pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.4.0 / lucene / src / java / org / apache / lucene / util / SetOnce.java

diff --git a/lucene-java-3.4.0/lucene/src/java/org/apache/lucene/util/SetOnce.java b/lucene-java-3.4.0/lucene/src/java/org/apache/lucene/util/SetOnce.java
deleted file mode 100644 (file)
index f280ee7..0000000
--- a/lucene-java-3.4.0/lucene/src/java/org/apache/lucene/util/SetOnce.java
+++ /dev/null
@@ -1,77 +0,0 @@
-package org.apache.lucene.util;
-
-import java.util.concurrent.atomic.AtomicBoolean;
-
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/**
- * A convenient class which offers a semi-immutable object wrapper
- * implementation which allows one to set the value of an object exactly once,
- * and retrieve it many times. If {@link #set(Object)} is called more than once,
- * {@link AlreadySetException} is thrown and the operation
- * will fail.
- *
- * @lucene.experimental
- */
-public final class SetOnce<T> {
-
-  /** Thrown when {@link SetOnce#set(Object)} is called more than once. */
-  public static final class AlreadySetException extends RuntimeException {
-    public AlreadySetException() {
-      super("The object cannot be set twice!");
-    }
-  }
-  
-  private volatile T obj = null;
-  private final AtomicBoolean set;
-  
-  /**
-   * A default constructor which does not set the internal object, and allows
-   * setting it by calling {@link #set(Object)}.
-   */
-  public SetOnce() {
-    set = new AtomicBoolean(false);
-  }
-
-  /**
-   * Creates a new instance with the internal object set to the given object.
-   * Note that any calls to {@link #set(Object)} afterwards will result in
-   * {@link AlreadySetException}
-   *
-   * @throws AlreadySetException if called more than once
-   * @see #set(Object)
-   */
-  public SetOnce(T obj) {
-    this.obj = obj;
-    set = new AtomicBoolean(true);
-  }
-  
-  /** Sets the given object. If the object has already been set, an exception is thrown. */
-  public final void set(T obj) {
-    if (set.compareAndSet(false, true)) {
-      this.obj = obj;
-    } else {
-      throw new AlreadySetException();
-    }
-  }
-  
-  /** Returns the object set by {@link #set(Object)}. */
-  public final T get() {
-    return obj;
-  }
-}