user-proxy.apt

关于 RFID 读写器的相关内容

              -------------------
              User Guide Proxy
              -------------------
              Jonas Haller
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              03.01.2008
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User Guide Reader RP Proxy


* Contents

  [[1]] {{{#Features}Features}}

  [[2]] {{{#Application}Field of Application}}

  [[3]] {{{#Installing}Installing the Fosstrak Reader RP Proxy}}

  [[4]] {{{#First}First Steps}}

    * {{{#method}Use proxy with method calls}}

    * {{{#configuration}Use proxy with configuration engine}}


* {Features}

  The Fosstrak Reader RP Proxy is a Java class library that supports the
  communication with a reader that implements the EPCglobal Reader Protocol
  Version 1.1.

  Implemented elements of the protocol include:

  * Transport Binding: TCP and HTTP

  * Message Binding: XML and Text

  * Synchronous and Asynchronous Messaging (Notification Channels)

  * Triggers

  * Data Selectors

  []

  The reader can be configured through a method call for each command or all
  the settings can be written into a configuration file which is processed by
  an automated configurator.


* Field of {Application}

  * Communicate with a reader via the EPCglobal Reader Protocol Version 1.1
    from within your Java application.

  * Implement the <<<NotificationChannelListener>>> interface to receive
    notifications from the reader in your Java application.

  []

[../images/ReaderProxy_architecture.png]


* {Installing} the Fosstrak Reader RP Proxy

   The following instructions show how to install the Fosstrak Reader RP Proxy:

   * Download the Reader RP Proxy binaries with the dependencies included from
     the {{{../download.html}download}} section of the website.

   * Unzip the downloaded file.

   * Add the jar to your classpath.

   * All the {{{dependencies.html} dependencies}} should be accessible through
     your classpath as well. This should be the case if you use the zip with
     all the dependencies included.

   * Make sure you are using a Java Runtime Environment 1.5 or higher.

   * Use the proxy as outlined in the two examples below.


* {First} Steps

** Configure the reader with a series of Java {method} calls

  This example requires that there is a reader running that supports the
  HTTP/XML transport message binding of the Reader Protocol available at
  localhost:8000. If these settings are incorrect for your setup, you will need
  to adjust the following variables:

  * MESSAGE_FORMAT

  * TRANSPORT_PROTOCOL

  * COMMAND_CHANNEL_HOST

  * COMMAND_CHANNEL_PORT
  
  []

  You might also want to consider using our existing Java implementation of a
  {{{../index.html}reader}} which includes a simulation engine.

+---
import org.fosstrak.reader.rprm.core.EventType;
import org.fosstrak.reader.rprm.core.FieldName;
import org.fosstrak.reader.rp.proxy.DataSelector;
import org.fosstrak.reader.rp.proxy.NotificationChannel;
import org.fosstrak.reader.rp.proxy.ReaderDevice;
import org.fosstrak.reader.rp.proxy.Source;
import org.fosstrak.reader.rp.proxy.Trigger;
import org.fosstrak.reader.rp.proxy.factories.DataSelectorFactory;
import org.fosstrak.reader.rp.proxy.factories.NotificationChannelFactory;
import org.fosstrak.reader.rp.proxy.factories.ReaderDeviceFactory;
import org.fosstrak.reader.rp.proxy.factories.TriggerFactory;
import org.fosstrak.reader.rp.proxy.msg.Handshake;

public class ReaderProxyExample {

   private static int MESSAGE_FORMAT = Handshake.FORMAT_XML;
   private static int TRANSPORT_PROTOCOL = Handshake.HTTP;

   private static final String COMMAND_CHANNEL_HOST = "localhost";
   private static final int COMMAND_CHANNEL_PORT = 8000;

   private static final String READ_TRIGGER_NAME = "ReadTrigger";
   private static final String READ_TRIGGER_TYPE = Trigger.TIMER;
   private static final String READ_TRIGGER_VALUE = "ms=2000";

   private static final String NOTIFICATION_TRIGGER_NAME = "NotificationTrigger";
   private static final String NOTIFICATION_TRIGGER_TYPE = Trigger.CONTINUOUS;
   private static final String NOTIFICATION_TRIGGER_VALUE = "";

   private static final String DATA_SELECTOR_NAME = "DataSelector";
   private static final String[] EVENT_FILTERS = new String[] {
         EventType.EV_OBSERVED, EventType.EV_LOST};
   private static final String[] FIELD_NAMES = new String[] {
         FieldName.EVENT_TYPE, FieldName.READER_NAME, FieldName.TAG_ID,
         FieldName.TAG_ID_AS_PURE_URI, FieldName.TAG_ID_AS_TAG_URI,
         FieldName.SOURCE_NAME};

   private static final String NOTIFICATION_CHANNEL_NAME = "NotificationChannel";
   private static final String NOTIFICATION_CHANNEL_HOST = "localhost";
   private static final int NOTIFICATION_CHANNEL_PORT = 9000;
   private static final String NOTIFICATION_CHANNEL_MODE = "connect";
   private static final String NOTIFICATION_CHANNEL_ADDRESS = "tcp://"
         + NOTIFICATION_CHANNEL_HOST + ":" + NOTIFICATION_CHANNEL_PORT
         + "?mode=" + NOTIFICATION_CHANNEL_MODE;

   public static void main(String[] args) throws Exception {
      // create handshake
      Handshake handshake = new Handshake();
      handshake.setMessageFormat(MESSAGE_FORMAT);
      handshake.setTransportProtocol(TRANSPORT_PROTOCOL);

      // get reader device proxy
      System.out.println("Get reader device proxy.");
      ReaderDevice readerDevice = ReaderDeviceFactory.getReaderDevice(
            COMMAND_CHANNEL_HOST, COMMAND_CHANNEL_PORT, handshake);

      // get current source proxy
      System.out.println("Get current source.");
      Source source = readerDevice.getCurrentSource();
      System.out.println("Name of current source is: " + source.getName());

      // create read trigger
      System.out.println("Create read trigger.");
      Trigger readTrigger = TriggerFactory.createTrigger(READ_TRIGGER_NAME,
            READ_TRIGGER_TYPE, READ_TRIGGER_VALUE, readerDevice);

      // create notification trigger
      System.out.println("Create notification trigger.");
      Trigger notificationTrigger = TriggerFactory.createTrigger(
            NOTIFICATION_TRIGGER_NAME, NOTIFICATION_TRIGGER_TYPE,
            NOTIFICATION_TRIGGER_VALUE, readerDevice);

      // data selector
      System.out.println("Create data selector.");
      DataSelector dataSelector = DataSelectorFactory.createDataSelector(
            DATA_SELECTOR_NAME, readerDevice);
      System.out.println("Add event filters to data selector.");
      dataSelector.addEventFilters(EVENT_FILTERS);
      System.out.println("Add field names to data selector.");
      dataSelector.addFieldNames(FIELD_NAMES);
      //System.out.println("Add tag fields to data selector.");
      //dataSelector.addTagFieldNames(TAG_FIELDS);

      // create notification channel
      System.out.println("Create notification channel.");
      NotificationChannel notificationChannel = NotificationChannelFactory
            .createNotificationChannel(NOTIFICATION_CHANNEL_NAME,
            NOTIFICATION_CHANNEL_ADDRESS, readerDevice);
      System.out.println("Set data selector of notification channel.");
      notificationChannel.setDataSelector(dataSelector);
      System.out.println("Add notification trigger to notification channel.");
      notificationChannel.addNotificationTriggers(
            new Trigger[] {notificationTrigger});

      // add current source to notification channel
      System.out.println("Add source to notification channel.");
      notificationChannel.addSources(new Source[] {source});

      // add read trigger to source
      System.out.println("Add read trigger to source.");
      source.addReadTriggers(new Trigger[] {readTrigger});
   }
}
+---

    In order to process the notification messages from the reader, the proxy
    provides the class org.fosstrak.reader.rp.proxy.NotificationChannelEndPoint.
    The class that is interested in receiving the notification messages has to
    implement the interface org.fosstrak.reader.rp.proxy.NotificationChannelListener
    and has to be registered with the NotificationChannelEndPoint as shown
    below.

+---
import org.fosstrak.reader.rp.proxy.NotificationChannelListener;
import org.fosstrak.reader.rprm.core.msg.notification.Notification;

public class ReaderNotificationChannelListener implements NotificationChannelListener {

   public void dataReceived(Notification notification) {
      System.out.println("Notification received: " + notification);

      // add your code to process notification message here
   }
}
+---

   Code to create a NotificationChannelListener and to add a listener to it:

+---
   NotificationChannelListener notificationChannelListener =
         new ReaderNotificationChannelListener();

   // create notification channel endpoint to receive messages
   System.out.println("Create NotificationChannelEndpoint at port '"
         + NOTIFICATION_CHANNEL_PORT + "'.");
   NotificationChannelEndPoint notificationChannelEndPoint =
         new NotificationChannelEndPoint(NOTIFICATION_CHANNEL_PORT);

   // add listerner to notification channel endpoint
   notificationChannelEndPoint.addListener(notificationChannelListener);
+---


** Configure the reader with the {configuration} engine and a corresponding
  configuration file

  An other way to configure the reader is to use the <<<ReaderConfigurator>>>
  that is part of the Fosstrak Reader RP Proxy module. It is less flexible than
  using method calls for each configuration item but needs less code too.

+---
import org.apache.log4j.Logger;
import org.apache.log4j.BasicConfigurator;
import org.fosstrak.reader.proxy.configurator.ReaderConfigurator;

public class ReaderConfiguratorExample {

   private static final String CONFIG_FILE_PATH =
         "./props/ReaderDeviceConfiguration.xml";

   private static final Logger LOG = Logger.getLogger(
         ReaderConfiguratorExample.class);

   public static void main(String[] args) throws Exception {

      // initialize the logger
      BasicConfigurator.configure();

      // configure the reader
      LOG.info("Configurate reader device.");
      ReaderConfigurator.initReaderDeviceConfiguration(CONFIG_FILE_PATH);
   }
}
+---

   The corresponding ReaderDeviceConfiguration.xml configuration file looks
   like this:

+---
<?xml version="1.0" encoding="UTF-8"?>
<configurationDocument xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="ReaderDeviceConfiguration.xsd">
   <readerDeviceConfiguration>

      <!-- reader configuration -->
      <readerConfig>
         <commandChannelHost>localhost</commandChannelHost>
         <commandChannelPort>8000</commandChannelPort>
         <transportProtocol>HTTP</transportProtocol>
         <transportFormat>XML</transportFormat>
      </readerConfig>

      <!-- read triggers -->
      <triggers>
         <timerTrigger name="ReadTrigger">
            <value>2000</value>
         </timerTrigger>
      </triggers>

      <!-- notification triggers -->
      <triggers>
         <continuousTrigger name="NotificationTrigger"/>
      </triggers>

      <!-- data selectors -->
      <dataSelectors>
         <dataSelector name="DataSelector">
            <fieldNames>
               <fieldName>eventType</fieldName>
               <fieldName>readerName</fieldName>
               <fieldName>tagID</fieldName>
               <fieldName>tagIDasPureURI</fieldName>
               <fieldName>tagIDasTagURI</fieldName>
               <fieldName>sourceName</fieldName>
            </fieldNames>
            <eventFilters>
               <eventFilter>evObserved</eventFilter>
               <eventFilter>evLost</eventFilter>
            </eventFilters>
         </dataSelector>
      </dataSelectors>

      <!-- notification channels -->
      <notificationChannels>
         <notificationChannel name="NotificationChannel">
            <notificationChannelHost>localhost</notificationChannelHost>
            <notificationChannelPort>9000</notificationChannelPort>
            <transportProtocol>TCP</transportProtocol>
            <notificationChannelMode>connect</notificationChannelMode>
            <sources>
               <source>Shelf1</source>
            </sources>
            <notificationTriggers>
               <triggerName>NotificationTrigger</triggerName>
            </notificationTriggers>
            <dataSelector>DataSelector</dataSelector>
         </notificationChannel>
      </notificationChannels>

      <!-- sources -->
      <sources>
         <source name="Shelf1">
            <triggerName>ReadTrigger</triggerName>
         </source>
      </sources>

   </readerDeviceConfiguration>
</configurationDocument>
+---