smclass.java

计算机技术的快速发展

/*
 * 创建日期 2005-5-5
 */
package com.suninformation.schoolmate;

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.suninformation.database.DBManager;
import com.suninformation.user.UnacceptableException;
import java.text.SimpleDateFormat;
import java.text.DateFormat;

/**
 * @author 刘镇
 *
 * 校友录班级类
 */
public class SMClass {

  private static final String LOAD_CLASS_BY_CLASSID = "SELECT schoolid,classname,beginyear,initiator,createdate,classpronunciamento FROM sm_class WHERE classid=?";

  private static final String LOAD_CLASS_BY_CLASSNAME = "SELECT schoolid,classid,beginyear,initiator,createdate,classpronunciamento FROM sm_class WHERE classname=?";

  private static final String INSERT_CLASS = "INSERT INTO sm_class(classname,schoolid,beginyear,createdate,initiator) VALUES(?,?,?,?,?)";

  private static final String SAVE_CLASS = "UPDATE sm_class SET classname=?,schoolid=?,beginyear=?,initiator=?,createdate=?,classpronunciamento=? WHERE classid=?";

  private static final String MEMBER_COUNT =
      "SELECT count(1) FROM sm_member WHERE classid=?";

  private static final String ALL_MEMBER_FOR_THIS_CLASS =
      "SELECT username FROM sm_member WHERE classid=?";

  private static final String SEARCH_MEMBER_FROM_THIS_CLASS = "SELECT username FROM sm_member WHERE schoolid=? AND beginyear=? AND classname LIKE %?% ORDER BY classname";

  private static final String MESSAGE_COUNT =
      "SELECT count(1) FROM sm_message WHERE classid=?";

  private static final String ALL_MESSAGE_FOR_THIS_CLASS =
      "SELECT msgid FROM sm_message WHERE classid=? ORDER BY msgid DESC, modifyTime DESC";

  private static final String DELETE_MEMBER =
      "DELETE FROM sm_member WHERE username=? AND classid=?";

  private static final String DELETE_ALL_MEMBER =
      "DELETE FROM sm_member WHERE classid=?";

  private static final String DELETE_MESSAGE =
      "DELETE FROM sm_message WHERE msgid=?";

  private static final String DELETE_ALL_MESSAGE =
      "DELETE FROM sm_message WHERE classid=?";

  private int classId = -1; //班级ID

  private int schoolId = -1; //所属学校ID

  private String className = null; //班级名称

  private String beginYear = null; //入学年份

  private String initiator = null; //创始人用户名

  private Date createDate = null; //创建日期

  private String classPronunciamento = null; //班级宣言

  private boolean isChanged = false; //已修改标记

  /**
   * 构造方法，其可以通过classid读取班级信息。
   *
   * @param classid int
   * @throws SMClassNotFoundException
   * @throws UnacceptableException
   */
  public SMClass(int classid) throws SMClassNotFoundException,
      UnacceptableException {
    this.classId = classid;
    loadFromDB();
  }

  /**
   * 构造方法，用来为该学校创建一个新的班级。
   *
   * @param schoolid int
   * @param classname String
   * @param beginyear String
   * @param username String
   * @throws SMClassAlreadyExistsException
   * @throws UnacceptableException
   */
  public SMClass(int schoolid, String classname, String beginyear,
                 String username) throws SMClassAlreadyExistsException,
      UnacceptableException {
    this.className = classname;
    this.schoolId = schoolid;
    this.beginYear = beginyear;
    this.createDate = new Date(System.currentTimeMillis());
    this.initiator = username;
    insertIntoDB();
    try {
      loadFromDB();
      SMMember smm = new SMMember(username, 1, this.classId, 1);
    }
    catch (Exception ee) {
    }
  }

  /**
   * 读取班级信息
   *
   * @throws SMClassNotFoundException
   * @throws UnacceptableException
   */
  private void loadFromDB() throws SMClassNotFoundException,
      UnacceptableException {
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = DBManager.getConnection();
      if (this.classId == -1) {
        pstmt = conn.prepareStatement(LOAD_CLASS_BY_CLASSNAME);
        pstmt.setString(1, this.className);
        rs = pstmt.executeQuery();
        if (!rs.next()) {
          throw new SMClassNotFoundException("班级“" + this.className
                                             + "”不存在。");
        }
        this.schoolId = rs.getInt(1);
        this.classId = rs.getInt(2);
        this.beginYear = rs.getString(3);
        this.initiator = rs.getString(4);
        this.createDate = rs.getDate(5);
        this.classPronunciamento = rs.getString(6);
      }
      else {
        pstmt = conn.prepareStatement(LOAD_CLASS_BY_CLASSID);
        pstmt.setInt(1, this.classId);
        rs = pstmt.executeQuery();
        if (!rs.next()) {
          throw new SMClassNotFoundException("班级ID“" + this.classId
                                             + "”不存在。");
        }
        this.schoolId = rs.getInt(1);
        this.className = rs.getString(2);
        this.beginYear = rs.getString(3);
        this.initiator = rs.getString(4);
        this.createDate = rs.getDate(5);
        this.classPronunciamento = rs.getString(6);
      }
    }
    catch (SQLException sqle) {
      throw new UnacceptableException("读取班级数据失败。", sqle);
    }
    finally {
      DBManager.closeObject(conn, pstmt, rs);
    }
  }

  /**
   * 添加新班级操作
   *
   * @throws SMClassAlreadyExistsException
   * @throws UnacceptableException
   */
  private void insertIntoDB() throws SMClassAlreadyExistsException,
      UnacceptableException {
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      loadFromDB();
      throw new SMClassAlreadyExistsException("该班级已存在！");
    }
    catch (SMClassNotFoundException unfe) {
      try {
        conn = DBManager.getConnection();
        pstmt = conn.prepareStatement(INSERT_CLASS);
        pstmt.setString(1, this.className);
        pstmt.setInt(2, this.schoolId);
        pstmt.setString(3, this.beginYear);
        pstmt.setDate(4, this.createDate);
        pstmt.setString(5, this.initiator);
        pstmt.executeUpdate();
      }
      catch (SQLException e) {
        throw new UnacceptableException("写入班级数据失败.", e);
      }
      finally {
        DBManager.closeObject(conn, pstmt, rs);
      }
    }
  }

  /**
   * 保存数据到DB
   *
   * @throws UnacceptableException
   */
  private void saveToDB() throws UnacceptableException {
    Connection conn = null;
    try {
      conn = DBManager.getConnection();
      saveToDB(conn);
    }
    catch (SQLException sqle) {
      throw new UnacceptableException("保存数据出错", sqle);
    }
    finally {
      try {
        conn.close();
      }
      catch (Exception e) {
        e.printStackTrace();
      }
    }
  }

  /**
   * 保存数据库到DB
   *
   * @param con Connection
   * @throws SQLException
   */
  private void saveToDB(Connection con) throws SQLException {
    PreparedStatement pstmt = null;
    try {
      pstmt = con.prepareStatement(SAVE_CLASS);
      pstmt.setString(1, this.className);
      pstmt.setInt(2, this.schoolId);
      pstmt.setString(3, this.beginYear);
      pstmt.setDate(4, this.createDate);
      pstmt.setString(5, this.initiator);
      pstmt.setString(6, this.classPronunciamento);
      pstmt.setInt(7, this.classId);
      pstmt.executeUpdate();
    }
    finally {
      try {
        pstmt.close();
      }
      catch (Exception e) {
        e.printStackTrace();
      }
    }
  }

  /**
   * 保存信息修改；当对该类的属性进行更改后，可以使用该方法进行写入数据库操作。
   *
   */
  public void save() {
    if (this.isChanged) {
      try {
        saveToDB();
      }
      catch (UnacceptableException ue) {
      }

    }
  }

  /**
   * 添加班级成员
   *
   * @param username String
   * @param membertype int
   * @return com.suninformation.schoolmate.SMMember
   * @throws SMMemberAlreadyExistsException
   * @throws UnacceptableException
   */
  public SMMember addNewSMMember(String username, int membertype) throws
      SMMemberAlreadyExistsException, UnacceptableException {
    return new SMMember(username, membertype, this.classId, 0);
  }

  /**
   * 删除班级成员username
   *
   * @param username String
   * @throws SMMemberNotFoundException
   * @throws UnacceptableException
   */
  public void deleteSMMember(String username) throws SMMemberNotFoundException,
      UnacceptableException {
    this.getSMMember(username).deleteMessages();
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = DBManager.getConnection();
      pstmt = conn.prepareStatement(DELETE_MEMBER);
      pstmt.setString(1, username);
      pstmt.setInt(2, this.classId);
      pstmt.executeUpdate();
    }
    catch (SQLException sqle) {
      throw new UnacceptableException("删除班级成员失败!", sqle);
    }
    finally {
      DBManager.closeObject(conn, pstmt, rs);
    }
  }

  /**
   * 删除班级全部成员
   *
   * @throws SMMemberNotFoundException
   * @throws UnacceptableException
   */
  public void deleteSMMembers() throws SMMemberNotFoundException,
      UnacceptableException {
    this.deleteSMMessages(); //删除班级所有留言;然后下面代码为删除班级所有成员
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = DBManager.getConnection();
      pstmt = conn.prepareStatement(DELETE_ALL_MEMBER);
      pstmt.setInt(1, this.classId);
      pstmt.executeUpdate();
    }
    catch (SQLException sqle) {
      throw new UnacceptableException("删除班级成员失败!", sqle);
    }
    finally {
      DBManager.closeObject(conn, pstmt, rs);
    }
  }

  /**
   * 通过username获取该班的班级成员
   *
   * @param username String
   * @return com.suninformation.schoolmate.SMMember
   * @throws SMMemberNotFoundException
   * @throws UnacceptableException
   */
  public SMMember getSMMember(String username) throws SMMemberNotFoundException,
      UnacceptableException {
    return new SMMember(username, this.classId);
  }

  /**
   * 获取该班级所拥有的成员总数
   *
   * @return int
   * @throws UnacceptableException
   */
  public int getSMMemberCount() throws UnacceptableException {
    int count = -1;
    Connection conn = null;