taglibs-rdc/src/main/java/org/apache/taglibs/rdc/core/GroupTag.java - tomcat-taglibs-rdc - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.taglibs.rdc.core;

 import java.io.IOException;
 import java.text.MessageFormat;

 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.jsp.JspContext;
 import javax.servlet.jsp.PageContext;
 import javax.servlet.jsp.JspException;
 import javax.servlet.jsp.tagext.SimpleTagSupport;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.taglibs.rdc.RDCUtils;

 /**
  * <p>This is the implementation of the RDC helper tag group.
  * Group is a container with pluggable DM strategies.</p>
  *
  * @author Rahul Akolkar
  */
 public class GroupTag extends SimpleTagSupport {

     // Error messages (to be i18n'zed)
     private static final String ERR_NO_STRATEGY = "<!-- GroupTag: " +
         "strategy attribute value - \"{0}\" contains whitespace only -->\n";
     private static final String ERR_NO_SUCH_STRATEGY = "<!-- GroupTag: No " +
         "strategy class found - \"{0}\" -->\n";
     private static final String ERR_NOT_A_DM_STRATEGY = "<!-- GroupTag: " +
         "Class - \"{0}\" does not implement the DialogManager interface -->\n";
     private static final String ERR_INSTANTIATING_STRATEGY = "<!-- GroupTag:" +
         " Error instantiating the specified strategy class - \"{0}\" -->\n";

     // Logging
     private static Log log = LogFactory.getLog(GroupTag.class);

     // CLASS PROPERTIES
     // The unique identifier associated with the group
     private String id;
     // Holds the submit url
     private String submit;
     // Holds the configuration details for the dialog management strategy
     // The interpretation of this attribute is upto the DM strategy plugged in
     private String config;
     // Indicates whether group level confirmation is requested
     // Overrides atom level confirmation, if specified
     private Boolean confirm;
     // The class name that implements the dialog management strategy
     private String strategy;
     // The DialogManager overseeing this group instance
     private DialogManager dm = null;

     /* Constructor */
     public GroupTag() {
         super();
         id = null;
         submit = null;
         config = null;
         strategy = null;
         confirm = Boolean.FALSE;
         dm = null;
     }

     /**
      * Gets the ID of the group
      *
      * @return ID The group's strategy
      */
     public String getId() {
         return id;
     }

     /**
      * Sets the id of the group
      *
      * @param id The group's id
      */
     public void setId(String id) {
         this.id = id;
     }

     /**
      * Gets the submit URL where group should submit
      *
      * @return submit The group's submit URL
      */
     public String getSubmit() {
         return submit;
     }

     /**
      * Sets the submit URL for the group
      *
      * @param submit The group's submit URL
      */
     public void setSubmit(String submit) {
         this.submit = submit;
     }

     /**
      * Gets the configuration URI of the group
      *
      * @return config The group's configuration URI
      */
     public String getConfig() {
         return config;
     }

     /**
      * Sets the configuration URI of the group
      *
      * @param config The group's configuration URI
      */
     public void setConfig(String config) {
         this.config = config;
     }

     /**
      * Get the group level confirmation
      *
      * @return confirm
      */
     public Boolean getConfirm() {
         return confirm;
     }

     /**
      * Set the group level confirmation
      *
      * @param confirm The group confirmation
      */
     public void setConfirm(Boolean confirm) {
         this.confirm = confirm;
     }

     /**
      * Get the class name that implements the DM strategy
      *
      * @return strategy the class name
      */
     public String getStrategy() {
         return strategy;
     }

     /**
      * Set the class name that implements the DM strategy
      *
      * @param strategy the class name
      */
     public void setStrategy(String strategy) {
         this.strategy = strategy;
     }

     /**
      * Make JspContext visible to the DM strategy
      *
      * @return JspContext
      */
     public JspContext getJspContext() {
         return super.getJspContext();
     }

     /**
      * Has the state machine for the group
      *
      * Uses a pluggable dialog management strategy
      */
     public void doTag() throws JspException, IOException {

         if (dm == null) {
             PageContext ctx = (PageContext) getJspContext();
             try {
                 dm = getStrategyInstance(ctx);
             } catch (ClassNotFoundException cnfe) {
                 write(ctx, ERR_NO_SUCH_STRATEGY,
                     new Object[] {strategy}, cnfe);
             }
         }

         if (submit == null || submit.length() == 0) {
             submit = ((HttpServletRequest) ((PageContext) getJspContext()).
                 getRequest()).getRequestURI();
         }

         dm.setGroupTag(this);

         if (!dm.initialize(getJspContext(), getJspBody())) {
             return;
         }

         dm.collect(getJspContext(), getJspBody());

         // Deprecated (since RDC 1.1)
         dm.confirm();

         dm.finish(getJspContext());

     }

     /**
      * Instantiate the strategy for this group instance.
      *
      * @param ctx The host JSP PageContext
      * @return DialogManager The DM strategy instance
      */
     private DialogManager getStrategyInstance(PageContext ctx)
     throws ClassNotFoundException {
         final Object[] errMsgArgs = new Object[] {strategy};
         if (RDCUtils.isStringEmpty(strategy)) {
             write(ctx, ERR_NO_STRATEGY, errMsgArgs, null);
             return null;
         }
         Class dmClass = null;
         DialogManager dialogManager = null;
         try {
             dmClass = Class.forName(strategy);
         } catch (ClassNotFoundException cnfe) {
             // Try the classloader for this thread
             dmClass = Class.forName(strategy, true, Thread.currentThread().
                         getContextClassLoader());
         } catch (Exception e) {
             // Log error
             log.error(e.getMessage(), e);
             write(ctx, ERR_INSTANTIATING_STRATEGY, errMsgArgs, null);
         }

         if (dmClass != null) {
             try {
                 dialogManager = (DialogManager) dmClass.newInstance();
             } catch (ClassCastException cce) {
                 write(ctx, ERR_NOT_A_DM_STRATEGY, errMsgArgs, cce);
             } catch (Exception e) {
                 // Log error
                 log.error(e.getMessage(), e);
                 write(ctx, ERR_INSTANTIATING_STRATEGY, errMsgArgs, e);
             }
         }
         return dialogManager;
     }

     /**
      * Attempt to write given message to JSP writer.
      *
      * @param ctx The host JSP PageContext
      * @param msg The message to be sent to the JSP writer
      * @return boolean Outcome of write attempt
      */
     private void write(final PageContext ctx, final String errMsgName,
             final Object[] msgArgs, final Exception e) {
         MessageFormat msgFormat = new MessageFormat(errMsgName);
         String errMsg = msgFormat.format(msgArgs);
         // Log error
         if (e == null) {
             log.error(errMsg);
         } else {
             log.error(errMsg, e);
         }
         // Attempt to send message to client
         try {
             ctx.getOut().write(errMsg);
         } catch (IOException ioe) {
             log.error(ioe.getMessage(),ioe);
         }
     }

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.apache.taglibs.rdc.core;

	import java.io.IOException;
	import java.text.MessageFormat;

	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.jsp.JspContext;
	import javax.servlet.jsp.PageContext;
	import javax.servlet.jsp.JspException;
	import javax.servlet.jsp.tagext.SimpleTagSupport;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.taglibs.rdc.RDCUtils;

	/**
	* <p>This is the implementation of the RDC helper tag group.
	* Group is a container with pluggable DM strategies.</p>
	*
	* @author Rahul Akolkar
	*/
	public class GroupTag extends SimpleTagSupport {

	// Error messages (to be i18n'zed)
	private static final String ERR_NO_STRATEGY = "<!-- GroupTag: " +
	"strategy attribute value - \"{0}\" contains whitespace only -->\n";
	private static final String ERR_NO_SUCH_STRATEGY = "<!-- GroupTag: No " +
	"strategy class found - \"{0}\" -->\n";
	private static final String ERR_NOT_A_DM_STRATEGY = "<!-- GroupTag: " +
	"Class - \"{0}\" does not implement the DialogManager interface -->\n";
	private static final String ERR_INSTANTIATING_STRATEGY = "<!-- GroupTag:" +
	" Error instantiating the specified strategy class - \"{0}\" -->\n";

	// Logging
	private static Log log = LogFactory.getLog(GroupTag.class);

	// CLASS PROPERTIES
	// The unique identifier associated with the group
	private String id;
	// Holds the submit url
	private String submit;
	// Holds the configuration details for the dialog management strategy
	// The interpretation of this attribute is upto the DM strategy plugged in
	private String config;
	// Indicates whether group level confirmation is requested
	// Overrides atom level confirmation, if specified
	private Boolean confirm;
	// The class name that implements the dialog management strategy
	private String strategy;
	// The DialogManager overseeing this group instance
	private DialogManager dm = null;

	/* Constructor */
	public GroupTag() {
	super();
	id = null;
	submit = null;
	config = null;
	strategy = null;
	confirm = Boolean.FALSE;
	dm = null;
	}

	/**
	* Gets the ID of the group
	*
	* @return ID The group's strategy
	*/
	public String getId() {
	return id;
	}

	/**
	* Sets the id of the group
	*
	* @param id The group's id
	*/
	public void setId(String id) {
	this.id = id;
	}

	/**
	* Gets the submit URL where group should submit
	*
	* @return submit The group's submit URL
	*/
	public String getSubmit() {
	return submit;
	}

	/**
	* Sets the submit URL for the group
	*
	* @param submit The group's submit URL
	*/
	public void setSubmit(String submit) {
	this.submit = submit;
	}

	/**
	* Gets the configuration URI of the group
	*
	* @return config The group's configuration URI
	*/
	public String getConfig() {
	return config;
	}

	/**
	* Sets the configuration URI of the group
	*
	* @param config The group's configuration URI
	*/
	public void setConfig(String config) {
	this.config = config;
	}

	/**
	* Get the group level confirmation
	*
	* @return confirm
	*/
	public Boolean getConfirm() {
	return confirm;
	}

	/**
	* Set the group level confirmation
	*
	* @param confirm The group confirmation
	*/
	public void setConfirm(Boolean confirm) {
	this.confirm = confirm;
	}

	/**
	* Get the class name that implements the DM strategy
	*
	* @return strategy the class name
	*/
	public String getStrategy() {
	return strategy;
	}

	/**
	* Set the class name that implements the DM strategy
	*
	* @param strategy the class name
	*/
	public void setStrategy(String strategy) {
	this.strategy = strategy;
	}

	/**
	* Make JspContext visible to the DM strategy
	*
	* @return JspContext
	*/
	public JspContext getJspContext() {
	return super.getJspContext();
	}

	/**
	* Has the state machine for the group
	*
	* Uses a pluggable dialog management strategy
	*/
	public void doTag() throws JspException, IOException {

	if (dm == null) {
	PageContext ctx = (PageContext) getJspContext();
	try {
	dm = getStrategyInstance(ctx);
	} catch (ClassNotFoundException cnfe) {
	write(ctx, ERR_NO_SUCH_STRATEGY,
	new Object[] {strategy}, cnfe);
	}
	}

	if (submit == null \|\| submit.length() == 0) {
	submit = ((HttpServletRequest) ((PageContext) getJspContext()).
	getRequest()).getRequestURI();
	}

	dm.setGroupTag(this);

	if (!dm.initialize(getJspContext(), getJspBody())) {
	return;
	}

	dm.collect(getJspContext(), getJspBody());

	// Deprecated (since RDC 1.1)
	dm.confirm();

	dm.finish(getJspContext());

	}

	/**
	* Instantiate the strategy for this group instance.
	*
	* @param ctx The host JSP PageContext
	* @return DialogManager The DM strategy instance
	*/
	private DialogManager getStrategyInstance(PageContext ctx)
	throws ClassNotFoundException {
	final Object[] errMsgArgs = new Object[] {strategy};
	if (RDCUtils.isStringEmpty(strategy)) {
	write(ctx, ERR_NO_STRATEGY, errMsgArgs, null);
	return null;
	}
	Class dmClass = null;
	DialogManager dialogManager = null;
	try {
	dmClass = Class.forName(strategy);
	} catch (ClassNotFoundException cnfe) {
	// Try the classloader for this thread
	dmClass = Class.forName(strategy, true, Thread.currentThread().
	getContextClassLoader());
	} catch (Exception e) {
	// Log error
	log.error(e.getMessage(), e);
	write(ctx, ERR_INSTANTIATING_STRATEGY, errMsgArgs, null);
	}

	if (dmClass != null) {
	try {
	dialogManager = (DialogManager) dmClass.newInstance();
	} catch (ClassCastException cce) {
	write(ctx, ERR_NOT_A_DM_STRATEGY, errMsgArgs, cce);
	} catch (Exception e) {
	// Log error
	log.error(e.getMessage(), e);
	write(ctx, ERR_INSTANTIATING_STRATEGY, errMsgArgs, e);
	}
	}
	return dialogManager;
	}

	/**
	* Attempt to write given message to JSP writer.
	*
	* @param ctx The host JSP PageContext
	* @param msg The message to be sent to the JSP writer
	* @return boolean Outcome of write attempt
	*/
	private void write(final PageContext ctx, final String errMsgName,
	final Object[] msgArgs, final Exception e) {
	MessageFormat msgFormat = new MessageFormat(errMsgName);
	String errMsg = msgFormat.format(msgArgs);
	// Log error
	if (e == null) {
	log.error(errMsg);
	} else {
	log.error(errMsg, e);
	}
	// Attempt to send message to client
	try {
	ctx.getOut().write(errMsg);
	} catch (IOException ioe) {
	log.error(ioe.getMessage(),ioe);
	}
	}

	}