Update Gradle Wrapper 6.3 und Asciidoctor 3.3.0 - OP#193

src/main/java/de/thpeetz/tools/ObjectPool.java

@@ -0,0 +1,97 @@
+package de.thpeetz.tools;
+
+import java.util.Vector;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import de.thpeetz.network.osi.transport.RFC1006Service;
+
+/**
+ * @author Thomas Peetz
+ *
+ * @param <T> type of objects in ObjectPool
+ */
+public class ObjectPool<T> {
+    /**
+     * Vector of unused object references.
+     */
+    private final Vector<T> freeStack;
+
+    Logger logger;
+
+    /**
+     * Construct an object pool for a specific class type.
+     *
+     * @param clazz
+     *            Class type of object pool
+     * @throws IllegalAccessException
+     * @throws InstantiationException
+     */
+    public ObjectPool(final Class<T> clazz) {
+        this.freeStack = new Vector<T>();
+        init(clazz);
+        logger = Logger.getLogger(ObjectPool.class.getName());
+
+    }
+
+    /**************************************************************************
+     * Construct an object pool for a specific class type. Initialize object
+     * pool with given number of objects.
+     *
+     * @param clazz
+     *            Class type of object pool
+     * @param size
+     *            Initial number of objects in pool
+     * @throws IllegalAccessException
+     * @throws InstantiationException
+     ***************************************************************************/
+    public ObjectPool(final Class<T> clazz, final int size) {
+        this.freeStack = new Vector<T>(size);
+        init(clazz);
+    }
+
+    /**************************************************************************
+     * Construct an object pool for a specific class type. Initialize object
+     * pool with number of objects equal to stack size.
+     *
+     * @param clazz
+     *            Class type of object pool
+     ***************************************************************************/
+    private void init(final Class<T> clazz) {
+        for (int i = 0; i < freeStack.capacity(); i++) {
+            try {
+                freeStack.add(i, clazz.newInstance());
+            } catch (InstantiationException e) {
+                logger.log(Level.FINE, e.getMessage());
+            } catch (IllegalAccessException e) {
+                logger.log(Level.FINE, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Get instance from object pool.
+     *
+     * @return Reference of object
+     */
+    public final synchronized T getInstance() {
+        // Check if the pool is empty.
+        if (this.freeStack.isEmpty()) {
+            return null;
+        }
+        // Remove object from end of free pool.
+        T result = this.freeStack.lastElement();
+        this.freeStack.setSize(this.freeStack.size() - 1);
+        return result;
+    }
+
+    /**************************************************************************
+     * Return object to object pool.
+     *
+     * @param obj
+     *            Reference of unsed object
+     ***************************************************************************/
+    public final synchronized void freeInstance(final T obj) {
+        this.freeStack.addElement(obj);
+    }
+}