classesdao.java

Java企业级开发项目实践,这是他的附光盘

//---------------------------------------------------------
// Application: eShop of Network
// Author     : eSingle
// File       : ClassesDAO.java
//
// Copyright 2002 LandSoft Corp.
// Generated at Mon Nov 18 20:15:26 CST 2002
// Created by caoguangxin
// mailto:[e-mail]
//---------------------------------------------------------

package com.landsoft.eshop.dao;

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

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

public class ClassesDAO extends DAO {

  public ClassesDAO(DataSource ds) {
    super(ds);
  }
  //增加商品类别，参数为Classes，返回值void
  public void insert(Classes classes) throws SQLException {
    String sql;
    sql = "INSERT INTO classes (typesname, parent) VALUES (?, ?)";
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = ds.getConnection();
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, classes.getTypesname());
      pstmt.setString(2, classes.getParent());
      pstmt.executeUpdate();
      pstmt.close();
      conn.commit();
    } catch (SQLException sqle) {
      close(rs);
      close(pstmt);
      rollback(conn);
      sqle.printStackTrace();
      throw sqle;
    } finally {
    	close(conn);
    }
  }
  //更新商品类别
  public void update(Classes classes) throws SQLException {
  	Connection conn = null;
  	PreparedStatement pstmt = null;
    try {
      conn = ds.getConnection();
      String sql = "UPDATE classes SET parent=? WHERE typesname=?";
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, classes.getParent());
      pstmt.setString(2, classes.getTypesname());
      pstmt.executeUpdate();
      close(pstmt);
      conn.commit();
    } catch (SQLException e) {
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
  }
//删除商品类别
  public void delete(String typesname) throws SQLException {
  	Connection conn = null;
  	PreparedStatement pstmt = null;
    try {
      conn = ds.getConnection();
      String sql = "DELETE FROM classes WHERE typesname=?";
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, typesname);
      pstmt.executeUpdate();
      close(pstmt);
      conn.commit();
    } catch (SQLException e) {
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
    String[] objKeys = {"Classes", String.valueOf(typesname)};
    String objKey = CacheManager.createKey(objKeys);
    DAOCacheManager.invalidate(objKey);
  }
//检索商品类别
  public Classes retrieve(String typesname) throws SQLException {
    String[] objKeys = {"Classes", String.valueOf(typesname)};
    String objKey = CacheManager.createKey(objKeys);
    Classes classes = (Classes) DAOCacheManager.getCache(objKey);
    if (classes != null)
      return classes;
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    try {
      conn = ds.getConnection();
      String sql = "SELECT * FROM classes WHERE typesname=?";
      pstmt = conn.prepareStatement(sql);
      pstmt.setString(1, typesname);
      rs = pstmt.executeQuery();
      if (rs.next()) {
        classes = new Classes();
        populate(classes, rs);
      }
      close(rs);
      close(pstmt);
    } catch (SQLException e) {
      close(rs);
      close(pstmt);
      rollback(conn);
      e.printStackTrace();
    } finally {
    	close(conn);
    }
    DAOCacheManager.putCache(classes, objKey, 1);
    return classes;
  }

  public List list() throws SQLException {
    String[] objKeys = {"Classes", "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 parent, typesname FROM classes";
      pstmt = conn.prepareStatement(sql);
      rs = pstmt.executeQuery();
      while(rs.next()) {
        Classes classes = new Classes();
        populate(classes, rs);
        list.add(classes);
      }
      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 = {"Classes", "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 parent, typesname FROM classes";
      pstmt = conn.prepareStatement(sql);
      rs = pstmt.executeQuery();
      if(offset > 0) rs.absolute(offset);
      int recCount = 0;
      while((recCount++ < limit) && rs.next()) {
        Classes classes = new Classes();
        populate(classes, rs);
        list.add(classes);
      }
      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;
  }

}