ParserDecoratorTest.java

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 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     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 "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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package org.apache.tika.parser;

import static org.junit.Assert.assertEquals;

import java.io.ByteArrayInputStream;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;
import org.apache.tika.sax.BodyContentHandler;
import org.junit.Test;

public class ParserDecoratorTest {
    @Test
    public void withAndWithoutTypes() {
        Set<MediaType> onlyTxt = Collections.singleton(MediaType.TEXT_PLAIN);
        Set<MediaType> onlyOct = Collections.singleton(MediaType.OCTET_STREAM);
        Set<MediaType> both = new HashSet<MediaType>();
        both.addAll(onlyOct);
        both.addAll(onlyTxt);
        
        Parser p;
        Set<MediaType> types;
        ParseContext context = new ParseContext();

        
        // With a parser of no types, get the decorated type
        p = ParserDecorator.withTypes(EmptyParser.INSTANCE, onlyTxt);
        types = p.getSupportedTypes(context);
        assertEquals(1, types.size());
        assertEquals(types.toString(), true, types.contains(MediaType.TEXT_PLAIN));
        
        // With a parser with other types, still just the decorated type
        p = ParserDecorator.withTypes(
                new DummyParser(onlyOct, new HashMap<String,String>(), ""), onlyTxt);
        types = p.getSupportedTypes(context);
        assertEquals(1, types.size());
        assertEquals(types.toString(), true, types.contains(MediaType.TEXT_PLAIN));
        
        
        // Exclude will remove if there
        p = ParserDecorator.withoutTypes(EmptyParser.INSTANCE, onlyTxt);
        types = p.getSupportedTypes(context);
        assertEquals(0, types.size());
        
        p = ParserDecorator.withoutTypes(
                new DummyParser(onlyOct, new HashMap<String,String>(), ""), onlyTxt);
        types = p.getSupportedTypes(context);
        assertEquals(1, types.size());
        assertEquals(types.toString(), true, types.contains(MediaType.OCTET_STREAM));
        
        p = ParserDecorator.withoutTypes(
                new DummyParser(both, new HashMap<String,String>(), ""), onlyTxt);
        types = p.getSupportedTypes(context);
        assertEquals(1, types.size());
        assertEquals(types.toString(), true, types.contains(MediaType.OCTET_STREAM));
    }
    
    /**
     * Testing one proposed implementation for TIKA-1509
     */
    @Test
    public void withFallback() throws Exception {
        Set<MediaType> onlyOct = Collections.singleton(MediaType.OCTET_STREAM);
        Set<MediaType> octAndText = new HashSet<MediaType>(Arrays.asList(
                MediaType.OCTET_STREAM, MediaType.TEXT_PLAIN));

        ParseContext context = new ParseContext();
        BodyContentHandler handler;
        Metadata metadata;
        
        ErrorParser pFail = new ErrorParser();
        DummyParser pWork = new DummyParser(onlyOct, new HashMap<String,String>(), "Fell back!");
        EmptyParser pNothing = new EmptyParser();
        
        // Create a combination which will fail first
        @SuppressWarnings("deprecation")
        Parser p = ParserDecorator.withFallbacks(Arrays.asList(pFail, pWork), octAndText);
        
        // Will claim to support the types given, not those on the child parsers
        Set<MediaType> types = p.getSupportedTypes(context);
        assertEquals(2, types.size());
        assertEquals(types.toString(), true, types.contains(MediaType.TEXT_PLAIN));
        assertEquals(types.toString(), true, types.contains(MediaType.OCTET_STREAM));
        
        // Parsing will make it to the second one
        metadata = new Metadata();
        handler = new BodyContentHandler();
        p.parse(new ByteArrayInputStream(new byte[] {0,1,2,3,4}), handler, metadata, context);
        assertEquals("Fell back!", handler.toString());
        
        
        // With a parser that will work with no output, will get nothing
        p = ParserDecorator.withFallbacks(Arrays.asList(pNothing, pWork), octAndText);
        metadata = new Metadata();
        handler = new BodyContentHandler();
        p.parse(new ByteArrayInputStream(new byte[] {0,1,2,3,4}), handler, metadata, context);
        assertEquals("", handler.toString());
    }
}