The Java Version Almanac
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Read and Write Binary Files

The Files class offers a couple of convenience methods to read and write binary content from/to files.

Since Java 11

import; import; import; import java.nio.file.Files; import java.nio.file.StandardOpenOption; import java.util.HexFormat; public class ReadWriteBinaryFiles { static final HexFormat HEX = HexFormat.of(); static final byte[] TEST_CONTENT = HEX.parseHex("cafebabe"); public static void main(String... args) throws IOException { var file = Files.createTempFile("ReadWriteBinaryFiles", ".txt"); // Write out a raw byte array to a file Files.write(file, TEST_CONTENT); // Read the entire content as one byte array: var content = Files.readAllBytes(file); System.out.println(HEX.formatHex(content)); // Append binary content with an OutputStream: try (OutputStream out = Files.newOutputStream(file, StandardOpenOption.APPEND)) { out.write(TEST_CONTENT); } // Read binary content from an InputStream: try (InputStream in = Files.newInputStream(file)) { content = in.readAllBytes(); System.out.println(HEX.formatHex(content)); } Files.delete(file); } }

This snippet at GitHub