Java RandomAccessFile Read appendFile(RandomAccessFile main, RandomAccessFile extra)

Description

Append the contents of extra file to main.

License

Apache License

Declaration

public static void appendFile(RandomAccessFile main, RandomAccessFile extra) throws IOException 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright 2010 Dieselpoint, Inc./*from ww w.ja  va2s.  c om*/
 * 
 * Licensed 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.IOException;

import java.io.RandomAccessFile;

public class Main {
    /**
     * Append the contents of extra file to main.
     */
    public static void appendFile(RandomAccessFile main, RandomAccessFile extra) throws IOException {

        // this method uses NIO direct transfer. It delegates the task
        // to the operating system. Only works under 1.4+
        // Unfortunately, can't use this because it crashes with an out of memory error on big files
        //extra.getChannel().transferTo(0, Long.MAX_VALUE, mainFile.getChannel());

        byte[] buf = new byte[1024 * 1024]; // 1 mb
        main.seek(main.length());
        extra.seek(0);

        while (true) {
            int count = extra.read(buf);
            if (count == -1)
                break;
            main.write(buf, 0, count);
        }
    }
}

Related

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3. LoadDspaceMapFile(String filename)
4. LoadFloatFile(String filename)