Add Searcher class

pom.xml

@@ -29,6 +29,11 @@
         <artifactId>lucene-analyzers-common</artifactId>
         <version>8.6.3</version>
     </dependency>
+    <dependency>
+        <groupId>org.apache.lucene</groupId>
+        <artifactId>lucene-queryparser</artifactId>
+        <version>8.6.3</version>
+    </dependency>
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>

src/main/java/org/RI/P2/Searcher.java

@@ -0,0 +1,58 @@
+package org.RI.P2;
+
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.text.ParseException;
+
+import org.apache.lucene.analysis.core.WhitespaceAnalyzer;
+import org.apache.lucene.index.DirectoryReader;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.FSDirectory;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.TopDocs;
+import org.apache.lucene.queryparser.classic.QueryParser;
+
+public class Searcher {
+
+    IndexReader index;
+    String dataPath;
+    String indexPath;
+
+    Searcher(String dataPath, String indexPath) {
+        this.dataPath = dataPath;
+        this.indexPath = indexPath;
+    }
+
+    IndexSearcher createIndexSearcher() throws IOException {
+        Directory indexDirectory = FSDirectory.open(Paths.get(indexPath));
+        IndexReader indexReader = DirectoryReader.open(indexDirectory);
+        IndexSearcher searcher = new IndexSearcher(indexReader);
+        return searcher;
+    }
+
+    TopDocs searchFiles(String queryString, int resultNumber)
+            throws IOException, org.apache.lucene.queryparser.classic.ParseException {
+        IndexSearcher searcher = createIndexSearcher();
+        Query query = new QueryParser("abstract", new WhitespaceAnalyzer()).parse(queryString);
+        TopDocs topDocs = searcher.search(query, resultNumber);
+        return topDocs;
+    }
+
+    private static void usage() {
+        System.out.println("Usage: Searcher <directory>");
+        System.exit(1);
+    }
+
+    public static void main(String[] args) throws IOException, ParseException {
+        if (args.length != 1) {
+            usage();
+        }
+        String dataDirectory = args[0];
+        String indexDirectory = ".index";
+        Indexer indexer = new Indexer(dataDirectory, indexDirectory);
+        indexer.populateIndex();
+        Searcher searcher = new Searcher(dataDirectory, indexDirectory);
+    }
+}