jtfactory.java

来自「Java Pattern Oriented Framework (Jt) 是为了」· Java 代码 · 共 213 行

package Jt;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;


/**
 * Jt Factory
 */

public class JtFactory extends JtFactoryMethod {


  private static final long serialVersionUID = 1L;
  public static final String JtCLASS_NAME = JtFactory.class.getName();
  public static final String JtGET_ATTRIBUTES = "JtGET_ATTRIBUTES";
  public Class stopClass = null;
  

  public Class getStopClass() {
      return stopClass;
  }


  public void setStopClass(Class stopClass) {
      this.stopClass = stopClass;
  }


public JtFactory () {
  }
  
  
  private boolean checkModifiers (Class cl, String prop) {

      Field field;
      int mod;


      if (cl == null || prop == null)
          return (false);


      field = null;
      try {
          field = cl.getDeclaredField (prop); // property dup property names

      } catch (Exception e) {

          //handleException (e);

          if (cl.getSuperclass () == null) {
              handleWarning ("JtFactory.checkModifiers:" + e.getMessage());
              return (false);
          }
      }

      if (field == null) {
          cl = cl.getSuperclass ();
          return (checkModifiers (cl, prop));
      }

      mod = field.getModifiers ();

      if (Modifier.isTransient (mod)) {
          return (false);
      }
      if (Modifier.isStatic (mod)) {
          return (false);
      } 
      return (true);       
  }


  private JtHashTable getAttributes (Object obj) {

      PropertyDescriptor[] prop;
      int i;
      BeanInfo info = null;
      //Hashtable attr;
      JtMessage msg = new JtMessage (JtHashTable.JtPUT);
      JtHashTable table = new JtHashTable ();

      //attr = new Hashtable ();


      try {
          //info = Introspector.getBeanInfo(
          //        obj.getClass (), java.lang.Object.class);
          if (stopClass != null && stopClass.isAssignableFrom(obj.getClass ()))
              info = Introspector.getBeanInfo(
                      obj.getClass (), stopClass);
          else    
              info = Introspector.getBeanInfo(
                      obj.getClass (), java.lang.Object.class);
      } catch(Exception e) {
          handleException (e);
          return (null);
      }

      prop = info.getPropertyDescriptors();
      for(i = 0; i < prop.length; i++) {
          
          // Skip static and transient attributes

          if (!checkModifiers (obj.getClass (),prop[i].getName())) {
              continue;
          }

          msg.setMsgContent(prop[i]);
          msg.setMsgData (prop[i].getName()); 
          table.processMessage(msg);
          //attr.put (prop[i].getName(), null); 

      }

      return (table);
  }

  // Create an object of a specific class
 /* 
  private Object create (String className) {
    Class jtclass;
    
    if (className == null)
        return (null);      
    try {
        jtclass = Class.forName ((String) className);
        return (jtclass.newInstance ());
    } catch (Exception e) {
        handleException (e);
        return (null);
    }  

  }
*/
  /**
    * Process object messages.
    * <ul>
    * <li>JtCREATE - creates a new instance of a class. 
    * </ul>
    */

  public Object processMessage (Object event) {

      String msgid = null;
      JtMessage e = (JtMessage) event;
      Object content;


      if (e == null)
          return null;

      msgid = (String) e.getMsgId ();

      if (msgid == null)
          return null;
      
      if (msgid.equals (JtObject.JtCREATE_OBJECT)) {
          content = (String) e.getMsgContent ();
          if (content == null) {
              handleError ("JtCREATE_OBJECT: invalid message. Class name is null.");
              return (null);
          }    
          return (createObject ((String) e.getMsgContent (),
                            e.getMsgData()));
      }
      
      if (msgid.equals (JtFactory.JtGET_ATTRIBUTES)) {
          content = e.getMsgContent ();
          if (content == null) {
              handleError ("JtGET_ATTRIBUTES: invalid message (msgContent). Object is null.");
              return (null);
          }    
          return (getAttributes (e.getMsgContent ()));
      }
      return (super.processMessage (event)); 


  }

 
  /**
   * Demonstrates the messages processed by JtFactory
   */

  public static void main(String[] args) {

    JtFactory factory = new JtFactory ();
    JtObject obj;
    JtHashTable attributes;
    JtMessage msg = new JtMessage (JtFactory.JtGET_ATTRIBUTES);


    // Create JtFactory

    obj = (JtObject) factory.createObject (JtObject.JtCLASS_NAME, "object");
    System.out.println (obj);

    msg.setMsgContent (obj);
    attributes =  (JtHashTable) factory.processMessage(msg);
    
    factory.sendMessage (attributes, new JtMessage (JtObject.JtPRINT));

  }

}