));
-							
-			//write template to response
-			final byte[] content = writer.toString().getBytes("UTF-8");
-			httpResp.setStatus(HttpServletResponse.SC_OK);
-			httpResp.setContentLength(content.length);
-			httpResp.setContentType(contentType);						
-			httpResp.getOutputStream().write(content);
-			
-			if (log.isTraceEnabled()) {
-				log.trace("Write Content for viewName:" + viewName 
-						+ ". Contentsize:" + String.valueOf(content.length)
-						+ " BufferSize:" + httpResp.getBufferSize()
-						+ " ContentType:" + contentType);
-				for (final String el : httpResp.getHeaderNames())
-					log.trace(" * Headername:" + el + " Value:" + httpResp.getHeader(el));
-				
-			}
-			
-		} catch (final IOException e) {
-			log.error("GUI form-builder has an internal error.", e);
-			throw new GUIBuildException("GUI form-builder has an internal error.", e);
-						
-		} finally {
-			if (is != null)
-				try {
-					is.close();
-					
-				} catch (final IOException e) {
-					log.error("Can NOT close GUI-Template InputStream.", e);
-					
-				}
-		}
-		
-	}
-
-	/**
-	 * Generate a new {@link VelocityContext} and populate it with MOA-ID GUI parameters
-	 * 
-	 * @param config
-	 * @return
-	 */
-	@Override
-	public VelocityContext generateVelocityContextFromConfiguration(IVelocityGUIBuilderConfiguration config) {
-		return buildContextFromViewParams(config.getViewParameters());
-		
-	}
-	
-	/**
-	 * Load the template from different resources
-	 * 
-	 * @param config
-	 * @return An {@link InputStream} but never null. The {@link InputStream} had to be closed be the invoking method
-	 * @throws GUIBuildException
-	 */
-	@Override
-	public InputStream getTemplateInputStream(IVelocityGUIBuilderConfiguration config) throws GUIBuildException {
-		InputStream is = config.getTemplate(config.getViewName());
-		if (is == null) {
-			log.trace("Loading GUI template:" + config.getViewName() + " from default resources ... ");
-			is = getInternalTemplate(config);
-			
-			if (is == null) {
-				log.warn("No GUI with viewName:" + config.getViewName() + " FOUND.");
-				throw new GUIBuildException("No GUI with viewName:" + config.getViewName() + " FOUND.");
-		
-			}
-		}		
-		return is;
-		
-	}
-	
-	/**
-	 * Load an internal template from default resources
-	 * 
-	 * @param config
-	 * @return
-	 * @throws GUIBuildException
-	 */
-	abstract protected InputStream getInternalTemplate(IVelocityGUIBuilderConfiguration config) throws GUIBuildException;
-
-	
-	/**
-	 * @return
-	 */ 
-	protected String getInternalClasspathTemplateDir(IVelocityGUIBuilderConfiguration config, String defaultClassPathDir) {
-		String dir = config.getClasspathTemplateDir();
-		if (dir != null) {
-			if (!dir.endsWith("/"))
-				dir += "/";
-			
-			return dir;			
-			
-		} else
-			return defaultClassPathDir;
-	}
-	
-	/**
-	 * @param viewParams
-	 * @return
-	 */
-	private VelocityContext buildContextFromViewParams(Map<String, Object> viewParams) {
-		final VelocityContext context = new VelocityContext();
-				
-		if (viewParams != null) {
-			final Iterator<Entry<String, Object>> interator = viewParams.entrySet().iterator();
-			while (interator.hasNext()) {
-				final Entry<String, Object> el = interator.next();
-				context.put(el.getKey(), el.getValue());
-			}
-			
-		} 
-		
-		return context;
-	}
-	
-	private String getInternalContentType(IGUIBuilderConfiguration config) {
-		if (StringUtils.isEmpty(config.getDefaultContentType()))
-			return DEFAULT_CONTENT_TYPE;
-		
-		else
-			return config.getDefaultContentType();
-		
-	}
-
-}
diff --git a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractVelocityGuiFormBuilderImpl.java b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractVelocityGuiFormBuilderImpl.java
new file mode 100644
index 00000000..0ab5fa49
--- /dev/null
+++ b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/AbstractVelocityGuiFormBuilderImpl.java
@@ -0,0 +1,250 @@
+/*
+ * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
+ * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
+ *
+ * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by the European
+ * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
+ * compliance with the Licence. You may obtain a copy of the Licence at:
+ * https://joinup.ec.europa.eu/news/understanding-eupl-v12
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the Licence
+ * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the Licence for the specific language governing permissions and limitations under
+ * the Licence.
+ *
+ * This product combines work with different licenses. See the "NOTICE" text file for details on the
+ * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
+ * works that you distribute must include a readable copy of the "NOTICE" text file.
+*/
+
+package at.gv.egiz.eaaf.core.impl.gui;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.StringWriter;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Map.Entry;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import at.gv.egiz.eaaf.core.api.data.EAAFConstants;
+import at.gv.egiz.eaaf.core.api.gui.IGuiBuilderConfiguration;
+import at.gv.egiz.eaaf.core.api.gui.IVelocityGuiBuilderConfiguration;
+import at.gv.egiz.eaaf.core.api.gui.IVelocityGuiFormBuilder;
+import at.gv.egiz.eaaf.core.exceptions.GuiBuildException;
+import at.gv.egiz.eaaf.core.impl.gui.velocity.VelocityProvider;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.velocity.VelocityContext;
+import org.apache.velocity.app.VelocityEngine;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Abstract VeloCity based GUI builder implementation.
+ *
+ * @author tlenz
+ *
+ */
+public abstract class AbstractVelocityGuiFormBuilderImpl implements IVelocityGuiFormBuilder {
+  private static final Logger log =
+      LoggerFactory.getLogger(AbstractVelocityGuiFormBuilderImpl.class);
+  private static final String DEFAULT_CONTENT_TYPE = EAAFConstants.CONTENTTYPE_HTML_UTF8;
+
+  private VelocityEngine engine;
+
+  /**
+   * Velocity based GUI builder.
+   *
+   * @throws GuiBuildException In case of a error
+   */
+  public AbstractVelocityGuiFormBuilderImpl() throws GuiBuildException {
+    try {
+      engine = VelocityProvider.getClassPathVelocityEngine();
+
+    } catch (final Exception e) {
+      log.error("Initialization of Velocity-Engine to render GUI components FAILED.", e);
+      throw new GuiBuildException(
+          "Initialization of Velocity-Engine to render GUI components FAILED.", e);
+
+    }
+
+  }
+
+  @Override
+  public final void build(final HttpServletRequest httpReq, final HttpServletResponse httpResp,
+      final IGuiBuilderConfiguration config, final String loggerName) throws GuiBuildException {
+    if (config instanceof IVelocityGuiBuilderConfiguration) {
+      build(httpReq, httpResp, (IVelocityGuiBuilderConfiguration) config, loggerName);
+    } else {
+      throw new IllegalStateException(this.getClass().getName() + " needs a "
+          + IVelocityGuiBuilderConfiguration.class.getName());
+    }
+
+
+  }
+
+  @Override
+  public final void build(final HttpServletRequest httpReq, final HttpServletResponse httpResp,
+      final IGuiBuilderConfiguration config, final String contentType, final String loggerName)
+      throws GuiBuildException {
+    if (config instanceof IVelocityGuiBuilderConfiguration) {
+      build(httpReq, httpResp, (IVelocityGuiBuilderConfiguration) config, contentType, loggerName);
+    } else {
+      throw new IllegalStateException(this.getClass().getName() + " needs a "
+          + IVelocityGuiBuilderConfiguration.class.getName());
+    }
+
+  }
+
+  @Override
+  public void build(final HttpServletRequest httpReq, final HttpServletResponse httpResp,
+      final IVelocityGuiBuilderConfiguration config, final String loggerName)
+      throws GuiBuildException {
+    build(httpReq, httpResp, config, getInternalContentType(config), loggerName);
+
+  }
+
+  @Override
+  public void build(final HttpServletRequest httpReq, final HttpServletResponse httpResp,
+      final IVelocityGuiBuilderConfiguration config, final String contentType,
+      final String loggerName) throws GuiBuildException {
+
+    InputStream is = null;
+    try {
+      final String viewName = config.getViewName();
+      is = getTemplateInputStream(config);
+
+      // build Velocity Context from input paramters
+      final VelocityContext context = buildContextFromViewParams(config.getViewParameters());
+
+      // evaluate template
+      final StringWriter writer = new StringWriter();
+      engine.evaluate(context, writer, loggerName, new BufferedReader(new InputStreamReader(is, "UTF-8")));
+
+      // write template to response
+      final byte[] content = writer.toString().getBytes("UTF-8");
+      httpResp.setStatus(HttpServletResponse.SC_OK);
+      httpResp.setContentLength(content.length);
+      httpResp.setContentType(contentType);
+      httpResp.getOutputStream().write(content);
+
+      if (log.isTraceEnabled()) {
+        log.trace("Write Content for viewName:" + viewName + ". Contentsize:"
+            + String.valueOf(content.length) + " BufferSize:" + httpResp.getBufferSize()
+            + " ContentType:" + contentType);
+        for (final String el : httpResp.getHeaderNames()) {
+          log.trace(" * Headername:" + el + " Value:" + httpResp.getHeader(el));
+        }
+
+      }
+
+    } catch (final IOException e) {
+      log.error("GUI form-builder has an internal error.", e);
+      throw new GuiBuildException("GUI form-builder has an internal error.", e);
+
+    } finally {
+      if (is != null) {
+        try {
+          is.close();
+
+        } catch (final IOException e) {
+          log.error("Can NOT close GUI-Template InputStream.", e);
+
+        }
+      }
+    }
+
+  }
+
+  /**
+   * Generate a new {@link VelocityContext} and populate it with MOA-ID GUI parameters.
+   *
+   * @param config GUI builder config
+   * @return Context of Velocity engine
+   */
+  @Override
+  public VelocityContext generateVelocityContextFromConfiguration(
+      final IVelocityGuiBuilderConfiguration config) {
+    return buildContextFromViewParams(config.getViewParameters());
+
+  }
+
+  /**
+   * Load the template from different resources.
+   *
+   * @param config GUI builder config
+   * @return An {@link InputStream} but never null. The {@link InputStream} had to be closed be the
+   *         invoking method
+   * @throws GuiBuildException In case of an error
+   */
+  @Override
+  public InputStream getTemplateInputStream(final IVelocityGuiBuilderConfiguration config)
+      throws GuiBuildException {
+    InputStream is = config.getTemplate(config.getViewName());
+    if (is == null) {
+      log.trace("Loading GUI template:" + config.getViewName() + " from default resources ... ");
+      is = getInternalTemplate(config);
+
+      if (is == null) {
+        log.warn("No GUI with viewName:" + config.getViewName() + " FOUND.");
+        throw new GuiBuildException("No GUI with viewName:" + config.getViewName() + " FOUND.");
+
+      }
+    }
+    return is;
+
+  }
+
+  /**
+   * Load an internal template from default resources.
+   *
+   * @param config GUI builder config
+   * @return Template that should be used
+   * @throws GuiBuildException in case of an error
+   */
+  protected abstract InputStream getInternalTemplate(IVelocityGuiBuilderConfiguration config)
+      throws GuiBuildException;
+
+
+  protected String getInternalClasspathTemplateDir(final IVelocityGuiBuilderConfiguration config,
+      final String defaultClassPathDir) {
+    String dir = config.getClasspathTemplateDir();
+    if (dir != null) {
+      if (!dir.endsWith("/")) {
+        dir += "/";
+      }
+
+      return dir;
+
+    } else {
+      return defaultClassPathDir;
+    }
+  }
+
+  private VelocityContext buildContextFromViewParams(final Map<String, Object> viewParams) {
+    final VelocityContext context = new VelocityContext();
+
+    if (viewParams != null) {
+      final Iterator<Entry<String, Object>> interator = viewParams.entrySet().iterator();
+      while (interator.hasNext()) {
+        final Entry<String, Object> el = interator.next();
+        context.put(el.getKey(), el.getValue());
+      }
+
+    }
+
+    return context;
+  }
+
+  private String getInternalContentType(final IGuiBuilderConfiguration config) {
+    if (StringUtils.isEmpty(config.getDefaultContentType())) {
+      return DEFAULT_CONTENT_TYPE;
+    } else {
+      return config.getDefaultContentType();
+    }
+
+  }
+
+}
diff --git a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityLogAdapter.java b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityLogAdapter.java
index a118d7e1..05cbaf58 100644
--- a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityLogAdapter.java
+++ b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityLogAdapter.java
@@ -1,32 +1,26 @@
-/*******************************************************************************
- * Copyright 2017 Graz University of Technology
- * EAAF-Core Components has been developed in a cooperation between EGIZ,  
- * A-SIT Plus, A-SIT, and Graz University of Technology.
+/*
+ * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
+ * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
  *
- * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by
- * the European Commission - subsequent versions of the EUPL (the "Licence");
- * You may not use this work except in compliance with the Licence.
- * You may obtain a copy of the Licence at:
+ * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by the European
+ * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
+ * compliance with the Licence. You may obtain a copy of the Licence at:
  * https://joinup.ec.europa.eu/news/understanding-eupl-v12
  *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the Licence is distributed on an "AS IS" basis,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the Licence for the specific language governing permissions and
- * limitations under the Licence.
- *  
- * This product combines work with different licenses. See the "NOTICE" text
- * file for details on the various modules and licenses.
- * The "NOTICE" text file is part of the distribution. Any derivative works
- * that you distribute must include a readable copy of the "NOTICE" text file.
- *******************************************************************************/
-/*******************************************************************************
- *******************************************************************************/
-/*******************************************************************************
- *******************************************************************************/
+ * Unless required by applicable law or agreed to in writing, software distributed under the Licence
+ * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the Licence for the specific language governing permissions and limitations under
+ * the Licence.
+ *
+ * This product combines work with different licenses. See the "NOTICE" text file for details on the
+ * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
+ * works that you distribute must include a readable copy of the "NOTICE" text file.
+*/
+
 package at.gv.egiz.eaaf.core.impl.gui.velocity;
 
 import org.apache.velocity.app.Velocity;
+import org.apache.velocity.runtime.RuntimeConstants;
 import org.apache.velocity.runtime.RuntimeServices;
 import org.apache.velocity.runtime.log.LogChute;
 import org.slf4j.Logger;
@@ -34,72 +28,78 @@ import org.slf4j.LoggerFactory;
 
 public class VelocityLogAdapter implements LogChute {
 
-	private static final Logger log = LoggerFactory.getLogger(VelocityLogAdapter.class);
-	
-	public VelocityLogAdapter() {
-		try
-	    {
-	      /*
-	       *  register this class as a logger with the Velocity singleton
-	       *  (NOTE: this would not work for the non-singleton method.)
-	       */
-	      Velocity.setProperty(Velocity.RUNTIME_LOG_LOGSYSTEM, this );
-	      Velocity.init();
-	    }
-	    catch (Exception e)
-	    {
-	    	 log.error("Failed to register Velocity logger");
-	    }
-	}
-	
-	public void init(RuntimeServices arg0) throws Exception {
-	}
+  private static final Logger log = LoggerFactory.getLogger(VelocityLogAdapter.class);
+
+  /**
+   * VeloCity Logging adapter.
+   *
+   */
+  public VelocityLogAdapter() {
+    try {
+      /*
+       * register this class as a logger with the Velocity singleton (NOTE: this would not work for
+       * the non-singleton method.)
+       */
+      Velocity.setProperty(RuntimeConstants.RUNTIME_LOG_LOGSYSTEM, this);
+      Velocity.init();
+    } catch (final Exception e) {
+      log.error("Failed to register Velocity logger");
+    }
+  }
+
+  @Override
+  public void init(final RuntimeServices arg0) throws Exception {
+
+  }
+
+  @Override
+  public boolean isLevelEnabled(final int arg0) {
+    switch (arg0) {
+      case LogChute.DEBUG_ID:
+        return log.isDebugEnabled();
+      case LogChute.TRACE_ID:
+        return log.isTraceEnabled();
+      default:
+        return true;
+    }
+  }
 
-	public boolean isLevelEnabled(int arg0) {
-		switch(arg0) {
-		case LogChute.DEBUG_ID:
-			return  log.isDebugEnabled();
-		case LogChute.TRACE_ID:
-			return  log.isTraceEnabled();
-		default:
-			return true;
-		}
-	}
+  @Override
+  public void log(final int arg0, final String arg1) {
+    switch (arg0) {
+      case LogChute.DEBUG_ID:
+        log.debug(arg1);
+        break;
+      case LogChute.TRACE_ID:
+        log.trace(arg1);
+        break;
+      case LogChute.INFO_ID:
+        log.info(arg1);
+        break;
+      case LogChute.WARN_ID:
+        log.warn(arg1);
+        break;
+      case LogChute.ERROR_ID:
+      default:
+        log.error(arg1);
+        break;
+    }
+  }
 
-	public void log(int arg0, String arg1) {
-		switch(arg0) {
-		case LogChute.DEBUG_ID:
-			 log.debug(arg1);
-			break;
-		case LogChute.TRACE_ID:
-			 log.trace(arg1);
-			break;
-		case LogChute.INFO_ID:
-			 log.info(arg1);
-			break;
-		case LogChute.WARN_ID:
-			 log.warn(arg1);
-			break;
-		case LogChute.ERROR_ID:
-		default:
-			 log.error(arg1);
-			break;
-		}
-	}
+  @Override
+  public void log(final int arg0, final String arg1, final Throwable arg2) {
+    switch (arg0) {
+      case LogChute.DEBUG_ID:
+      case LogChute.TRACE_ID:
+      case LogChute.INFO_ID:
+      case LogChute.WARN_ID:
+        log.warn(arg1, arg2);
+        break;
+      case LogChute.ERROR_ID:
+      default:
+        log.error(arg1, arg2);
+        break;
+    }
+  }
 
-	public void log(int arg0, String arg1, Throwable arg2) {
-		switch(arg0) {
-		case LogChute.DEBUG_ID:
-		case LogChute.TRACE_ID:
-		case LogChute.INFO_ID:
-		case LogChute.WARN_ID:
-			 log.warn(arg1, arg2);
-			break;
-		case LogChute.ERROR_ID:
-		default:
-			 log.error(arg1, arg2);
-			break;
-		}
-	}
-	
 }
diff --git a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityProvider.java b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityProvider.java
index 5775e203..18594985 100644
--- a/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityProvider.java
+++ b/eaaf_core/src/main/java/at/gv/egiz/eaaf/core/impl/gui/velocity/VelocityProvider.java
@@ -1,121 +1,91 @@
-/*******************************************************************************
- * Copyright 2014 Federal Chancellery Austria
- * MOA-ID has been developed in a cooperation between BRZ, the Federal
- * Chancellery Austria - ICT staff unit, and Graz University of Technology.
- * 
- * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
- * the European Commission - subsequent versions of the EUPL (the "Licence");
- * You may not use this work except in compliance with the Licence.
- * You may obtain a copy of the Licence at:
- * http://www.osor.eu/eupl/
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the Licence is distributed on an "AS IS" basis,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the Licence for the specific language governing permissions and
- * limitations under the Licence.
- * 
- * This product combines work with different licenses. See the "NOTICE" text
- * file for details on the various modules and licenses.
- * The "NOTICE" text file is part of the distribution. Any derivative works
- * that you distribute must include a readable copy of the "NOTICE" text file.
- ******************************************************************************/
 /*
- * Copyright 2011 by Graz University of Technology, Austria
- * The Austrian STORK Modules have been developed by the E-Government
- * Innovation Center EGIZ, a joint initiative of the Federal Chancellery
- * Austria and Graz University of Technology.
+ * Copyright 2014 Federal Chancellery Austria MOA-ID has been developed in a cooperation between
+ * BRZ, the Federal Chancellery Austria - ICT staff unit, and Graz University of Technology.
  *
- * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
- * the European Commission - subsequent versions of the EUPL (the "Licence");
- * You may not use this work except in compliance with the Licence.
- * You may obtain a copy of the Licence at:
- * http://www.osor.eu/eupl/
+ * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by the European
+ * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
+ * compliance with the Licence. You may obtain a copy of the Licence at: http://www.osor.eu/eupl/
  *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the Licence is distributed on an "AS IS" basis,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the Licence for the specific language governing permissions and
- * limitations under the Licence.
+ * Unless required by applicable law or agreed to in writing, software distributed under the Licence
+ * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the Licence for the specific language governing permissions and limitations under
+ * the Licence.
  *
- * This product combines work with different licenses. See the "NOTICE" text
- * file for details on the various modules and licenses.
- * The "NOTICE" text file is part of the distribution. Any derivative works
- * that you distribute must include a readable copy of the "NOTICE" text file.
- */
-
+ * This product combines work with different licenses. See the "NOTICE" text file for details on the
+ * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
+ * works that you distribute must include a readable copy of the "NOTICE" text file.
+*/
 
-/**
- * 
- */
 package at.gv.egiz.eaaf.core.impl.gui.velocity;
 
-import org.apache.velocity.app.Velocity;
 import org.apache.velocity.app.VelocityEngine;
 import org.apache.velocity.runtime.RuntimeConstants;
 
 /**
- * Gets a Velocity Engine
- * 
+ * Gets a Velocity Engine.
+ *
  * @author bzwattendorfer
  *
  */
 public class VelocityProvider {
 
-	private static VelocityEngine velocityEngine = null;
-	
-	/**
-	 * Gets velocityEngine from Classpath
-	 * @return VelocityEngine
-	 * @throws Exception
-	 */
-	public static VelocityEngine getClassPathVelocityEngine() throws Exception {
-		if (velocityEngine == null) {
-			velocityEngine = getBaseVelocityEngine();
-			velocityEngine.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
-			velocityEngine.setProperty("classpath.resource.loader.class",
-					"org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");                
-			velocityEngine.init();
-			
-		}
-		
-		return velocityEngine;
-	}
-	
-	/**
-	 * Gets VelocityEngine from File
-	 * @param rootPath File Path to template file
-	 * @return VelocityEngine
-	 * @throws Exception
-	 */
-	public static VelocityEngine getFileVelocityEngine(String rootPath) throws Exception {
-		if (velocityEngine == null) {
-			velocityEngine = getBaseVelocityEngine();
-			velocityEngine.setProperty(RuntimeConstants.RESOURCE_LOADER, "file");
-			velocityEngine.setProperty("file.resource.loader.class",
-					"org.apache.velocity.runtime.resource.loader.FileResourceLoader");
-			velocityEngine.setProperty("file.resource.loader.path", rootPath);
-        
-			velocityEngine.init();
-			
-		}
-		
-		return velocityEngine;
-	}
-	
-	/**
-	 * Gets a basic VelocityEngine
-	 * @return VelocityEngine
-	 */
-	private static VelocityEngine getBaseVelocityEngine() {
-		VelocityEngine velocityEngine = new VelocityEngine();
-        velocityEngine.setProperty(RuntimeConstants.INPUT_ENCODING, "UTF-8");
-        velocityEngine.setProperty(RuntimeConstants.OUTPUT_ENCODING, "UTF-8");
-//        velocityEngine.setProperty(RuntimeConstants.RUNTIME_LOG_LOGSYSTEM_CLASS,
-//				"org.apache.velocity.runtime.log.SimpleLog4JLogSystem");
-        velocityEngine.setProperty(Velocity.RUNTIME_LOG_LOGSYSTEM, new VelocityLogAdapter() );
-        
-        return velocityEngine;
-	}
-	
+  private static VelocityEngine velocityEngine = null;
+
+  /**
+   * Gets velocityEngine from Classpath.
+   *
+   * @return VelocityEngine
+   * @throws Exception In case of an error
+   */
+  public static VelocityEngine getClassPathVelocityEngine() throws Exception {
+    if (velocityEngine == null) {
+      velocityEngine = getBaseVelocityEngine();
+      velocityEngine.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
+      velocityEngine.setProperty("classpath.resource.loader.class",
+          "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
+      velocityEngine.init();
+
+    }
+
+    return velocityEngine;
+  }
+
+  /**
+   * Gets VelocityEngine from File.
+   *
+   * @param rootPath File Path to template file
+   * @return VelocityEngine
+   * @throws Exception in case of an error
+   */
+  public static VelocityEngine getFileVelocityEngine(final String rootPath) throws Exception {
+    if (velocityEngine == null) {
+      velocityEngine = getBaseVelocityEngine();
+      velocityEngine.setProperty(RuntimeConstants.RESOURCE_LOADER, "file");
+      velocityEngine.setProperty("file.resource.loader.class",
+          "org.apache.velocity.runtime.resource.loader.FileResourceLoader");
+      velocityEngine.setProperty("file.resource.loader.path", rootPath);
+
+      velocityEngine.init();
+
+    }
+
+    return velocityEngine;
+  }
+
+  /**
+   * Gets a basic VelocityEngine.
+   *
+   * @return VelocityEngine
+   */
+  private static VelocityEngine getBaseVelocityEngine() {
+    final VelocityEngine velocityEngine = new VelocityEngine();
+    velocityEngine.setProperty(RuntimeConstants.INPUT_ENCODING, "UTF-8");
+    velocityEngine.setProperty(RuntimeConstants.OUTPUT_ENCODING, "UTF-8");
+    // velocityEngine.setProperty(RuntimeConstants.RUNTIME_LOG_LOGSYSTEM_CLASS,
+    // "org.apache.velocity.runtime.log.SimpleLog4JLogSystem");
+    velocityEngine.setProperty(RuntimeConstants.RUNTIME_LOG_LOGSYSTEM, new VelocityLogAdapter());
+
+    return velocityEngine;
+  }
+
 }