commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From hus...@apache.org
Subject cvs commit: jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader ActionContextBase.java CheckLogonTag.java CommandAction.java Constants.java MemoryDatabasePlugIn.java
Date Thu, 25 Mar 2004 12:39:27 GMT
husted      2004/03/25 04:39:27

  Added:       chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader
                        ActionContextBase.java CheckLogonTag.java
                        CommandAction.java Constants.java
                        MemoryDatabasePlugIn.java
  Log:
  Initial import of MailReader Example application for Commons Chain
  
  Revision  Changes    Path
  1.1                  jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/ActionContextBase.java
  
  Index: ActionContextBase.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/ActionContextBase.java,v
1.1 2004/03/25 12:39:27 husted Exp $
   * $Revision: 1.1 $
   * $Date: 2004/03/25 12:39:27 $
   *
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * Licensed 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.commons.chain.mailreader;
  
  import org.apache.commons.chain.impl.ContextBase;
  import org.apache.struts.Globals;
  import org.apache.struts.action.*;
  import org.apache.struts.upload.MultipartRequestWrapper;
  import org.apache.struts.util.MessageResources;
  import org.apache.struts.util.RequestUtils;
  
  import javax.servlet.ServletContext;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.servlet.http.HttpSession;
  import javax.sql.DataSource;
  
  /**
   * <p>
   * [This class is based on the experimental ConfigHelper class,
   * and is under active development.]
   * <p>
   * A Context exposing the Struts shared resources,
   * which are be stored in the application, session, or
   * request contexts, as appropriate.
   * </p>
   * <p>
   * An instance should be created for each request
   * processed. The  methods which return resources from
   * the request or session contexts are not thread-safe.
   * </p>
   * <p>
   * Provided for use by Commands and other components in the
   * application so they can easily access the various Struts
   * shared resources. These resources may be stored under
   * attributes in the application, session, or request contexts,
   * but users of this class do not need to know where.
   * </p>
   * <p>
   * The ActionContextBase methods simply return the resources
   * from under the context and key used by the Struts
   * ActionServlet when the resources are created.
   * </p>
   * <p>
   * NOTE -- In the next version, a "ViewContext" interface
   * and implementation will be added to this class to allow
   * access to operations business Commands might use without
   * exposing Http signatures or other implementation details.
   * </p>
   * <p>
   * At some point, a "disconnected" implementation should be
   * available so that the Http resources do not have be cached
   * as class members.
   * </p>
   * <p>
   * NOTE -- This class may be migrated to a later release of Struts
   * when support for Commons Chains is added.
   * </p>
   */
  public class ActionContextBase extends ContextBase {
  
  // --------------------------------------------------------  Properties
  
      /**
       * The application associated with this instance.
       */
      private ServletContext application = null;
  
      /**
       * Set the application associated with this instance.
       * [servlet.getServletContext()]
       */
      public void setApplication(ServletContext application) {
          this.application = application;
      }
  
      /**
       * The session associated with this instance.
       */
      private HttpSession session = null;
  
      /**
       * Set the session associated with this instance.
       */
      public void setSession(HttpSession session) {
          this.session = session;
      }
  
      /**
       * The request associated with this instance.
       */
      private HttpServletRequest request = null;
  
      /**
       * Set the request associated with this object.
       * Session object is also set or cleared.
       */
      public void setRequest(HttpServletRequest request) {
          this.request = request;
          if (this.request == null)
              setSession(null);
          else
              setSession(this.request.getSession());
      }
  
      /**
       * The response associated with this instance.
       */
      private HttpServletResponse response = null;
  
      /**
       * Set the response associated with this isntance.
       * Session object is also set or cleared.
       */
      public void setResponse(HttpServletResponse response) {
          this.response = response;
      }
  
      /**
       * The forward associated with this instance.
       */
      private ActionForward forward = null;
  
      /**
       * Set the forward associated with this instance.
       */
      public void setForward(ActionForward forward) {
          this.forward = forward;
      }
  
      /**
       * Set the application and request for this object instance.
       * The ServletContext can be set by any servlet in the application.
       * The request should be the instant request.
       * Most of the other methods retrieve their own objects
       * by reference to the application, request, or session
       * attributes.
       * Do not call other methods without setting these first!
       * This is also called by the convenience constructor.
       *
       * @param application - The associated ServletContext.
       * @param request - The associated HTTP request.
       * @param response - The associated HTTP response.
       */
      public void setResources(
              ServletContext application,
              HttpServletRequest request,
              HttpServletResponse response) {
  
          setApplication(application);
          setRequest(request);
          setResponse(response);
      }
  
      public ActionContextBase() {
          super();
      }
  
      public ActionContextBase(
              ServletContext application,
              HttpServletRequest request,
              HttpServletResponse response) {
  
          super();
          this.setResources(application, request, response);
      }
  
  
      // ------------------------------------------------ Application Context
  
      /**
       * The <strong>default</strong>
       * configured data source (which must implement
       * <code>javax.sql.DataSource</code>),
       * if one is configured for this application.
       */
      public DataSource getDataSource() {
  
          if (this.application == null)
              return null;
          return (DataSource) this.application.getAttribute(Globals.DATA_SOURCE_KEY);
  
      }
  
      public ActionMessages getActionMessages() {
  
          if (this.application == null)
              return null;
          return (ActionMessages) this.application.getAttribute(Globals.MESSAGE_KEY);
  
      }
  
      /**
       * The application resources for this application.
       */
      public MessageResources getMessageResources() {
  
          if (this.application == null) {
              return null;
          }
          return (MessageResources) this.application.getAttribute(Globals.MESSAGES_KEY);
  
      }
  
      /**
       * The path-mapped pattern (<code>/action/*</code>) or
       * extension mapped pattern ((<code>*.do</code>)
       * used to determine our Action URIs in this application.
       */
      public String getServletMapping() {
  
          if (this.application == null) {
              return null;
          }
          return (String) this.application.getAttribute(Globals.SERVLET_KEY);
  
      }
  
      // ---------------------------------------------------- Session Context
  
      /**
       * The transaction token stored in this session, if it is used.
       */
      public String getToken() {
  
          if (this.session == null) {
              return null;
          }
          return (String) session.getAttribute(Globals.TRANSACTION_TOKEN_KEY);
  
      }
  
      // ---------------------------------------------------- Request Context
  
      /**
       * The runtime JspException that may be been thrown by a Struts tag
       * extension, or compatible presentation extension, and placed
       * in the request.
       */
      public Throwable getException() {
  
          if (this.request == null) {
              return null;
          }
          return (Throwable) this.request.getAttribute(Globals.EXCEPTION_KEY);
  
      }
  
      /**
       * The multipart object for this request.
       */
      public MultipartRequestWrapper getMultipartRequestWrapper() {
  
          if (this.request == null) {
              return null;
          }
          return (MultipartRequestWrapper) this.request.getAttribute(Globals.MULTIPART_KEY);
      }
  
      /**
       * The <code>org.apache.struts.ActionMapping</code>
       * instance for this request.
       */
      public ActionMapping getMapping() {
  
          if (this.request == null) {
              return null;
          }
          return (ActionMapping) this.request.getAttribute(Globals.MAPPING_KEY);
  
      }
  
      // ---------------------------------------------------- Utility Methods
  
      /**
       * Return true if a message string for the specified message key
       * is present for the user's Locale.
       *
       * @param key Message key
       */
      public boolean isMessage(String key) {
  
          // Look up the requested MessageResources
          MessageResources resources = getMessageResources();
  
          if (resources == null) {
              return false;
          }
  
          // Return the requested message presence indicator
          return resources.isPresent(RequestUtils.getUserLocale(request, null), key);
  
      }
  
      /*
       * Retrieve and return the <code>ActionForm</code> bean associated with
       * this mapping, creating and stashing one if necessary.  If there is no
       * form bean associated with this mapping, return <code>null</code>.
       *
       */
      public ActionForm getActionForm() {
  
          // Is there a mapping associated with this request?
          ActionMapping mapping = getMapping();
          if (mapping == null)
              return (null);
  
          // Is there a form bean associated with this mapping?
          String attribute = mapping.getAttribute();
          if (attribute == null)
              return (null);
  
          // Look up the existing form bean, if any
          ActionForm instance = null;
          if ("request".equals(mapping.getScope())) {
              instance = (ActionForm) this.request.getAttribute(attribute);
          } else {
              instance = (ActionForm) this.session.getAttribute(attribute);
          }
  
          return instance;
      }
  
      /**
       * Return the form bean definition associated with the specified
       * logical name, if any; otherwise return <code>null</code>.
       *
       * @param name Logical name of the requested form bean definition
       */
      public ActionFormBean getFormBean(String name) {
          return null;
      }
  
      /**
       * Return the forwarding associated with the specified logical name,
       * if any; otherwise return <code>null</code>.
       *
       * @param name Logical name of the requested forwarding
       */
      public ActionForward getActionForward(String name) {
          return null;
      }
  
      /**
       * Return the mapping associated with the specified request path, if any;
       * otherwise return <code>null</code>.
       *
       * @param path Request path for which a mapping is requested
       */
      public ActionMapping getActionMapping(String path) {
          return null;
      }
  
      /**
       * Return the form action converted into an action mapping path.  The
       * value of the <code>action</code> property is manipulated as follows in
       * computing the name of the requested mapping:
       * <ul>
       * <li>Any filename extension is removed (on the theory that extension
       *     mapping is being used to select the controller servlet).</li>
       * <li>If the resulting value does not start with a slash, then a
       *     slash is prepended.</li>
       * </ul>
       */
      public String getActionMappingName(String action) {
  
          String value = action;
          int question = action.indexOf("?");
          if (question >= 0)
              value = value.substring(0, question);
          int slash = value.lastIndexOf("/");
          int period = value.lastIndexOf(".");
          if ((period >= 0) && (period > slash))
              value = value.substring(0, period);
          if (value.startsWith("/"))
              return (value);
          else
              return ("/" + value);
  
      }
  
      /**
       * Return the form action converted into a server-relative URL.
       */
      public String getActionMappingURL(String action) {
  
          StringBuffer value = new StringBuffer(this.request.getContextPath());
  
          // Use our servlet mapping, if one is specified
          String servletMapping = getServletMapping();
  
          if (servletMapping != null) {
              String queryString = null;
              int question = action.indexOf("?");
              if (question >= 0)
                  queryString = action.substring(question);
              String actionMapping = getActionMappingName(action);
              if (servletMapping.startsWith("*.")) {
                  value.append(actionMapping);
                  value.append(servletMapping.substring(1));
              } else if (servletMapping.endsWith("/*")) {
                  value.append(servletMapping.substring(0, servletMapping.length() - 2));
                  value.append(actionMapping);
              }
              if (queryString != null)
                  value.append(queryString);
          }
  
          // Otherwise, assume extension mapping is in use and extension is
          // already included in the action property
          else {
              if (!action.startsWith("/"))
                  value.append("/");
              value.append(action);
          }
  
          // Return the completed value
          return (value.toString());
  
      }
  
      /**
       * Return the url encoded to maintain the user session, if any.
       */
      public String getEncodeURL(String url) {
  
          if ((session != null) && (response != null)) {
  
              boolean redirect = false;
              if (forward != null)
                  redirect = forward.getRedirect();
  
              if (redirect)
                  return response.encodeRedirectURL(url);
              else
                  return response.encodeURL(url);
          } else
              return (url);
      }
  
      // ------------------------------------------------ Presentation API
  
      /**
       * Renders the reference for a HTML <base> element
       */
      public String getOrigRef() {
  
          // HttpServletRequest request = (HttpServletRequest)pageContext.getRequest();
  
          if (request == null)
              return null;
          StringBuffer result = RequestUtils.requestToServerUriStringBuffer(request);
          return result.toString();
      }
  
      /**
       * Renders the reference for a HTML <base> element.
       */
      public String getBaseRef() {
  
          if (request == null)
              return null;
  
          StringBuffer result = RequestUtils.requestToServerStringBuffer(request);
          String path = null;
          if (forward == null)
              path = request.getRequestURI();
          else
              path = request.getContextPath() + forward.getPath();
          result.append(path);
  
          return result.toString();
      }
  
      /**
       * Return the path for the specified forward,
       * otherwise return <code>null</code>.
       *
       * @param name Name given to local or global forward.
       */
      public String getLink(String name) {
  
          ActionForward forward = getActionForward(name);
          if (forward == null)
              return null;
  
          StringBuffer path = new StringBuffer(this.request.getContextPath());
          path.append(forward.getPath());
  
          // TODO: What about runtime parameters?
  
          return getEncodeURL(path.toString());
  
      }
  
      /**
       * Return the localized message for the specified key,
       * otherwise return <code>null</code>.
       *
       * @param key Message key
       */
      public String getMessage(String key) {
  
          MessageResources resources = getMessageResources();
          if (resources == null)
              return null;
  
          return resources.getMessage(RequestUtils.getUserLocale(request, null), key);
  
      }
  
      /**
       * Look up and return a message string, based on the specified parameters.
       *
       * @param key Message key to be looked up and returned
       * @param args Replacement parameters for this message
       */
      public String getMessage(String key, Object args[]) {
  
          MessageResources resources = getMessageResources();
  
          if (resources == null)
              return null;
  
          // Return the requested message
          if (args == null)
              return resources.getMessage(
                      RequestUtils.getUserLocale(request, null),
                      key);
          else
              return resources.getMessage(
                      RequestUtils.getUserLocale(request, null),
                      key,
                      args);
  
      }
  
      /**
       * Return the URL for the specified ActionMapping,
       * otherwise return <code>null</code>.
       *
       * @param path Name given to local or global forward.
       */
      public String getAction(String path) {
          return getEncodeURL(getActionMappingURL(path));
      }
  
  
      // --------------------------------------------- Presentation Wrappers
  
      /**
       * Wrapper for getLink(String)
       *
       * @param name Name given to local or global forward.
       */
      public String link(String name) {
          return getLink(name);
      }
  
      /**
       * Wrapper for getMessage(String)
       *
       * @param key Message key
       */
      public String message(String key) {
          return getMessage(key);
      }
  
      /**
       * Wrapper for getMessage(String,Object[])
       *
       * @param key Message key to be looked up and returned
       * @param args Replacement parameters for this message
       */
      public String message(String key, Object args[]) {
          return getMessage(key, args);
      }
  
      /**
       * Wrapper for getAction(String)
       *
       * @param path Name given to local or global forward.
       */
      public String action(String path) {
          return getAction(path);
      }
  }
  
  
  
  1.1                  jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/CheckLogonTag.java
  
  Index: CheckLogonTag.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/CheckLogonTag.java,v
1.1 2004/03/25 12:39:27 husted Exp $
   * $Revision: 1.1 $
   * $Date: 2004/03/25 12:39:27 $
   *
   * Copyright 2000-2004 Apache Software Foundation
   *
   * Licensed 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.commons.chain.mailreader;
  
  import org.apache.struts.config.ModuleConfig;
  
  import javax.servlet.ServletException;
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.tagext.TagSupport;
  import java.io.IOException;
  
  
  /**
   * Check for a valid User logged on in the current session.  If there is no
   * such user, forward control to the logon page.
   *
   * @version $Revision: 1.1 $ $Date: 2004/03/25 12:39:27 $
   */
  public final class CheckLogonTag extends TagSupport {
  
  
      // --------------------------------------------------- Instance Variables
  
  
      /**
       * Path to use if a login is needed.
       */
      private static String LOGIN_PATH = "/Logon.do";
  
  
      // ------------------------------------------------------- Public Methods
  
  
      /**
       * Defer our checking until the end of this tag is encountered.
       *
       * @exception JspException if a JSP exception has occurred
       */
      public int doStartTag() throws JspException {
  
          return (SKIP_BODY);
  
      }
  
  
      /**
       * Perform our logged-in user check by looking for the existence of
       * a session scope bean under the specified name.  If this bean is not
       * present, control is forwarded to the specified logon page.
       *
       * @exception JspException if a JSP exception has occurred
       */
      public int doEndTag() throws JspException {
  
          // Is there a valid user logged on?
          boolean valid = (null != pageContext.getServletContext().getAttribute(Constants.USER_KEY));
  
          // Forward control based on the results
          if (valid) {
              return (EVAL_PAGE);
          } else {
              ModuleConfig config =
                      (ModuleConfig) pageContext.getServletContext().getAttribute(
                              org.apache.struts.Globals.MODULE_KEY);
  
              try {
                  pageContext.forward(config.getPrefix() + LOGIN_PATH);
              } catch (ServletException e) {
                  throw new JspException(e.toString());
              } catch (IOException e) {
                  throw new JspException(e.toString());
              }
  
              return (SKIP_PAGE);
          }
  
      }
  
  
      /**
       * Release any acquired resources.
       */
      public void release() {
  
          super.release();
  
      }
  
  }
  
  
  
  1.1                  jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/CommandAction.java
  
  Index: CommandAction.java
  ===================================================================
  package org.apache.commons.chain.mailreader;
  
  import org.apache.struts.action.Action;
  import org.apache.struts.action.ActionForm;
  import org.apache.struts.action.ActionForward;
  import org.apache.struts.action.ActionMapping;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  /**
   * <p>
   * Create ActionContextBase pass to Command corresponding to the ActionForm name.
   * On return, analyze Context, returning values in servlet contexts as
   * appropriate. The ActionContextBase is also exposed in the request under
   * the key "context".
   * </p>
   * <p>
   * The Struts ActionMapping should define exception handlers for any documented
   * exceptions thrown by a given Command object.
   * </p>
   * <p>
   * NOTE -- This class may be migrated to a later release of Struts
   * when support for Commons Chains is added.
   * </p>
   */
  public class CommandAction extends Action {
  
      public ActionForward execute(ActionMapping actionMapping, ActionForm actionForm, HttpServletRequest
httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
  
          throw new RuntimeException("TODO: Implement CommandAction");
      }
  
  }
  
  
  
  1.1                  jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/Constants.java
  
  Index: Constants.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/Constants.java,v
1.1 2004/03/25 12:39:27 husted Exp $
   * $Revision: 1.1 $
   * $Date: 2004/03/25 12:39:27 $
   *
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * Licensed 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.commons.chain.mailreader;
  
  
  /**
   * Manifest constants for the example application.
   *
   * @version $Revision: 1.1 $ $Date: 2004/03/25 12:39:27 $
   */
  
  public final class Constants {
  
  
      /**
       * The package name for this application.
       */
      public static final String PACKAGE = "org.apache.struts.webapp.mailreader";
  
      /**
       * The token representing "failure" for this application.
       */
      public static final String FAILURE = "failure";
  
  
      /**
       * The token representing "success" for this application.
       */
      public static final String SUCCESS = "success";
  
  
      /**
       * The token representing "logon" for this application.
       */
      public static final String LOGON = "logon";
  
  
      /**
       * The token representing "logoff" for this application.
       */
      public static final String LOGOFF = "logoff";
  
  
      /**
       * The token representing "cancel" for this application.
       */
      public static final String CANCEL = "cancel";
  
  
      /**
       * The application scope attribute under which our facade
       * is stored.
       */
      public static final String FACADE_KEY = "facade";
  
      /**
       * The application scope attribute under which our user database
       * is stored.
       */
      public static final String DATABASE_KEY = "database";
  
  
      /**
       * The session scope attribute under which the Subscription object
       * currently selected by our logged-in User is stored.
       */
      public static final String SUBSCRIPTION_KEY = "subscription";
  
  
      /**
       * The session scope attribute under which the User object
       * for the currently logged in user is stored.
       */
      public static final String USER_KEY = "user";
  
  
      /**
       * A static message in case database resource is not loaded.
       */
      public static final String ERROR_DATABASE_NOT_LOADED =
              "ERROR:  User database not loaded -- check servlet container logs for error
messages.";
  
  
      /**
       * A static message in case message resource is not loaded.
       */
      public static final String ERROR_MESSAGES_NOT_LOADED =
              "ERROR:  Message resources not loaded -- check servlet container logs for error
messages.";
  
  
      /**
       * The request attributes key under the WelcomeAction stores an ArrayList
       * of error messages, if required resources are missing.
       */
      public static final String ERROR_KEY = "ERROR";
  
      /**
       * Name of username field ["username"].
       */
      static String USERNAME = "username";
  
      /**
       * Name of password field ["password"].
       */
      static String PASSWORD = "password";
  
      /**
       * Name of password confirmation field ["password2"].
       */
      public static final String PASSWORD2 = "password2";
  
  }
  
  
  
  1.1                  jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/MemoryDatabasePlugIn.java
  
  Index: MemoryDatabasePlugIn.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons-sandbox/chain/apps/mailreader/src/java/org/apache/commons/chain/mailreader/MemoryDatabasePlugIn.java,v
1.1 2004/03/25 12:39:27 husted Exp $
   * $Revision: 1.1 $
   * $Date: 2004/03/25 12:39:27 $
   *
   * Copyright 2000-2004 Apache Software Foundation
   *
   * Licensed 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.commons.chain.mailreader;
  
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.struts.action.ActionServlet;
  import org.apache.struts.action.PlugIn;
  import org.apache.struts.config.ModuleConfig;
  import org.apache.struts.webapp.example.memory.MemoryUserDatabase;
  
  import javax.servlet.ServletException;
  import java.io.*;
  
  /**
   * <p><strong>MemoryDatabasePlugIn</strong> initializes and finalizes
the
   * persistent storage of User and Subscription information for the Struts
   * Demonstration Application, using an in-memory database backed by an
   * XML file.</p>
   *
   * <p><strong>IMPLEMENTATION WARNING</strong> - If this web application
is run
   * from a WAR file, or in another environment where reading and writing of the
   * web application resource is impossible, the initial contents will be copied
   * to a file in the web application temporary directory provided by the
   * container.  This is for demonstration purposes only - you should
   * <strong>NOT</strong> assume that files written here will survive a restart
   * of your servlet container.</p>
   *
   * @version $Revision: 1.1 $ $Date: 2004/03/25 12:39:27 $
   */
  
  public final class MemoryDatabasePlugIn implements PlugIn {
  
  
      // ----------------------------------------------------- Instance Variables
  
  
      /**
       * The {@link org.apache.struts.webapp.example.memory.MemoryUserDatabase} object we
construct and make available.
       */
      private MemoryUserDatabase database = null;
  
  
      /**
       * Logging output for this plug in instance.
       */
      private Log log = LogFactory.getLog(this.getClass());
  
  
      /**
       * The {@link ActionServlet} owning this application.
       */
      private ActionServlet servlet = null;
  
  
      // ------------------------------------------------------------- Properties
  
  
      /**
       * The web application resource path of our persistent database
       * storage file.
       */
      private String pathname = "/WEB-INF/database.xml";
  
      public String getPathname() {
          return (this.pathname);
      }
  
      public void setPathname(String pathname) {
          this.pathname = pathname;
      }
  
  
      // --------------------------------------------------------- PlugIn Methods
  
  
      /**
       * Gracefully shut down this database, releasing any resources
       * that were allocated at initialization.
       */
      public void destroy() {
  
          log.info("Finalizing memory database plug in");
  
          if (database != null) {
              try {
                  database.close();
              } catch (Exception e) {
                  log.error("Closing memory database", e);
              }
          }
  
          servlet.getServletContext().removeAttribute(Constants.DATABASE_KEY);
          database = null;
          servlet = null;
      }
  
  
      /**
       * Initialize and load our initial database from persistent storage.
       *
       * @param servlet The ActionServlet for this web application
       * @param config The ApplicationConfig for our owning module
       *
       * @exception ServletException if we cannot configure ourselves correctly
       */
      public void init(ActionServlet servlet, ModuleConfig config)
              throws ServletException {
  
          log.info("Initializing memory database plug in from '" +
                  pathname + "'");
  
          // Remember our associated configuration and servlet
          this.servlet = servlet;
  
          // Construct a new database and make it available
          database = new MemoryUserDatabase();
          try {
              String path = calculatePath();
              if (log.isDebugEnabled()) {
                  log.debug(" Loading database from '" + path + "'");
              }
              database.setPathname(path);
              database.open();
          } catch (Exception e) {
              log.error("Opening memory database", e);
              throw new ServletException("Cannot load database from '" +
                      pathname + "'", e);
          }
  
          // Make the initialized database available
          servlet.getServletContext().setAttribute(Constants.DATABASE_KEY,
                  database);
  
      }
  
  
      // --------------------------------------------------------- Public Methods
  
  
      // ------------------------------------------------------ Protected Methods
  
  
      // -------------------------------------------------------- Private Methods
  
  
      /**
       * Calculate and return an absolute pathname to the XML file to contain
       * our persistent storage information.
       *
       * @exception Exception if an input/output error occurs
       */
      private String calculatePath() throws Exception {
  
          // Can we access the database via file I/O?
          String path = servlet.getServletContext().getRealPath(pathname);
          if (path != null) {
              return (path);
          }
  
          // Does a copy of this file already exist in our temporary directory
          File dir = (File)
                  servlet.getServletContext().getAttribute
                  ("javax.servlet.context.tempdir");
          File file = new File(dir, "struts-example-database.xml");
          if (file.exists()) {
              return (file.getAbsolutePath());
          }
  
          // Copy the static resource to a temporary file and return its path
          InputStream is =
                  servlet.getServletContext().getResourceAsStream(pathname);
          BufferedInputStream bis = new BufferedInputStream(is, 1024);
          FileOutputStream os =
                  new FileOutputStream(file);
          BufferedOutputStream bos = new BufferedOutputStream(os, 1024);
          byte buffer[] = new byte[1024];
          while (true) {
              int n = bis.read(buffer);
              if (n <= 0) {
                  break;
              }
              bos.write(buffer, 0, n);
          }
          bos.close();
          bis.close();
          return (file.getAbsolutePath());
  
      }
  
  
  }
  
  
  

---------------------------------------------------------------------
To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: commons-dev-help@jakarta.apache.org


Mime
View raw message