Changes according to the code review

Author: mkorzhemanova

pom.xml

@@ -72,5 +72,10 @@
             <artifactId>lucene-queryparser</artifactId>
             <version>5.0.0</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>18.0</version>
+        </dependency>
     </dependencies>
 </project>

resources/indexer/indexer_config.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <indexerConfiguration>
-    <indexPath>D:\CS\Projects\Prompter\resources\index\arXiv\test</indexPath>
-    <directory>D:\CS\Projects\Prompter\resources\test\arXiv</directory>
+    <indexPath>resources\data\index\test</indexPath>
+    <directory>resources\data\test\arXiv</directory>
 </indexerConfiguration>

resources/retriever/oai_retrieve_config.xml

@@ -6,6 +6,6 @@
         <prefix>oai_dc</prefix>
         <class>com.bardsoftware.papeeria.sufler.retriever.oai.metadata.DublinCoreMetadata</class>
     </metadata>
-    <path>D:\CS\Projects\Prompter\resources\test\</path>
+    <path>resources\data\test\</path>
     <source>arXiv</source>
 </oaiConfiguration>

resources/searcher/searcher_config.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <searcherConfiguration>
-    <indexDirectory>D:\CS\Projects\Prompter\resources\index\arXiv\test</indexDirectory>
+    <indexDirectory>resources\data\index\test</indexDirectory>
     <size>10</size>
 </searcherConfiguration>

src/com/bardsoftware/papeeria/sufler/indexer/IndexedField.java

@@ -1,3 +1,17 @@
+/*
+ Copyright 2015 BarD Software s.r.o
+
+ Licensed 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
+ limitations under the License.
+ */
+
 package com.bardsoftware.papeeria.sufler.indexer;
 
 import org.apache.log4j.Logger;
@@ -15,25 +29,25 @@ public enum IndexedField {
     SUBJECT(StringField.class, Field.Store.YES),
     DATE(StringField.class, Field.Store.YES);
 
-    private static Logger logger = Logger.getLogger(IndexedField.class);
+    private static final Logger LOGGER = Logger.getLogger(IndexedField.class);
 
-    private Class<? extends Field> fieldClass;
-    private Field.Store fieldStore;
+    private Class<? extends Field> myFieldClass;
+    private Field.Store myFieldStore;
 
-    IndexedField(Class<? extends Field> fieldClass, Field.Store fieldStore) {
-        this.fieldClass = fieldClass;
-        this.fieldStore = fieldStore;
+    IndexedField(Class<? extends Field> myFieldClass, Field.Store myFieldStore) {
+        this.myFieldClass = myFieldClass;
+        this.myFieldStore = myFieldStore;
     }
 
     public Field createField(String value) {
-        logger.debug("Creating field in index: name=" + this.name().toLowerCase() + ", value=" + value);
+        LOGGER.debug("Creating field in index: name=" + this.name().toLowerCase() + ", value=" + value);
         Field result = null;
 
         try {
-            Constructor constructor = fieldClass.getConstructor(String.class, String.class, Field.Store.class);
-            result = (Field) constructor.newInstance(this.name().toLowerCase(), value, this.fieldStore);
+            Constructor constructor = myFieldClass.getConstructor(String.class, String.class, Field.Store.class);
+            result = (Field) constructor.newInstance(this.name().toLowerCase(), value, this.myFieldStore);
         } catch (Exception e) {
-            logger.error("Error instantiating index field: " + this.name().toLowerCase(), e);
+            LOGGER.error("Error instantiating index field: " + this.name().toLowerCase(), e);
         }
         return result;
     }

src/com/bardsoftware/papeeria/sufler/indexer/Indexer.java

@@ -1,5 +1,21 @@
+/*
+ Copyright 2015 BarD Software s.r.o
+
+ Licensed 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
+ limitations under the License.
+ */
+
 package com.bardsoftware.papeeria.sufler.indexer;
 
+import com.bardsoftware.papeeria.sufler.indexer.configuration.IndexerConfiguration;
+import com.google.common.base.Preconditions;
 import org.apache.log4j.Logger;
 import org.apache.lucene.analysis.standard.StandardAnalyzer;
 import org.apache.lucene.index.IndexWriter;
@@ -13,29 +29,30 @@
 import java.nio.file.Paths;
 
 public abstract class Indexer {
-    protected static Logger logger = Logger.getLogger(Indexer.class);
+    private static final Logger LOGGER = Logger.getLogger(Indexer.class);
 
-    private IndexerConfiguration configuration;
-    protected IndexWriter writer;
+    private IndexerConfiguration myConfiguration;
+    protected IndexWriter myWriter;
 
-    public Indexer() {
-        configuration = IndexerConfiguration.getInstance();
+    public Indexer(IndexerConfiguration configuration) {
+        myConfiguration = configuration;
+        Preconditions.checkNotNull(myConfiguration);
     }
 
     public void index() throws IOException {
-        writer = createWriter();
-        for (String path : configuration.getDirectories()) {
+        myWriter = createWriter();
+        for (String path : myConfiguration.getDirectories()) {
             File directory = new File(path);
             if (isValidDirectory(directory)) {
                 indexDirectory(directory);
             }
         }
-        writer.commit();
-        writer.close();
+        myWriter.commit();
+        myWriter.close();
     }
 
     private void indexDirectory(File directory) throws IOException {
-        logger.debug("Indexing directory: " + directory.getName());
+        LOGGER.debug("Indexing directory: " + directory.getName());
         File[] files = directory.listFiles();
         for (File file : files) {
             if (isValidFile(file)) {
@@ -47,23 +64,14 @@ private void indexDirectory(File directory) throws IOException {
     protected abstract void indexFile(File file) throws IOException;
 
     private IndexWriter createWriter() throws IOException {
-        Path path = Paths.get(configuration.getIndexPath());
+        Path path = Paths.get(myConfiguration.getIndexPath());
         Directory indexDir = FSDirectory.open(path);
         IndexWriterConfig config = new IndexWriterConfig(new StandardAnalyzer());
-        IndexWriter indexWriter = new IndexWriter(indexDir, config);
-        return indexWriter;
+        return new IndexWriter(indexDir, config);
     }
 
     private static boolean isValidDirectory(File directory) {
-        if (!directory.exists()) {
-            return false;
-        }
-
-        if (!directory.isDirectory()) {
-            return false;
-        }
-
-        return true;
+        return (directory.isDirectory());
     }
 
     private boolean isValidFile(File file) {

src/com/bardsoftware/papeeria/sufler/indexer/IndexerConfiguration.java

@@ -0,0 +1,26 @@
+/*
+ Copyright 2015 BarD Software s.r.o
+
+ Licensed 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
+ limitations under the License.
+ */
+
+package com.bardsoftware.papeeria.sufler.indexer.configuration;
+
+import java.util.List;
+
+public interface IndexerConfiguration {
+    public enum Type {
+        OAI
+    }
+    String getIndexPath();
+
+    List<String> getDirectories();
+}

src/com/bardsoftware/papeeria/sufler/indexer/configuration/IndexerConfiguration.java

@@ -0,0 +1,67 @@
+/*
+ Copyright 2015 BarD Software s.r.o
+
+ Licensed 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
+ limitations under the License.
+ */
+
+package com.bardsoftware.papeeria.sufler.indexer.configuration;
+
+import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.annotations.XStreamAlias;
+import com.thoughtworks.xstream.annotations.XStreamImplicit;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+@XStreamAlias("indexerConfiguration")
+public class IndexerConfigurationXml implements IndexerConfiguration {
+
+    private static final String CONFIGURATION_PATH = "resources/indexer/";
+    private static final String CONFIGURATION_FILENAME = "indexer_config.xml";
+
+    private static IndexerConfiguration ourInstance;
+
+    @XStreamAlias("indexPath")
+    private String myIndexPath;
+
+    @XStreamImplicit(itemFieldName = "directory")
+    private List<String> myDirectories = new ArrayList<>();
+
+    public IndexerConfigurationXml() {
+
+    }
+
+    private static void readFromFile() {
+        XStream xstream = new XStream();
+        xstream.processAnnotations(IndexerConfigurationXml.class);
+        File file = new File(CONFIGURATION_PATH + CONFIGURATION_FILENAME);
+        ourInstance = (IndexerConfiguration) (xstream.fromXML(file));
+    }
+
+    @Override
+    public String getIndexPath() {
+        return myIndexPath;
+    }
+
+    @Override
+    public List<String> getDirectories() {
+        return myDirectories;
+    }
+
+    public static IndexerConfiguration getInstance() {
+        if (ourInstance == null) {
+            readFromFile();
+        }
+        return ourInstance;
+    }
+}
+