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Convert Byte Array to String

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csongyu/byte-to-string

Text Data

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public class CharacterByteToStringServiceImpl implements ByteToStringService {
    @Override
    public String encode(final byte[] bytes, final Charset charset) {
        return new String(bytes, charset);
    }

    @Override
    public byte[] decode(final String str, final Charset charset) {
        return str.getBytes(charset);
    }
}

Binary Data

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public class BinaryByteToStringServiceImpl implements ByteToStringService {
    @Override
    public String encode(final byte[] bytes, final Encoding encoding) {
        return switch (encoding) {
            case HEX -> Hex.encodeHexString(bytes);
            case BASE_64 -> Base64.getEncoder().encodeToString(bytes);
            case ISO_8859_1 -> new String(bytes, StandardCharsets.ISO_8859_1);
        };
    }

    @Override
    public byte[] decode(final String str, final Encoding encoding) throws DecoderException {
        return switch (encoding) {
            case HEX -> Hex.decodeHex(str);
            case BASE_64 -> Base64.getDecoder().decode(str);
            case ISO_8859_1 -> str.getBytes(StandardCharsets.ISO_8859_1);
        };
    }
}

错误场景

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// UTF-8 编码的字节 unique byte sequence 和字符 unique character sequence 不能一一对应
// 使用 Hex、Base64、ISO-8859-1 编码处理 Binary Data 场景
@Test
public void givenBinaryData_whenUseUtf8ConvertBytesToStringThenBackToBytes_thenIncorrect() throws IOException {
    final byte[] source = Files.readAllBytes(Paths.get("src/test/resources/profile.png"));
    // byteToStringService = new CharacterByteToStringServiceImpl();
    final String str = this.byteToStringService.encode(source, StandardCharsets.UTF_8);
    final byte[] target = this.byteToStringService.decode(str, StandardCharsets.UTF_8);
    assertNotEquals(Arrays.toString(source), Arrays.toString(target));
}