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package org.apache.any23.writer; |
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import java.io.OutputStream; |
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import java.util.ArrayList; |
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import java.util.HashMap; |
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import java.util.List; |
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import java.util.Map; |
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public class WriterRegistry { |
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private static WriterRegistry instance; |
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41 | 0 | private final List<Class<? extends FormatWriter>> writers = |
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new ArrayList<Class<? extends FormatWriter>>(); |
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47 | 0 | private final Map<String,List<Class<? extends FormatWriter>>> mimeToWriter = |
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new HashMap<String, List<Class<? extends FormatWriter>>>(); |
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53 | 0 | private final Map<String,Class<? extends FormatWriter>> idToWriter = |
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new HashMap<String, Class<? extends FormatWriter>>(); |
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public static String getIdentifier(Class<? extends FormatWriter> writerClass) { |
63 | 0 | return getWriterAnnotation(writerClass).identifier(); |
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} |
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public static String getMimeType(Class<? extends FormatWriter> writerClass) { |
73 | 0 | return getWriterAnnotation(writerClass).mimeType(); |
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} |
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public synchronized static WriterRegistry getInstance() { |
80 | 0 | if(instance == null) { |
81 | 0 | instance = new WriterRegistry(); |
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} |
83 | 0 | return instance; |
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} |
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private static Writer getWriterAnnotation(Class<? extends FormatWriter> writerClass) { |
94 | 0 | final Writer writer = writerClass.getAnnotation(Writer.class); |
95 | 0 | if(writer == null) |
96 | 0 | throw new IllegalArgumentException( |
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String.format("Class %s must be annotated with %s .",writerClass, Writer.class) |
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); |
99 | 0 | return writer; |
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} |
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102 | 0 | private WriterRegistry() { |
103 | 0 | register(TurtleWriter.class); |
104 | 0 | register(RDFXMLWriter.class); |
105 | 0 | register(NTriplesWriter.class); |
106 | 0 | register(NQuadsWriter.class); |
107 | 0 | register(TriXWriter.class); |
108 | 0 | register(JSONWriter.class); |
109 | 0 | register(URIListWriter.class); |
110 | 0 | } |
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public synchronized void register(Class<? extends FormatWriter> writerClass) { |
120 | 0 | if(writerClass == null) throw new NullPointerException("writerClass cannot be null."); |
121 | 0 | final Writer writer = getWriterAnnotation(writerClass); |
122 | 0 | final String id = writer.identifier(); |
123 | 0 | final String mimeType = writer.mimeType(); |
124 | 0 | if(id == null || id.trim().length() == 0) { |
125 | 0 | throw new IllegalArgumentException("Invalid identifier returned by writer " + writer); |
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} |
127 | 0 | if(mimeType == null || mimeType.trim().length() == 0) { |
128 | 0 | throw new IllegalArgumentException("Invalid MIME type returned by writer " + writer); |
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} |
130 | 0 | if(idToWriter.containsKey(id)) |
131 | 0 | throw new IllegalArgumentException("The writer identifier is already declared."); |
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133 | 0 | writers.add(writerClass); |
134 | 0 | List<Class<? extends FormatWriter>> writerClasses = mimeToWriter.get(mimeType); |
135 | 0 | if(writerClasses == null) { |
136 | 0 | writerClasses = new ArrayList<Class<? extends FormatWriter>>(); |
137 | 0 | mimeToWriter.put(mimeType, writerClasses); |
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} |
139 | 0 | writerClasses.add(writerClass); |
140 | 0 | idToWriter.put(id, writerClass); |
141 | 0 | } |
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public synchronized boolean hasIdentifier(String id) { |
150 | 0 | return idToWriter.containsKey(id); |
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} |
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public synchronized String[] getIdentifiers() { |
157 | 0 | final String[] ids = new String[writers.size()]; |
158 | 0 | for (int i = 0; i < ids.length; i++) { |
159 | 0 | ids[i] = getIdentifier( writers.get(i) ); |
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} |
161 | 0 | return ids; |
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} |
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public synchronized String[] getMimeTypes() { |
168 | 0 | return mimeToWriter.keySet().toArray( new String[mimeToWriter.keySet().size()] ); |
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} |
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@SuppressWarnings("unchecked") |
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public synchronized Class<? extends FormatWriter>[] getWriters() { |
176 | 0 | return writers.toArray( new Class[ writers.size() ] ); |
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} |
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public synchronized Class<? extends FormatWriter> getWriterByIdentifier(String id) { |
187 | 0 | return idToWriter.get(id); |
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} |
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@SuppressWarnings("unchecked") |
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public synchronized Class<? extends FormatWriter>[] getWritersByMimeType(String mimeType) { |
198 | 0 | final List<Class<? extends FormatWriter>> writerClasses = mimeToWriter.get(mimeType); |
199 | 0 | return writerClasses.toArray( new Class[writerClasses.size()] ); |
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} |
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public synchronized FormatWriter getWriterInstanceByIdentifier(String id, OutputStream os) { |
212 | 0 | final Class<? extends FormatWriter> writerClazz = getWriterByIdentifier(id); |
213 | 0 | if(writerClazz == null) |
214 | 0 | throw new NullPointerException( |
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String.format("Cannot find writer with id '%s' .", id) |
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); |
217 | 0 | return createWriter(writerClazz, os); |
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} |
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private FormatWriter createWriter(Class<? extends FormatWriter> clazz, OutputStream os) { |
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try { |
230 | 0 | return clazz.getConstructor(OutputStream.class).newInstance(os); |
231 | 0 | } catch (Exception e) { |
232 | 0 | throw new IllegalArgumentException("Error while initializing format writer " + clazz + " ."); |
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} |
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} |
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} |