customerdao.java

《Developing Applications with Java and UML》一书的源代码。

package com.jacksonreed;

import java.io.*;
import java.sql.*;
import java.text.*;
import java.util.*;
import javax.sql.*;

/**
 * This class is an example of data access object (DAO) for the
 * customerBean. It wraps all the database calls and insulates
 * the business logic implemented in CustomerBean from the underlying
 * physical database store.
 *
 * Part of this insulation is via implementing the DataAccess.java interface
 *
 * @author Paul Reed, Jackson-Reed, Inc. <[e-mail]>
 * @version 1.0
 */
public class CustomerDAO implements Serializable, DataAccess {
    private transient TransactionContext globalTran = null;
    private transient CustomerValue custVal   = null;

    /**
     * Class constructor
     */
    public CustomerDAO(TransactionContext transactionContext) {
          globalTran = transactionContext;
    }

    /**
     * Returns an CustomerValue initialized with the information
     * found in the database for the specified customer, or null if
     * not found.
     */
    public Object findByName(String name)
        throws DAOSysException, DAOFinderException {
          log("CustomerDAO: start findByCustomerNumber");
          if (itemExistsByName(name)) {
              log("CustomerDAO: returning " + custVal.getCustomerId());
              return custVal;
              }
          throw new DAOFinderException ("Customer Not Found = "
                  + name);
    }

    private boolean itemExistsByName(String customerNumber) throws DAOSysException {
        String queryStr ="SELECT customerId, customerNumber, firstName " +
                        ",middleInitial, prefix, suffix, lastName, phone1, phone2 " +
                        ",eMail " +
                        "FROM T_Customer " +
                        "WHERE customerNumber = " + "'" + customerNumber.trim() + "'";

         return doQuery(queryStr);
    }
    /**
     * Returns an CustomerValue initialized with the information
     * found in the database for the specified customer, or null if
     * not found.
     */
    public Object findByPrimaryKey(Integer id)
        throws DAOSysException, DAOFinderException {

        if (itemExistsById(id)) {
              log("CustomerDAO: returning " + custVal.getCustomerId());
              return custVal;
              }
          throw new DAOFinderException ("Customer Not Found = "
                  + id);
    }

    private boolean itemExistsById(Integer customerId) throws DAOSysException {
        String queryStr ="SELECT customerId, customerNumber, firstName " +
                        ",middleInitial, prefix, suffix, lastName, phone1, phone2 " +
                        ",eMail " +
                        "FROM T_Customer " +
                        "WHERE customerId = " + customerId;

        return doQuery(queryStr);
    }

    public void deleteObject(Integer id) throws
               DAOSysException, DAODBUpdateException {

        String queryStr = "DELETE FROM " + "T_Customer" +
                " WHERE customerId = "
                    + id;
        log("queryString is: "+ queryStr);
        Statement stmt = null;
        try {
            stmt = globalTran.getDBConnection().createStatement();
            int resultCount = stmt.executeUpdate(queryStr);
            if ( resultCount != 1 )
                throw new DAODBUpdateException("ERROR deleteing Customer from" + " Customer_TABLE!! resultCount = " + resultCount);
        } catch(SQLException se) {
            throw new DAOSysException("Unable to delete for item " + id + "\n" + se);
        } finally {
            globalTran.closeStatement(stmt);
            log("CustomerDAO: closeStatement");
        }
    }

    public void updateObject(Object model) throws
                    DAOSysException, DAODBUpdateException {

        CustomerValue custVal = (CustomerValue) model;

        PreparedStatement stmt = null;
        try {
            String queryStr = "UPDATE " + "T_Customer" +
              " SET " + "customerNumber = ?, " +
              "firstName = ?, " +
              "middleInitial = ?, " +
              "prefix = ?, " +
              "suffix = ?, " +
              "lastName = ?, " +
              "phone1 = ?, " +
              "phone2 = ?, " +
              "eMail = ? " +
              "WHERE customerId = ?";

            log("CustomerDAO: Update String " + queryStr);
            stmt = globalTran.getDBConnection().prepareStatement(queryStr);
            log("CustomerDAO: Prepare Worked ");

            int i = 1;
            stmt.setString(i++, custVal.getCustomerNumber());
            log("CustomerDAO: Setting items " + custVal.getCustomerNumber());
            stmt.setString(i++, custVal.getFirstName());
            stmt.setString(i++, custVal.getMiddleInitial());
            stmt.setString(i++, custVal.getPrefix());
            stmt.setString(i++, custVal.getSuffix());
            stmt.setString(i++, custVal.getLastName());
            stmt.setString(i++, custVal.getPhone1());
            stmt.setString(i++, custVal.getPhone2());
            stmt.setString(i++, custVal.getEMail());
            stmt.setInt(i++, custVal.getCustomerId().intValue());

            log("CustomerDAO: done setting items ");

            int resultCount = stmt.executeUpdate();
            if ( resultCount != 1 ) {
                log("CustomerDAO: update failed");
                throw new DAODBUpdateException ("ERROR updating Customer in" + " Customer_TABLE!! resultCount = " + resultCount);
            }
            log("CustomerDAO: update worked...result count = " + resultCount);
        } catch(SQLException se) {
            throw new DAOSysException("Unable to update item " + custVal.getCustomerId() + " \n" + se);
        } finally {
            globalTran.closeStatement(stmt);
            log("CustomerDAO: closeStatement");
        }
    }

    public void insertObject(Object model) throws
                    DAOSysException, DAODBUpdateException {

        CustomerValue custVal = (CustomerValue) model;

        PreparedStatement stmt = null;
        try {
            String queryStr = "INSERT INTO " + "T_Customer" + " (" +
              "customerId, " +
              "customerNumber, " +
              "firstName, " +
              "middleInitial, " +
              "prefix, " +
              "suffix, " +
              "lastName, " +
              "phone1, " +
              "phone2, " +
              "eMail) " +
              "VALUES " +
              "(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";

            log("CustomerDAO: Insert String " + queryStr);
            stmt = globalTran.getDBConnection().
                        prepareStatement(queryStr);

            int i = 1;
            stmt.setInt(i++, custVal.getCustomerId().intValue());
            stmt.setString(i++, custVal.getCustomerNumber());
            stmt.setString(i++, custVal.getFirstName());
            stmt.setString(i++, custVal.getMiddleInitial());
            stmt.setString(i++, custVal.getPrefix());
            stmt.setString(i++, custVal.getSuffix());
            stmt.setString(i++, custVal.getLastName());
            stmt.setString(i++, custVal.getPhone1());
            stmt.setString(i++, custVal.getPhone2());
            stmt.setString(i++, custVal.getEMail());

            int resultCount = stmt.executeUpdate();
            if ( resultCount != 1 )
                throw new DAODBUpdateException ("ERROR inserting Customer in" + " Customer_TABLE!! resultCount = " + resultCount);
        } catch(SQLException se) {
            throw new DAOSysException("Unable to insert item " + custVal.getCustomerId() + " \n" + se);
        } finally {
            globalTran.closeStatement(stmt);
            log("CustomerDAO: closeStatement");
        }
    }
    private boolean doQuery (String qryString) throws DAOSysException {
        Statement stmt = null;
        ResultSet result = null;
        boolean returnValue = false;
        try {
            log("CustomerDAO: before statement creationg");
            stmt = globalTran.getDBConnection().createStatement();
            log("CustomerDAO: statement created");
			log("CustomerDAO: query is" + qryString);
            result = stmt.executeQuery(qryString);
            log("CustomerDAO: statement executed");
            if ( !result.next() ) {
                log("CustomerDAO: customer not found");
                returnValue = false;
            }
            else {
                log("CustomerDAO: customer found");

                custVal = new CustomerValue();
                int i = 1;
                custVal.setCustomerId(new Integer(result.getInt(i++)));
                custVal.setCustomerNumber(result.getString(i++));
                custVal.setFirstName(result.getString(i++));
                custVal.setMiddleInitial(result.getString(i++));
                custVal.setPrefix(result.getString(i++));
                custVal.setSuffix(result.getString(i++));
                custVal.setLastName(result.getString(i++));
                custVal.setPhone1(result.getString(i++));
                custVal.setPhone2(result.getString(i++));
                custVal.setEMail(result.getString(i++));
                returnValue = true;
            }
        } catch(SQLException se) {
			se.printStackTrace();
            throw new DAOSysException("Unable to Query for item " +
                                 "\n" + se);
        } finally {
            log("CustomerDAO: prior");
            globalTran.closeResultSet(result);
            log("CustomerDAO: closeResult");
            globalTran.closeStatement(stmt);
            log("CustomerDAO: closeStatement");
        }
        return returnValue;
    }

    private void closeResultSet(ResultSet result) throws DAOSysException {
        try {
            if (result != null) {
                result.close();
            }
        } catch (SQLException se) {
            throw new DAOSysException("SQL Exception while closing " +
                                        "Result Set : \n" + se);
        }
    }

    private void closeStatement(Statement stmt) throws DAOSysException {
        try {
            if (stmt != null) {
                stmt.close();
            }
        } catch (SQLException se) {
            throw new DAOSysException("SQL Exception while closing " +
                                        "Statement : \n" + se);
        }
    }
     private void log(String s) {
        System.out.println(s);
    }
}