beanutils.java

该源码包括了基于J2EE的数据持久层设计,设计中使用了DAO,Service,等模式,并在Struts下进行了测试．

package org.conference.pagination;
import java.util.List;
import java.util.Arrays;
import java.beans.PropertyDescriptor;
import org.javawing.component.logging.Log;
import org.javawing.component.logging.LogFactory;


/**
 * <p><strong>BeanUtils</strong>,
 * A utility class that provides methods that are useful for dealing with
 * Java Beans.
 *
 * @author   ZXM 
 * @package  gov.cd.gzcx.pagination
 * @since 2.0
 */
public abstract class BeanUtils {
	
	 private static final Log logger = LogFactory.getLog(BeanUtils.class);
	 /**
	   * Copy the property values of the given source bean into the given target
	   * bean, ignoring the given ignoreProperties.
	   *
	   * @param source the source bean
	   * @param target the target bean
	   * @param ignoreProperties array of property names to ignore
	   * @throws IllegalArgumentException if the classes of source and target do
	   *   not match
	   * @throws BeansException
	   */
	  public static void copyProperties(Object source, Object target,
	                                    String[] ignoreProperties ) throws
	      IllegalArgumentException, BeansException {

	   // Assert.notNull(source, "source must not be null");
	   // Assert.notNull(target, "source must not be null");

	    List ignoreList = (ignoreProperties != null) ? Arrays.asList(ignoreProperties) : null;
	    PropertyDescriptor[] sourceDescs = getPropertyDescriptors(source.getClass());

	    try {
	      for (int i=0;i<sourceDescs.length;i++) {
	    	  PropertyDescriptor sourceDesc =sourceDescs[i];    
	        String name = sourceDesc.getName();
	        if (ignoreProperties == null || (!ignoreList.contains(name))) {
	          /**
	           * Create a property descriptor for the named property. If
	           * the target bean doesn't have the named property, an
	           * IntrospectionException will be thrown.
	           */
	          PropertyDescriptor targetDesc = getPropertyDescriptor(name, target.getClass());
	          if (sourceDesc.getReadMethod() != null &&
	              targetDesc.getWriteMethod() != null &&
	              targetDesc.getReadMethod() != null) {
	            /** Get the value from source bean and set it to the target bean. */
	            Object value = sourceDesc.getReadMethod().invoke(source,(Object[])null);

	           if (logger.isDebugEnabled()) {
	              logger.debug("Copying property{name=" + name + ", value=" +
	                          value + "} to target " + target);
	            }

	            targetDesc.getWriteMethod().invoke(target, new Object[]{value});
	          } else {
	            if (logger.isInfoEnabled()) {
	             logger.info("Could not copy property{name=" + name + "}");
	            }
	          }
	        } else {
	          if(logger.isDebugEnabled()){
	            logger.debug("Ignored property{name=" + name + "}");
	          }
	        }
	      }
	    }
	    catch (BeansException ex){
	      throw ex;
	    }
	    catch (Exception ex) {
	      throw new FatalBeanException(ex);
	    } 
	  }
	  
	  /**
	   * Retrieve the JavaBeans <code>PropertyDescriptor</code> of a given class and property name.
	   * @param propertyName the name of the property to retrieve the propertyDescriptor for
	   * @param clazz the Class to retrieve the PropertyDescriptor for
	   * @return a <code>PropertyDescriptor</code> for the given class and property name.
	   * @throws BeansException if PropertyDescriptor look fails
	   */
	  public static PropertyDescriptor getPropertyDescriptor(String propertyName,Class clazz) throws BeansException {
		    CachedIntrospectionResults cr = CachedIntrospectionResults.forClass(clazz);
		    return cr.getPropertyDescriptor(propertyName);
		  }
	  
	  /**
	   * Retrieve the JavaBeans <code>PropertyDescriptor</code>s of a given class.
	   * @param clazz the Class to retrieve the PropertyDescriptors for
	   * @return an array of <code>PropertyDescriptors</code> for the given class
	   * @throws BeansException if PropertyDescriptor look fails
	   */
	  public static PropertyDescriptor[] getPropertyDescriptors(Class clazz) throws
	      BeansException {
	    CachedIntrospectionResults cr = CachedIntrospectionResults.forClass(clazz);
	    return cr.getBeanInfo().getPropertyDescriptors();
	  }
	
}