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| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
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| // to you under the Apache License, Version 2.0 (the |
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| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
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| // specific language governing permissions and limitations |
| // under the License. |
| |
| [[_ugr.tools.uimafit.pipelines]] |
| = Pipelines |
| |
| UIMA is a component-based architecture that allows composing various processing components into a complex processing pipeline. |
| A pipeline typically involves a _collection |
| reader_ which ingests documents and _analysis engines_ that do the actual processing. |
| |
| Normally, you would run a pipeline using a UIMA Collection Processing Engine or using UIMA AS. |
| uimaFIT offers a third alternative that is much simpler to use and well suited for embedding UIMA pipelines into applications or for writing tests. |
| |
| As uimaFIT does not supply any readers or processing components, we just assume that we have written three components: |
| |
| * [class]``TextReader`` - reads text files from a directory |
| * [class]``Tokenizer`` - annotates tokens |
| * [class]``TokenFrequencyWriter`` - writes a list of tokens and their frequency to a file |
| |
| We create descriptors for all components and run them as a pipeline: |
| |
| [source,java] |
| ---- |
| CollectionReaderDescription reader = |
| CollectionReaderFactory.createReaderDescription( |
| TextReader.class, |
| TextReader.PARAM_INPUT, "/home/uimafit/documents"); |
| |
| AnalysisEngineDescription tokenizer = |
| AnalysisEngineFactory.createEngineDescription( |
| Tokenizer.class); |
| |
| AnalysisEngineDescription tokenFrequencyWriter = |
| AnalysisEngineFactory.createEngineDescription( |
| TokenFrequencyWriter.class, |
| TokenFrequencyWriter.PARAM_OUTPUT, "counts.txt"); |
| |
| SimplePipeline.runPipeline(reader, tokenizer, writer); |
| ---- |
| |
| Instead of running the full pipeline end-to-end, we can also process one document at a time and inspect the analysis results: |
| |
| [source,java] |
| ---- |
| CollectionReaderDescription reader = |
| CollectionReaderFactory.createReaderDescription( |
| TextReader.class, |
| TextReader.PARAM_INPUT, "/home/uimafit/documents"); |
| |
| AnalysisEngineDescription tokenizer = |
| AnalysisEngineFactory.createEngineDescription( |
| Tokenizer.class); |
| |
| for (JCas jcas : SimplePipeline.iteratePipeline(reader, tokenizer)) { |
| System.out.printf("Found %d tokens%n", |
| JCasUtil.select(jcas, Token.class).size()); |
| } |
| ---- |
