Container-Managed Persistence Entity Beans EJB2 – Employees Example

Container-Managed Persistence Entity Beans Example

A. Tạo CSDL trong SQL Server với tên Employee, tạo bảng có tên tbl_emp có cấu trúc như bảng sau:

Field Name	Type
EmpId	nvarchar (Primary Key)
FirstName	nvarchar
LastName	nvarchar
DateOfBirth	nvarchar
Address	nvarchar
Salary	Int
DepartmentNo	int

B. Thiết kế CMP:

1. Tạo file EmployeeHome.java với nội dung sau:

package emp; import java.rmi.RemoteException; import java.util.Collection; import javax.ejb.CreateException; import javax.ejb.EJBHome; import javax.ejb.FinderException; public interface EmployeeHome extends EJBHome { public Employee create(String empid, String fName, String lName,String doBirth, String address, int salary,int dpNo) throws CreateException, RemoteException; public Employee findByPrimaryKey(String empid) throws FinderException, RemoteException; public Collection findByLastName(String s) throws FinderException,RemoteException; }

2. Tạo file Employee.java với nội dung sau

package emp; import java.rmi.RemoteException; import javax.ejb.EJBObject; public interface Employee extends EJBObject { public String getEmpid() throws RemoteException; public void setFName(String fName) throws RemoteException; public String getFName() throws RemoteException; public void setLName(String lName) throws RemoteException; public String getLName() throws RemoteException; public void setDoBirth(String doBirth) throws RemoteException; public String getDoBirth() throws RemoteException; public void setAddress(String address) throws RemoteException; public String getAddress() throws RemoteException; public void setSalary(int salary) throws RemoteException; public int getSalary() throws RemoteException; public void setDpNo(int dpNo) throws RemoteException; public int getDpNo() throws RemoteException; }

3. Tạo file EmployeeBean.java với nội dung sau

package emp; import javax.ejb.CreateException; import javax.ejb.EntityContext; import javax.ejb.RemoveException; public abstract class EmployeeBean implements javax.ejb.EntityBean { EntityContext entityContext; public String ejbCreate(String empid, String fName, lName, doBirth, String address, int salary, int dpNo) throws CreateException { setEmpid(empid); setFName(fName); setLName(lName); setDoBirth(doBirth); setAddress(address); setSalary(salary); setDpNo(dpNo); return empid; } public void ejbPostCreate(String empid, String fName, String lName, doBirth, String address, int salary, int dpNo) throws CreateException { } public void ejbRemove() throws RemoveException { } public void ejbLoad() { } public void ejbStore() { } public void ejbActivate() { } public void ejbPassivate() { } public void unsetEntityContext() { this.entityContext = null; } public void setEntityContext(EntityContext entityContext) { this.entityContext = entityContext; } public abstract void setDpNo(int dpNo); public abstract void setSalary(int salary); public abstract void setAddress(String address); public abstract void setDoBirth(String doBirth); public abstract void setLName(String lName); public abstract void setFName(String fName); public abstract void setEmpid(String empid); public abstract String getEmpid(); public abstract String getFName(); public abstract String getLName(); public abstract String getDoBirth(); public abstract String getAddress(); public abstract int getSalary(); public abstract int getDpNo(); }

C. Cấu hình triển khai

4. Tạo file file ejb-jar.xml trong thư mục META-INF với nội dung sau

<?xml version=“1.0“ encoding=“UTF-8“?> <!DOCTYPE ejb-jar PUBLIC “-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN“ “http://java.sun.com/dtd/ejb-jar_2_0.dtd“> <ejb-jar> <enterprise-beans> <entity> <ejb-name>EmployeeBean</ejb-name> <home>emp.EmployeeHome</home> <remote>emp.Employee</remote> <ejb-class>emp.EmployeeBean</ejb-class> <persistence-type>Container</persistence-type> <prim-key-class>java.lang.String</prim-key-class> <reentrant>false</reentrant> <cmp-version>2.x</cmp-version> <abstract-schema-name>tbl_emp</abstract-schema-name> <cmp-field> <field-name>empid</field-name> </cmp-field> <cmp-field> <field-name>fName</field-name> </cmp-field> <cmp-field> <field-name>lName</field-name> </cmp-field> <cmp-field> <field-name>doBirth</field-name> </cmp-field> <cmp-field> <field-name>address</field-name> </cmp-field> <cmp-field> <field-name>salary</field-name> </cmp-field> <cmp-field> <field-name>dpNo</field-name> </cmp-field> <primkey-field>empid</primkey-field> <query> <query-method> <method-name>findByLastName</method-name> <method-params> <method-param>java.lang.String</method-param> </method-params> </query-method> <ejb-ql> <![CDATA[SELECT OBJECT(o) FROM tbl_emp AS o WHERE o.lName = ?1]]> </ejb-ql> </query> </entity> </enterprise-beans> <assembly-descriptor> <container-transaction> <method> <ejb-name>EmployeeBean</ejb-name> <method-name>*</method-name> </method> <trans-attribute>Required</trans-attribute> </container-transaction> </assembly-descriptor> </ejb-jar>

5. Tạo file file jboss.xml trong thư mục META-INF với nội dung sau

<?xml version=“1.0“ encoding=“UTF-8“?> <!DOCTYPE jboss PUBLIC “-//JBoss//DTD JBOSS 4.0//EN“ “http://www.jboss.org/j2ee/dtd/jboss_4_0.dtd“> <jboss> <enterprise-beans> <entity> <ejb-name>EmployeeBean</ejb-name> <jndi-name>EmployeeEJB</jndi-name> </entity> </enterprise-beans> </jboss>

6. Tạo file file jbosscmp-jdbc.xml trong thư mục META-INF với nội dung sau

<?xml version=“1.0“ encoding=“UTF-8“?> <!DOCTYPE jbosscmp-jdbc PUBLIC “-//JBoss//DTD JBOSSCMP-JDBC 4.0//EN“ “http://www.jboss.org/j2ee/dtd/jbosscmp-jdbc_4_0.dtd“> <jbosscmp-jdbc> <defaults> <datasource>java:/MSSQLDS</datasource> <datasource-mapping>MS SQLSERVER</datasource-mapping> <create-table>true</create-table> <remove-table>true</remove-table> </defaults> <enterprise-beans> <entity> <ejb-name>EmployeeBean</ejb-name> <datasource>java:/MSSQLDS</datasource> <datasource-mapping>MS SQLSERVER</datasource-mapping> <create-table>true</create-table> <table-name>tbl_emp</table-name> <cmp-field> <field-name>empid</field-name> <column-name>EmpId</column-name> </cmp-field> <cmp-field> <field-name>fName</field-name> <column-name>FirstName</column-name> </cmp-field> <cmp-field> <field-name>lName</field-name> <column-name>LastName</column-name> </cmp-field> <cmp-field> <field-name>doBirth</field-name> <column-name>DateOfBirth</column-name> </cmp-field> <cmp-field> <field-name>address</field-name> <column-name>Address</column-name> </cmp-field> <cmp-field> <field-name>salary</field-name> <column-name>Salary</column-name> </cmp-field> <cmp-field> <field-name>dpNo</field-name> <column-name>DepartmentNo</column-name> </cmp-field> </entity> </enterprise-beans> </jbosscmp-jdbc>

7. Tạo/cấu hình file mssql-ds.xml trong thư mục %JBOSS-HOME%\server\default\deploy

<?xml version=“1.0“ encoding=“UTF-8“?> <datasources> <local-tx-datasource> <jndi-name>MSSQLDS</jndi-name> <connection-url> jdbc:sqlserver://localhost:1433;databaseName=Employee </connection-url> <driver-class> com.microsoft.sqlserver.jdbc.SQLServerDriver </driver-class> <user-name>sa</user-name> <password></password> <metadata> <type-mapping>MS SQLSERVER2000</type-mapping> </metadata> </local-tx-datasource> </datasources>

D. Triển khai

1. 1. Tạo file compile.bat có nội dung

javac -d . *.java pause

1. 1. Tạo file CreateJarFile.bat có nội dung

jar cvf EmployeesBean.jar emp/*.class META-INF/*.xml pause

1. 1. Biên dịch: Chạy file compile.bat
   2. Tạo file jar: Chạy file CreateJarFile.bat
   3. Sao chép file EmployeesBean.jar vào thư mục %JBOSS-HOME%\server\default\deploy. Kết quả triển khai trên console của JBOSS có dạng như sau:

12:53:23,604 INFO [EjbModule] Deploying EmployeeBean 12:53:23,698 INFO [ProxyFactory] Bound EJB Home ‘EmployeeBean’ to jndi ‘EmployeeEJB’ 12:53:23,698 INFO [EJBDeployer] Deployed: file:/C:/javaSoft/jboss-4.2.2.GA/server/default/deploy/EmployeesBean.jar

E. Tạo client

1. Tạo thư mục client,Copy thu mục emp vào đây, bỏ đi file EmployeeBean.class

2. Tạo file EMP_Client.java trong thư mục client với nội dung sau

package client; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.naming.Context; import javax.naming.InitialContext; import javax.swing.Box; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.JTextField; import javax.swing.table.DefaultTableModel; import java.util.Collection; import java.util.Iterator; import javax.rmi.PortableRemoteObject; import emp.*; public class EMP_Client extends JFrame implements ActionListener{ private static final long serialVersionUID = 7170837407824840942L; private JPanel pTop=new JPanel(new BorderLayout()); private JTextField tfID,tfFN,tfLN,tfDOB,tfAD,tfSAL,tfDeptNo; private JButton btAdd,btUpdate,btFindByKey,btFindByLN,btExit; private JLabel lblStatus; private DefaultTableModel tableModel; private JTable table; private EmployeeHome home; public EMP_Client() { super(“Employees EJB Client”); setDefaultCloseOperation(EXIT_ON_CLOSE); setSize(500,450); JLabel lblTitle=new JLabel(“Employees EJB Client”,JLabel.CENTER); lblTitle.setFont(new Font(“Arial”,Font.BOLD,18)); lblTitle.setForeground(Color.blue);pTop.add(lblTitle,BorderLayout.NORTH); lblStatus=new JLabel(“init…”); this.add(lblStatus,BorderLayout.SOUTH); this.add(pTop,BorderLayout.NORTH); createGUI(); createTable(); initContext(); } void initContext() { try { System.setProperty(“java.naming.factory.initial”,“org.jnp.interfaces.NamingContextFactory”); System.setProperty(“java.naming.provider.url”,“localhost:1099”); Context initial = new InitialContext(); Object objref = initial.lookup(“EmployeeEJB”); home = (EmployeeHome) PortableRemoteObject.narrow(objref,EmployeeHome.class); lblStatus.setText(“Binding context completed…”); } catch (Exception e) { JOptionPane.showMessageDialog(null, e.getMessage()); System.exit(0); } } void createGUI() { Box b=Box.createVerticalBox(); Box b1=Box.createHorizontalBox(); Box b2=Box.createHorizontalBox(); Box b3=Box.createHorizontalBox(); Box b4=Box.createHorizontalBox(); Box b5=Box.createHorizontalBox(); Box b6=Box.createHorizontalBox(); Box b7=Box.createHorizontalBox(); Box b8=Box.createHorizontalBox(); b.add(b1);b.add(Box.createVerticalStrut(8)); b.add(b2);b.add(Box.createVerticalStrut(8)); b.add(b3);b.add(Box.createVerticalStrut(8)); b.add(b4);b.add(Box.createVerticalStrut(8)); b.add(b5);b.add(Box.createVerticalStrut(8)); b.add(b6);b.add(Box.createVerticalStrut(8)); b.add(b7);b.add(Box.createVerticalStrut(8)); b.add(b8);b.add(Box.createVerticalStrut(8)); JLabel l1,l2,l3,l4,l5,l6,l7; b1.add(l1=new JLabel(“Employee ID:”,JLabel.RIGHT)); b2.add(l2=new JLabel(“First Name:”,JLabel.RIGHT)); b3.add(l3=new JLabel(“Last Name:”,JLabel.RIGHT)); b4.add(l4=new JLabel(“Date of Birth:”,JLabel.RIGHT)); b5.add(l5=new JLabel(“Address:”,JLabel.RIGHT)); b6.add(l6=new JLabel(“Salary:”,JLabel.RIGHT)); b7.add(l7=new JLabel(“Department Number:”,JLabel.RIGHT)); l1.setPreferredSize(l7.getPreferredSize()); l2.setPreferredSize(l7.getPreferredSize()); l3.setPreferredSize(l7.getPreferredSize()); l4.setPreferredSize(l7.getPreferredSize()); l5.setPreferredSize(l7.getPreferredSize()); l6.setPreferredSize(l7.getPreferredSize()); b1.add(tfID=new JTextField(20)); b2.add(tfFN=new JTextField(20)); b3.add(tfLN=new JTextField(20)); b4.add(tfDOB=new JTextField(20)); b5.add(tfAD=new JTextField(20)); b6.add(tfSAL=new JTextField(20)); b7.add(tfDeptNo=new JTextField(20)); b8.add(btAdd=new JButton(“Add”)); b8.add(Box.createHorizontalStrut(10)); b8.add(btFindByKey=new JButton(“Find By ID”)); b8.add(Box.createHorizontalStrut(10)); b8.add(btFindByLN=new JButton(“Find By Last Name”)); b8.add(Box.createHorizontalStrut(10)); b8.add(btUpdate=new JButton(“Update”)); b8.add(Box.createHorizontalStrut(10)); b8.add(btExit=new JButton(“Exit”)); btAdd.addActionListener(this); btFindByKey.addActionListener(this); btFindByLN.addActionListener(this); btUpdate.addActionListener(this); btExit.addActionListener(this); pTop.add(b,BorderLayout.CENTER); } void createTable(){ String []header= {“Employee ID”,“First Name”, “Last Name”,“Date of Birth”, “Address”,“Salary”,“Department No”}; tableModel=new DefaultTableModel(header,0); table=new JTable(tableModel); this.add(new JScrollPane(table),BorderLayout.CENTER); } @Override public void actionPerformed(ActionEvent e) { Object o=e.getSource(); if(o.equals(btExit)) System.exit(1); else if(o.equals(btAdd)) { if(checkData()) try { lblStatus.setText(“Bat dau them”); home.create(tfID.getText(),tfFN.getText(), tfLN.getText(),tfDOB.getText(), tfAD.getText(),Integer.parseInt(tfSAL.getText()), Integer.parseInt(tfDeptNo.getText())); lblStatus.setText(“Them thanh cong”); } catch (Exception e1) { lblStatus.setText(e1.getMessage()); } } else if(o.equals(btFindByKey)) { String key=tfID.getText().trim(); if(key.equals(“”)) lblStatus.setText(“Khong có gi de tim…”); else{ try { Employee emp = home.findByPrimaryKey(key); lblStatus.setText(“Tim nhan vien “+key); if(emp!=null){ tfID.setText(emp.getEmpid()); tfAD.setText(emp.getAddress()); tfDeptNo.setText(emp.getDpNo()+“”); tfDOB.setText(emp.getDoBirth()); tfFN.setText(emp.getFName()); tfLN.setText(emp.getLName()); tfSAL.setText(emp.getSalary()+“”); } else lblStatus.setText(“Khong tim thay nhan vien nay”); } catch (Exception ex) { lblStatus.setText(“Loi tim kiem:”+ex.getMessage()); } } } else if(o.equals(btFindByLN)) { if(tfLN.getText().trim().equals(“”)) lblStatus.setText(“Khong co gi de ma tim…”); else{ try { lblStatus.setText(“Tim nhan vien theo ten: “+tfLN.getText()); Collection cols=home.findByLastName(tfLN.getText()); tableModel.setRowCount(0);//xoa bang Iterator i=cols.iterator(); while (i.hasNext()) { Employee emp = (Employee)i.next(); String empid = (String)emp.getPrimaryKey(); String fn = emp.getFName(); String ln = emp.getLName(); String dob = emp.getDoBirth(); String add = emp.getAddress(); int sal = emp.getSalary(); int de = emp.getDpNo(); String []row={empid,fn,ln,dob,add,sal+“”,de+“” }; tableModel.addRow(row); } } catch (Exception ex) { lblStatus.setText(“Loi tim kiem:”+ex.getMessage()); } } } else if(o.equals(btUpdate)) { String key=tfID.getText().trim(); if(key.equals(“”)) lblStatus.setText(“Khong có gi de update…”); else{ try{ Employee emp = home.findByPrimaryKey(key); lblStatus.setText(“Update thong tin nhan viên “+key); if(emp!=null){ emp.setLName(tfLN.getText()); emp.setFName(tfFN.getText()); emp.setAddress(tfAD.getText()); emp.setDoBirth(tfDOB.getText()); emp.setDpNo(Integer.parseInt(tfDeptNo.getText())); emp.setSalary(Integer.parseInt(tfSAL.getText())); } else lblStatus.setText(“Khong update duoc vi khong tim thay”); }catch(Exception ex){ lblStatus.setText(ex.getMessage()); } } } } private boolean checkData() { return true; } public static void main(String[] args) { new EMP_Client().setVisible(true); } }

3. Compile EMP_Client.java, chạy nó, ta có kết quả:

By Võ Văn Hải