Thank you.It's OK.
This is my source.
I want to know what wrong is with my original source.
What difference is between my original source nad new source?
Thank you
levels
_____________________________________original source__________________________
/*
*
* Copyright 2000 Sun Microsystems, Inc. All Rights Reserved.
*
* This software is the proprietary information of Sun Microsystems, Inc.
* Use is subject to license terms.
*
*/
package com.sasgz.ejb.account;
import java.sql.*;
import javax.sql.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.*;
public class AccountEJB implements EntityBean {
private String id;
private String firstName;
private String lastName;
private double balance;
private EntityContext context;
private Connection con;
private String dbName = "java:comp/env/jdbc/AccountDB";
public void debit(double amount)
throws InsufficientBalanceException {
if (balance - amount < 0) {
throw new InsufficientBalanceException();
}
balance -= amount;
}
public void credit(double amount) {
balance += amount;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public double getBalance() {
return balance;
}
public String ejbCreate(String id, String firstName,
String lastName, double balance)
throws CreateException {
if (balance < 0.00) {
throw new CreateException
("A negative initial balance is not allowed.");
}
try {
insertRow(id, firstName, lastName, balance);
} catch (Exception ex) {
throw new EJBException("ejbCreate: " +
ex.getMessage());
}
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.balance = balance;
return id;
}
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 ejbFindByLastName(String lastName)
throws FinderException {
Collection result;
try {
result = selectByLastName(lastName);
} catch (Exception ex) {
throw new EJBException("ejbFindByLastName " +
ex.getMessage());
}
if (result.isEmpty()) {
throw new ObjectNotFoundException("No rows found.");
}
else {
return result;
}
}
public Collection ejbFindInRange(double low, double high)
throws FinderException {
Collection result;
try {
result = selectInRange(low, high);
} catch (Exception ex) {
throw new EJBException("ejbFindInRange: " +
ex.getMessage());
}
if (result.isEmpty()) {
throw new ObjectNotFoundException("No rows found.");
}
else {
return result;
}
}
public void ejbRemove() {
try {
deleteRow(id);
} catch (Exception ex) {
throw new EJBException("ejbRemove: " +
ex.getMessage());
}
}
public void setEntityContext(EntityContext context) {
this.context = context;
try {
makeConnection();
} catch (Exception ex) {
throw new EJBException("Unable to connect to database. " +
ex.getMessage());
}
}
public void unsetEntityContext() {
try {
con.close();
} catch (SQLException ex) {
throw new EJBException("unsetEntityContext: " + ex.getMessage());
}
}
public void ejbActivate() {
id = (String)context.getPrimaryKey();
}
public void ejbPassivate() {
id = null;
}
public void ejbLoad() {
try {
loadRow();
} catch (Exception ex) {
throw new EJBException("ejbLoad: " +
ex.getMessage());
}
}
public void ejbStore() {
try {
storeRow();
} catch (Exception ex) {
throw new EJBException("ejbLoad: " +
ex.getMessage());
}
}
public void ejbPostCreate(String id, String firstName,
String lastName, double balance) { }
/*********************** Database Routines *************************/
private void makeConnection() throws NamingException, SQLException {
InitialContext ic = new InitialContext();
DataSource ds = (DataSource) ic.lookup(dbName);
con = ds.getConnection();
}
private void insertRow (String id, String firstName, String lastName,
double balance) throws SQLException {
String insertStatement =
"insert into account values ( ? , ? , ? , ? )";
PreparedStatement prepStmt =
con.prepareStatement(insertStatement);
prepStmt.setString(1, id);
prepStmt.setString(2, firstName);
prepStmt.setString(3, lastName);
prepStmt.setDouble(4, balance);
prepStmt.executeUpdate();
prepStmt.close();
System.out.println("insert"+id);
}
private void deleteRow(String id) throws SQLException {
String deleteStatement =
"delete from account where id = ? ";
PreparedStatement prepStmt =
con.prepareStatement(deleteStatement);
prepStmt.setString(1, id);
prepStmt.executeUpdate();
prepStmt.close();
}
private boolean selectByPrimaryKey(String primaryKey)
throws SQLException {
String selectStatement =
"select id " +
"from account where id = ? ";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setString(1, primaryKey);
ResultSet rs = prepStmt.executeQuery();
boolean result = rs.next();
prepStmt.close();
return result;
}
private Collection selectByLastName(String lastName)
throws SQLException {
String selectStatement =
"select id " +
"from account where lastname = ? ";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setString(1, lastName);
ResultSet rs = prepStmt.executeQuery();
ArrayList a = new ArrayList();
while (rs.next()) {
String id = rs.getString(1);
a.add(id);
}
prepStmt.close();
return a;
}
private Collection selectInRange(double low, double high)
throws SQLException {
String selectStatement =
"select id from account " +
"where balance between ? and ?";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setDouble(1, low);
prepStmt.setDouble(2, high);
ResultSet rs = prepStmt.executeQuery();
ArrayList a = new ArrayList();
while (rs.next()) {
String id = rs.getString(1);
a.add(id);
}
prepStmt.close();
return a;
}
private void loadRow() throws SQLException {
String selectStatement =
"select firstname, lastname, balance " +
"from account where id = ? ";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setString(1, this.id);
ResultSet rs = prepStmt.executeQuery();
if (rs.next()) {
this.firstName = rs.getString(1);
this.lastName = rs.getString(2);
this.balance = rs.getDouble(3);
prepStmt.close();
}
else {
prepStmt.close();
throw new NoSuchEntityException("Row for id " + id +
" not found in database.");
}
}
private void storeRow() throws SQLException {
String updateStatement =
"update account set firstname = ? ," +
"lastname = ? , balance = ? " +
"where id = ?";
PreparedStatement prepStmt =
con.prepareStatement(updateStatement);
prepStmt.setString(1, firstName);
prepStmt.setString(2, lastName);
prepStmt.setDouble(3, balance);
prepStmt.setString(4, id);
int rowCount = prepStmt.executeUpdate();
prepStmt.close();
if (rowCount == 0) {
throw new EJBException("Storing row for id " + id + " failed.");
}
}
} // AccountEJB
_____________________________________new source_____________________________
/*
*
* Copyright 2000 Sun Microsystems, Inc. All Rights Reserved.
*
* This software is the proprietary information of Sun Microsystems, Inc.
* Use is subject to license terms.
*
*/
package com.sasgz.ejb.account;
import java.sql.*;
import javax.sql.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.*;
public class AccountEJB implements EntityBean {
private String id;
private String firstName;
private String lastName;
private double balance;
private EntityContext context;
private Connection con;
private String dbName = "java:comp/env/jdbc/AccountDB";
private DataSource ds = null;
public void debit(double amount)
throws InsufficientBalanceException {
if (balance - amount < 0) {
throw new InsufficientBalanceException();
}
balance -= amount;
}
public void credit(double amount) {
balance += amount;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public double getBalance() {
return balance;
}
public String ejbCreate(String id, String firstName,
String lastName, double balance)
throws CreateException {
Connection conn = null;
if (balance < 0.00) {
throw new CreateException
("A negative initial balance is not allowed.");
}
try {
conn = ds.getConnection();
insertRow(id, firstName, lastName, balance, conn);
} catch (Exception ex) {
throw new EJBException("ejbCreate: " +
ex.getMessage());
}
finally {
try { conn.close(); } catch (Exception ex) { }
}
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.balance = balance;
return id;
}
public String ejbFindByPrimaryKey(String primaryKey)
throws FinderException {
boolean result;
try {
Connection conn = null;
conn = ds.getConnection();
result = selectByPrimaryKey(primaryKey,conn);
} 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 ejbFindByLastName(String lastName)
throws FinderException {
Collection result;
try {
Connection conn = null;
conn = ds.getConnection();
result = selectByLastName(lastName,conn);
} catch (Exception ex) {
throw new EJBException("ejbFindByLastName " +
ex.getMessage());
}
if (result.isEmpty()) {
throw new ObjectNotFoundException("No rows found.");
}
else {
return result;
}
}
public Collection ejbFindInRange(double low, double high)
throws FinderException {
Collection result;
try {
Connection conn = null;
conn = ds.getConnection();
result = selectInRange(low, high,conn);
} catch (Exception ex) {
throw new EJBException("ejbFindInRange: " +
ex.getMessage());
}
if (result.isEmpty()) {
throw new ObjectNotFoundException("No rows found.");
}
else {
return result;
}
}
public void ejbRemove() {
Connection conn = null;
try {
conn = ds.getConnection();
deleteRow(id,conn);
} catch (Exception ex) {
throw new EJBException("ejbRemove: " +
ex.getMessage());
}
}
public void setEntityContext(EntityContext context) {
this.context = context;
try {
// makeConnection();
InitialContext ic = new InitialContext();
ds = (DataSource) ic.lookup(dbName);
} catch (Exception ex) {
throw new EJBException("Unable to connect to database. " +
ex.getMessage());
}
System.out.println("Connected to Oracle!");
}
public void unsetEntityContext() {
try {
con.close();
} catch (SQLException ex) {
throw new EJBException("unsetEntityContext: " + ex.getMessage());
}
}
public void ejbActivate() {
id = (String)context.getPrimaryKey();
}
public void ejbPassivate() {
id = null;
}
public void ejbLoad() {
try {
Connection conn = null;
conn = ds.getConnection();
loadRow(conn);
} catch (Exception ex) {
throw new EJBException("ejbLoad: " +
ex.getMessage());
}
}
public void ejbStore() {
try {
Connection conn = null;
conn = ds.getConnection();
storeRow(conn);
} catch (Exception ex) {
throw new EJBException("ejbLoad: " +
ex.getMessage());
}
}
public void ejbPostCreate(String id, String firstName,
String lastName, double balance) { }
/*********************** Database Routines *************************/
private void makeConnection() throws NamingException, SQLException {
InitialContext ic = new InitialContext();
DataSource ds = (DataSource) ic.lookup(dbName);
con = ds.getConnection();
}
private void insertRow (String id, String firstName, String lastName,
double balance, Connection con) throws SQLException {
String insertStatement =
"insert into account values ( ? , ? , ? , ? )";
PreparedStatement prepStmt =
con.prepareStatement(insertStatement);
prepStmt.setString(1, id);
prepStmt.setString(2, firstName);
prepStmt.setString(3, lastName);
prepStmt.setDouble(4, balance);
prepStmt.executeUpdate();
prepStmt.close();
}
private void deleteRow(String id, Connection con) throws SQLException {
String deleteStatement =
"delete from account where id = ? ";
PreparedStatement prepStmt =
con.prepareStatement(deleteStatement);
prepStmt.setString(1, id);
prepStmt.executeUpdate();
prepStmt.close();
}
private boolean selectByPrimaryKey(String primaryKey, Connection con)
throws SQLException {
String selectStatement =
"select id " +
"from account where id = ? ";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setString(1, primaryKey);
ResultSet rs = prepStmt.executeQuery();
boolean result = rs.next();
prepStmt.close();
return result;
}
private Collection selectByLastName(String lastName, Connection con)
throws SQLException {
String selectStatement =
"select id " +
"from account where lastname = ? ";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setString(1, lastName);
ResultSet rs = prepStmt.executeQuery();
ArrayList a = new ArrayList();
while (rs.next()) {
String id = rs.getString(1);
a.add(id);
}
prepStmt.close();
return a;
}
private Collection selectInRange(double low, double high, Connection con)
throws SQLException {
String selectStatement =
"select id from account " +
"where balance between ? and ?";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setDouble(1, low);
prepStmt.setDouble(2, high);
ResultSet rs = prepStmt.executeQuery();
ArrayList a = new ArrayList();
while (rs.next()) {
String id = rs.getString(1);
a.add(id);
}
prepStmt.close();
return a;
}
private void loadRow(Connection con) throws SQLException {
String selectStatement =
"select firstname, lastname, balance " +
"from account where id = ? ";
PreparedStatement prepStmt =
con.prepareStatement(selectStatement);
prepStmt.setString(1, this.id);
ResultSet rs = prepStmt.executeQuery();
if (rs.next()) {
this.firstName = rs.getString(1);
this.lastName = rs.getString(2);
this.balance = rs.getDouble(3);
prepStmt.close();
}
else {
prepStmt.close();
throw new NoSuchEntityException("Row for id " + id +
" not found in database.");
}
}
private void storeRow(Connection con) throws SQLException {
String updateStatement =
"update account set firstname = ? ," +
"lastname = ? , balance = ? " +
"where id = ?";
PreparedStatement prepStmt =
con.prepareStatement(updateStatement);
prepStmt.setString(1, firstName);
prepStmt.setString(2, lastName);
prepStmt.setDouble(3, balance);
prepStmt.setString(4, id);
int rowCount = prepStmt.executeUpdate();
prepStmt.close();
if (rowCount == 0) {
throw new EJBException("Storing row for id " + id + " failed.");
}
}
} // AccountEJB
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