OPENNLP-421 - Updates JavaDoc

opennlp-tools/src/jmh/java/opennlp/tools/util/jvm/jmh/ExecutionPlan.java

@@ -53,4 +53,4 @@ private static String generateRandomString(int length) {
 
     return randomString.toString();
   }
-}
+}

opennlp-tools/src/main/java/opennlp/tools/util/jvm/CHMStringDeduplicator.java

@@ -22,10 +22,11 @@
 import java.util.concurrent.ThreadLocalRandom;
 
 import opennlp.tools.commons.Internal;
+import opennlp.tools.commons.ThreadSafe;
 
 /**
- * A {@link StringInterner} (more a deduplication) implementation by Aleksey Shipilëv
- * with relaxed canonical requirements. Default probability is set to <code>0.5</code>.
+ * A {@link StringInterner} implementation by Aleksey Shipilëv with relaxed canonical requirements.
+ * It is a probabilistic deduplication implementation with a default probability of {@code 0.5}.
  * Users may implement a custom class with a different probability value.
  * <p>
  * Origin:
@@ -34,6 +35,7 @@
  * <p>
  */
 @Internal
+@ThreadSafe
 class CHMStringDeduplicator implements StringInterner {
 
   private final int prob;
@@ -43,6 +45,9 @@ public CHMStringDeduplicator() {
     this(0.5);
   }
 
+  /**
+   * @param prob represents the probability, that a given String will be interned
+   */
   public CHMStringDeduplicator(double prob) {
     this.prob = (int) (Integer.MIN_VALUE + prob * (1L << 32));
     this.map = new ConcurrentHashMap<>();

opennlp-tools/src/main/java/opennlp/tools/util/jvm/CHMStringInterner.java

@@ -21,16 +21,18 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 import opennlp.tools.commons.Internal;
+import opennlp.tools.commons.ThreadSafe;
 
 /**
- * A {@link StringInterner}implementation by Aleksey Shipilëv.
+ * A {@link StringInterner} implementation based on {@link ConcurrentHashMap} by Aleksey Shipilëv.
  * <p>
  * Origin:
  * <a href="https://shipilev.net/jvm/anatomy-quarks/10-string-intern/">
  * https://shipilev.net/jvm/anatomy-quarks/10-string-intern/</a>
  * <p>
  */
 @Internal
+@ThreadSafe
 class CHMStringInterner implements StringInterner {
   private final Map<String, String> map;
 

opennlp-tools/src/main/java/opennlp/tools/util/jvm/HMStringInterner.java

@@ -22,7 +22,8 @@
 import opennlp.tools.commons.Internal;
 
 /**
- * A {@link StringInterner} implementation by Aleksey Shipilëv.
+ * A {@link StringInterner} implementation based on {@link HashMap} by Aleksey Shipilëv.
+ * This implementation is <b>not</b> thread-safe.
  * <p>
  * Origin:
  * <a href="https://shipilev.net/jvm/anatomy-quarks/10-string-intern/">

opennlp-tools/src/main/java/opennlp/tools/util/jvm/JvmStringInterner.java

@@ -17,11 +17,13 @@
 package opennlp.tools.util.jvm;
 
 import opennlp.tools.commons.Internal;
+import opennlp.tools.commons.ThreadSafe;
 
 /**
- * A {@link StringInterner} implementation based on String.intern().
+ * A {@link StringInterner} implementation based on {@code String.intern()}.
  */
 @Internal
+@ThreadSafe
 class JvmStringInterner implements StringInterner {
   /**
    * {@inheritDoc}

opennlp-tools/src/main/java/opennlp/tools/util/jvm/NoOpStringInterner.java

@@ -17,11 +17,14 @@
 package opennlp.tools.util.jvm;
 
 import opennlp.tools.commons.Internal;
+import opennlp.tools.commons.ThreadSafe;
 
 /**
  * A no-op {@link StringInterner} implementation, which does not intern.
+ * It just returns the input as is.
  */
 @Internal
+@ThreadSafe
 class NoOpStringInterner implements StringInterner {
 
   /**

opennlp-tools/src/main/java/opennlp/tools/util/jvm/StringInterners.java

@@ -24,11 +24,10 @@
 
 /**
  * Provides string interning utility methods. Interning mechanism can be configured via the
- * system property <code>opennlp.interner.class</code> by specifying an implementation via its
- * full qualified classname. It needs to implement the interface {@link StringInterner}.
+ * system property {@code opennlp.interner.class} by specifying an implementation via its
+ * full qualified classname. It needs to implement {@link StringInterner}.
  * <p>
- * If not specified by the user, the default interner
- * implementation {@link CHMStringInterner} is used.
+ * If not specified by the user, the default interner is {@link CHMStringInterner}.
  */
 public class StringInterners {
 
@@ -41,8 +40,8 @@ public class StringInterners {
         CHMStringInterner.class.getCanonicalName());
 
     try {
-      Class<?> clazz = Class.forName(clazzName);
-      Constructor<?> cons = clazz.getDeclaredConstructor();
+      final Class<?> clazz = Class.forName(clazzName);
+      final Constructor<?> cons = clazz.getDeclaredConstructor();
       INTERNER = (StringInterner) cons.newInstance();
       LOGGER.debug("Using '{}' as String interner implementation.", clazzName);
     } catch (Exception e) {