实现dao

package com.sxt.dao.impl;

import java.sql.ResultSet;
import java.util.List;

import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import com.sxt.bean.Goods;
import com.sxt.dao.GoodsDao;
import com.sxt.util.JDBCUtil;
import com.sxt.util.PageBean;

public class GoodsDaoImpl implements GoodsDao {

@Override
public PageBean findGoods(String gname, String pStart, String pEnd,
        String dStart, String dEnd, String gstatus,int page,int rows) throws Exception {
    String sql = "select * from goods where 1=1";
    if (null != gname && !"".equals(gname)) {
        sql += " and gname like '%" + gname + "%'";
    }
    if (null != pStart && !"".equals(pStart)) {
        sql += " and gprice >= " + pStart + "";
    }
    if (null != pEnd && !"".equals(pEnd)) {
        sql += " and gprice <= " + pEnd + "";
    }
    //注意日期格式化
    if (null != dStart && !"".equals(dStart)) {
        sql += " and DATE_FORMAT(prodate,'%Y-%m-%d') >= '" + dStart + "'";
    }
    if (null != dEnd && !"".equals(dEnd)) {
        sql += " and DATE_FORMAT(prodate,'%Y-%m-%d') <= '" + dEnd + "'";
    }
    if (null != gstatus && !"".equals(gstatus)) {
        sql += " and gstatus = " + gstatus + "";
    }
    String fysql="select count(1) from("+sql+") a";
    sql+=" order by gid desc limit "+(page-1)*rows+","+rows;
    //查询一共多条记录
    ResultSet rs = JDBCUtil.query(fysql);
    int total=0;
    if(rs.next()){
        total=rs.getInt(1);
    }
    List<Goods> gs = new BeanListHandler<Goods>(Goods.class).handle(JDBCUtil.query(sql));
    PageBean pb = new PageBean();
    pb.setTotal(total);
    pb.setRows(gs);
    JDBCUtil.close();
    return pb;
}

@Override
public boolean delGoods(String gid) throws Exception {
    String sql = "delete from goods where gid = " + gid;
    int i = JDBCUtil.update(sql);
    if (i > 0) {
        return true;
    }
    return false;
}

@Override
public boolean saveGoods(Goods g) throws Exception {
    int i = 0;
    if (g != null) {
        String sql = "";
        if (g.getGid() != null) {
            // 修改
            sql += "update goods set gname=?,gprice=?,gnum=?,prodate=?,gaddr=?,gtel=?,gstatus=?,gurl=? where gid=?";
            i = JDBCUtil.update(sql, g.getGname(), g.getGprice(),
                    g.getGnum(), g.getProdate(), 
                    g.getGaddr(), g.getGtel(), g.getGstatus(), g.getGurl(),
                    g.getGid());
        } else {
            // 新增
            sql += "insert into goods values(null,?,?,?,?,?,?,?,?)";
            i = JDBCUtil.update(sql, g.getGname(), g.getGprice(),
                    g.getGnum(), g.getProdate(),
                    g.getGaddr(), g.getGtel(), g.getGstatus(), g.getGurl());

        }
    }
    if (i > 0) {
        return true;
    }
    return false;
}

@Override
public Goods findGoodsById(String gid) throws Exception {
    String sql = "select * from goods where gid = " + gid;
    ResultSet rs = JDBCUtil.query(sql);
    BeanHandler<Goods> bh = new BeanHandler<Goods>(Goods.class);
    Goods g = bh.handle(rs);
    JDBCUtil.close();
    return g;
}

}