在Java中将InputStream转换为字节数组
如何将整个在Java中将InputStream转换为字节数组,java,bytearray,inputstream,Java,Bytearray,Inputstream,如何将整个InputStream读取到字节数组中？您需要从InputStream中读取每个字节，然后将其写入ByteArrayOutputStream 然后，您可以通过调用toByteArray（）来检索底层字节数组： 您可以使用Apache来处理此任务和类似任务 IOUtils类型有一个静态方法来读取InputStream并返回字节[] InputStream is; byte[] bytes = IOUtils.toByteArray(is); 这会在内部创建一个ByteArrayOutp
InputStreamInputStreamByteArrayOutputStreamtoByteArray（）IOUtilsInputStream字节[]InputStream is;
byte[] bytes = IOUtils.toByteArray(is);
这会在内部创建一个
ByteArrayOutputStreamtoByteArray（）字节[]字节[]字节[]字节[]javax.ImageIOBufferedImage image = ImageIO.read(new File("image.jpg"));
buffereImage字节[]buffereImagegetRaster（）grastergetPixel（）getPixels（）javax.imageio.imageiojava.awt.image.buffereImagejava.awt.image.Raster另请参阅以下教程：@Adamski:您可以完全避免缓冲区 从复制的代码（是的，非常冗长，但需要的内存大小只有其他解决方案的一半。）
//以字节数组的形式返回文件的内容。
公共静态字节[]getBytesFromFile（文件文件）引发IOException{
InputStream is=新文件InputStream（文件）；
//获取文件的大小
long length=file.length（）；
//不能使用长类型创建数组。
//它必须是int类型。
//在转换为int类型之前，请检查
//以确保文件不大于Integer.MAX_值。
if（长度>整数最大值）{
//文件太大
}
//创建字节数组以保存数据
字节[]字节=新字节[（int）长度]；
//读入字节
整数偏移=0；
int numRead=0；
while（偏移量=0）{
偏移量+=numRead；
}
//确保已读入所有字节
if（偏移量<字节长度）{
抛出新IOException（“无法完全读取文件”+file.getName（））；
}
//关闭输入流并返回字节
is.close（）；
返回字节；
}
DataInputStream方法（至少从Java 1.4开始存在）：
这个方法还有其他一些风格，但我一直在这个用例中使用它。我试图编辑@numan的答案，并修复了写入垃圾数据的问题，但编辑被拒绝。虽然这段代码并不精彩，但我看不到其他更好的答案。以下是对我最有意义的：
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buffer = new byte[1024]; // you can configure the buffer size
int length;
while ((length = in.read(buffer)) != -1) out.write(buffer, 0, length); //copy streams
in.close(); // call this in a finally block
byte[] result = out.toByteArray();
顺便说一句，ByteArrayOutputStream无需关闭。try/finally为了可读性省略了结构如果您碰巧使用了，它将非常简单：
public static byte[] getBytesFromInputStream(InputStream is) throws IOException {
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] buffer = new byte[0xFFFF];
for (int len = is.read(buffer); len != -1; len = is.read(buffer)) {
os.write(buffer, 0, len);
}
return os.toByteArray();
}
byte[] bytes = ByteStreams.toByteArray(inputStream);
如果不想使用Apache commons io库，则此代码段取自sun.misc.IOUtils类。它的速度几乎是使用ByteBuffers的常见实现的两倍：
public static byte[] readFully(InputStream is, int length, boolean readAll)
throws IOException {
byte[] output = {};
if (length == -1) length = Integer.MAX_VALUE;
int pos = 0;
while (pos < length) {
int bytesToRead;
if (pos >= output.length) { // Only expand when there's no room
bytesToRead = Math.min(length - pos, output.length + 1024);
if (output.length < pos + bytesToRead) {
output = Arrays.copyOf(output, pos + bytesToRead);
}
} else {
bytesToRead = output.length - pos;
}
int cc = is.read(output, pos, bytesToRead);
if (cc < 0) {
if (readAll && length != Integer.MAX_VALUE) {
throw new EOFException("Detect premature EOF");
} else {
if (output.length != pos) {
output = Arrays.copyOf(output, pos);
}
break;
}
}
pos += cc;
}
return output;
}
publicstaticbyte[]已准备就绪（InputStream为，int-length，boolean readAll）
抛出IOException{
字节[]输出={}；
如果（长度==-1）长度=Integer.MAX_值；
int pos=0；
while（pos=output.length）{//仅在没有空间时展开
bytesToRead=Math.min（长度-pos，output.length+1024）；
if（output.length
这是一个优化版本，它尽量避免复制数据字节：
private static byte[] loadStream (InputStream stream) throws IOException {
int available = stream.available();
int expectedSize = available > 0 ? available : -1;
return loadStream(stream, expectedSize);
}
private static byte[] loadStream (InputStream stream, int expectedSize) throws IOException {
int basicBufferSize = 0x4000;
int initialBufferSize = (expectedSize >= 0) ? expectedSize : basicBufferSize;
byte[] buf = new byte[initialBufferSize];
int pos = 0;
while (true) {
if (pos == buf.length) {
int readAhead = -1;
if (pos == expectedSize) {
readAhead = stream.read(); // test whether EOF is at expectedSize
if (readAhead == -1) {
return buf;
}
}
int newBufferSize = Math.max(2 * buf.length, basicBufferSize);
buf = Arrays.copyOf(buf, newBufferSize);
if (readAhead != -1) {
buf[pos++] = (byte)readAhead;
}
}
int len = stream.read(buf, pos, buf.length - pos);
if (len < 0) {
return Arrays.copyOf(buf, pos);
}
pos += len;
}
}
私有静态字节[]加载流（InputStream流）引发IOException{
int available=stream.available（）；
int expectedSize=可用>0？可用：-1；
返回加载流（流，预期大小）；
}
私有静态字节[]loadStream（InputStream stream，int expectedSize）引发IOException{
int basicBufferSize=0x4000；
int initialBufferSize=（expectedSize>=0）？expectedSize:basicBufferSize；
字节[]buf=新字节[initialBufferSize]；
int pos=0；
while（true）{
如果（位置==基本长度）{
int readAhead=-1；
如果（位置==预期大小）{
readAhead=stream.read（）；//测试EOF是否为expectedSize
public static byte[] getBytesFromInputStream(InputStream is) throws IOException {
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] buffer = new byte[0xFFFF];
for (int len = is.read(buffer); len != -1; len = is.read(buffer)) {
os.write(buffer, 0, len);
}
return os.toByteArray();
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
while (true) {
int r = in.read(buffer);
if (r == -1) break;
out.write(buffer, 0, r);
}
byte[] ret = out.toByteArray();
byte[] bytes = ByteStreams.toByteArray(inputStream);
public static byte[] readFully(InputStream is, int length, boolean readAll)
throws IOException {
byte[] output = {};
if (length == -1) length = Integer.MAX_VALUE;
int pos = 0;
while (pos < length) {
int bytesToRead;
if (pos >= output.length) { // Only expand when there's no room
bytesToRead = Math.min(length - pos, output.length + 1024);
if (output.length < pos + bytesToRead) {
output = Arrays.copyOf(output, pos + bytesToRead);
}
} else {
bytesToRead = output.length - pos;
}
int cc = is.read(output, pos, bytesToRead);
if (cc < 0) {
if (readAll && length != Integer.MAX_VALUE) {
throw new EOFException("Detect premature EOF");
} else {
if (output.length != pos) {
output = Arrays.copyOf(output, pos);
}
break;
}
}
pos += cc;
}
return output;
}
private static byte[] loadStream (InputStream stream) throws IOException {
int available = stream.available();
int expectedSize = available > 0 ? available : -1;
return loadStream(stream, expectedSize);
}
private static byte[] loadStream (InputStream stream, int expectedSize) throws IOException {
int basicBufferSize = 0x4000;
int initialBufferSize = (expectedSize >= 0) ? expectedSize : basicBufferSize;
byte[] buf = new byte[initialBufferSize];
int pos = 0;
while (true) {
if (pos == buf.length) {
int readAhead = -1;
if (pos == expectedSize) {
readAhead = stream.read(); // test whether EOF is at expectedSize
if (readAhead == -1) {
return buf;
}
}
int newBufferSize = Math.max(2 * buf.length, basicBufferSize);
buf = Arrays.copyOf(buf, newBufferSize);
if (readAhead != -1) {
buf[pos++] = (byte)readAhead;
}
}
int len = stream.read(buf, pos, buf.length - pos);
if (len < 0) {
return Arrays.copyOf(buf, pos);
}
pos += len;
}
}
/**
* method converts {@link InputStream} Object into byte[] array.
*
* @param stream the {@link InputStream} Object.
* @return the byte[] array representation of received {@link InputStream} Object.
* @throws IOException if an error occurs.
*/
public static byte[] streamToByteArray(InputStream stream) throws IOException {
byte[] buffer = new byte[1024];
ByteArrayOutputStream os = new ByteArrayOutputStream();
int line = 0;
// read bytes from stream, and store them in buffer
while ((line = stream.read(buffer)) != -1) {
// Writes bytes from byte array (buffer) into output stream.
os.write(buffer, 0, line);
}
stream.close();
os.flush();
os.close();
return os.toByteArray();
}
/**
* Begin setup TCP connection to PC app
* to open integrate connection between mobile app and pc app (or mobile app)
*/
mSocket = new Socket(IP, port);
// mSocket.setSoTimeout(30000);
DataOutputStream mDos = new DataOutputStream(mSocket.getOutputStream());
String str = "MobileRequest#" + params[0] + "#<EOF>";
mDos.write(str.getBytes());
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
/* Since data are accepted as byte, all of them will be collected in the
following byte array which initialised with accepted data length. */
DataInputStream mDis = new DataInputStream(mSocket.getInputStream());
byte[] data = new byte[mDis.available()];
// Collecting data into byte array
for (int i = 0; i < data.length; i++)
data[i] = mDis.readByte();
// Converting collected data in byte array into String.
String RESPONSE = new String(data);
// Read the file contents into a byte[] array
byte[] buf = new byte[inputStreamLength];
int bytesRead = Math.max(0, inputStream.read(buf));
// If needed: for safety, truncate the array if the file may somehow get
// truncated during the read operation
byte[] contents = bytesRead == inputStreamLength ? buf
: Arrays.copyOf(buf, bytesRead);
public static byte[] toByteArray(InputStream is) throws IOException {
ByteArrayOutputStream output = new ByteArrayOutputStream();
try {
byte[] b = new byte[4096];
int n = 0;
while ((n = is.read(b)) != -1) {
output.write(b, 0, n);
}
return output.toByteArray();
} finally {
output.close();
}
}
@SuppressWarnings("empty-statement")
public static byte[] inputStreamToByte(InputStream is) throws IOException {
if (is == null) {
return null;
}
// Define a size if you have an idea of it.
ByteArrayOutputStream r = new ByteArrayOutputStream(2048);
byte[] read = new byte[512]; // Your buffer size.
for (int i; -1 != (i = is.read(read)); r.write(read, 0, i));
is.close();
return r.toByteArray();
}
import sun.misc.IOUtils;
...
InputStream in = ...;
byte[] buf = IOUtils.readFully(in, -1, false);
InputStream is;
…
byte[] array = is.readAllBytes();
public int readFully(InputStream in, byte[] data) throws IOException {
int offset = 0;
int bytesRead;
boolean read = false;
while ((bytesRead = in.read(data, offset, data.length - offset)) != -1) {
read = true;
offset += bytesRead;
if (offset >= data.length) {
break;
}
}
return (read) ? offset : -1;
}
InputStream in = ...;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
in.transferTo( bos );
byte[] bytes = bos.toByteArray();
byte[] data = new byte[(int) file.length()];
DataInputStream dis = new DataInputStream(new FileInputStream(file));
dis.readFully(data);
dis.close();
InputStream is = new FileInputStream(file);
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int nRead;
byte[] data = new byte[(int) file.length()];
while ((nRead = is.read(data, 0, data.length)) != -1) {
buffer.write(data, 0, nRead);
}
RandomAccessFile raf = new RandomAccessFile(file, "r");
byte[] data = new byte[(int) raf.length()];
raf.readFully(data);
private static byte[] readFully(InputStream input) throws IOException {
try (BufferedReader buffer = new BufferedReader(new InputStreamReader(input))) {
return buffer.lines().collect(Collectors.joining("\n")).getBytes(<charset_can_be_specified>);
}
}
byte[] array = new BytesOf(stream).bytes();
import org.apache.commons.io.IOUtils;
is = s3object.getObjectContent();
content =IOUtils.toByteArray(is);
import com.amazonaws.util.IOUtils;
is = s3object.getObjectContent();
content =IOUtils.toByteArray(is);
final byte[] bytes;
try (inputStream) {
bytes = inputStream.readAllBytes();
}
public static byte[] readAllBytes(InputStream inputStream) throws IOException {
final int bufLen = 4 * 0x400; // 4KB
byte[] buf = new byte[bufLen];
int readLen;
IOException exception = null;
try {
try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
while ((readLen = inputStream.read(buf, 0, bufLen)) != -1)
outputStream.write(buf, 0, readLen);
return outputStream.toByteArray();
}
} catch (IOException e) {
exception = e;
throw e;
} finally {
if (exception == null) inputStream.close();
else try {
inputStream.close();
} catch (IOException e) {
exception.addSuppressed(e);
}
}
}
@Throws(IOException::class)
fun InputStream.readAllBytes(): ByteArray {
val bufLen = 4 * 0x400 // 4KB
val buf = ByteArray(bufLen)
var readLen: Int = 0
ByteArrayOutputStream().use { o ->
this.use { i ->
while (i.read(buf, 0, bufLen).also { readLen = it } != -1)
o.write(buf, 0, readLen)
}
return o.toByteArray()
}
}
def readAllBytes(inputStream: InputStream): Array[Byte] =
Stream.continually(inputStream.read).takeWhile(_ != -1).map(_.toByte).toArray
fun InputStream.readBytesWithSize(size: Long): ByteArray? {
return when {
size < 0L -> this.readBytes()
size == 0L -> ByteArray(0)
size > Int.MAX_VALUE -> null
else -> {
val sizeInt = size.toInt()
val result = ByteArray(sizeInt)
readBytesIntoByteArray(result, sizeInt)
result
}
}
}
fun InputStream.readBytesIntoByteArray(byteArray: ByteArray,bytesToRead:Int=byteArray.size) {
var offset = 0
while (true) {
val read = this.read(byteArray, offset, bytesToRead - offset)
if (read == -1)
break
offset += read
if (offset >= bytesToRead)
break
}
}
fun getStreamLengthFromUri(context: Context, uri: Uri): Long {
context.contentResolver.query(uri, arrayOf(MediaStore.MediaColumns.SIZE), null, null, null)?.use {
if (!it.moveToNext())
return@use
val fileSize = it.getLong(it.getColumnIndex(MediaStore.MediaColumns.SIZE))
if (fileSize > 0)
return fileSize
}
//if you wish, you can also get the file-path from the uri here, and then try to get its size, using this: https://stackoverflow.com/a/61835665/878126
FileUtilEx.getFilePathFromUri(context, uri, false)?.use {
val file = it.file
val fileSize = file.length()
if (fileSize > 0)
return fileSize
}
context.contentResolver.openInputStream(uri)?.use { inputStream ->
if (inputStream is FileInputStream)
return inputStream.channel.size()
else {
var bytesCount = 0L
while (true) {
val available = inputStream.available()
if (available == 0)
break
val skip = inputStream.skip(available.toLong())
if (skip < 0)
break
bytesCount += skip
}
if (bytesCount > 0L)
return bytesCount
}
}
return -1L
}
final InputStream input = ...;
final Bytes bytes = new BytesOf(input);
final byte[] array = bytes.asBytes();
Assert.assertArrayEquals(
array,
new byte[]{65, 66, 67}
);
final Bytes decoded = new Base64Bytes(
new BytesBase64(
new BytesOf(
new InputStreamOf("XYZ")
)
)
);
Assert.assertEquals(new TextOf(decoded).asString(), "XYZ");