userbean.java

Java实现的图书管理系统

/*
 * UserBean.java
 *
 * Created on 2003年5月13日, 上午10:12
 */

/**
 *
 * @author  administrator
 */
import java.sql.*;
import javax.sql.*;
import java.util.*;
import java.math.*;
import javax.ejb.*;
import javax.naming.*;
import javax.rmi.PortableRemoteObject;
import java.rmi.RemoteException;

public class UserBean implements EntityBean{
    //entity variables
    private String id;
    private String userName;
    private String userPassword;
    private String userSex;
    private String userAge;
    private String userJob;
    private String userEdu;
    
    //other variables
    private EntityContext context;
    private Connection con;
    private String dbName = "java:comp/env/jdbc/book";
    
    //business method
    public String getUserName() throws RemoteException
    {
        System.out.println("In UserBean:getUserName(),userName="+userName);
        
        return userName;
    }
   
   
   public String getUserPassword() throws RemoteException
   {
       return userPassword;
   }
   
 
   public String getUserSex() throws RemoteException
   {
       return userSex;
   }
   
  
   public String getUserAge() throws RemoteException
   {
       return userAge;
   }
   
  
   public String getUserJob() throws RemoteException
   {
       return userJob;
   }
   
   public String getUserEdu() throws RemoteException
   {
       return userEdu;
   }
    
    //entity bean's method
    public void ejbActivate() throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
        System.out.println("In UserBean:ejbActive()");
        
        id = (String)context.getPrimaryKey();
        
        System.out.println("End UserBean:ejbActive(),id="+id);
    }
    
    public void ejbLoad() throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
        System.out.println("In UserBean:ejbLoad(),id="+id);
        
        try {
         loadRow();
       } catch (Exception ex) {
           throw new EJBException("ejbLoad: " + 
              ex.getMessage());
       }
    }
    
    public void ejbPassivate() throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
        id = null;
    }
    
    //we don't use this method for this programm
    public void ejbRemove() throws javax.ejb.RemoveException, javax.ejb.EJBException, java.rmi.RemoteException 
    {
    }
    
    public void ejbStore() throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
        System.out.println("In UserBean:ejbStore()");
        try {
         storeRow();
       } catch (Exception ex) {
           throw new EJBException("ejbStore: " + 
              ex.getMessage());
       }
    }
    
    public void setEntityContext(javax.ejb.EntityContext entityContext) throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
      this.context = entityContext;
      try {
         makeConnection();
      } catch (Exception ex) {
          throw new EJBException("Unable to connect to database. " +
             ex.getMessage());
      }
    }
    
    public void unsetEntityContext() throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
        try {
         con.close();
      } catch (SQLException ex) {
          throw new EJBException("unsetEntityContext: " + ex.getMessage());
      }
    }
    
  
    //home method
    //we don't use this method for this programm
    public String ejbCreate() throws CreateException 
    {
        return "1";
    }
    
    public void ejbPostCreate() 
    {
    }
    
    public String ejbFindByPrimaryKey(String primaryKey) throws FinderException 
    {
      boolean result;
      try {
         result = selectByPrimaryKey(primaryKey);
       } catch (Exception ex) {
           throw new EJBException("ejbFindByPrimaryKey: " + 
              ex.getMessage());
       }
      if (result) {
         return primaryKey;
      }
      else {
         throw new ObjectNotFoundException
            ("Row for id " + primaryKey + " not found.");
      }
    }
    
    public Collection ejbFindByUserName(String userName) throws FinderException 
    {
      System.out.println("In UserBean:ejbFindByUserName(),userName="+userName);
      Collection result;

      try {
         result = selectByUserName(userName);
       } catch (Exception ex) {
           throw new EJBException("ejbFindByUserName " + 
              ex.getMessage());
       }
      System.out.println("End UserBean:ejbFindByUserName()"); 
      return result;
    }
    
    
    
    //========================helper functions========================
    private void makeConnection() throws NamingException, SQLException 
    {
      InitialContext ic = new InitialContext();
      DataSource ds = (DataSource) ic.lookup(dbName);
      con =  ds.getConnection();
    }
    
    private boolean selectByPrimaryKey(String primaryKey) throws SQLException 
    {

      String selectStatement =
            "select id " +
            "from user where id = ? ";
      PreparedStatement prepStmt =con.prepareStatement(selectStatement);
      prepStmt.setInt(1, Integer.parseInt(primaryKey));

      ResultSet rs = prepStmt.executeQuery();
      boolean result = rs.next();
      prepStmt.close();
      return result;
    }
    
    private Collection selectByUserName(String userName) throws SQLException 
    {
      System.out.println("In UserBean:ejbSelectByUserName(),userName="+userName);
      
      String selectStatement =
            "select id " +
            "from user where user_name like ? ";
      PreparedStatement prepStmt = 
            con.prepareStatement(selectStatement);

      prepStmt.setString(1, "%"+userName+"%");
      
           
      ResultSet rs = prepStmt.executeQuery();
      ArrayList a = new ArrayList();

      while (rs.next()) {
         String id = rs.getString(1);
         
         System.out.println("In UserBean:ejbSelectByUserName(),id="+id);
         
         a.add(id);
      }

      prepStmt.close();
       
      System.out.println("End UserBean:ejbSelectByUserName()");
      return a;
    }
    
    private void loadRow() throws SQLException {
        
        System.out.println("In UserBean:loadRow()");
        
      String selectStatement =
            "select user_name,user_password,user_sex,user_age,user_job,user_edu " +
            "from user where id = ? ";
      PreparedStatement prepStmt = 
            con.prepareStatement(selectStatement);

      prepStmt.setInt(1, Integer.parseInt(this.id));

      ResultSet rs = prepStmt.executeQuery();

      if (rs.next()) {
         this.userName = rs.getString(1);
         this.userPassword = rs.getString(2);
         this.userSex = rs.getString(3);
         this.userAge = rs.getString(4);
         this.userJob = rs.getString(5);
         this.userEdu = rs.getString(6);
         
         System.out.println("In UserBean:loadRow(),userPassword="+this.userPassword);
         
         prepStmt.close();
      }
      else {
         prepStmt.close();
         throw new NoSuchEntityException("Row for id " + id +
            " not found in database.");
      }
   }


   private void storeRow() throws SQLException 
   {
      System.out.println("In UserBean:storeRow()");
      
       String updateStatement =
            "update user set user_name =  ? ," +
            "user_password = ? , user_sex = ? ," +
            "user_age = ? , user_job = ? , user_edu = ? " +
            "where id = ?";
      PreparedStatement prepStmt = 
            con.prepareStatement(updateStatement);

      prepStmt.setString(1, userName);
      prepStmt.setString(2, userPassword);
      prepStmt.setString(3, userSex);
      prepStmt.setString(4, userAge);
      prepStmt.setString(5, userJob);
      prepStmt.setString(6, userEdu);
      prepStmt.setInt(7, Integer.parseInt(this.id));
      int rowCount = prepStmt.executeUpdate();
      prepStmt.close();
      
      System.out.println("End UserBean:storeRow()");
      
      if (rowCount == 0) {
         throw new EJBException("Storing row for id " + id + " failed.");
      }
   }
    
    
    
}