Java Utililty Methods File Read via ByteBuffer

List of utility methods to do File Read via ByteBuffer

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Description

The list of methods to do File Read via ByteBuffer are organized into topic(s).

Method

intreadInt(InputStream inputStream)
read Int 
byte[] bytesToRead = new byte[4];
int readBytes = inputStream.read(bytesToRead);
if (readBytes == -1) {
    return -1;
ByteBuffer buffer = ByteBuffer.wrap(bytesToRead);
buffer.order(ByteOrder.LITTLE_ENDIAN);
return buffer.getInt();
...
intreadInt(ReadableByteChannel channel)
Read an integer value from a channel. 
ByteBuffer buf = ByteBuffer.allocate(4);
int count = 0;
while (count < 4) {
    int n = 0;
    while (n == 0)
        n = channel.read(buf);
    if (n < 0)
        throw new ClosedChannelException();
...
intreadInt(ReadableByteChannel channel)
read Int 
ByteBuffer buf = ByteBuffer.allocate(4);
if (fillBuffer(channel, buf, true)) {
    buf.rewind();
    return buf.getInt();
return -1;
intreadInt16(DataInput di)
Read a 16-bit big-endian signed integer 
final byte[] buf = { 0x00, 0x00 };
di.readFully(buf, 0, 2);
final int i = ByteBuffer.wrap(buf).getShort();
return i;
int[]readIntArray(DataInput input)
read Int Array 
int length = input.readInt();
byte[] bytes = new byte[length * 4];
input.readFully(bytes);
int[] data = new int[length];
ByteBuffer.wrap(bytes).asIntBuffer().get(data);
return data;
intreadIntLittleEndian(InputStream in)
read Int Little Endian 
int ch1 = in.read();
int ch2 = in.read();
int ch3 = in.read();
int ch4 = in.read();
if ((ch1 | ch2 | ch3 | ch4) < 0) {
    throw new EOFException();
return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0));
...
ByteBufferreadIntoBuffer(RandomAccessFile file, int offset, int size)
Reading bytes from a file into a ByteBuffer 
ByteBuffer buffer = ByteBuffer.allocate(size);
buffer.order(BYTE_ORDER);
file.seek(offset);
file.read(buffer.array());
return buffer;
JSONObjectreadJsonFromFile(String path)
Reads JSON object (in string format) from specified file. 
return new JSONObject(readStringFromFile(path));
StringreadLargeFile(File file)
Read large > 5Mb text files to String. 
FileChannel channel = new FileInputStream(file).getChannel();
ByteBuffer buffer = ByteBuffer.allocate((int) channel.size());
channel.read(buffer);
channel.close();
return new String(buffer.array());
longreadLong(byte[] src, int pointer)
read Long 
return ByteBuffer.wrap(src, pointer, 8).getLong();