Parsing Vector into a Table
Hi all,
Firstly, an advanced thankyou for anyone willing to help.
I'm writing a JSP to display a table from a database, but the bean used passes back a vector (consisiting of more vectors) to the JSP and I have no idea how to parse through said vectors so I can output it to a table.
Here's my code so far:
The (segment of) bean:
public Vector<Vector><Object>> getAllStock()
throws SQLException
{
Vector<Object> row =null;
Vector<Vector><Object>> rows =
new Vector<Vector><Object>>();
connectToDb();
try
{
results = statement.executeQuery(
"SELECT * FROM Stock");
while (results.next())
{
row =new Vector<Object>();
row.add(results.getString(1));
row.add(results.getString(2));
row.add(results.getInt(3));
row.add(results.getInt(4));
row.add(results.getFloat(5));
rows.add(row);
}
}
catch (SQLException sqlEx)
{
//Error message
}
disconnectFromDb();
return rows;
}
And then the JSP:
<HTML>
<HEAD>
<TITLE>The tableName Database Table </TITLE>
</HEAD>
<BODY>
<H1>Displaying full stock list </H1>
<%
Vector resultset = stockacc.getAllStock();
%>
<TABLE BORDER="1">
<TR>
<TH>Stock Code</TH>
<TH>Stock Desc</TH>
<TH>Current Level</TH>
<TH>Reorder Level</TH>
<TH>Price</TH>
</TR>
<%while(resultset.next()){ %>
<TR>
<TD> <%= resultset.getString(1) %></td>
<TD> <%= resultset.getString(2) %></TD>
<TD> <%= resultset.getString(3) %></TD>
<TD> <%= resultset.getString(4) %></TD>
<TD> <%= resultset.getString(5) %></TD>
</TR>
<%} %>
</TABLE>
</BODY>
</HTML>
All help and advice greatly appreciated!
[2877 byte] By [
pedanta] at [2007-11-27 2:10:14]
# 1
See http://java.sun.com/j2se/1.5.0/docs/api/ for the API. You can look up Vector on the bottom left corner and see what functions you can call from it.
The procedure would be this, though:
<% Vector table = getVectorOfRows...%>
<!-- Set up header for table -->
<% //get an iterator for rows to make it easy to walk through
Iterator rows = table.iterator();
while (rows.hasNext()) {
//get the list of all columns (one row), from the iterator. Make sure it is a Vector
Vector currentRow = (Vector)rows.next();
//get an iterator for the columns
Iterator columns = currentRow.iterator();
%>
<!-- Build a table using <% columns.next(); %>, or <% currentRow.get(index) %> to get value for each column -->
# 2
Vector resultset = stockacc.getAllStock();
while (results.next())
Your variable resultset is a Vector not a ResultSet.
You should use a for loop and retrieve the elements with using elementAt
http://java.sun.com/j2se/1.4.2/docs/api/java/util/Vector.html#elementAt(int)
I don't recommend you using Vector of Vector.
You should create a StockDetail class with getters and setters.
You may store those StockDetails in a Vector (or someone would suggest you to use an ArrayList).
for result set has next
getString, getInt to get the data
create a StockDetail using setters or constructor
Add this StockDetail object to a Vector or ArrayList
end for
// in your jsp
for vector size (or ArrayList)
get the StockDetail element
using getters to get individual data
end for
# 3
well so gud to hear that you are following the right approach...
if i were you i could have used a vector of Maps(Vector<Map><String,Object>>) or Vector of a custom built bean Vector<ResultSetBean> which could be very easy to resolve using a custom tags like JSTL,struts(logic & bean) tags..
# 4
Many thanks for all the timely replies!
I'm trying to implement your solution (stevejluke), and here's what I've got so far:
<HTML>
<%@ page import="java.util.*" %>
<%@ page import="java.net.*" %>
<jsp:useBean id="stockacc" class="stockBeans.StockAccess" />
<HEAD>
<TITLE>The tableName Database Table </TITLE>
</HEAD>
<BODY>
<H1>The tableName Database Table </H1>
<%
Vector table = (Vector)stockacc.getAllStock();
Iterator rows = table.iterator();
Vector currentRow = (Vector)rows.next();
Iterator columns = currentRow.iterator();
%>
<%= columns.next() %>
<TABLE BORDER="1">
<TR>
<TH>Stock Code</TH>
<TH>Stock Desc</TH>
<TH>Current Level</TH>
<TH>Reorder Level</TH>
<TH>Price</TH>
</TR>
<TR>
</TR>
</TABLE>
</BODY>
</HTML>
Bearing in mind I'm just trying to see if anythings making it through, hence I'm just using <%= columns.next() %> for now.
However, I don't think the vector (of vectors; not too confusing!) is being created when I do:
Vector table = (Vector)stockacc.getAllStock();
As I'm getting a NoSuchElement exception being thrown.
Can anyone advise?
Thanks again.
# 5
Vector of Vectors in here.Vector < Vector <Object>> rows =new Vector < Vector <Object>>();
# 6
- deleted -Message was edited by: rym82
# 7
So it should read:
<%
Vector<Vector<Object>> table = new Vector<Vector><Object>>();
table =stockacc.getAllStock();
Iterator rows = table.iterator();
Vector currentRow = (Vector)rows.next();
Iterator columns = currentRow.iterator();
%>
<%= currentRow.get(1) %>
?
Many thanks!
# 8
Anyone any ideas? Still stuck on trying to get it working :(
# 9
One last bump before my deadline passes.
It's definitely a problem with my first line, that is,
Vector<Vector><Object>> results = (Vector<Vector><Object>>)stockacc.getAllStock();
As when doing a simple <%= results.isEmpty() %> , it always comes back true.
I've tried several variations but none seem to work (that is, I always have an empty results vector). Am I doing something monumentally stupid?
# 10
public Vector<Vector><Object>> getAllStock()
throws SQLException
{
Vector<Object> row = null;
Vector<Vector><Object>> rows =
new Vector<Vector><Object>>();
connectToDb();
try
{
results = statement.executeQuery(
"SELECT * FROM Stock");
while (results.next())
{
row = new Vector<Object>();
row.add(results.getString(1));
row.add(results.getString(2));
row.add(results.getInt(3));
row.add(results.getInt(4));
row.add(results.getFloat(5));
rows.add(row);
}
}
catch (SQLException sqlEx)
{
throw new SQLException("Error retrieving stock list!!");
}
disconnectFromDb();
return rows;
}
