Java implements complete instances of timed tasks based on thread pools and reflection mechanisms

This article illustrates a Java approach to timing tasks based on thread pools and reflection mechanisms. Share with you for your reference, as follows:

It mainly includes the following implementation classes:

1. The Main categories:

Entry to task execution:

Call the main method to start loading the task configuration and executing the task

package com.yanek.task; 
import java.util.List; 
import java.util.concurrent.Executors; 
import java.util.concurrent.ScheduledExecutorService; 
import java.util.concurrent.TimeUnit; 
public class Main { 
  
 public static void main(String[] args) { 
  ScheduledExecutorService scheduExec = Executors.newScheduledThreadPool(1); 
   
  List tasks=XmlReader.getTasks(); 
  for (int i=0;i<tasks.size();i++) 
  { 
   TaskModel tm=(TaskModel)tasks.get(i); 
   scheduExec.scheduleAtFixedRate(new MyTask(tm),tm.getInitialDelay(), tm.getPeriod(), TimeUnit.SECONDS); 
  } 
 } 
}

2. MyTask class implements the Runnable interface, called in the main class

package com.yanek.task; 
import java.lang.reflect.InvocationTargetException; 
import java.lang.reflect.Method; 
import java.util.Date; 
public class MyTask implements Runnable { 
 private TaskModel taskModel; 
 public MyTask() {} 
 public MyTask(TaskModel tm) { 
  this.taskModel = tm; 
 } 
 public void run() { 
   System.out.println("call at " + (new Date())); 
   try { 
    Class<?> classType = Class.forName(taskModel.getClassName()); 
    Method getMethod = classType.getMethod(taskModel.getMethodName()); 
    getMethod.invoke(classType); 
   } catch (SecurityException e) { 
    e.printStackTrace(); 
   } catch (IllegalArgumentException e) { 
    e.printStackTrace(); 
   } catch (ClassNotFoundException e) { 
    e.printStackTrace(); 
   } catch (NoSuchMethodException e) { 
    e.printStackTrace(); 
   } catch (IllegalAccessException e) { 
    e.printStackTrace(); 
   } catch (InvocationTargetException e) { 
    e.printStackTrace(); 
   } 
 } 
}

3. TaskModel: encapsulation of task classes

package com.yanek.task; 
public class TaskModel { 
 public String getClassName() { 
  return className; 
 } 
 public void setClassName(String className) { 
  this.className = className; 
 } 
 public String getMethodName() { 
  return methodName; 
 } 
 public void setMethodName(String methodName) { 
  this.methodName = methodName; 
 } 
 public long getInitialDelay() { 
  return initialDelay; 
 } 
 public void setInitialDelay(long initialDelay) { 
  this.initialDelay = initialDelay; 
 } 
 public long getPeriod() { 
  return period; 
 } 
 public void setPeriod(long period) { 
  this.period = period; 
 } 
 private String className; 
 private String methodName; 
 private long initialDelay; 
 private long period; 
}

4. The XmlReader task configures the parse class

package com.yanek.task; 
import java.io.File; 
import java.io.IOException; 
import java.util.ArrayList; 
import java.util.List; 
import org.apache.commons.lang.StringUtils; 
import org.jdom.Document; 
import org.jdom.Element; 
import org.jdom.JDOMException; 
import org.jdom.input.SAXBuilder; 
public class XmlReader { 
 public static void main(String[] args) { 
  XmlReader.getTasks(); 
 } 
 public static List getTasks() { 
  List tasks = new ArrayList(); 
  System.out.println("load task config start..."); 
  String path = "/work/TaskManager/conf/taskconfig.xml"; 
  File file = new File(path); 
  if (file.exists() && !file.isDirectory()) { 
   try { 
    SAXBuilder sx = new SAXBuilder(); 
    Document doc = sx.build(file); 
    Element rootelement = doc.getRootElement(); 
     List<Element> childs = rootelement.getChildren(); 
     for (int i = 0; i < childs.size(); i++) { 
      TaskModel tModel = new TaskModel(); 
      tModel.setClassName(childs.get(i).getChildText("class")); 
      System.out.println(childs.get(i).getChildText("class")); 
      tModel.setMethodName(childs.get(i).getChildText("method")); 
      System.out.println(childs.get(i).getChildText("method")); 
      String initialDelay = childs.get(i).getChildText("initialDelay"); 
      tModel.setInitialDelay((Long.valueOf(initialDelay))); 
      System.out.println(" It's not even close to its first run " + initialDelay + " Seconds! "); 
      tModel.setPeriod(Integer.valueOf(childs.get(i).getChildText("period"))); 
      System.out.println(childs.get(i).getChildText("period")); 
      tasks.add(tModel); 
    } 
   } catch (NumberFormatException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
   } catch (JDOMException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
   } catch (IOException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
   } 
  } else { 
   System.out.println("file no exist!"); 
  } 
  System.out.println("load task config end !"); 
  return tasks; 
 } 
}

5. Configuration file:

<?xml version="1.0" encoding="UTF-8"?> 
<taskconfig> 
  <task> 
    <class>com.yanek.task.TaskA</class> 
    <method>testA</method> 
    <initialDelay>5</initialDelay> 
    <period>2</period> 
  </task> 
  <task> 
    <class>com.yanek.task.TaskB</class> 
    <method>testB</method> 
    <initialDelay>5</initialDelay> 
    <period>3</period> 
  </task> 
  <task> 
    <class>com.yanek.task.TaskC</class> 
    <method>testC</method> 
    <initialDelay>5</initialDelay> 
    <period>3</period> 
  </task> 
</taskconfig>

6. Test tasks:

TaskA TaskB TaskC defines static methods whose static methods are configured in an XML file and called.

package com.yanek.task; 
public class TaskA { 
  
 public static void main(String[] args) { 
  System.out.println("task a test"); 
 } 
 public static void testA() 
 { 
  System.out.println("taska testA method call!"); 
 } 
} 
package com.yanek.task; 
public class TaskB { 
  
 public static void main(String[] args) { 
  System.out.println("task b test"); 
 } 
 public static void testB() 
 { 
  System.out.println("TaskB testB method call!"); 
 } 
} 
package com.yanek.task; 
public class TaskC { 
  
 public static void main(String[] args) { 
  System.out.println("task c test"); 
 } 
 public static void testC() 
 { 
  System.out.println("Taskc testC method call!"); 
 } 
} 

I hope this article has been helpful to you in Java programming.