Quartz Job Scheduling Framework［翻译］第八章. 使用 Quartz 插件 (第四部分)

  1package org.cavaness.quartzbook.chapter8;
  2
  3import java.util.ArrayList;
  4import java.util.List;
  5import java.util.StringTokenizer;
  6
  7import org.apache.commons.logging.Log;
  8import org.apache.commons.logging.LogFactory;
  9import org.quartz.Scheduler;
 10import org.quartz.SchedulerConfigException;
 11import org.quartz.SchedulerException;
 12import org.quartz.spi.SchedulerPlugin;
 13
 14public class ParentPlugin implements SchedulerPlugin {
 15    private static Log logger = LogFactory.getLog(ParentPlugin.class);
 16
 17    // A list of child plug-ins
 18    private List childPlugins = new ArrayList();
 19
 20    private String childPluginNames;
 21
 22    private String pluginName;
 23
 24    private Scheduler scheduler;
 25
 26    /**
 27     * Default no-arg Constructor
 28     *
 29     */
 30    public ParentPlugin() {
 31    }
 32
 33    /**
 34     * Pass the initialize call on to the child plug-ins.
 35     *
 36     * @throws SchedulerConfigException
 37     *             if there is an error initializing.
 38     */
 39
 40    public void initialize(String name, final Scheduler scheduler)
 41              throws SchedulerException {
 42
 43         this.pluginName = name;
 44         this.scheduler = scheduler;
 45
 46         logger.info("Searching for child plugins to load");
 47
 48         // The child plug-ins are comma-separated
 49         StringTokenizer tokenizer =
 50              new StringTokenizer(childPluginNames, ",");
 51
 52         while (tokenizer.hasMoreElements()) {
 53              String pluginClassname = tokenizer.nextToken();
 54
 55              try {
 56                   Class pluginClass =
 57                        Class.forName(pluginClassname);
 58
 59                   Object obj = pluginClass.newInstance();
 60
 61                   // Make sure the specified class is a plug-in
 62                   if (obj instanceof SchedulerPlugin) {
 63                        // Initialize the Plugin
 64                        SchedulerPlugin childPlugin =
 65                              (SchedulerPlugin) obj;
 66
 67                             logger.info("Init child Plugin " +
 68                                  pluginClassname);
 69
 70                        childPlugin.initialize(pluginClassname,
 71                             scheduler);
 72
 73                        // Store the child plug-in in the list
 74                        childPlugins.add(childPlugin);
 75                   } else {
 76                        // Skip loading class
 77                        logger.error("Class is not a plugin " +
 78                             pluginClass);
 79                   }
 80
 81              } catch (Exception ex) {
 82                   // On error, log and go to next child plug-in
 83                   logger.error("Error loading plugin " +
 84                        pluginClassname, ex);
 85              }
 86         }
 87    }
 88    public void start() {
 89         // Start each child plug-in
 90         int size = childPlugins.size();
 91         for (int i = 0; i < size; i++) {
 92              SchedulerPlugin childPlugin =
 93                   ((SchedulerPlugin) childPlugins.get(i));
 94
 95              logger.info("Starting Child Plugin " + childPlugin);
 96              childPlugin.start();
 97         }
 98    }
 99
100    public void shutdown() {
101         // Stop each child plug-in
102         int size = childPlugins.size();
103         for (int i = 0; i < size; i++) {
104              SchedulerPlugin childPlugin =
105                   ((SchedulerPlugin) childPlugins.get(i));
106
107              logger.info("Stopping Plugin " + childPlugin);
108              childPlugin.shutdown();
109         }
110    }
111
112    public String getPluginName() {
113         return pluginName;
114    }
115
116    public void setPluginName(String pluginName) {
117         this.pluginName = pluginName;
118    }
119
120    public String getChildPluginNames() {
121         return childPluginNames;
122    }
123
124    public void setChildPluginNames(String childPluginNames) {
125         this.childPluginNames = childPluginNames;
126    }
127}