ant-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From cos...@apache.org
Subject cvs commit: jakarta-ant/proposal/embed/src/java/org/apache/tools/ant/helper TaskAdapter2.java
Date Sat, 27 Jul 2002 02:21:34 GMT
costin      2002/07/26 19:21:34

  Added:       proposal/embed/src/java/org/apache/tools/ant/helper
                        TaskAdapter2.java
  Log:
  Added (back) TaskAdapter2. It'll allow more flexibility on how 'normal'
  beans are turned into tasks - it allows to specify the method name.
  
  It'll also be extended to support mbeans or other types of tasks.
  
  Revision  Changes    Path
  1.1                  jakarta-ant/proposal/embed/src/java/org/apache/tools/ant/helper/TaskAdapter2.java
  
  Index: TaskAdapter2.java
  ===================================================================
  /*
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights 
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer. 
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:  
   *       "This product includes software developed by the 
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Ant", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written 
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  
  package org.apache.tools.ant.helper;
  
  import java.lang.reflect.Method;
  import org.apache.tools.ant.*;
  
  /**
   * Uses introspection to "adapt" an arbitrary Bean which doesn't
   * itself extend Task, but still contains an execute method and optionally 
   * a setProject method.
   *
   *  The adapter can also be used to wrap tasks that are loaded in a different class loader
   *  by ant, when used in programatic mode.
   *
   * @author Costin Manolache
   */
  public class TaskAdapter2 extends Task {
  
      /** Object to act as a proxy for. */
      private Object proxy;
      private String methodName="execute";
      
      /**
       * Checks whether or not a class is suitable to be adapted by TaskAdapter.
       *
       * This only checks conditions which are additionally required for 
       * tasks adapted by TaskAdapter. Thus, this method should be called by
       * Project.checkTaskClass.
       *
       * Throws a BuildException and logs as Project.MSG_ERR for
       * conditions that will cause the task execution to fail.
       * Logs other suspicious conditions with Project.MSG_WARN.
       * 
       * @param taskClass Class to test for suitability. 
       *                  Must not be <code>null</code>.
       * @param project   Project to log warnings/errors to. 
       *                  Must not be <code>null</code>.
       * 
       * @see Project#checkTaskClass(Class)
       */
      public static void checkTaskClass(final Class taskClass, final Project project) {
          // Any task can be used via adapter. If it doesn't have any execute()
          // method, no problem - it will do nothing, but still get an 'id'
          // and be registered in the project reference table and useable by other
          // tasks.
          
          if( true )
              return;
  
          // don't have to check for interface, since then
          // taskClass would be abstract too.
          try {
              final Method executeM = taskClass.getMethod( "execute", null );
              // don't have to check for public, since
              // getMethod finds public method only.
              // don't have to check for abstract, since then
              // taskClass would be abstract too.
              if(!Void.TYPE.equals(executeM.getReturnType())) {
                  final String message =
                      "return type of execute() should be void but was \""+
                      executeM.getReturnType()+"\" in " + taskClass;
                  project.log(message, Project.MSG_WARN);
              }
          } catch(NoSuchMethodException e) {
              final String message = "No public execute() in " + taskClass;
              project.log(message, Project.MSG_ERR);
              throw new BuildException(message);
          }
      }
  
      private IntrospectionHelper ih;
  
      void setIntrospectionHelper( IntrospectionHelper ih ) {
          this.ih=ih;
      }
  
      IntrospectionHelper getIntrospectionHelper() {
          if( ih==null ) {
              ih = IntrospectionHelper.getHelper(target.getClass());
          }
          return ih;
      }
      
      /** Experimental, non-public method for better 'adaptation'
       *
       */
      void setAttribute( String name, String value )
          throws BuildException
      {
          try {
              ih.setAttribute( project, proxy, name, value );
          } catch( BuildException ex ) {
              if( "do".equals( name ) ) {
                  setDo( value );
              } else {
                  throw ex;
              }
          }
      }
          
      /** Set the 'action' method. This allow beans implementing multiple
       * actions or using methods other than 'execute()' to be used in ant
       * without any modification.
       * 
       *  @ant:experimental 
       */
      public void setDo(String methodName ) {
          this.methodName=methodName;
      }
      
      /**
       * Executes the proxied task.
       */
      public void execute() throws BuildException {
          Method setProjectM = null;
          try {
              Class c = proxy.getClass();
              setProjectM = 
                  c.getMethod( "setProject", new Class[] {Project.class});
              if(setProjectM != null) {
                  setProjectM.invoke(proxy, new Object[] {project});
              }
          } catch (NoSuchMethodException e) {
              // ignore this if the class being used as a task does not have
              // a set project method.
          } catch( Exception ex ) {
              log("Error setting project in " + proxy.getClass(), 
                  Project.MSG_ERR);
              throw new BuildException( ex );
          }
  
  
          Method executeM=null;
          try {
              Class c=proxy.getClass();
              executeM=c.getMethod( methodName, new Class[0] );
              if( executeM == null ) {
                  log("No public " + methodName + "() in " + proxy.getClass(), Project.MSG_ERR);
                  throw new BuildException("No public " + methodName +"() in " + proxy.getClass());
              }
              executeM.invoke(proxy, null);
              return; 
          } catch (java.lang.reflect.InvocationTargetException ie) {
              log("Error in " + proxy.getClass(), Project.MSG_ERR);
              Throwable t = ie.getTargetException();
              if (t instanceof BuildException) {
                  throw ((BuildException) t);
              } else {
                  throw new BuildException(t);
              }
          } catch( Exception ex ) {
              log("Error in " + proxy.getClass(), Project.MSG_ERR);
              throw new BuildException( ex );
          }
  
      }
      
      /**
       * Sets the target object to proxy for.
       * 
       * @param o The target object. Must not be <code>null</code>.
       */
      public void setProxy(Object o) {
          this.proxy = o;
      }
  
      /**
       * Returns the target object being proxied.
       * 
       * @return the target proxy object
       */
      public Object getProxy() {
          return this.proxy ;
      }
  
  }
  
  
  

--
To unsubscribe, e-mail:   <mailto:ant-dev-unsubscribe@jakarta.apache.org>
For additional commands, e-mail: <mailto:ant-dev-help@jakarta.apache.org>


Mime
View raw message