Swing Hacks

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Chapter 3, Tables and Trees

#26 Search Through JTables Easily

HACK

First, add a field with the row index in the inner table model. You’ll use this

to link back to that row later in the row-to-model index. Each field needs a

name and a value, so create a constant called

ROW_NUMBER

that you’ll refer to

later when retrieving the links:

Document document = new Document( );

document.add(new Field(ROW_NUMBER, "" + row, true, true, true));

//more indexing to come

writer.addDocument(document);

Then, iterate through all of the columns and add a Field for each column

name/value pair:

for (int column=0; column < tableModel.getColumnCount( ); column++){

String columnName = tableModel.getColumnName(column);

String columnValue = String.valueOf(

tableModel.getValueAt(row, column)

).toLowerCase( );

document.add(new Field(columnName, columnValue, true, true, true));

}

Searching

There are two parts to the searching. First, you have to hit the Lucene index

with a search string. This will give you a list of rows in the inner table model

that match the search. Then you need to reset the row-to-model index,

pointing to those rows.

Getting results from the index. To actually get the search results, you need an

IndexSearcher that speaks to the index and returns your search results:

IndexSearcher is = new IndexSearcher(directory);

You want to make sure all of the fields get searched, so iterate through the

table model and put all of the column names in an array that you’ll pass into

the Lucene search call:

String[] fields = new String[tableModel.getColumnCount( )];

for (int t=0; t<tableModel.getColumnCount( ); t++){

fields[t]=tableModel.getColumnName(t);

}

Next, create a Query object to pass to the IndexSearcher; there is a helper

method on

MultiFieldQueryParser to do just that. Pass it the fields you want

to search, your search

String, and the analyzer:

Query query = MultiFieldQueryParser.parse(searchString, fields, analyzer);

Then run the search. Hits is the object type returned by the search call.

You’ll process the hits in the next section when you map the results back to

the inner table model:

Hits hits = is.search(query);