InputStream to Byte Array, ByteBuffer

Java로 InputStream 에서 Byte Array, ByteBuffer 변환

 

방법1

public void conv1() 
  throws IOException {
    InputStream is = new ByteArrayInputStream(new byte[] { 0, 1, 2, 3, 4, 5, 6 });
    byte[] targetArray = new byte[is.available()];
    is.read(targetArray);
}

 

 

방법2

public void cnv2() 
  throws IOException {
    InputStream is = new ByteArrayInputStream(new byte[] { 0, 1, 2, 3, 4, 5, 6 }); // not really known
    ByteArrayOutputStream buffer = new ByteArrayOutputStream();

    int nRead;
    byte[] data = new byte[4];

    //Starting with Java 9: while ((nRead = is.readNBytes(data, 0, data.length)) != 0) { 
    //read()는 최대로 읽고, readNBytes()는 요청된 만큼만 읽는다.
    while ((nRead = is.read(data, 0, data.length)) != -1) {
        buffer.write(data, 0, nRead);
    }

    buffer.flush();
    byte[] targetArray = buffer.toByteArray();
}

 

방법3

public void
  cnv3()
  throws IOException {
    InputStream is = new ByteArrayInputStream(new byte[] { 0, 1, 2 });

    byte[] data = is.readAllBytes();
}