committing StopWords class

Author: gdesiato

logicaldoc-core/src/main/java/com/logicaldoc/core/i18n/StopWords.java

@@ -0,0 +1,61 @@
+package com.logicaldoc.core.i18n;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.logicaldoc.util.LocaleUtil;
+import com.logicaldoc.util.io.ResourceUtil;
+
+/**
+ * Class for retrieving the words from the stopwords files
+ * 
+ * @author Giuseppe Desiato - LogicalDOC
+ * @since 9.1.1
+ */
+public abstract class StopWords {
+
+	protected static Logger log = LoggerFactory.getLogger(StopWords.class);
+
+	private static final Map<Locale, Set<String>> cacheMap = new HashMap<>();
+	
+	private StopWords() {
+		// do nothing
+	}
+
+	public static Set<String> getStopWords(String locale) {
+		return cacheMap.computeIfAbsent(LocaleUtil.toLocale(locale), StopWords::loadStopWords);
+	}
+
+	public static Set<String> getStopWords(Locale locale) {
+		return cacheMap.computeIfAbsent(locale, StopWords::loadStopWords);
+	}
+
+	private static Set<String> loadStopWords(Locale locale) {
+		String resource = "/stopwords/stopwords_" + locale + ".txt";
+		if (!ResourceUtil.existsResource(resource))
+			resource = "/stopwords/stopwords_" + locale.getLanguage() + ".txt";
+		if (!ResourceUtil.existsResource(resource))
+			resource = "/stopwords/stopwords_en.txt";
+		log.debug("Loading stopwords from: {}", resource);
+		try (BufferedReader reader = new BufferedReader(new StringReader(ResourceUtil.readAsString(resource)));) {
+			String line = "";
+			Set<String> words = new HashSet<>();
+			while ((line = reader.readLine()) != null)
+				words.add(line.trim());
+			return words;
+		} catch (IOException e) {
+			log.warn(e.getMessage(), e);
+			return Collections.emptySet();
+		}
+	}
+}