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    1   /**
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
   10    *
   11    * Unless required by applicable law or agreed to in writing, software
   12    * distributed under the License is distributed on an "AS IS" BASIS,
   13    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   14    * See the License for the specific language governing permissions and
   15    * limitations under the License.
   16    */
   17   package org.apache.activemq.kaha.impl.async;
   18   
   19   import java.io.File;
   20   import java.io.IOException;
   21   import java.io.RandomAccessFile;
   22   
   23   import org.apache.activemq.util.IOHelper;
   24   
   25   /**
   26    * Allows you to open a data file in read only mode.  Useful when working with 
   27    * archived data files.
   28    */
   29   public class ReadOnlyDataFile extends DataFile {
   30   
   31       ReadOnlyDataFile(File file, int number, int preferedSize) {
   32           super(file, number, preferedSize);
   33       }
   34       
   35       
   36       public RandomAccessFile openRandomAccessFile(boolean appender) throws IOException {
   37           RandomAccessFile rc = new RandomAccessFile(file, "r");
   38           // When we start to write files size them up so that the OS has a chance
   39           // to allocate the file contigously.
   40           if (appender) {
   41               if (length < preferedSize) {
   42                   rc.setLength(preferedSize);
   43               }
   44           }
   45           return rc;
   46       }
   47   
   48       public void closeRandomAccessFile(RandomAccessFile file) throws IOException {
   49           file.close();
   50       }
   51   
   52       public synchronized boolean delete() throws IOException {
   53           throw new RuntimeException("Not valid on a read only file.");
   54       }
   55       
   56       public synchronized void move(File targetDirectory) throws IOException{
   57           throw new RuntimeException("Not valid on a read only file.");
   58       }
   59   
   60   }

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Home » activemq-parent-5.3.1-source-release » org.apache » activemq » kaha » impl » async » [javadoc | source]