title: Combine filters on a JTable
author: depierre
published: 2013-06-01
categories: Java
keywords: project, swing, java, awt, jtable, filter, regex, trick


Since few days, I'm working on a school project. Its goal is to use
[Java](https://www.java.com/) and
[Swing](https://en.wikipedia.org/wiki/Swing_%28Java%29) to create an interface
for the [Crew Scheduling Problem](https://en.wikipedia.org/wiki/Crew_scheduling).

Dealing with a list of tasks, I choose to use a
[JTable](https://docs.oracle.com/javase/6/docs/api/javax/swing/JTable.html) as
the graphical view.  
One feature I want to implement is some filters to display/hide the tasks.

If you read the Java doc, you will see a lot of examples on [how to use
filters](https://docs.oracle.com/javase/tutorial/uiswing/components/table.html#sorting).  
My problem here is that these examples only deals with simple filter, i.e. one
filter for the whole row.  
What I need is several filters, each one for a specific cell on a row.
At this point, the doc becomes useless.

Hopefully, while looking for some similar issues on the Internet, I stumble on
[really few
topics](http://pulkitsinghal.blogspot.fr/2010/06/multiple-row-filters-for-jtable.html)
which explain how to perform a more advanced filtering system.  
Therefore I am writing this post to sum them up.

<!---summary-->

With a JTable, you can not straightfully create several filters and ask Swing
to appy each one on a specific cell (lame!).  
But what you can do is create a list of RowFilter and then combine them using a
[RowFilter.andFilter](https://docs.oracle.com/javase/6/docs/api/javax/swing/RowFilter.html#andFilter%28java.lang.Iterable%29).

    :::java
    /* Match the filter with the column 0 */
    final RowFilter<TableModel, Object> firstFilter = RowFilter.regexFilter(firstFilter, 0);
    /* Match the filter with the column 1 */
    final RowFilter<TableModel, Object> secondFilter = RowFilter.regexFilter(secondFilter, 1);
    /* Match the filter with the column 2 */
    final RowFilter<TableModel, Object> thirdFilter = RowFilter.regexFilter(thirdFilter, 2);

    final List<RowFilter<TableModel, Object>> filters = new ArrayList<RowFilter<TableModel, Object>>();
    filters.add(firstFilter);
    filters.add(secondFilter);
    filters.add(thirdFilter);

    /* The row must match every filters */
    final RowFilter<TableModel, Object>  compoundRowFilter = RowFilter.andFilter(filters);

    final TableRowSorter sorter = new TableRowSorter<TableModel>();
    sorter.setRowFilter(compoundRowFilter);

    final JTable tasksTable = new JTable();
    tasksTable.setRowSorter(sorter);

The code above shows the principle using three filters and an 'and' clause.  
Hence only the row matching every filters will be shown.

In my project, I use JComboBox to let the user decides. Using this system of
multiple filters, a result may look like below.

![JTable without filter](/static/images/jtable/zero_filter.png)

![JTable with two filters](/static/images/jtable/two_filters.png)

![JTable with three filters](/static/images/jtable/three_filters.png)

Hopefully, I don't have to filter tons of columns \o/