studentejb.java

来自「100多M的J2EE培训内容」· Java 代码 · 共 335 行

package bible.ejb.entity.bmp;

import javax.ejb.*;
import java.sql.*;
import javax.sql.DataSource;
import javax.naming.InitialContext;
import java.util.Collection;
import java.util.Vector;

public class StudentEJB implements EntityBean
{
  private EntityContext context;
  private static final String DATASOURCE
    = "java:comp/env/jdbc/connectionPool";

  public String id;
  public String firstName;
  public String lastName;
  public String eMailAddr;
  public String phone;
  public String ssNum;


  public void setEntityContext(EntityContext ec) {
    context = ec;
  }

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

  public StudentPK ejbCreate(StudentVO student)
      throws CreateException
  {
    this.id = student.getId();
    setStudentData(student);

    Connection con = null;
    PreparedStatement ps = null;
    StudentPK key = null;
    try {
      con = getConnection();
      ps = con.prepareStatement("insert into STUDENT (ID,FIRST_NAME, LAST_NAME, EMAIL_ADDR, PHONE, SSNUM) values (?, ?, ?, ?, ?, ?)");
      ps.setString(1, id);
      ps.setString(2, firstName);
      ps.setString(3, lastName);
      ps.setString(4, eMailAddr);
      ps.setString(5, phone);
      ps.setString(6, ssNum);
      int ret = ps.executeUpdate();
      if (ret != 1) {
        throw new CreateException("Create failed");
      }
      key = new StudentPK();
      key.id = id;
      return key;
    }
    catch (Exception e) {
      throw new CreateException(e.getMessage());
    }
    finally {
      cleanup(con, ps);
    }
  }

  public void ejbPostCreate(StudentVO student) {
  }

  public void ejbLoad()
  {
    StudentPK key = (StudentPK)context.getPrimaryKey();

    try {
      readData(key);
    }
    catch(Exception e) {
      throw new EJBException(e.getMessage());
    }
  }

  public void ejbStore()
  {
    Connection con = null;
    PreparedStatement ps = null;
    try {
      con = getConnection();
      StudentPK key =
        (StudentPK)context.getPrimaryKey();

      ps = con.prepareStatement("update STUDENT set FIRST_NAME = ?,LAST_NAME = ?,EMAIL_ADDR = ?,PHONE = ?,SSNUM = ? where ID = ?");
      ps.setString(1, firstName);
      ps.setString(2, lastName);
      ps.setString(3, eMailAddr);
      ps.setString(4, phone);
      ps.setString(5, ssNum);
      ps.setString(6, key.id);
      int ret = ps.executeUpdate();
      if (ret == 0) {
        throw new EJBException("ejbStore failed");
      }
    }
    catch (Exception e) {
      throw new EJBException(e.getMessage());
    }
    finally {
      cleanup(con, ps);
    }
  }

  public void ejbRemove() throws RemoveException
  {
    Connection con = null;
    PreparedStatement ps = null;
    try {
      con = getConnection();
      StudentPK key =
          (StudentPK) context.getPrimaryKey();

      ps = con.prepareStatement("delete from STUDENT where ID=?");
      ps.setString(1, key.id);
      int result = ps.executeUpdate();
      if (result == 0) {
        throw new RemoveException("Remove failed");
      }
    }
    catch (Exception e) {
      throw new RemoveException(e.getMessage());
    }
    finally {
      cleanup(con, ps);
    }
  }

  public void ejbActivate() {
  }

  public void ejbPassivate() {
  }

  public StudentPK ejbFindByPrimaryKey(StudentPK key)
      throws FinderException
  {
    try {
      readData(key);
      return key;
    }
    catch (Exception e) {
      throw new FinderException(e.getMessage());
    }
  }

  public StudentPK ejbFindBySSNum(String ssNum)
    throws FinderException
  {
    Connection con = null;
    PreparedStatement ps = null;
    try {
      con = getConnection();
      ps = con.prepareStatement("select ID, FIRST_NAME,LAST_NAME,EMAIL_ADDR,PHONE,SSNUM from STUDENT where SSNUM = ?");
      ps.setString(1, ssNum);
      ResultSet rs = ps.executeQuery();
      if (!rs.next()) {
        throw new FinderException("Record not found");
      }
      else {
        loadAttributes(rs);
      }
      rs.close();
      StudentPK key = new StudentPK();
      key.id = id;
      return key;
    }
    catch (Exception e) {
      throw new EJBException(e.getMessage());
    }
    finally {
      cleanup(con, ps);
    }
  }

  public Collection ejbFindByLastName(String lastName)
    throws FinderException
  {
    Connection con = null;
    PreparedStatement ps = null;
    try {
      con = getConnection();
      ps = con.prepareStatement("select ID from STUDENT where LAST_NAME = ?");
      ps.setString(1, lastName);
      ResultSet rs = ps.executeQuery();
      Vector students = new Vector();
      StudentPK key = null;
      while (rs.next()) {
        key = new StudentPK();
        key.id = rs.getString(1);
        students.addElement(key);
      }
      rs.close();
      return students;
    }
    catch (Exception e) {
      throw new FinderException(e.getMessage());
    }
    finally {
      cleanup(con, ps);
    }
  }

  private void loadAttributes(ResultSet rs)
      throws SQLException
  {
    id = rs.getString(1);
    firstName = rs.getString(2);
    lastName = rs.getString(3);
    eMailAddr = rs.getString(4);
    phone = rs.getString(5);
    ssNum = rs.getString(6);
  }

  private void cleanup(Connection con, PreparedStatement ps)
  {
    try {
      if (ps != null) {
        ps.close();
      }
      if (con != null) {
        con.close();
      }
    }
    catch (Exception e) {
      throw new EJBException (e);
    }
  }

  public StudentVO getStudentData()
  {
    StudentVO student = new StudentVO();
    student.setFirstName(firstName);
    student.setLastName(lastName);
    student.setPhone(phone);
    student.setEMailAddr(eMailAddr);
    student.setSSNum(ssNum);
    return student;
  }

  public void setStudentData(StudentVO student)
  {
    firstName = student.getFirstName();
    lastName = student.getLastName();
    eMailAddr = student.getEMailAddr();
    phone = student.getPhone();
    ssNum = student.getSSNum();
  }

  public String getFirstName() {
    return(firstName);
  }

  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public String getLastName() {
    return lastName;
  }

  public void setLastName(String lastName) {
    this.lastName = lastName;
  }

  public String getEMailAddr() {
    return eMailAddr;
  }

  public void setEMailAddr(String eMailAddr) {
    this.eMailAddr = eMailAddr;
  }

  public String getPhone() {
    return phone;
  }

  public void setPhone(String phone) {
    this.phone = phone;
  }

  public String getSSNum() {
    return ssNum;
  }

  public void setSSNum(String ssNum) {
    this.ssNum = ssNum;
  }

  private Connection getConnection() throws EJBException
  {
    try {
      InitialContext ic = new InitialContext();
      DataSource ds = (DataSource)ic.lookup(DATASOURCE);
      return ds.getConnection();
    }
    catch (Exception e) {
      throw new EJBException(e.getMessage());
    }
  }

  private void readData(StudentPK key) throws
        FinderException, EJBException
  {
    Connection con = null;
    PreparedStatement ps = null;
    try {
      con = getConnection();
      ps = con.prepareStatement("select ID, FIRST_NAME,LAST_NAME,EMAIL_ADDR,PHONE,SSNUM from STUDENT where ID = ?");
      ps.setString(1, key.id);
      ResultSet rs = ps.executeQuery();
      if (!rs.next()) {
        throw new FinderException("Record not found");
      }
      else {
        loadAttributes(rs);
      }
      rs.close();
    }
    catch (Exception e){
      throw new EJBException(e.getMessage());
    }
    finally {
      cleanup(con, ps);
    }
  }
}