agencybean.java

21天学通J2EE的例子

package agency;

import java.rmi.*;
import java.sql.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.* ;
import javax.sql.*;

import data.*;

public class AgencyBean implements SessionBean
{
    private DataSource dataSource;
    private CustomerLocalHome customerHome;
    private JobLocalHome jobHome;
    private LocationLocalHome locationHome;
    private SkillLocalHome skillHome;
    private String agencyName = "";

    public String getAgencyName() {
        return agencyName;
    }

    public Collection getApplicants() {
        Connection con = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        try {
            con = dataSource.getConnection();
            stmt = con.prepareStatement(
            "SELECT login FROM Applicant");

            rs = stmt.executeQuery();

            Collection col = new TreeSet();
            while (rs.next()) {
                col.add(rs.getString(1));
            }

            return col;
        }
        catch (SQLException e) {
            error("Error getting Applicant list",e);
        }
        finally {
            closeConnection(con, stmt, rs);
        }
        return null;
    }

    public void createApplicant(String login, String name, String email) throws DuplicateException, CreateException{
        Collection apps = getApplicants();
        Iterator it = apps.iterator();
        while (it.hasNext()) {
            String s = (String)it.next();
            if (s.equalsIgnoreCase(login))
                throw (new DuplicateException(s+" applicant already defined"));
        }
        Connection con = null;
        PreparedStatement stmt = null;
        try {
            con = dataSource.getConnection();
            stmt = con.prepareStatement(
            "INSERT INTO Applicant (login,name,email) VALUES (?, ?, ?)");

            stmt.setString(1, login);
            stmt.setString(2, name);
            stmt.setString(3, email);

            stmt.executeUpdate();
        }
        catch (SQLException e) {
            error("Error creating Applicant "+login,e);
        }
        finally {
            closeConnection(con, stmt, null);
        }
    }

    public void deleteApplicant (String login) throws NotFoundException{
        Connection con = null;
        PreparedStatement stmt = null;
        try {
            con = dataSource.getConnection();
            stmt = con.prepareStatement(
            "DELETE FROM ApplicantSkill WHERE applicant = ?");

            stmt.setString(1, login);
            stmt.executeUpdate();

            stmt = con.prepareStatement(
            "DELETE FROM Applicant WHERE login = ?");

            stmt.setString(1, login);
            stmt.executeUpdate();
        }
        catch (SQLException e) {
            error("Error deleting Applicant "+login,e);
        }
        finally {
            closeConnection(con, stmt, null);
        }
    }

    public Collection getCustomers() {
        try {
            Collection res = new ArrayList();
            Collection col = customerHome.findAll();
            Iterator it = col.iterator();
            while (it.hasNext())
            {
                CustomerLocal customer = (CustomerLocal)it.next();
                res.add(customer.getLogin());
            }
            return res;
        }
        catch (FinderException e) {
            error("Error getting Customer list",e);
        }
        return null;
    }


    public void createCustomer(String login, String name, String email) throws DuplicateException, CreateException{
        try {
            CustomerLocal customer = customerHome.create(login,name,email);
        }
        catch (CreateException e) {
            error("Error adding Customer "+login,e);
        }
    }

    public void deleteCustomer (String login) throws NotFoundException {
        try {
            customerHome.remove(login);
        }
        catch (RemoveException e) {
            error("Error removing customer "+login,e);
        }
    }

    public Collection getLocations() {
        try {
            Collection res = new ArrayList();
            Collection col = locationHome.findAll();
            Iterator it = col.iterator();
            while (it.hasNext())
            {
                LocationLocal location = (LocationLocal)it.next();
                res.add(location.getName());
            }
            return res;
        }
        catch (FinderException e) {
            error("Error getting Location list",e);
        }
        return null;
    }

    public String getLocationDescription(String name) throws NotFoundException {
        try {
            LocationLocal location = locationHome.findByPrimaryKey(name);
            return location.getDescription();
        }
        catch (FinderException e) {
            error("Error finding Location description for "+name,e);
        }
        return null;
    }

    public void updateLocation(String name, String description) throws NotFoundException {
        try {
            LocationLocal location = locationHome.findByPrimaryKey(name);
            location.setDescription(description);
        }
        catch (FinderException e) {
            error("Error updating Location description for "+name,e);
        }
    }

    public void addLocation(String name, String description) throws DuplicateException {
        try {
            LocationLocal location = locationHome.create(name,description);
        }
        catch (CreateException e) {
            error("Error adding Location "+name,e);
        }
    }

    public void removeLocation(String name) throws NotFoundException {
        try {
            LocationLocal location = locationHome.findByPrimaryKey(name);
            location.remove();
        }
        catch (FinderException e) {
            error("Remove error finding Location "+name,e);
        }
        catch (RemoveException e) {
            error("Error removing Location "+name,e);
        }
    }

    public Collection getSkills() {
        try {
            Collection res = new ArrayList();
            Collection col = skillHome.findAll();
            Iterator it = col.iterator();
            while (it.hasNext())
            {
                SkillLocal skill = (SkillLocal)it.next();
                res.add(skill.getName());
            }
            return res;
        }
        catch (FinderException e) {
            error("Error getting Skill list",e);
        }
        return null;
    }

    public String getSkillDescription(String name) throws NotFoundException {
        try {
            SkillLocal skill = skillHome.findByPrimaryKey(name);
            return skill.getDescription();
        }
        catch (FinderException e) {
            error("Error finding skill description for "+name,e);
        }
        return null;
    }

    public void updateSkill(String name, String description) throws NotFoundException {
        try {
            SkillLocal skill = skillHome.findByPrimaryKey(name);
            skill.setDescription(description);
        }
        catch (FinderException e) {
            error("Error updating skill description for "+name,e);
        }
    }

    public void addSkill(String name, String description) throws DuplicateException {
        try {
            SkillLocal skill = skillHome.create(name,description);
        }
        catch (CreateException e) {
            error("Error adding skill "+name,e);
        }
    }

    public void removeSkill(String name) throws NotFoundException {
        try {
            SkillLocal skill = skillHome.findByPrimaryKey(name);
            skill.remove();
        }
        catch (FinderException e) {
            error("Remove error finding skill "+name,e);
        }
        catch (RemoveException e) {
            error("Error removing skill "+name,e);
        }
    }

    public List select(String table) {
        Connection con = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        try {
            con = dataSource.getConnection();
            stmt = con.prepareStatement(
            "SELECT * FROM "+table);

            rs = stmt.executeQuery();
            ResultSetMetaData rsmd = rs.getMetaData();
            int numCols = rsmd.getColumnCount();

            List ans = new ArrayList();
            String[] hdr = new String[numCols];

            // get column header info
            for (int i=1; i <= numCols; i++)
                hdr[i-1] = rsmd.getColumnLabel(i);
            ans.add(hdr);

            while (rs.next()) {
                String[] row = new String[numCols];
                for (int i=1; i <= numCols; i++)
                    row[i-1] = rs.getString(i);
                ans.add(row);
            }

            return ans;
        }
        catch (SQLException e) {
            error("Error getting table rows",e);
        }
        finally {
            closeConnection(con, stmt, rs);
        }
        return null;
    }

    private void closeConnection (Connection con, PreparedStatement stmt, ResultSet rslt) {
        if (rslt != null) {
            try {
                rslt.close();
            }
            catch (SQLException e) {}
        }
        if (stmt != null) {
            try {
                stmt.close();
            }
            catch (SQLException e) {}
        }
        if (con != null) {
            try {
                con.close();
            }
            catch (SQLException e) {}
        }
    }

    // EJB methods start here

    private void error (String msg, Exception ex) {
        String s = "AgencyBean: "+msg + "\n" + ex;
        System.out.println(s);
        throw new EJBException(s,ex);
    }

    public void ejbCreate () throws CreateException {
    }

    public void ejbActivate(){
    }

    public void ejbPassivate(){
    }

    public void ejbRemove(){
        dataSource = null;
    }

    private SessionContext ctx;

    public void setSessionContext(SessionContext ctx) {
        this.ctx = ctx;
        InitialContext ic = null;
        try {
            ic = new InitialContext();
            dataSource = (DataSource)ic.lookup("java:comp/env/jdbc/Agency");
            agencyName = (String)ic.lookup("java:comp/env/AgencyName");
            customerHome = (CustomerLocalHome)ic.lookup("java:comp/env/ejb/CustomerLocal");
            jobHome = (JobLocalHome)ic.lookup("java:comp/env/ejb/JobLocal");
            locationHome = (LocationLocalHome)ic.lookup("java:comp/env/ejb/LocationLocal");
            skillHome = (SkillLocalHome)ic.lookup("java:comp/env/ejb/SkillLocal");
        }
        catch (NamingException ex) {
            error("Error looking up depended EJB or resource",ex);
            return;
        }
    }
}