bbsdao.java

Java企业级开发项目实践,这是他的附光盘

//---------------------------------------------------------
// Application: Portal of Enterprice
// Author     : eSingle
// File       : BbsDAO.java
//
// Copyright 2002 LandSoft Corp.
// Generated at Mon Nov 18 20:04:55 CST 2002
// Created by caoguangxin
// mailto:[e-mail]
//---------------------------------------------------------

package com.landsoft.portal.dao;

import java.io.*;
import java.sql.*;
import java.util.*;
import javax.sql.*;

import com.landsoft.portal.model.*;
import com.landsoft.portal.util.CacheManager;

public class BbsDAO extends DAO {

  public BbsDAO(DataSource ds) {
    super(ds);
  }

  public void insert(Bbs bbs) throws SQLException {
    String sql;
    sql = "INSERT INTO bbs (title, typename, author) VALUES (?, ?, ?)";
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = ds.getConnection();
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, bbs.getTitle());
      pstmt.setString(2, bbs.getTypename());
      pstmt.setString(3, bbs.getAuthor());
      pstmt.executeUpdate();
      pstmt.close();
      conn.commit();
    } catch (SQLException sqle) {
      close(rs);
      close(pstmt);
      rollback(conn);
      sqle.printStackTrace();
      throw sqle;
    } finally {
    	close(conn);
    }
  }

  public void update(Bbs bbs) throws SQLException {
  	Connection conn = null;
  	PreparedStatement pstmt = null;
    try {
      conn = ds.getConnection();
      String sql = "UPDATE bbs SET author=? WHERE title=? AND typename=?";
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, bbs.getAuthor());
      pstmt.setString(2, bbs.getTitle());
      pstmt.setString(3, bbs.getTypename());
      pstmt.executeUpdate();
      close(pstmt);
      conn.commit();
    } catch (SQLException e) {
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
  }

  public void delete(String title, String typename) throws SQLException {
  	Connection conn = null;
  	PreparedStatement pstmt = null;
    try {
      conn = ds.getConnection();
      String sql = "DELETE FROM bbs WHERE title=? AND typename=?";
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, title);
      pstmt.setString(2, typename);
      pstmt.executeUpdate();
      close(pstmt);
      conn.commit();
    } catch (SQLException e) {
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
    String[] objKeys = {"Bbs", String.valueOf(title), String.valueOf(typename)};
    String objKey = CacheManager.createKey(objKeys);
    DAOCacheManager.invalidate(objKey);
  }

  public Bbs retrieve(String title, String typename) throws SQLException {
    String[] objKeys = {"Bbs", String.valueOf(title), String.valueOf(typename)};
    String objKey = CacheManager.createKey(objKeys);
    Bbs bbs = (Bbs) DAOCacheManager.getCache(objKey);
    if (bbs != null)
      return bbs;
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = ds.getConnection();
      String sql = "SELECT * FROM bbs WHERE title=? AND typename=?";
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, title);
      pstmt.setString(2, typename);
      rs = pstmt.executeQuery();
      if (rs.next()) {
        bbs = new Bbs();
        bbs.setTitle(rs.getString(1));
        bbs.setTypename(rs.getString(2));
        bbs.setAuthor(rs.getString(3));
        populate(bbs, rs);
      }
      close(rs);
      close(pstmt);
    } catch (SQLException e) {
      close(rs);
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
    DAOCacheManager.putCache(bbs, objKey, 1);
    return bbs;
  }

  public List list() throws SQLException {
    String[] objKeys = {"Bbs", "list"};
    String objKey = CacheManager.createKey(objKeys);
    ArrayList list = (ArrayList) DAOCacheManager.getCache(objKey);
    if (list != null)
      return list;
    list = new ArrayList();
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = ds.getConnection();
      String sql = "SELECT author, title, typename FROM bbs";
      pstmt = conn.prepareStatement(sql);
      rs = pstmt.executeQuery();
      while(rs.next()) {
        Bbs bbs = new Bbs();
        bbs.setAuthor(rs.getString(1));
        bbs.setTitle(rs.getString(2));
        bbs.setTypename(rs.getString(3));
        populate(bbs, rs);
        list.add(bbs);
      }
      close(rs);
      close(pstmt);
    } catch (SQLException e) {
      close(rs);
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
    DAOCacheManager.putCache(list, objKey, 1);
    return list;
  }

  public List list(int offset, int limit) throws SQLException {
    String[] objKeys = {"Bbs", "list", String.valueOf(offset), String.valueOf(limit)};
    String objKey = CacheManager.createKey(objKeys);
    ArrayList list = (ArrayList) DAOCacheManager.getCache(objKey);
    if (list != null)
      return list;
    list = new ArrayList();
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = ds.getConnection();
      String sql = "SELECT author, title, typename FROM bbs";
      pstmt = conn.prepareStatement(sql);
      rs = pstmt.executeQuery();
      if(offset > 0) rs.absolute(offset);
      int recCount = 0;
      while((recCount++ < limit) && rs.next()) {
        Bbs bbs = new Bbs();
        bbs.setAuthor(rs.getString(1));
        bbs.setTitle(rs.getString(2));
        bbs.setTypename(rs.getString(3));
        populate(bbs, rs);
        list.add(bbs);
      }
      close(rs);
      close(pstmt);
    } catch (SQLException e) {
      close(rs);
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
    DAOCacheManager.putCache(list, objKey, 1);
    return list;
  }

}