1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   *  contributor license agreements.  The ASF licenses this file to You
     4   * under the Apache License, Version 2.0 (the "License"); you may not
     5   * use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.  For additional information regarding
    15   * copyright in this work, please see the NOTICE file in the top level
    16   * directory of this distribution.
    17   */
    18  
    19  package org.apache.roller.weblogger.business;
    20  
    21  import org.apache.commons.logging.Log;
    22  import org.apache.commons.logging.LogFactory;
    23  import org.apache.roller.weblogger.business.startup.WebloggerStartup;
    24  import org.apache.roller.weblogger.config.WebloggerConfig;
    25  
    26  
    27  /**
    28   * Provides access to the Weblogger instance and bootstraps the business tier.
    29   */
    30  public final class WebloggerFactory {
    31      
             /* 
    P/P       *  Method: org.apache.roller.weblogger.business.WebloggerFactory__static_init
              * 
              *  Postconditions:
              *    init'ed(log)
              *    webloggerProvider == null
              */
    32      private static final Log log = LogFactory.getLog(WebloggerFactory.class);
    33      
    34      // our configured weblogger provider
    35      private static WebloggerProvider webloggerProvider = null;
    36      
    37      
    38      // non-instantiable
             /* 
    P/P       *  Method: void org.apache.roller.weblogger.business.WebloggerFactory()
              */
    39      private WebloggerFactory() {
    40          // hello all you beautiful people
    41      }
    42      
    43      
    44      /**
    45       * True if bootstrap process has been completed, False otherwise.
    46       */
    47      public static boolean isBootstrapped() {
                 /* 
    P/P           *  Method: bool isBootstrapped()
                  * 
                  *  Preconditions:
                  *    init'ed(webloggerProvider)
                  * 
                  *  Postconditions:
                  *    init'ed(return_value)
                  */
    48          return (webloggerProvider != null);
    49      }
    50      
    51      
    52      /**
    53       * Accessor to the Weblogger Weblogger business tier.
    54       * 
    55       * @return Weblogger An instance of Weblogger.
    56       * @throws IllegalStateException If the app has not been properly bootstrapped yet.
    57       */
    58      public static final Weblogger getWeblogger() {
                 /* 
    P/P           *  Method: Weblogger getWeblogger()
                  * 
                  *  Preconditions:
                  *    webloggerProvider != null
                  *    init'ed(webloggerProvider.webloggerInstance)
                  * 
                  *  Postconditions:
                  *    return_value == webloggerProvider.webloggerInstance
                  *    init'ed(return_value)
                  */
    59          if (webloggerProvider == null) {
    60              throw new IllegalStateException("Roller Weblogger has not been bootstrapped yet");
    61          }
    62          
    63          return webloggerProvider.getWeblogger();
    64      }
    65      
    66      
    67      /**
    68       * Bootstrap the Roller Weblogger business tier, uses default WebloggerProvider.
    69       *
    70       * Bootstrapping the application effectively instantiates all the necessary
    71       * pieces of the business tier and wires them together so that the app is 
    72       * ready to run.
    73       *
    74       * @throws IllegalStateException If the app has not been properly prepared yet.
    75       * @throws BootstrapException If an error happens during the bootstrap process.
    76       */
    77      public static final void bootstrap() throws BootstrapException {
    78          
    79          // if the app hasn't been properly started so far then bail
                 /* 
    P/P           *  Method: void bootstrap()
                  * 
                  *  Preconditions:
                  *    org/apache/roller/weblogger/business/startup/WebloggerStartup.prepared == 1
                  *    org/apache/roller/weblogger/config/WebloggerConfig.config != null
                  *    org/apache/roller/weblogger/config/WebloggerConfig.log != null
                  * 
                  *  Presumptions:
                  *    defaultProvider.injector@90 != null
                  *    java.lang.Class:forName(...)@89 != null
                  * 
                  *  Postconditions:
                  *    webloggerProvider != null
                  *    webloggerProvider.webloggerInstance != null
                  */
    80          if (!WebloggerStartup.isPrepared()) {
    81              throw new IllegalStateException("Cannot bootstrap until application has been properly prepared");
    82          }
    83          
    84          // lookup our default provider and instantiate it
    85          WebloggerProvider defaultProvider;
    86          String providerClassname = WebloggerConfig.getProperty("weblogger.provider.class");
+   87          if(providerClassname != null) {
    88              try {
    89                  Class providerClass = Class.forName(providerClassname);
    90                  defaultProvider = (WebloggerProvider) providerClass.newInstance();
    91              } catch (Exception ex) {
    92                  throw new BootstrapException("Error instantiating default provider: "+providerClassname, ex);
    93              }
    94          } else {
    95              throw new NullPointerException("No provider specified in config property 'weblogger.provider.class'");
    96          }
    97  
    98          // now just bootstrap using our default provider
    99          bootstrap(defaultProvider);
   100      }
   101      
   102      
   103      /**
   104       * Bootstrap the Roller Weblogger business tier, uses specified WebloggerProvider.
   105       *
   106       * Bootstrapping the application effectively instantiates all the necessary
   107       * pieces of the business tier and wires them together so that the app is 
   108       * ready to run.
   109       *
   110       * @param provider A WebloggerProvider to use for bootstrapping.
   111       * @throws IllegalStateException If the app has not been properly prepared yet.
   112       * @throws BootstrapException If an error happens during the bootstrap process.
   113       */
   114      public static final void bootstrap(WebloggerProvider provider) 
   115              throws BootstrapException {
   116          
   117          // if the app hasn't been properly started so far then bail
                 /* 
    P/P           *  Method: void bootstrap(WebloggerProvider)
                  * 
                  *  Preconditions:
                  *    org/apache/roller/weblogger/business/startup/WebloggerStartup.prepared == 1
                  *    provider != null
                  *    provider.injector != null
                  * 
                  *  Presumptions:
                  *    com.google.inject.Injector:getInstance(...)@87 != null
                  *    java.lang.Object:getClass(...)@128 != null
                  *    org.apache.commons.logging.LogFactory:getLog(...)@32 != null
                  * 
                  *  Postconditions:
                  *    (soft) provider.webloggerInstance != null
                  *    webloggerProvider.webloggerInstance == provider.webloggerInstance
                  *    webloggerProvider == provider
                  *    webloggerProvider != null
                  */
   118          if (!WebloggerStartup.isPrepared()) {
   119              throw new IllegalStateException("Cannot bootstrap until application has been properly prepared");
   120          }
   121          
   122          if (provider == null) {
   123              throw new NullPointerException("WebloggerProvider is null");
   124          }
   125          
   126          log.info("Bootstrapping Roller Weblogger business tier");
   127          
   128          log.info("Weblogger Provider = "+provider.getClass().getName());
   129          
   130          // save reference to provider
   131          webloggerProvider = provider;
   132          
   133          // bootstrap weblogger provider
   134          webloggerProvider.bootstrap();
   135          
   136          // make sure we are all set
   137          if(webloggerProvider.getWeblogger() == null) {
   138              throw new BootstrapException("Bootstrapping failed, Weblogger instance is null");
   139          }
   140          
   141          log.info("Roller Weblogger business tier successfully bootstrapped");
   142          log.info("   Version: " + webloggerProvider.getWeblogger().getVersion());
   143          log.info("   Revision: " + webloggerProvider.getWeblogger().getRevision());
   144      }
   145      
   146  }