Lucene offers great full text search capabilities. It is based on an index, which is maintained by Lucene. With Luke, the Lucene Index Toolbox (http://www.getopt.org/luke/) you can analyze your index and let explain queries.
After startup, you have to select your index. For this example, I created a test index with one file. It’s content is “this is a lucene test”. I used the StandardAnalyzer, which uses the WhitespaceTokenizer and filters out all tokens less than 3 characters and stop words. This will result in an index of the terms “lucene” and “test”.
In the register Documents, you can browse through all documents. Because we only have one file in our test index, we can directly jump to document 0. In the “Brows by term:” panel, we can browse through all terms, which are “lucene” and “test”. Very useful, to analyze the index for a specific document.
Also very interesting is the register Search. I typed in the phrase “this is a lucene test”. In the “Query Details” panel, we can see, that the query will be “lucene test”. The reason is simple. Every query get’s also analyzed by the same analyzer, which is used for building the index.
If you are using Lucene, just try Luke out. You can start it with Java Web Start from here.