Oracle Seeker, Oracle探索者

/**
 * @(#)CustomManagedBean.java
 * 
 * HAND Enterprise Solution Company.
 *                          All rights reserved
 * 
 */
package hand.hadf.common.view.backing;
 
import hand.hadf.common.view.HadfException;
 
import javax.el.ELContext;
import javax.el.ExpressionFactory;
import javax.el.ValueExpression;
 
import javax.faces.application.Application;
import javax.faces.context.FacesContext;
 
 
import oracle.adf.model.binding.DCBindingContainer;
 
import oracle.adf.model.binding.DCIteratorBinding;
 
import oracle.binding.AttributeBinding;
import oracle.binding.BindingContainer;
import oracle.binding.ControlBinding;
import oracle.binding.OperationBinding;
 
/**
 * 所有基于HADF框架进行的应用开发的BackingBean的基类，即所有客户化开发创建的BackingBean均继承于该类，
 * 同时要求所有子类实现Serializable接口
 * @author Eleven.Xu Nov.26th, 2009
 * @version 1.0.0.0
 */
public class CustomManagedBean {
 
 
  /**
   * 默认的构造器
   */
  public CustomManagedBean() {
  }
 
  /**
   * 解析EL表达式，并返回匹配对象或创建出相应对象
   * @param expression 待解析的EL表达式
   * @return 匹配的受管对象
   */
  public Object resolveExpression(String expression) {
    FacesContext facesContext = getFacesContext();
    Application app = facesContext.getApplication();
    ExpressionFactory elFactory = app.getExpressionFactory();
    ELContext elContext = facesContext.getELContext();
    ValueExpression valueExp =
      elFactory.createValueExpression(elContext, expression, Object.class);
    return valueExp.getValue(elContext);
  }
 
  /**
   * 获取当前FacesContext对象
   */
  public FacesContext getFacesContext() {
    return FacesContext.getCurrentInstance();
  }
 
  /**
   * 获取当前页面的BindingContainer对象
   * @return 当前页面的BindingContainer对象
   */
  public BindingContainer getBindingContainer() {
    return (BindingContainer)resolveExpression("#{bindings}");
  }
 
  /**
   * 获取当前页面对应的DCBindingContainer
   * @return 当前页面对应的DCBindingContainer
   */
  public DCBindingContainer getDCBindingContainer() {
    return (DCBindingContainer)getBindingContainer();
  }
 
  /**
   * 在当前的DCBindingContainer中获取OperationBinding
   * @param name 待获取的OperationBinding名称
   * @return OperationBinding对象
   */
  public OperationBinding findOperation(String name) {
    OperationBinding operationBinding =
      getDCBindingContainer().getOperationBinding(name);
    if (operationBinding == null) {
      throw new HadfException("Operation '" + name + "' not found");
    }
    return operationBinding;
  }
 
  /**
   * 在当前BindingContainer中查找Iterator Binding
   * @param iteratorName Iterator名称
   * @return Iterator Binding
   */
  public DCIteratorBinding findIterator(String iteratorName) {
    DCIteratorBinding iter =
      getDCBindingContainer().findIteratorBinding(iteratorName);
    if (iter == null) {
      throw new HadfException("Iterator '" + iteratorName + "' not found");
    }
    return iter;
  }
 
  /**
   * 获取当前页面绑定文件中指定属性的绑定值
   * @param attributeName 属性名称
   * @return 该属性的值
   */
  public Object getBoundAttributeValue(String attributeName) {
    return findControlBinding(attributeName).getInputValue();
  }
 
 
  /**
   * 为当前页面绑定中的指定属性设值
   * @param attributeName 属性名称
   * @param value 属性值
   */
  public void setBoundAttributeValue(String attributeName, Object value) {
    findControlBinding(attributeName).setInputValue(value);
  }
 
 
  /**
   * 根据属性名查找该属性对应的绑定
   * @param attributeName 属性名称
   * @return 属性绑定
   */
  public AttributeBinding findControlBinding(String attributeName) {
    return findControlBinding(getBindingContainer(), attributeName);
  }
 
 
 
  private AttributeBinding findControlBinding(BindingContainer bindingContainer,
                                              String attributeName) {
    if (attributeName != null) {
      if (bindingContainer != null) {
        ControlBinding ctrlBinding =
          bindingContainer.getControlBinding(attributeName);
        if (ctrlBinding instanceof AttributeBinding) {
          return (AttributeBinding)ctrlBinding;
        }
      }
    }
    return null;
  }
}