Engine RMI Interface - Revision history

Jerrito at 00:09, 6 November 2011

2011-11-06T00:09:52Z

Allensmith at 13:22, 10 July 2011

2011-07-10T13:22:49Z

Allensmith: /* RMI in action: An example */

2011-05-11T07:03:39Z

‎RMI in action: An example

Matt: Reverted edits by Amesycyxa (Talk); changed back to last version by Kyle

2010-11-26T19:43:40Z

Reverted edits by Amesycyxa (Talk); changed back to last version by Kyle

Amesycyxa at 23:12, 23 November 2010

2010-11-23T23:12:05Z

Kyle at 17:55, 29 November 2007

2007-11-29T17:55:43Z

Andreas: /* Reader Server Components */

2007-11-27T17:45:42Z

‎Reader Server Components

Kyle at 17:31, 26 November 2007

2007-11-26T17:31:42Z

Kyle: /* Typical Usage */

2007-11-26T17:29:32Z

‎Typical Usage

Kyle: /* Typical Usage */

2007-11-26T17:28:05Z

‎Typical Usage

@@ Line 9: / Line 9: @@
 :The client (such as the IDE, Tag Streamer, or Designer) runs on a local machine.  Its purpose is to allow the user to manipulate readers (i.e. start, stop, add tags, etc).
 ;Reader Server
-:The Reader Server manages one or more readers on a particular machine by creating and destroying readers.  There is one instance of a reader manager per machine.
+:The Reader Server manages one or more readers on a <span class="plainlinks">[http://www.supplementstoweightloss.com/ <span style="color:black;font-weight:normal; text-decoration:none!important; background:none!important; text-decoration:none;">weight loss pills</span>] particular machine by creating and destroying readers.  There is one instance of a reader manager per machine.
 ;Reader
 :A reader is the program that emulates a particular reader, such as an LLRP Reader.  There can be multiple instances of a reader on a single machine.
@@ Line 21: / Line 21: @@
 [[Image:Cajo_architecture.png|thumb|800px|none|A block diagram explaining the basics of the cajo server]]
-The above diagram shows how the cajo server typically works.  The cajo process is started as a process on a particular port (normally 1198) on a server.  Now java objects can bind themselves to the cajo server.  This means that the cajo server enters a name-value pair in a table (called the registry).  The name is a unique string used to locate the reference to the object.  The client can then use this name to get a copy of the object using the getItem() method.
+The above diagram shows how the cajo server typically works.  The cajo process is started as a process on a particular port (normally 1198) on a server.  Now java objects can bind themselves to the cajo server.  This means that the cajo server enters a name-value pair in a table (called the registry).  The name is a unique string used to <span class="plainlinks">[http://www.shoppharmacycounter.com/ <span style="color:black;font-weight:normal; text-decoration:none!important; background:none!important; text-decoration:none;">weight loss pills</span>] locate the reference to the object.  The client can then use this name to get a copy of the object using the getItem() method.
 ==Remote Interfaces==

@@ Line 150: / Line 150: @@
 #At this point the reader's client (The program that controlls the reader, such as an edgeserver) changes the EPC ID of a tag
 ##This change requires the reader to notify the IDE through the use of the callback manager, so the reader uses the tagIDChanged() method in the callback manager.
-###The callbackManager calls the necessary methods in the IDE to reflect the change.
+###The callbackManager calls the necessary methods in the IDE to <span class="plainlinks">[http://www.andrewflusche.com/ <span style="color:black;font-weight:normal; text-decoration:none!important; background:none!important; text-decoration:none;">Fredericksburg DUI Lawyer</span>] reflect the change.
 =Reference Client=

@@ Line 130: / Line 130: @@
 ==RMI in action: An example==
-This example consists of a timing diagram that goes through a typical usage of the RMI implementation in Rifidi.  In this example, The client (IDE) and the server (RifidiManager) are on a local machine.  This is typical of how the IDE is used, because a user norally just wants to start playing around with readers and does not care if the server is on a separate computer.  After the client creates and starts the reader, it add tags to it.  Then the client program to the reader will change the ID of a tag, which requires that the reader inform the IDE through an RMI callback.
+This example consists of a timing diagram that goes through a typical usage of the RMI implementation in Rifidi.  In this example, The client (IDE) and the server (RifidiManager) are on a local machine.  This is typical of how the IDE is used, because a user norally just wants to start playing around with <span class="plainlinks">[http://www.mmesquire.com/ <span style="color:black;font-weight:normal; text-decoration:none!important; background:none!important; text-decoration:none;">accident attorney Visalia</span>] readers and does not care if the server is on a separate computer.  After the client creates and starts the reader, it add tags to it.  Then the client program to the reader will change the ID of a tag, which requires that the reader inform the IDE through an RMI callback.
 ===Timing Diagram===
 [[Image:RMI_Timing_Diagram.png|thumb|1000px|none|A UML Class Diagram depicting the components of the RMI Architecture in Rifidi]]

@@ Line 1: / Line 1: @@
 [[category:developerDoc]] [[category:EmulatorDoc]] [[category:EngineImplementation]]
 RMI (Remote Method Invocation) is an architecture that allows clients to invoke methods on remote machines.  Rifidi uses this architecture to allow the IDE (and the Tag Streamer) to communicate with the reader.  It uses the [https://cajo.dev.java.net/ cajo] library to provide the RMI functionality.
@@ Line 25: / Line 17: @@
 =Introduction to Cajo and RMI=
-Cajo is &quot;a small, free library, enabling powerful dynamic multi-machine cooperation; both within and between, both free and proprietary Java applications. It provides a surprisingly easy to use, yet completely understandable framework to dramatically simplify the use of RMI; whilst at the same time harnessing its full potential.&quot; (https://cajo.dev.java.net/).  If you are not familiar with cajo and/or RMI, you should read through the examples on cajo's website and wiki.
+Cajo is "a small, free library, enabling powerful dynamic multi-machine cooperation; both within and between, both free and proprietary Java applications. It provides a surprisingly easy to use, yet completely understandable framework to dramatically simplify the use of RMI; whilst at the same time harnessing its full potential." (https://cajo.dev.java.net/).  If you are not familiar with cajo and/or RMI, you should read through the examples on cajo's website and wiki.
 ==Typical Usage==
 [[Image:Cajo_architecture.png|thumb|800px|none|A block diagram explaining the basics of the cajo server]]
@@ Line 35: / Line 27: @@
 For example, suppose Object_A looked like this:
-&lt;pre&gt;
+<pre>
 public class Object_A implements Serializable{
@@ Line 47: / Line 39: @@
 	public String getValue(){
-		return &quot;object A's value is: &quot; +Integer.toString( value);
+		return "object A's value is: " +Integer.toString( value);
+	}
+}
-&lt;/pre&gt;
+</pre>
 A simple way that a client could access Object_A's functionality is like this:
-&lt;pre&gt;
+<pre>
-Object object = Remote.getItem(&quot;//serverHost:1198/obj_a&quot;);
+Object object = Remote.getItem("//serverHost:1198/obj_a");
-Remote.invoke(object, &quot;incrementValue&quot;, null);
+Remote.invoke(object, "incrementValue", null);
-String s = (String)Remote.invoke(object, &quot;getValue&quot;, null);
+String s = (String)Remote.invoke(object, "getValue", null);
-&lt;/pre&gt;
+</pre>
 However, another way that the client could access Object_A's functionality is if Object_A implemented an interface that exposed its methods that are available via RMI.  For example, suppose there was an interface that looked like this:
-&lt;pre&gt;
+<pre>
 public interface Object_A_Interface {
@@ Line 69: / Line 61: @@
+}
-&lt;/pre&gt;
+</pre>
 Now Object_A looks like this:
-&lt;pre&gt;
+<pre>
 public class Object_A implements Serializable, Object_A_Interface{
@@ Line 90: / Line 82: @@
 	 */
 	public String getValue(){
-		return &quot;object A's value is: &quot; +Integer.toString( value);
+		return "object A's value is: " +Integer.toString( value);
+	}
+}
-&lt;/pre&gt;
+</pre>
 A client can now access Object_A's functionality by getting an interface and calling the methods.  This enables the compiler to throw errors if something is wrong.
-&lt;pre&gt;
+<pre>
 Object_A_Interface obja = (Object_A_Interface) TransparentItemProxy.getItem(
-                                                &quot;//serverHost:1198/obj_a&quot;,
+                                                "//serverHost:1198/obj_a",
                                                 new Class[] { Object_A_Interface.class });
 obja.incrementValue()
 String s = obja.getValue();
 System.out.println(s);
-&lt;/pre&gt;
+</pre>
 ==Callbacks==

@@ Line 1: / Line 1: @@
 [[category:developerDoc]] [[category:EmulatorDoc]] [[category:EngineImplementation]]
 RMI (Remote Method Invocation) is an architecture that allows clients to invoke methods on remote machines.  Rifidi uses this architecture to allow the IDE (and the Tag Streamer) to communicate with the reader.  It uses the [https://cajo.dev.java.net/ cajo] library to provide the RMI functionality.
@@ Line 17: / Line 25: @@
 =Introduction to Cajo and RMI=
-Cajo is "a small, free library, enabling powerful dynamic multi-machine cooperation; both within and between, both free and proprietary Java applications. It provides a surprisingly easy to use, yet completely understandable framework to dramatically simplify the use of RMI; whilst at the same time harnessing its full potential." (https://cajo.dev.java.net/).  If you are not familiar with cajo and/or RMI, you should read through the examples on cajo's website and wiki.
+Cajo is &quot;a small, free library, enabling powerful dynamic multi-machine cooperation; both within and between, both free and proprietary Java applications. It provides a surprisingly easy to use, yet completely understandable framework to dramatically simplify the use of RMI; whilst at the same time harnessing its full potential.&quot; (https://cajo.dev.java.net/).  If you are not familiar with cajo and/or RMI, you should read through the examples on cajo's website and wiki.
 ==Typical Usage==
 [[Image:Cajo_architecture.png|thumb|800px|none|A block diagram explaining the basics of the cajo server]]
@@ Line 27: / Line 35: @@
 For example, suppose Object_A looked like this:
-<pre>
+&lt;pre&gt;
 public class Object_A implements Serializable{
@@ Line 39: / Line 47: @@
 	public String getValue(){
-		return "object A's value is: " +Integer.toString( value);
+		return &quot;object A's value is: &quot; +Integer.toString( value);
+	}
+}
-</pre>
+&lt;/pre&gt;
 A simple way that a client could access Object_A's functionality is like this:
-<pre>
+&lt;pre&gt;
-Object object = Remote.getItem("//serverHost:1198/obj_a");
+Object object = Remote.getItem(&quot;//serverHost:1198/obj_a&quot;);
-Remote.invoke(object, "incrementValue", null);
+Remote.invoke(object, &quot;incrementValue&quot;, null);
-String s = (String)Remote.invoke(object, "getValue", null);
+String s = (String)Remote.invoke(object, &quot;getValue&quot;, null);
-</pre>
+&lt;/pre&gt;
 However, another way that the client could access Object_A's functionality is if Object_A implemented an interface that exposed its methods that are available via RMI.  For example, suppose there was an interface that looked like this:
-<pre>
+&lt;pre&gt;
 public interface Object_A_Interface {
@@ Line 61: / Line 69: @@
+}
-</pre>
+&lt;/pre&gt;
 Now Object_A looks like this:
-<pre>
+&lt;pre&gt;
 public class Object_A implements Serializable, Object_A_Interface{
@@ Line 82: / Line 90: @@
 	 */
 	public String getValue(){
-		return "object A's value is: " +Integer.toString( value);
+		return &quot;object A's value is: &quot; +Integer.toString( value);
+	}
+}
-</pre>
+&lt;/pre&gt;
 A client can now access Object_A's functionality by getting an interface and calling the methods.  This enables the compiler to throw errors if something is wrong.
-<pre>
+&lt;pre&gt;
 Object_A_Interface obja = (Object_A_Interface) TransparentItemProxy.getItem(
-                                                "//serverHost:1198/obj_a",
+                                                &quot;//serverHost:1198/obj_a&quot;,
                                                 new Class[] { Object_A_Interface.class });
 obja.incrementValue()
 String s = obja.getValue();
 System.out.println(s);
-</pre>
+&lt;/pre&gt;
 ==Callbacks==

@@ Line 118: / Line 118: @@
 ;RifidiManager
 :The rifidiManager is the object that manages readers on a specific machine.  There is exactly one RifidiManager per machine.  It is in charge of keeping track of the readers (i.e. creating and destroying).  There are two distinct ways to start the manager, depending on how it is to be used.
-# '''Remotely''' If you wish to start the server on a remote machine, you must use the RifidiManager's main method to start it running.  The client will now need to know the RifidiManager's IP and port (normally the port is cajo's default port of 1198.
+# '''Remotely''' If you wish to start the server on a remote machine, you must use the RifidiManager's main method to start it running.  The client will now need to know the RifidiManager's IP and port (normally the port is cajo's default port of 1198).
 # '''Locally''' If the RifidiManger is to be started locally, a method is provided so that the client can do it programmaticly.  This method is provided for convenience, so that  It is simpler for the user when he just wants to start up the IDE and play around with a reader.
 ;RifidiManagerInterface

@@ Line 15: / Line 15: @@
 One important aspect of this architecture is that The client doesn't care if a Reader Server is local or remote.  That fact is transparent to the client.
-=Rifidi RMI Implementation=
-This section describes how RMI is implemented in Rifidi.
+=Introduction to Cajo and RMI=
-==Using Cajo==
 Cajo is "a small, free library, enabling powerful dynamic multi-machine cooperation; both within and between, both free and proprietary Java applications. It provides a surprisingly easy to use, yet completely understandable framework to dramatically simplify the use of RMI; whilst at the same time harnessing its full potential." (https://cajo.dev.java.net/).  If you are not familiar with cajo and/or RMI, you should read through the examples on cajo's website and wiki.
-===Typical Usage===
+==Typical Usage==
 [[Image:Cajo_architecture.png|thumb|800px|none|A block diagram explaining the basics of the cajo server]]
 The above diagram shows how the cajo server typically works.  The cajo process is started as a process on a particular port (normally 1198) on a server.  Now java objects can bind themselves to the cajo server.  This means that the cajo server enters a name-value pair in a table (called the registry).  The name is a unique string used to locate the reference to the object.  The client can then use this name to get a copy of the object using the getItem() method.
-===Remote Interfaces===
+==Remote Interfaces==
 One of the advantages of cajo is that it allows an object to easily expose functionality through an interface that another object can get and use.  The advantage to using an interface as opposed to invoking calls using text is that typechecking can be done at compile time.
@@ Line 100: / Line 99: @@
 </pre>
-===Callbacks===
+==Callbacks==
 Another advantage of using RMI and cajo is that it allows for callbacks.  This means that a client can call methods on a server using the method above, and the server can also  invoke methods on the client using a similar method.  This is important for Rifidi in situations with the GUI needs to be updated based on changes in the reader, such as when a TagID changes or when a GPO line goes high.
 ==RMI Class Diagram==
 [[Image:RMI_Class_Diagram.png|thumb|800px|none|A UML Class Diagram depicting the components of the RMI Architecture in Rifidi]]