commentcontrollerbean.java

一个java

package bookstore.ejb;

import bookstore.util.*;

import java.sql.*;
import javax.sql.*;
import java.util.*;
import javax.ejb.*;


public class CommentControllerBean implements SessionBean
{
  SessionContext sessionContext;
  private String commentID;
  private CommentHome commentHome;
  private Comment comment;
  private Connection con;

  /*************************** removal methods*****************************/

public String createComment(CommentDetails commentValue) throws Exception {
      // makes a new comment and enters it into db,
      // returns commentId

      System.out.println("commentControllerBean createcomment");

      try
      {
        comment = commentHome.create(commentValue);
      }
      catch (Exception ex)
      {
          throw new EJBException
           ("createcomment: " + ex.getMessage());
      }

      return commentID;
  }// createcomment

  public void removeComment(String commentId) throws NoSuchEntityException {
    //抛出RunTimeException的子类,有利于事务管理

       // removes comment from db

        System.out.println("commentControllerBean removecomment");

        if (isCommentExist(commentId) == false)
            throw new NoSuchEntityException(commentId);

        try {
             comment.remove();//comment已在iscommentExist中获得
            }catch (Exception ex)
            {
             throw new EJBException
             ("removecomment: " + ex.getMessage());
        }

    } // removecomment

    public void updateComment(CommentDetails commentValue)
        throws NoSuchEntityException
     {
       System.out.println("commentControllerBean updatecomment");

       if (isCommentExist(commentValue.getCommentID()) == false)
            throw new NoSuchEntityException(commentValue.getCommentID());

         comment.setCustomerID(commentValue.getCustomerID());
         comment.setBookID(commentValue.getBookID());
         comment.setRank(commentValue.getRank());
         comment.setContent(commentValue.getContent());

     }//updatecomment

     public CommentDetails getCommentValue(String commentId)
           {
             System.out.println("commentControllerBean getcommentValue");
             try
                  {
                      comment = commentHome.findByPrimaryKey(commentId);
                      this.commentID = commentId;
                  } catch (Exception ex)
                  {
                      return null;
                  }
                  return comment.getDetails();
           }


/******************************ejb methods*********************************/

  public void ejbCreate() throws CreateException {
    System.out.println("commentControllerBean ejbCreate");

        try {
            //创建下一层的引导接口
            commentHome=EJBGetter.getCommentHome();

        } catch (Exception ex) {
             System.out.println("commentControllerBean catch");
             throw new EJBException("ejbCreate: " +
                 ex.getMessage());
        }

        comment = null;
        commentID = null;
  }//ejbCreate

  public void ejbRemove() {
    /**@todo Complete this method*/
  }
  public void ejbActivate() {
    /**@todo Complete this method*/
  }
  public void ejbPassivate() {
    /**@todo Complete this method*/
  }
  public void setSessionContext(SessionContext sessionContext) {
    this.sessionContext = sessionContext;
  }
  /**********************************util methods****************************/
  private boolean isCommentExist(String commentId) {

        // If a business method has been invoked with
        // a different commentId, then update the
        // commentId and comment variables.
        // Return null if the comment is not found.

        System.out.println("commentControllerBean iscommentExist");

        if (commentId.equals(this.commentID) == false)
        {
            try
            {
                comment = commentHome.findByPrimaryKey(commentId);
                this.commentID = commentId;
            } catch (Exception ex)
            {
                return false;
            }
        } // if
        return true;

    }// iscommentExist

}