Examples of org.apache.commons.chain.Command

org.apache.commons.chain.Command
A {@link Command} encapsulates a unit of processing work to beperformed, whose purpose is to examine and/or modify the state of a transaction that is represented by a {@link Context}. Individual {@link Command}s can be assembled into a {@link Chain}, which allows them to either complete the required processing or delegate further processing to the next {@link Command} in the {@link Chain}.

{@link Command} implementations should be designed in a thread-safemanner, suitable for inclusion in multiple {@link Chain}s that might be processed by different threads simultaneously. In general, this implies that {@link Command} classes should not maintain state information ininstance variables. Instead, state information should be maintained via suitable modifications to the attributes of the {@link Context} that ispassed to the execute() command.

{@link Command} implementations typically retrieve and store stateinformation in the {@link Context} instance that is passed as a parameterto the execute() method, using particular keys into the Map that can be acquired via Context.getAttributes(). To improve interoperability of {@link Command} implementations, a useful design pattern is to expose thekey values used as JavaBeans properties of the {@link Command}implementation class itself. For example, a {@link Command} that requiresan input and an output key might implement the following properties:
```
 private String inputKey = "input"; public String getInputKey() { return (this.inputKey); } public void setInputKey(String inputKey) { this.inputKey = inputKey; } private String outputKey = "output"; public String getOutputKey() { return (this.outputKey); } public void setOutputKey(String outputKey) { this.outputKey = outputKey; } 
```
And the operation of accessing the "input" information in the context would be executed by calling:
```
 String input = (String) context.get(getInputKey()); 
```
instead of hard coding the attribute name. The use of the "Key" suffix on such property names is a useful convention to identify properties being used in this fashion, as opposed to JavaBeans properties that simply configure the internal operation of this {@link Command}.
@author Craig R. McClanahan @version $Revision: 1.5 $ $Date: 2004/02/25 00:01:07 $

         throw new ServletException("Path undefined " + request.getParameter("path") + " Request: "
            + request.getRequestURI());


      try
      {
         Command cmd;
         if (catalogName == null)
            cmd = commandService.getCatalog().getCommand("displayResource");
         else
            cmd = commandService.getCatalog(catalogName).getCommand("displayResource");


         if (cmd == null)
            throw new Exception("No 'displayResource' command found");
         ctx.put("path", currentPath);
         ctx.put("cache-control-max-age", getServletConfig().getInitParameter("cache-control-max-age"));
         cmd.execute(ctx);
      }
      catch (Exception e)
      {
         e.printStackTrace();
         throw new ServletException(e);

View Full Code Here


      // command from context
      String commandName = (String)ctx.get("Command");
      if (commandName == null)
         throw new ServletException("No Command found at the Context");
      Command cmd;
      if (catalogName == null)
         cmd = commandService.getCatalog().getCommand(commandName);
      else
         cmd = commandService.getCatalog(catalogName).getCommand(commandName);


      if (cmd == null)
         throw new ServletException("No Command found " + commandName);
      try
      {
         cmd.execute(ctx);
      }
      catch (Exception e)
      {
         e.printStackTrace();
         throw new ServletException(e);

View Full Code Here

   }


   public void testSetProperty() throws Exception
   {


      Command c = cservice.getCatalog().getCommand("setProperty");
      ctx.put("currentNode", "/test");
      ctx.put("name", "testProperty");
      ctx.put("propertyType", PropertyType.TYPENAME_STRING);
      ctx.put("values", "testValue");
      ctx.put("multiValued", Boolean.FALSE);


      c.execute(ctx);


      Command save = cservice.getCatalog().getCommand("save");
      save.execute(ctx);


   }

View Full Code Here

   }


   public void testGetNodes() throws Exception
   {


      Command c = cservice.getCatalog().getCommand("getNodes");
      ctx.put("currentNode", "/");
      c.execute(ctx);


      assertTrue(ctx.get("result") instanceof NodeIterator);
      NodeIterator nodes = (NodeIterator)ctx.get("result");


      // System.out.println("> getNodes >> "+nodes.getSize());

View Full Code Here

   }


   public void testAddResourceFile() throws Exception
   {


      Command c = cservice.getCatalog().getCommand("addResourceFile");
      ctx.put("currentNode", "/");
      ctx.put("path", "resource");
      ctx.put("data", "Node data");
      ctx.put("mimeType", "text/html");


      c.execute(ctx);


      Command save = cservice.getCatalog().getCommand("save");
      ctx.put("path", "/");
      save.execute(ctx);


   }

View Full Code Here


   }


   public void testGetNodeChain() throws Exception
   {
      Command cmd = cservice.getCatalog().getCommand("retrieveNodeCommand");
      ctx.put("currentNode", "/");
      ctx.put("path", "test");
      cmd.execute(ctx);
   }

View Full Code Here

            if (exceptionCommand == null) {
                log.error("No exceptionCommand property specified");
                throw new IllegalStateException
                    ("No exceptionCommand property specfied");
            }
            Command command = catalog.getCommand(exceptionCommand);
            if (command == null) {
                log.error("Cannot find exceptionCommand '" +
                          exceptionCommand + "'");
                throw new IllegalStateException
                    ("Cannot find exceptionCommand '" +
                     exceptionCommand + "'");
            }
            if (log.isTraceEnabled()) {
                log.trace("Calling exceptionCommand '" + exceptionCommand
                          + "'");
            }
            command.execute(context);
        } catch (Exception e) {
            log.warn("Exception from exceptionCommand '" +
                     exceptionCommand + "'", e);
            throw new IllegalStateException("Exception chain threw exception");
        }

View Full Code Here

        context.put("mapping", mapping);
        context.put("form", form);


        // Delegate to the specified command
        String name = mapping.getParameter();
        Command command = getCatalog().getCommand(request.getParameter(name));
        command.execute(context); // Ignore return state


        // Return results as appropriate
        Exception exception = null;
        try {
            exception = (Exception) context.get("exception");

View Full Code Here

            (getServlet().getServletContext(), request, response);
        context.put("mapping", mapping);
        context.put("form", form);


        // Delegate to the specified command
        Command command = getCatalog().getCommand(mapping.getParameter());
        command.execute(context); // Ignore return state


        // Return results as appropriate
        Exception exception = null;
        try {
            exception = (Exception) context.get("exception");

View Full Code Here

   * @throws Exception
   *             on any error
   */
  public boolean execute(ActionContext actionCtx) throws Exception {
    if (shouldProcess(actionCtx)) {
      Command command = getCommand(actionCtx);


      if (command != null) {
        return (command.execute(actionCtx));
      }
    }


    return (false);
  }

View Full Code Here

0 1 2 3 4 5 6 7 8 9

TOP

Related Classes of org.apache.commons.chain.Command

ch.nerdin.generators.testdata.BeanFactory

com.azaptree.services.command.http.handler.CommandServiceHandler

com.azaptree.services.command.impl.CommandServiceImpl

com.google.code.mgnlgroovy.scheduler.CommandJob

org.apache.commons.chain.apps.example.ExampleServlet

org.apache.commons.chain.config.ConfigParser2TestCase

org.apache.commons.chain.config.ConfigParserTestCase

org.apache.commons.chain.config.ConfigRegisterRule

org.apache.commons.chain.generic.DispatchLookupCommand

org.apache.commons.chain.generic.LookupCommand

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.