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I wrote a program that gets all bytes from an InputStream in Java 9 with
InputStream.readAllBytes()
Now, I want to export it to Java 1.8 and below. Is there an equivalent function? Couldn't find one.
933
To convert an InputStream Object int to a String using this method. Instantiate the Scanner class by passing your InputStream object as parameter. Read each line from this Scanner using the nextLine() method and append it to a StringBuffer object. Finally convert the StringBuffer to String using the toString() method.
Example 1: Java Program to Convert InputStream to Byte Arraybyte[] array = stream. readAllBytes(); Here, the readAllBytes() method returns all the data from the stream and stores in the byte array. Note: We have used the Arrays.
InputStream is; byte[] bytes = IOUtils. toByteArray(is); Internally this creates a ByteArrayOutputStream and copies the bytes to the output, then calls toByteArray() . It handles large files by copying the bytes in blocks of 4KiB.
Since Java 9, we can use the readAllBytes() method from InputStream class to read all bytes into a byte array. This method reads all bytes from an InputStream object at once and blocks until all remaining bytes have read and end of a stream is detected, or an exception is thrown.
When to use the readAllBytes () method of InputStream in Java 9? Since Java 9, we can use the readAllBytes () method from InputStream class to read all bytes into a byte array. This method reads all bytes from an InputStream object at once and blocks until all remaining bytes have read and end of a stream is detected, or an exception is thrown.
For this, we read each byte from a InputStream class and write it to a ByteArrayOutputStreamclass. Later we call toByteArray () that returns the output stream in the form of a byte array. ByteStreams utility class from the Guava Library has a direct method to convert input stream to a byte array.
To overcome the drawback of having to know the input size beforehand, we have another method called readAllBytes () since Java 9. This method can read all bytes available in the input stream. The method is way more faster and efficient in converting input stream to a byte array.
Java Object Oriented Programming Programming Since Java 9, we can use the readAllBytes () method from InputStream class to read all bytes into a byte array. This method reads all bytes from an InputStream object at once and blocks until all remaining bytes have read and end of a stream is detected, or an exception is thrown.
You can use the good old read method like this:
public static byte[] readAllBytes(InputStream inputStream) throws IOException {
final int bufLen = 1024;
byte[] buf = new byte[bufLen];
int readLen;
IOException exception = null;
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);
}
}
}
InputStream.readAllBytes() is available since java 9 not java 7...
Other than that you can (no thirdparties):
byte[] bytes = new byte[(int) file.length()];
DataInputStream dataInputStream = new DataInputStream(new FileInputStream(file));
dataInputStream .readFully(bytes);
Or if you don't mind using thirdparties (Commons IO):
byte[] bytes = IOUtils.toByteArray(is);
Guava also helps:
byte[] bytes = ByteStreams.toByteArray(inputStream);
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