本系列博客内容为：做DRP系统中Dao层常用功能。
该项目采用MVC架构
- C（Controller）控制器，主要职责;1、取得表单参数；2、调用业务逻辑；3、转向页面
- M（Model）模型，主要职责：1、业务逻辑；2、保存数据的状态
- V（View）视图，主要职责：显示
本文主要是针对于Dao层的常见使用方法：增删改查sql语句及常用操作。
1 package com.bjpowernode.drp.basedata.dao;
2
3 import java.sql.Connection;
4 import java.sql.PreparedStatement;
5 import java.sql.ResultSet;
6 import java.sql.SQLException;
7 import java.util.ArrayList;
8 import java.util.List;
9
10 import com.bjpowernode.drp.basedata.domain.Item;
11 import com.bjpowernode.drp.util.ApplicationException;
12 import com.bjpowernode.drp.util.DbUtil;
13 import com.bjpowernode.drp.util.PageModel;
14 import com.bjpowernode.drp.util.datadict.domain.ItemCategory;
15 import com.bjpowernode.drp.util.datadict.domain.ItemUnit;
16
17 public class ItemDao4OracleImpl implements ItemDao {
18 //增加物料信息
19 public void addItem(Connection conn, Item item) {
20 String sql = "insert into t_items (item_no, item_name, spec, pattern, item_category_id, item_unit_id) ";
21 sql+=" values (?, ?, ?, ?, ?, ?)";
22 PreparedStatement pstmt = null;
23 try {
24 //Dao的设计粒度一般是细粒度的，如果没有特殊需求，Dao和Manager粒度可以一样，不同考虑太多
25 //Dao的设计是比较单纯的，不应该放入过多的业务逻辑（业务规则）
26 //如果放置了业务逻辑，有些Manager不采用此业务逻辑，这样这个Dao方法就没有复用率了
27 //对于我们的应用来说Dao最底层的，所以应该越通用越好
28 // if (findItemById(conn, item.getItemNo()) != null) {
29 // throw new ApplicationException("物料代码已经存在，代码=" + item.getItemNo() + "");
30 // }
31 pstmt = conn.prepareStatement(sql);
32 pstmt.setString(1, item.getItemNo());
33 pstmt.setString(2, item.getItemName());
34 pstmt.setString(3, item.getSpec());
35 pstmt.setString(4, item.getPattern());
36 pstmt.setString(5, item.getItemCategory().getId());
37 pstmt.setString(6, item.getItemUnit().getId());
38 pstmt.executeUpdate();
39 }catch(SQLException e) {
40 e.printStackTrace();
41 //System.out.println("errorCode=" + e.getErrorCode());
42 //System.out.println("description=" + e.getMessage());
43 // if (e.getErrorCode() == 1) {
44 // throw new ApplicationException("物料代码已经存在，代码【" + item.getItemNo() + "】");
45 // }
46 throw new ApplicationException("添加物料失败！");
47 }finally {
48 DbUtil.close(pstmt);
49 }
50 }
51 //删除物料信息数组
52 public void delItem(Connection conn, String[] itemNos) {
53 StringBuffer sbString = new StringBuffer();
54 for (int i=0; i<itemNos.length; i++) {
55 sbString.append("?");
56 if (i < (itemNos.length - 1)) {
57 sbString.append(",");
58 }
59 }
60 String sql = "delete from t_items where item_no in(" + sbString.toString() + ")";
61 PreparedStatement pstmt = null;
62 try {
63 pstmt = conn.prepareStatement(sql);
64 for (int i=0; i<itemNos.length; i++) {
65 pstmt.setString(i+1, itemNos[i]);
66 }
67 pstmt.executeUpdate();
68 }catch(SQLException e) {
69 e.printStackTrace();
70 throw new ApplicationException("删除物料失败！");
71 }finally {
72 DbUtil.close(pstmt);
73 }
74 }
75 //通过Id查询物料信息
76 public Item findItemById(Connection conn, String itemNo) {
77 StringBuffer sbSql = new StringBuffer();
78 //第一中方法
79 sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.item_category_id, ")
80 .append("b.name as item_category_name, a.item_unit_id, c.name as item_unit_name ")
81 .append("from t_items a, t_data_dict b, t_data_dict c ")
82 .append("where a.item_category_id=b.id and a.item_unit_id=c.id and a.item_no=?");
83
84 // //第二中方法
85 // sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.category as category_id, ")
86 // .append("(select b.name from t_data_dict b where a.category=b.id) as category_name, ")
87 // .append("a.unit as unit_id, ")
88 // .append("(select c.name from t_data_dict c where a.unit=c.id) as unit_name ")
89 // .append("from t_items a where a.item_no=?");
90
91 //通常采用日志组件记录，如log4j, 级别：info,debug,error...
92
93 PreparedStatement pstmt = null;
94 ResultSet rs = null;
95 Item item = null;
96 try {
97 pstmt = conn.prepareStatement(sbSql.toString());
98 pstmt.setString(1, itemNo);
99 rs = pstmt.executeQuery();
100 if (rs.next()) {
101 item = new Item();
102 item.setItemNo(rs.getString("item_no"));
103 item.setItemName(rs.getString("item_name"));
104 item.setSpec(rs.getString("spec"));
105 item.setPattern(rs.getString("pattern"));
106 //构造ItemCategory
107 ItemCategory ic = new ItemCategory();
108 ic.setId(rs.getString("item_category_id"));
109 ic.setName(rs.getString("item_category_name"));
110 item.setItemCategory(ic);
111
112
113 //构造ItemUnit
114 ItemUnit iu = new ItemUnit();
115 iu.setId(rs.getString("item_unit_id"));
116 iu.setName(rs.getString("item_unit_name"));
117 item.setItemUnit(iu);
118 }
119 }catch(SQLException e) {
120 e.printStackTrace();
121 //记录到日志文件 error
122 throw new ApplicationException("根据物料代码查询出错，物料代码[" + itemNo + "]");
123 }finally {
124 DbUtil.close(rs);
125 DbUtil.close(pstmt);
126 }
127 return item;
128 }
129 //根据pageNO、pageSize、condation显示很多物料信息列表
130 public PageModel findItemList(Connection conn, int pageNo, int pageSize, String condation) {
131 StringBuffer sbSql = new StringBuffer();
132
133 //第一中方法
134 // sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.item_category_id, ")
135 // .append("b.name as item_category_name, a.item_unit_id, c.name as item_unit_name ")
136 // .append("from t_items a, t_data_dict b, t_data_dict c ")
137 // .append("where a.item_category_id=b.id and a.item_unit_id=c.id and a.item_no=?");
138
139 // //第二中方法
140 // sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.category as category_id, ")
141 // .append("(select b.name from t_data_dict b where a.category=b.id) as category_name, ")
142 // .append("a.unit as unit_id, ")
143 // .append("(select c.name from t_data_dict c where a.unit=c.id) as unit_name ")
144 // .append("from t_items a where a.item_no=?");
145
146 sbSql.append("select * ")
147 .append("from (")
148 .append("select i.*, rownum rn from (")
149 .append("select a.item_no, a.item_name, a.spec, a.pattern, a.item_category_id, ")
150 .append("b.name as item_category_name, a.item_unit_id, c.name as item_unit_name ")
151 .append("from t_items a, t_data_dict b, t_data_dict c ")
152 .append("where a.item_category_id=b.id and a.item_unit_id=c.id ");
153 if (condation != null && !"".equals(condation)) {
154 sbSql.append(" and (a.item_no like ‘" + condation + "%‘ or a.item_name like ‘" + condation + "%‘) ");
155 }
156 sbSql.append(" order by a.item_no")
157 .append(") i where rownum<=? ")
158 .append(") ")
159 .append("where rn >? ");
160 System.out.println("sql=" + sbSql.toString());
161
162 //通常采用日志组件记录，如log4j, 级别：info,debug,error...
163 PreparedStatement pstmt = null;
164 ResultSet rs = null;
165 PageModel pageModel = null;
166 try {
167 pstmt = conn.prepareStatement(sbSql.toString());
168 pstmt.setInt(1, pageNo * pageSize);
169 pstmt.setInt(2, (pageNo - 1) * pageSize);
170 rs = pstmt.executeQuery();
171 List itemList = new ArrayList();
172 while (rs.next()) {
173 Item item = new Item();
174 item.setItemNo(rs.getString("item_no"));
175 item.setItemName(rs.getString("item_name"));
176 item.setSpec(rs.getString("spec"));
177 item.setPattern(rs.getString("pattern"));
178 //构造ItemCategory
179 ItemCategory ic = new ItemCategory();
180 ic.setId(rs.getString("item_category_id"));
181 ic.setName(rs.getString("item_category_name"));
182 item.setItemCategory(ic);
183
184 //构造ItemUnit
185 ItemUnit iu = new ItemUnit();
186 iu.setId(rs.getString("item_unit_id"));
187 iu.setName(rs.getString("item_unit_name"));
188 item.setItemUnit(iu);
189
190 itemList.add(item);
191 }
192 pageModel = new PageModel();
193 pageModel.setPageNo(pageNo);
194 pageModel.setPageSize(pageSize);
195 pageModel.setList(itemList);
196 //根据条件取得记录数
197 int totalRecords = getTotalRecords(conn, condation);
198 pageModel.setTotalRecords(totalRecords);
199 }catch(SQLException e) {
200 e.printStackTrace();
201 //记录到日志文件 error
202 throw new ApplicationException("分页查询失败");
203 }finally {
204 DbUtil.close(rs);
205 DbUtil.close(pstmt);
206 }
207 return pageModel;
208 }
209
210 /**
211 * 根据条件取得记录数
212 * @param conn
213 * @param queryStr
214 * @return
215 */
216 private int getTotalRecords(Connection conn, String condation)
217 throws SQLException {
218 String sql = "select count(*) from t_items ";
219 if (condation != null && !"".equals(condation)) {
220 sql+="where item_no like ‘" + condation + "%‘ or item_name like ‘" + condation + "%‘ ";
221 }
222 PreparedStatement pstmt = null;
223 ResultSet rs = null;
224 int temp = 0;
225 try {
226 pstmt = conn.prepareStatement(sql);
227 rs = pstmt.executeQuery();
228 rs.next();
229 temp = rs.getInt(1);
230 }finally {
231 DbUtil.close(rs);
232 DbUtil.close(pstmt);
233 }
234 return temp;
235 }
236 //修改物料信息
237 public void modifyItem(Connection conn, Item item) {
238 String sql = "update t_items set item_name=?, spec=?, pattern=?, item_category_id=?, item_unit_id=? ";
239 sql+=" where item_no=?";
240 PreparedStatement pstmt = null;
241 try {
242 pstmt = conn.prepareStatement(sql);
243 pstmt.setString(1, item.getItemName());
244 pstmt.setString(2, item.getSpec());
245 pstmt.setString(3, item.getPattern());
246 pstmt.setString(4, item.getItemCategory().getId());
247 pstmt.setString(5, item.getItemUnit().getId());
248 pstmt.setString(6, item.getItemNo());
249 pstmt.executeUpdate();
250 }catch(SQLException e) {
251 e.printStackTrace();
252 throw new ApplicationException("修改物料失败！");
253 }finally {
254 DbUtil.close(pstmt);
255 }
256 }
257
258
259 }
【DRP】-Dao层常用功能代码：增删改查,布布扣,bubuko.com
时间： 2024-11-06 17:25:39