Android File to Byte Array Read readBytes(@NotNull File file)

Description

Reads the contents of a File into a byte[].

License

Apache License

Declaration

@NotNull
public static byte[] readBytes(@NotNull File file) throws IOException 

Method Source Code

/*/*from   ww  w . j a va2 s .  c o m*/
 * Copyright 2002-2013 Drew Noakes
 *
 *    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.
 *
 * More information about this project is available at:
 *
 *    http://drewnoakes.com/code/exif/
 *    http://code.google.com/p/metadata-extractor/
 */

import com.drew.lang.annotations.NotNull;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class Main{
    /**
     * Reads the contents of a {@link File} into a <code>byte[]</code>. This relies upon <code>File.length()</code>
     * returning the correct value, which may not be the case when using a network file system. However this method is
     * intended for unit test support, in which case the files should be on the local volume.
     */
    @NotNull
    public static byte[] readBytes(@NotNull File file) throws IOException {
        int length = (int) file.length();
        // should only be zero if loading from a network or similar
        assert (length != 0);
        byte[] bytes = new byte[length];

        int totalBytesRead = 0;
        FileInputStream inputStream = null;
        try {
            inputStream = new FileInputStream(file);
            while (totalBytesRead != length) {
                int bytesRead = inputStream.read(bytes, totalBytesRead,
                        length - totalBytesRead);
                if (bytesRead == -1) {
                    break;
                }
                totalBytesRead += bytesRead;
            }
        } finally {
            if (inputStream != null) {
                inputStream.close();
            }
        }

        return bytes;
    }
    /**
     * Reads the contents of a {@link File} into a <code>byte[]</code>. This relies upon <code>File.length()</code>
     * returning the correct value, which may not be the case when using a network file system. However this method is
     * intended for unit test support, in which case the files should be on the local volume.
     */
    @NotNull
    public static byte[] readBytes(@NotNull String filePath)
            throws IOException {
        return readBytes(new File(filePath));
    }
}

Related

1. getBytes(File file)
2. getBytesFromFile(File file)
3. getBytesFromFile(File file, long startPostion, long numberOfBytesToRead)
4. getFileAsByteArray(File file)
5. getFileAsByteArrayOutputStream( File file)
6. readBytes(@NotNull String filePath)
7. readFileBytes(File fx)
8. readFileToByteArray(File file)
9. readFileToByteArray(String filePath)