--- /dev/null
+package org.apache.lucene.store;
+
+/**
+ * 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.
+ */
+
+import java.io.File;
+
+/**
+ * Base class for file system based locking implementation.
+ */
+
+public abstract class FSLockFactory extends LockFactory {
+
+ /**
+ * Directory for the lock files.
+ */
+ protected File lockDir = null;
+
+ /**
+ * Set the lock directory. This method can be only called
+ * once to initialize the lock directory. It is used by {@link FSDirectory}
+ * to set the lock directory to itself.
+ * Subclasses can also use this method to set the directory
+ * in the constructor.
+ */
+ protected final void setLockDir(File lockDir) {
+ if (this.lockDir != null)
+ throw new IllegalStateException("You can set the lock directory for this factory only once.");
+ this.lockDir = lockDir;
+ }
+
+ /**
+ * Retrieve the lock directory.
+ */
+ public File getLockDir() {
+ return lockDir;
+ }
+
+}