Example usage for java.lang.ref SoftReference SoftReference

Introduction

In this page you can find the example usage for java.lang.ref SoftReference SoftReference.

Prototype

public SoftReference(T referent, ReferenceQueue<? super T> q) 

Source Link

Document

Creates a new soft reference that refers to the given object and is registered with the given queue.

Usage

From source file:Main.java

public static void main(String[] args) {
    ReferenceQueue referenceQueue = new ReferenceQueue();
    Object object = new Object() {
        public String toString() {
            return "Referenced Object";
        }//from  w  w w.ja v  a2 s . c  o  m
    };
    Object data = new Object() {
        public String toString() {
            return "Data";
        }
    };

    HashMap map = new HashMap();
    Reference reference = new SoftReference(object, referenceQueue);

    map.put(reference, data);

    System.out.println(reference.get());
    System.out.println(map.get(reference));
    System.out.println(reference.isEnqueued());

    System.gc();
    System.out.println(reference.get());
    System.out.println(map.get(reference));
    System.out.println(reference.isEnqueued());

    object = null;
    data = null;

    System.gc();
    System.out.println(reference.get());
    System.out.println(map.get(reference));
    System.out.println(reference.isEnqueued());
}

---

From source file:Main.java

public static void main(String[] args) {
    ReferenceQueue referenceQueue = new ReferenceQueue();
    Object object = new Object() {
        public String toString() {
            return "Referenced Object";
        }/* w  ww .j  a v  a  2s. c o  m*/
    };

    Object data = new Object() {
        public String toString() {
            return "Data";
        }
    };

    HashMap map = new HashMap();
    Reference reference = new SoftReference(object, referenceQueue);

    map.put(reference, data);

    System.out.println(reference.get());
    System.out.println(map.get(reference));
    System.out.println(reference.isEnqueued());

    System.gc();
    System.out.println(reference.get());
    System.out.println(map.get(reference));
    System.out.println(reference.isEnqueued());

    object = null;
    data = null;

    System.gc();
    System.out.println(reference.get());
    System.out.println(map.get(reference));
    System.out.println(reference.isEnqueued());
}

---

From source file:SoftValueMap.java

protected Reference newReference(Object value) {
    return new SoftReference(value, refQueue);
}

---

From source file:org.entrystore.repository.impl.SoftCache.java

public void put(Entry entry) {
    synchronized (cache) {
        URI entryURI = entry.getEntryURI();
        cache.put(entryURI, new SoftReference(entry, clearedRefs));
        push(entry.getLocalMetadataURI(), entryURI);
        push(entry.getExternalMetadataURI(), entryURI);
        push(entry.getResourceURI(), entryURI);
        push(entry.getRelationURI(), entryURI);
    }/*from w  w w .jav  a 2  s.c  o  m*/
}

---

From source file:org.srs.vfs.VfsSoftCache.java

protected Reference<V> createReference(final V file, final ReferenceQueue<V> refqueue) {
    return new SoftReference<>(file, refqueue);
}

---

From source file:com.slytechs.utils.memory.Malloc.java

public void recordAllocatedBlock(Entry a, Buffer block) {

    /*//from  ww w .  j  a  v a 2  s.  c om
     * The software reference linked to reference queue "freedQueue". When
     * the referenced buffer is released, the reference is recorded in
     * the freeQueue so we can check and get a list of references (not the
     * buffer's anymore) that have been freed up by garbage collector.
     * 
     * Since the reference released is also the key in our allocated Map,
     * which stores the Entry value with the details of the allocated block 
     * (But no references to the buffer), we can later expand our free
     * blocks to reclaim the memory as its released.
     */
    SoftReference<? extends Buffer> pr = new SoftReference<Buffer>(block, freedQueue);

    allocated.put(pr, a);
}

---

From source file:org.orbeon.oxf.util.SoftReferenceObjectPool.java

/**
 * <p>Returns an instance to the pool after successful validation and passivation. The returning instance
 * is destroyed if any of the following are true:<ul>
 *   <li>the pool is closed</li>
 *   <li>{@link PoolableObjectFactory#validateObject(Object) validation} fails</li>
 *   <li>{@link PoolableObjectFactory#passivateObject(Object) passivation} throws an exception</li>
 * </ul>/* w ww  .  j  ava2 s  .  c om*/
 *</p>
 *
 * <p>Exceptions passivating or destroying instances are silently swallowed.  Exceptions validating
 * instances are propagated to the client.</p>
 *
 * @param obj instance to return to the pool
 */
@Override
public synchronized void returnObject(T obj) throws Exception {
    boolean success = !isClosed();
    if (_factory != null) {
        if (!_factory.validateObject(obj)) {
            success = false;
        } else {
            try {
                _factory.passivateObject(obj);
            } catch (Exception e) {
                success = false;
            }
        }
    }

    boolean shouldDestroy = !success;
    _numActive--;
    if (success) {
        _pool.add(new SoftReference<T>(obj, refQueue));
    }
    //        notifyAll(); // _numActive has changed

    if (shouldDestroy && _factory != null) {
        try {
            _factory.destroyObject(obj);
        } catch (Exception e) {
            // ignored
        }
    }
}

---

From source file:com.datos.vfs.cache.SoftRefFilesCache.java

protected Reference<FileObject> createReference(final FileObject file,
        final ReferenceQueue<FileObject> refqueue) {
    return new SoftReference<>(file, refqueue);
}

---

From source file:org.orbeon.oxf.util.SoftReferenceObjectPool.java

/**
 * <p>Create an object, and place it into the pool.
 * addObject() is useful for "pre-loading" a pool with idle objects.</p>
 *
 * <p>Before being added to the pool, the newly created instance is
 * {@link PoolableObjectFactory#validateObject(Object) validated} and
 * {@link PoolableObjectFactory#passivateObject(Object) passivated}.  If validation
 * fails, the new instance is {@link PoolableObjectFactory#destroyObject(Object) destroyed}.
 * Exceptions generated by the factory <code>makeObject</code> or <code>passivate</code> are
 * propagated to the caller. Exceptions destroying instances are silently swallowed.</p>
 *
 * @throws IllegalStateException if invoked on a {@link #close() closed} pool
 * @throws Exception when the {@link #getFactory() factory} has a problem creating or passivating an object.
 *///from w ww  .  j av  a  2 s  . co m
@Override
public synchronized void addObject() throws Exception {
    assertOpen();
    if (_factory == null) {
        throw new IllegalStateException("Cannot add objects without a factory.");
    }
    T obj = _factory.makeObject();

    boolean success = true;
    if (!_factory.validateObject(obj)) {
        success = false;
    } else {
        _factory.passivateObject(obj);
    }

    boolean shouldDestroy = !success;
    if (success) {
        _pool.add(new SoftReference<T>(obj, refQueue));
        //            notifyAll(); // _numActive has changed
    }

    if (shouldDestroy) {
        try {
            _factory.destroyObject(obj);
        } catch (Exception e) {
            // ignored
        }
    }
}

---