Java File Read via ByteBuffer readInt(ReadableByteChannel channel)

Description

read Int

License

Apache License

Declaration

public static int readInt(ReadableByteChannel channel) throws IOException 

Method Source Code

//package com.java2s;
/*//from  w  w  w  .  ja v a 2 s.  c  om
 * 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.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;

public class Main {
    public static int readInt(ReadableByteChannel channel) throws IOException {
        ByteBuffer buf = ByteBuffer.allocate(4);
        if (fillBuffer(channel, buf, true)) {
            buf.rewind();
            return buf.getInt();
        }
        return -1;
    }

    public static boolean fillBuffer(ReadableByteChannel channel, ByteBuffer buf, boolean clear)
            throws IOException {
        if (clear) {
            buf.clear();
        }

        while (true) {
            int cnt = channel.read(buf);
            if (cnt < 0) {
                return false;
            }
            if (buf.position() == buf.capacity()) {
                break;// fill to capacity
            }
        }
        return true;
    }
}

Related

1. readInt(ByteArrayInputStream bin)
2. readInt(InputStream in, ByteOrder order)
3. readInt(InputStream input)
4. readInt(InputStream inputStream)
5. readInt(ReadableByteChannel channel)
6. readInt16(DataInput di)
7. readIntArray(DataInput input)
8. readIntLittleEndian(InputStream in)
9. readIntoBuffer(RandomAccessFile file, int offset, int size)