So far we have discussed the complete ExtJs 4 MVC architecture and needed sources for our Item Maintenance application. We have started to work on the Server Side and created our Item bean.
Step 11: Define the Item utility function that will work with our database - ItemInformation.java
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 | package com.as400samplecode.util;import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.PreparedStatement; import java.util.ArrayList;import javax.naming.Context; import javax.naming.InitialContext; import javax.sql.DataSource; public class ItemInformation { Connection conn = null; PreparedStatement stmt = null; String sql = null; String company = null; int numberOfRows = 0; public ItemInformation(String company) { this.company = company; } //this method gets us a list of items based on the parameters start and limit //these parameters are sent to use by the ExtJs Grid paging toolbar //we use a scrollable resultset and position it to start from where we need our records public ArrayList<Item> getItems(String start, String limit) { ArrayList<Item> itemList = new ArrayList<Item>(); try { Context ctx = (Context) new InitialContext().lookup("java:comp/env"); conn = ((DataSource) ctx.lookup("jdbc/mydb2")).getConnection(); int skipRows = Integer.parseInt(start); numberOfRows = skipRows + Integer.parseInt(limit); sql = "Select ITEMNO,DESC1,DESC2,WEIGHT,STATUS " + " from PRODUCTS where COMPANY = ? order by COMPANY,ITEMNO FETCH FIRST " + numberOfRows + " ROWS ONLY"; stmt = conn.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); stmt.setInt(1,Integer.parseInt(company)); ResultSet rs = stmt.executeQuery(); rs.relative(skipRows); while(rs.next()){ Item item = new Item(); item.setItem(rs.getString("ITEMNO").trim()); item.setDesc1(rs.getString("DESC1").trim()); item.setDesc2(rs.getString("DESC2").trim()); item.setWeight(Double.parseDouble(rs.getString("WEIGHT").trim())); item.setStatus(rs.getString("STATUS").trim()); itemList.add(item); } rs.close(); stmt.close(); stmt = null; conn.close(); conn = null; } catch(Exception e){System.out.println(e);} finally { if (stmt != null) { try { stmt.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } stmt = null; } if (conn != null) { try { conn.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } conn = null; } } return itemList; } //this method gets us the Total Number of Items that we have in our database public int getTotalCount() { int totalCount = 0; try { Context ctx = (Context) new InitialContext().lookup("java:comp/env"); conn = ((DataSource) ctx.lookup("jdbc/mydb2")).getConnection(); sql = "Select count(*) from PRODUCTS where COMPANY = ?"; stmt = conn.prepareStatement(sql); stmt.setInt(1,Integer.parseInt(company)); ResultSet rs = stmt.executeQuery(); while(rs.next()){ totalCount = rs.getInt(1); break; } rs.close(); stmt.close(); stmt = null; conn.close(); conn = null; } catch(Exception e){System.out.println(e);} finally { if (stmt != null) { try { stmt.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } stmt = null; } if (conn != null) { try { conn.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } conn = null; } } return totalCount; } //this methods loops thru an arraylist of Items and update the changed information public boolean updateItems(ArrayList<Item> itemList) { boolean success = true; try { Context ctx = (Context) new InitialContext().lookup("java:comp/env"); conn = ((DataSource) ctx.lookup("jdbc/mydb2")).getConnection(); sql = "UPDATE PRODUCTS set DESC1 = ?,DESC2 = ?,WEIGHT = ? where COMPANY = ? and ITEMNO = ?"; stmt = conn.prepareStatement(sql); for(int i=0;i<itemList.size();i++){ Item item = itemList.get(i); stmt.setString(1,item.getDesc1()); stmt.setString(2,item.getDesc2()); stmt.setDouble(3,item.getWeight()); stmt.setInt(4,Integer.parseInt(company)); stmt.setString(5,item.getItem()); stmt.addBatch(); } stmt.executeBatch(); stmt.close(); stmt = null; conn.close(); conn = null; } catch(Exception e){ success = false; System.out.println(e); } finally { if (stmt != null) { try { stmt.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } stmt = null; } if (conn != null) { try { conn.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } conn = null; } } return success; } //this method creates a new Item in the database public boolean addItems(ArrayList<Item> itemList) { boolean success = true; try { Context ctx = (Context) new InitialContext().lookup("java:comp/env"); conn = ((DataSource) ctx.lookup("jdbc/mydb2")).getConnection(); sql = "INSERT into PRODUCTS (COMPANY,ITEMNO,DESC1,DESC2,WEIGHT,STATUS) VALUES(?,?,?,?,?,?)"; stmt = conn.prepareStatement(sql); for(int i=0;i<itemList.size();i++){ Item item = itemList.get(i); stmt.setInt(1,Integer.parseInt(company)); stmt.setString(2,item.getItem()); stmt.setString(3,item.getDesc1()); stmt.setString(4,item.getDesc2()); stmt.setDouble(5,item.getWeight()); stmt.setString(6,"A"); stmt.addBatch(); } stmt.executeBatch(); stmt.close(); stmt = null; conn.close(); conn = null; } catch(Exception e){ success = false; System.out.println(e); } finally { if (stmt != null) { try { stmt.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } stmt = null; } if (conn != null) { try { conn.close(); } catch (SQLException sqlex) { // ignore -- as we can't do anything about it here } conn = null; } } return success; } } |
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