Demonstration of speed of reflexive versus programmatic invocation : Class « Reflection « Java

1. Java
2. Reflection
3. Class

Demonstration of speed of reflexive versus programmatic invocation

         
 
 
 
 

/*
 *     file: ReflexiveInvocation.java
 *  package: oreilly.hcj.reflection
 *
 * This software is granted under the terms of the Common Public License,
 * CPL, which may be found at the following URL:
 * http://www-124.ibm.com/developerworks/oss/CPLv1.0.htm
 *
 * Copyright(c) 2003-2005 by the authors indicated in the @author tags.
 * All Rights are Reserved by the various authors.
 *
 ########## DO NOT EDIT ABOVE THIS LINE ########## */

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * Demonstration of speed of reflexive versus programatic invocation.
 * 
 * @author <a href=mailto:kraythe@arcor.de>Robert Simmons jr. (kraythe)</a>
 * @version $Revision: 1.3 $
 */
public class ReflexiveInvocation {
  /** Holds value of property value. */
  private String value = "some value";

  /**
   * Creates a new instance of ReflexiveInvocation
   */
  public ReflexiveInvocation() {
  }

  /**
   * Main demo method.
   * 
   * @param args
   *          the command line arguments
   * 
   * @throws RuntimeException
   *           __UNDOCUMENTED__
   */
  public static void main(final String[] args) {
    try {
      final int CALL_AMOUNT = 1000000;
      final ReflexiveInvocation ri = new ReflexiveInvocation();
      int idx = 0;

      // Call the method without using reflection.
      long millis = System.currentTimeMillis();

      for (idx = 0; idx < CALL_AMOUNT; idx++) {
        ri.getValue();
      }

      System.out.println("Calling method " + CALL_AMOUNT + " times programatically took "
          + (System.currentTimeMillis() - millis) + " millis");

      // Call while looking up the method in each iteration.
      Method md = null;
      millis = System.currentTimeMillis();

      for (idx = 0; idx < CALL_AMOUNT; idx++) {
        md = ri.getClass().getMethod("getValue", null);
        md.invoke(ri, null);
      }

      System.out.println("Calling method " + CALL_AMOUNT + " times reflexively with lookup took "
          + (System.currentTimeMillis() - millis) + " millis");

      // Call using a cache of the method.
      md = ri.getClass().getMethod("getValue", null);
      millis = System.currentTimeMillis();

      for (idx = 0; idx < CALL_AMOUNT; idx++) {
        md.invoke(ri, null);
      }

      System.out.println("Calling method " + CALL_AMOUNT + " times reflexively with cache took "
          + (System.currentTimeMillis() - millis) + " millis");
    } catch (final NoSuchMethodException ex) {
      throw new RuntimeException(ex);
    } catch (final InvocationTargetException ex) {
      throw new RuntimeException(ex);
    } catch (final IllegalAccessException ex) {
      throw new RuntimeException(ex);
    }
  }

  /**
   * Getter for property value.
   * 
   * @return Value of property value.
   */
  public String getValue() {
    return this.value;
  }
}

/* ########## End of File ########## */

 

   
    
    
    
    
    
    
    
    
  

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