可重用的sql操作类
1 public ResultSet doQuery(String sql,Object[] params){
2 ResultSet rs = null;
3 conn = this.getConnection();
4 try{
5 PreparedStatement pstmt = conn.prepareStatement(sql);
6 for(int i =0;i<params.length;i++){
7 pstmt.setObject(i+1, params[i]);
8 }
9 rs = pstmt.executeQuery();
10 }catch(Exception e){
11 e.printStackTrace();
12 }
13 return rs;
14 }
1 public int doUpdate(String sql,Object[] params){
2 int res = 0;
3 conn = this.getConnection();
4 try{
5 PreparedStatement pstmt = conn.prepareStatement(sql);
6 for(int i=0;i<params.length;i++){
7 pstmt.setObject(i+1, params[i]);
8 }
9 res = pstmt.executeUpdate();
10 }catch(Exception e){
11 e.printStackTrace();
12 }
13 return res;
14 }
1 public List<Object> doQueryList(String sql,Object []params){
2 List<Object> list = new ArrayList<Object>();
3 ResultSet rs = this.doQuery(sql, params);
4 try{
5 ResultSetMetaData rsmd = rs.getMetaData();
6 int columnLength = rsmd.getColumnCount();
7 while(rs.next()){
8 Map<String,Object> map = new HashMap<String,Object>();
9 for(int i = 1;i<=columnLength;i++){
10 map.put(rsmd.getColumnLabel(i), rs.getObject(i));
11 }
12 list.add(map);
13 }
14 }catch(Exception e){
15 e.printStackTrace();
16 }
17 return list;
18 }
查询所有信息的jsp关键代码如下
1 <%
2 DBCon dbc = new DBCon();
3 String sql = "select * from schema.admin";
4 List list = dbc.doQueryList(sql, new Object[]{});
5
6 %>
7 <table border="1">
8 <%for(int i =0;i<list.size();i++){
9 Map<String,Object> map = (Map<String,Object>)list.get(i);
10 %>
11 <tr>
12 <td><%=map.get("id") %></td>
13 <td><%=map.get("username") %></td>
14 <td><%=map.get("password") %></td>
15 <td><a href="do_delete.jsp?id=<%=map.get("id")%>">删除</a></td>
16 <td><a href="do_edit.jsp?id=<%=map.get("id")%>">编辑</a></td>
17 </tr>
18 <%}
19 dbc.close();
20 %>
21 </table>
22 <a href="addAdmin.jsp">添加用户</a>
更新、删除登操作同理，不再列出。