entity bean 用Collection selectByLastname(String name)取回的記錄中關鍵欄位是重複的

huhongbo發表於2005-04-28
BeanAST
entity bean 用Collection selectByLastname(String name)取回的記錄中關鍵欄位是重複的，而其他欄位是正常的。執行測試程式後，第一行中除關鍵字外，其餘欄位變成了符合查詢條件的最後的一條記錄。資料庫為ms sql ,id為自動增長的，ejbCreate()方法為insert into userDesc(name,address) values(?,?),關鍵字id作為UserDescPK類，在傳回的vector中，放入UserDescPK.
比如關鍵字id值為 資料庫中記錄是

id name address
0 0value oaddress
1 1value 1address
5 5value 5address


列印出來後，如下
id name address
0 0value oaddress
0 1value 1address <-----id值由1變為0
0 5value 5address <-----id值由1變為0



再到資料庫中查詢，如下
id name address
0 5value 5address <-----值由0value,0address變化成5value,5address.而我沒有操作變化。
1 1value 1address
5 5value 5address

原碼如下：
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package com.hhb;

import javax.ejb.EntityBean;
import javax.ejb.EntityContext;
import javax.ejb.CreateException;
import javax.ejb.RemoveException;
import java.sql.Connection;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.ejb.FinderException;
import java.rmi.RemoteException;
import java.util.Collection;
import java.util.Vector;

public class UserDescBean
implements EntityBean {
EntityContext entityContext;
private int id;
private String name;
private String email;
private String address;
private UserDescDetail userDescDetail = new UserDescDetail();
public int getId() {
return id;
}

public String getName() {
return name;
}

public String getEmail() {
return email;
}

public String getAddress() {
return address;
}

public EntityContext getEntityContext() {
return entityContext;
}

public UserDescDetail getUserDescDetail() {
userDescDetail.setId(id);
userDescDetail.setAddress(address);
userDescDetail.setMail(email);
userDescDetail.setName(name);
return userDescDetail;
}

/**
* ejbCreate
* @param id int
* @param name String
* @param email String
* @param address String
* @throws CreateException
* @return UserDescPK
*/

public UserDescPK ejbCreate(int id, String name, String email, String address) throws
CreateException {
setId(id);
setName(name);
setEmail(email);
setAddress(address);

PreparedStatement psmt = null;
Connection conn = null;
String sql = "insert into userDesc(name,mail,address) values(?,?,?)";
String idSql = "select max(id) from userDesc";
try {
conn = getConnection();
psmt = conn.prepareStatement(sql);
//psmt.setInt(1, id);
psmt.setString(1, name);
psmt.setString(2, email);
psmt.setString(3, address);
psmt.execute();

//獲取最大
psmt = conn.prepareStatement(sql);
ResultSet rset = psmt.executeQuery();
id = rset.getInt(1);

return new UserDescPK(id);
}
catch (Exception ex) {
ex.printStackTrace();
throw new CreateException(ex.getMessage());
}
finally {
try {
if (psmt != null) {
psmt.close();
}
if (conn != null) {
conn.close();
}
}
catch (Exception ex) {
ex.printStackTrace();
}
}
} //end ejbCreate

public void ejbPostCreate(int id, String name, String email, String address) throws
CreateException {
}

public void ejbRemove() throws RemoveException {
UserDescPK key = (UserDescPK) entityContext.getPrimaryKey();
int intKey = key.id;
PreparedStatement pstmt = null;
Connection conn = null;
try {
conn = getConnection();
pstmt = conn.prepareStatement("delete from userDesc where id = ?");
pstmt.setInt(1, intKey);
pstmt.execute();
}
catch (Exception ex) {
ex.printStackTrace();
}
finally {
try {
if (pstmt != null) {
pstmt.close();
}
}
catch (Exception e) {}
try {
if (conn != null) {
conn.close();
}
}
catch (Exception e) {}
}

}

public void ejbLoad() {
UserDescPK key = (UserDescPK) entityContext.getPrimaryKey();
int intKey = key.id;
PreparedStatement pstmt = null;
Connection conn = null;
try {
conn = getConnection();
pstmt = conn.prepareStatement("select * from userDesc where id = ?");
pstmt.setInt(1, intKey);
ResultSet rs = pstmt.executeQuery();
rs.next();
name = rs.getString(2);
email = rs.getString(3);
address = rs.getString(4);
}
catch (Exception ex) {
ex.printStackTrace();
}
finally {
try {
if (pstmt != null) {
pstmt.close();
}
}
catch (Exception e) {}
try {
if (conn != null) {
conn.close();
}
}
catch (Exception e) {}
}

}
/**
* ejbStore
*/

public void ejbStore() {
PreparedStatement psmt = null;
Connection conn = null;
String sql = "update userDesc set name=?,mail=?,address=? where id=?";
try {
conn = getConnection();
psmt = conn.prepareStatement(sql);
//psmt.setInt(1, id);
psmt.setString(1, name);
psmt.setString(2, email);
psmt.setString(3, address);
psmt.setInt(4, id);
psmt.executeUpdate();
}
catch (Exception ex) {
ex.printStackTrace();
}
finally {
try {
if (psmt != null) {
psmt.close();
}
if (conn != null) {
conn.close();
}
}
catch (Exception ex) {
ex.printStackTrace();
}
}

}

public void ejbActivate() {
}

public void ejbPassivate() {
}

public void setEntityContext(EntityContext entityContext) {
this.entityContext = entityContext;
}

public void setId(int id) {
this.id = id;
}

public void setName(String name) {
this.name = name;
}

public void setEmail(String email) {
this.email = email;
}

public void setAddress(String address) {
this.address = address;
}

public void setUserDescDetail(UserDescDetail userDescDetail) {
this.userDescDetail = userDescDetail;
id = userDescDetail.getId();
name = userDescDetail.getName();
address = userDescDetail.getAddress();
email = userDescDetail.getMail();
}

public void unsetEntityContext() {
this.entityContext = null;
}

public UserDescPK ejbFindByPrimaryKey(UserDescPK key) throws FinderException {
String sql = "select * from userDesc where id = ?";
Connection conn = null;
PreparedStatement psmt = null;
try {
conn = getConnection();
psmt = conn.prepareStatement(sql);
psmt.setInt(1, key.id);
ResultSet reset = psmt.executeQuery();
while(reset.next()){
id = reset.getInt(1);
name = reset.getString(2);
email = reset.getString(3);
address = reset.getString(4);
}
return key;
}
catch (Exception ex) {
ex.printStackTrace();
throw new FinderException(ex.toString());
}
finally {
try {
if (psmt != null) {
psmt.close();
}
if (conn != null) {
conn.close();
}
}
catch (Exception ex) {
ex.printStackTrace();
}
}
}

public Collection ejbFindByName(String name) throws FinderException {
String sql = "select * from userDesc where name = ?";
Connection conn = null;
PreparedStatement psmt = null;
Vector v = new Vector();
try {
conn = getConnection();
psmt = conn.prepareStatement(sql);
psmt.setString(1, name);
ResultSet reset = psmt.executeQuery();
while (reset.next()) {
System.out.println("primary key = " + reset.getInt("id"));
v.addElement(new UserDescPK(reset.getInt("id")));
}
for (int i = 0; i < v.size(); i++) {
System.out.println("v key= " + v.get(i).toString());
}
return v;
}
catch (Exception ex) {
ex.printStackTrace();
throw new FinderException(ex.toString());
}
finally {
try {
if (psmt != null) {
psmt.close();
}
if (conn != null) {
conn.close();
}
}
catch (Exception ex) {
ex.printStackTrace();
}
}

}

/**
* getConnect
*/
public Connection getConnection() throws Exception {
try {
Context ctx = new InitialContext();
DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/ejbPool");
return ds.getConnection();
}
catch (Exception ex) {
ex.printStackTrace();
throw ex;
}
}
}

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package com.hhb;

import java.io.Serializable;
/**
* 設定資訊，利於分析
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2005</p>
* <p>Company: </p>
* @author not attributable
* @version 1.0
*/
public class UserDescDetail implements Serializable{
private int id;
private String name;
private String mail;
private String address;
public int getId() {
return id;
}

public String getName() {
return name;
}

public String getMail() {
return mail;
}

public void setAddress(String address) {
this.address = address;
}

public void setId(int id) {
this.id = id;
}

public void setName(String name) {
this.name = name;
}

public void setMail(String mail) {
this.mail = mail;
}

public String getAddress() {
return address;
}

public UserDescDetail() {
}
}

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package com.hhb;

import javax.ejb.EJBObject;
import java.rmi.RemoteException;
import java.sql.ResultSet;

public interface UserDesc
extends EJBObject {

public int getId() throws RemoteException;

public void setId(int id) throws RemoteException;

public void setName(String name) throws RemoteException;

public String getName() throws RemoteException;

public void setEmail(String email) throws RemoteException;

public String getEmail() throws RemoteException;

public void setAddress(String address) throws RemoteException;

public String getAddress() throws RemoteException;

public UserDescDetail getUserDescDetail() throws RemoteException;

public void setUserDescDetail(UserDescDetail userDescDetail) throws
RemoteException;

}


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package com.hhb;

import javax.ejb.EJBHome;
import javax.ejb.CreateException;
import java.rmi.RemoteException;
import javax.ejb.FinderException;
import java.util.Collection;

public interface UserDescHome
extends EJBHome {
public UserDesc create(int id, String name, String email, String address) throws
CreateException, RemoteException;

public UserDesc findByPrimaryKey(UserDescPK pk) throws
FinderException, RemoteException;

public Collection findByName(String name) throws FinderException,
RemoteException;
}
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package com.hhb;

import java.io.Serializable;

public class UserDescPK
implements Serializable {
public int id;
public UserDescPK() {
}

public UserDescPK(int id) {
this.id = id;
}

public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (! (obj instanceof UserDescPK)) {
return false;
}
UserDescPK that = (UserDescPK) obj;
if (that.id != this.id) {
return false;
}
return true;

}

public int hashCode() {
int result = 17;
result = 37 * result + (int)this.id;
return result;

}

public String toString(){
return Integer.toString(id);
}
測試的方法為
public void printCol(){
try {
Collection col = userDescHome.findByName("ch");
Iterator itor = col.iterator();
int ii = 0 ;
while (itor.hasNext()) {
UserDesc acc = (UserDesc)itor.next();
System.out.println("---------------------------");
ii++;
System.out.println("acc"+ ii +"=" + acc.getId());
System.out.println("acc"+ ii +"=" +acc.getName());
System.out.println("acc"+ ii +"=" + acc.getAddress());
}
}
catch (Exception ex) {
ex.printStackTrace();
}

}

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