diff --git a/core-java-modules/core-java-arrays-convert/pom.xml b/core-java-modules/core-java-arrays-convert/pom.xml index 4cb2946ac9..6e001e12b0 100644 --- a/core-java-modules/core-java-arrays-convert/pom.xml +++ b/core-java-modules/core-java-arrays-convert/pom.xml @@ -19,6 +19,11 @@ guava ${guava.version} + + org.apache.commons + commons-lang3 + ${commons-lang3.version} + diff --git a/core-java-modules/core-java-arrays-convert/src/main/java/com/baeldung/array/conversions/ByteArrayToNumericRepresentation.java b/core-java-modules/core-java-arrays-convert/src/main/java/com/baeldung/array/conversions/ByteArrayToNumericRepresentation.java new file mode 100644 index 0000000000..82d60e1666 --- /dev/null +++ b/core-java-modules/core-java-arrays-convert/src/main/java/com/baeldung/array/conversions/ByteArrayToNumericRepresentation.java @@ -0,0 +1,281 @@ +package com.baeldung.array.conversions; + +import com.google.common.primitives.Ints; +import com.google.common.primitives.Longs; +import org.apache.commons.lang3.ArrayUtils; +import org.apache.commons.lang3.Conversion; + +import java.math.BigInteger; +import java.nio.ByteBuffer; +import java.util.Arrays; + +class ByteArrayToNumericRepresentation { + + static int convertByteArrayToIntUsingShiftOperator(byte[] bytes) { + int value = 0; + for (byte b : bytes) { + value = (value << 8) + (b & 0xFF); + } + return value; + } + + static byte[] convertIntToByteArrayUsingShiftOperator(int value) { + byte[] bytes = new byte[Integer.BYTES]; + int length = bytes.length; + for (int i = 0; i < length; i++) { + bytes[length - i - 1] = (byte) (value & 0xFF); + value >>= 8; + } + return bytes; + } + + static long convertByteArrayToLongUsingShiftOperator(byte[] bytes) { + long value = 0; + for (byte b : bytes) { + value <<= 8; + value |= (b & 0xFF); + } + return value; + } + + static byte[] convertLongToByteArrayUsingShiftOperator(long value) { + byte[] bytes = new byte[Long.BYTES]; + int length = bytes.length; + for (int i = 0; i < length; i++) { + bytes[length - i - 1] = (byte) (value & 0xFF); + value >>= 8; + } + return bytes; + } + + static float convertByteArrayToFloatUsingShiftOperator(byte[] bytes) { + // convert bytes to int + int intValue = 0; + for (byte b : bytes) { + intValue = (intValue << 8) + (b & 0xFF); + } + + // convert int to float + return Float.intBitsToFloat(intValue); + } + + static byte[] convertFloatToByteArrayUsingShiftOperator(float value) { + // convert float to int + int intValue = Float.floatToIntBits(value); + + // convert int to bytes + byte[] bytes = new byte[Float.BYTES]; + int length = bytes.length; + for (int i = 0; i < length; i++) { + bytes[length - i - 1] = (byte) (intValue & 0xFF); + intValue >>= 8; + } + return bytes; + } + + static double convertingByteArrayToDoubleUsingShiftOperator(byte[] bytes) { + long longValue = 0; + for (byte b : bytes) { + longValue = (longValue << 8) + (b & 0xFF); + } + + return Double.longBitsToDouble(longValue); + } + + static byte[] convertDoubleToByteArrayUsingShiftOperator(double value) { + long longValue = Double.doubleToLongBits(value); + + byte[] bytes = new byte[Double.BYTES]; + int length = bytes.length; + for (int i = 0; i < length; i++) { + bytes[length - i - 1] = (byte) (longValue & 0xFF); + longValue >>= 8; + } + return bytes; + } + + static int convertByteArrayToIntUsingByteBuffer(byte[] bytes) { + ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES); + buffer.put(bytes); + buffer.rewind(); + return buffer.getInt(); + } + + static byte[] convertIntToByteArrayUsingByteBuffer(int value) { + ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES); + buffer.putInt(value); + buffer.rewind(); + return buffer.array(); + } + + static long convertByteArrayToLongUsingByteBuffer(byte[] bytes) { + ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES); + buffer.put(bytes); + buffer.rewind(); + return buffer.getLong(); + } + + static byte[] convertLongToByteArrayUsingByteBuffer(long value) { + ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES); + buffer.putLong(value); + buffer.rewind(); + return buffer.array(); + } + + static float convertByteArrayToFloatUsingByteBuffer(byte[] bytes) { + ByteBuffer buffer = ByteBuffer.allocate(Float.BYTES); + buffer.put(bytes); + buffer.rewind(); + return buffer.getFloat(); + } + + static byte[] convertFloatToByteArrayUsingByteBuffer(float value) { + ByteBuffer buffer = ByteBuffer.allocate(Float.BYTES); + buffer.putFloat(value); + buffer.rewind(); + return buffer.array(); + } + + static double convertByteArrayToDoubleUsingByteBuffer(byte[] bytes) { + ByteBuffer buffer = ByteBuffer.allocate(Double.BYTES); + buffer.put(bytes); + buffer.rewind(); + return buffer.getDouble(); + } + + static byte[] convertDoubleToByteArrayUsingByteBuffer(double value) { + ByteBuffer buffer = ByteBuffer.allocate(Double.BYTES); + buffer.putDouble(value); + buffer.rewind(); + return buffer.array(); + } + + static int convertByteArrayToIntUsingBigInteger(byte[] bytes) { + return new BigInteger(bytes).intValue(); + } + + static byte[] convertIntToByteArrayUsingBigInteger(int value) { + return BigInteger.valueOf(value).toByteArray(); + } + + static long convertByteArrayToLongUsingBigInteger(byte[] bytes) { + return new BigInteger(bytes).longValue(); + } + + static byte[] convertLongToByteArrayUsingBigInteger(long value) { + return BigInteger.valueOf(value).toByteArray(); + } + + static float convertByteArrayToFloatUsingBigInteger(byte[] bytes) { + int intValue = new BigInteger(bytes).intValue(); + return Float.intBitsToFloat(intValue); + } + + static byte[] convertFloatToByteArrayUsingBigInteger(float value) { + int intValue = Float.floatToIntBits(value); + return BigInteger.valueOf(intValue).toByteArray(); + } + + static double convertByteArrayToDoubleUsingBigInteger(byte[] bytes) { + long longValue = new BigInteger(bytes).longValue(); + return Double.longBitsToDouble(longValue); + } + + static byte[] convertDoubleToByteArrayUsingBigInteger(double value) { + long longValue = Double.doubleToLongBits(value); + return BigInteger.valueOf(longValue).toByteArray(); + } + + static int convertingByteArrayToIntUsingGuava(byte[] bytes) { + return Ints.fromByteArray(bytes); + } + + static byte[] convertIntToByteArrayUsingGuava(int value) { + return Ints.toByteArray(value); + } + + static long convertByteArrayToLongUsingGuava(byte[] bytes) { + return Longs.fromByteArray(bytes); + } + + static byte[] convertLongToByteArrayUsingGuava(long value) { + return Longs.toByteArray(value); + } + + static float convertByteArrayToFloatUsingGuava(byte[] bytes) { + int intValue = Ints.fromByteArray(bytes); + return Float.intBitsToFloat(intValue); + } + + static byte[] convertFloatToByteArrayUsingGuava(float value) { + int intValue = Float.floatToIntBits(value); + return Ints.toByteArray(intValue); + } + + static double convertByteArrayToDoubleUsingGuava(byte[] bytes) { + long longValue = Longs.fromByteArray(bytes); + return Double.longBitsToDouble(longValue); + } + + static byte[] convertDoubleToByteArrayUsingGuava(double value) { + long longValue = Double.doubleToLongBits(value); + return Longs.toByteArray(longValue); + } + + static int convertByteArrayToIntUsingCommonsLang(byte[] bytes) { + byte[] copyBytes = Arrays.copyOf(bytes, bytes.length); + ArrayUtils.reverse(copyBytes); + return Conversion.byteArrayToInt(copyBytes, 0, 0, 0, copyBytes.length); + } + + static byte[] convertIntToByteArrayUsingCommonsLang(int value) { + byte[] bytes = new byte[Integer.BYTES]; + Conversion.intToByteArray(value, 0, bytes, 0, bytes.length); + ArrayUtils.reverse(bytes); + return bytes; + } + + static long convertByteArrayToLongUsingCommonsLang(byte[] bytes) { + byte[] copyBytes = Arrays.copyOf(bytes, bytes.length); + ArrayUtils.reverse(copyBytes); + return Conversion.byteArrayToLong(copyBytes, 0, 0, 0, copyBytes.length); + } + + static byte[] convertLongToByteArrayUsingCommonsLang(long value) { + byte[] bytes = new byte[Long.BYTES]; + Conversion.longToByteArray(value, 0, bytes, 0, bytes.length); + ArrayUtils.reverse(bytes); + return bytes; + } + + static float convertByteArrayToFloatUsingCommonsLang(byte[] bytes) { + byte[] copyBytes = Arrays.copyOf(bytes, bytes.length); + ArrayUtils.reverse(copyBytes); + int intValue = Conversion.byteArrayToInt(copyBytes, 0, 0, 0, copyBytes.length); + return Float.intBitsToFloat(intValue); + } + + static byte[] convertFloatToByteArrayUsingCommonsLang(float value) { + int intValue = Float.floatToIntBits(value); + byte[] bytes = new byte[Float.BYTES]; + Conversion.intToByteArray(intValue, 0, bytes, 0, bytes.length); + ArrayUtils.reverse(bytes); + return bytes; + } + + static double convertByteArrayToDoubleUsingCommonsLang(byte[] bytes) { + byte[] copyBytes = Arrays.copyOf(bytes, bytes.length); + ArrayUtils.reverse(copyBytes); + long longValue = Conversion.byteArrayToLong(copyBytes, 0, 0, 0, copyBytes.length); + return Double.longBitsToDouble(longValue); + } + + static byte[] convertDoubleToByteArrayUsingCommonsLang(double value) { + long longValue = Double.doubleToLongBits(value); + byte[] bytes = new byte[Long.BYTES]; + Conversion.longToByteArray(longValue, 0, bytes, 0, bytes.length); + ArrayUtils.reverse(bytes); + return bytes; + } + +} \ No newline at end of file diff --git a/core-java-modules/core-java-arrays-convert/src/test/java/com/baeldung/array/conversions/ByteArrayToNumericRepresentationUnitTest.java b/core-java-modules/core-java-arrays-convert/src/test/java/com/baeldung/array/conversions/ByteArrayToNumericRepresentationUnitTest.java new file mode 100644 index 0000000000..0fae765d9c --- /dev/null +++ b/core-java-modules/core-java-arrays-convert/src/test/java/com/baeldung/array/conversions/ByteArrayToNumericRepresentationUnitTest.java @@ -0,0 +1,316 @@ +package com.baeldung.array.conversions; + +import org.junit.Test; + +import static com.baeldung.array.conversions.ByteArrayToNumericRepresentation.*; +import static org.junit.Assert.assertArrayEquals; +import static org.junit.Assert.assertEquals; + +public class ByteArrayToNumericRepresentationUnitTest { + private static final byte[] INT_BYTE_ARRAY = new byte[]{ + (byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE + }; + private static final int INT_VALUE = 0xCAFEBABE; + + + private static final byte[] FLOAT_BYTE_ARRAY = new byte[]{ + (byte) 0x40, (byte) 0x48, (byte) 0xF5, (byte) 0xC3 + }; + private static final float FLOAT_VALUE = 3.14F; + + + private static final byte[] LONG_BYTE_ARRAY = new byte[]{ + (byte) 0x01, (byte) 0x23, (byte) 0x45, (byte) 0x67, + (byte) 0x89, (byte) 0xAB, (byte) 0xCD, (byte) 0xEF + }; + private static final long LONG_VALUE = 0x0123456789ABCDEFL; + + + private static final byte[] DOUBLE_BYTE_ARRAY = new byte[]{ + (byte) 0x3F, (byte) 0xE3, (byte) 0xC6, (byte) 0xA7, + (byte) 0xEF, (byte) 0x9D, (byte) 0xB2, (byte) 0x2D + }; + private static final double DOUBLE_VALUE = 0.618D; + + + @Test + public void givenShiftOperator_whenConvertingByteArrayToInt_thenSuccess() { + int value = convertByteArrayToIntUsingShiftOperator(INT_BYTE_ARRAY); + + assertEquals(INT_VALUE, value); + } + + @Test + public void givenShiftOperator_whenConvertingIntToByteArray_thenSuccess() { + byte[] bytes = convertIntToByteArrayUsingShiftOperator(INT_VALUE); + + assertArrayEquals(INT_BYTE_ARRAY, bytes); + } + + @Test + public void givenShiftOperator_whenConvertingByteArrayToLong_thenSuccess() { + long value = convertByteArrayToLongUsingShiftOperator(LONG_BYTE_ARRAY); + + assertEquals(LONG_VALUE, value); + } + + @Test + public void givenShiftOperator_whenConvertingLongToByteArray_thenSuccess() { + byte[] bytes = convertLongToByteArrayUsingShiftOperator(LONG_VALUE); + + assertArrayEquals(LONG_BYTE_ARRAY, bytes); + } + + @Test + public void givenShiftOperator_whenConvertingByteArrayToFloat_thenSuccess() { + float value = convertByteArrayToFloatUsingShiftOperator(FLOAT_BYTE_ARRAY); + + assertEquals(Float.floatToIntBits(FLOAT_VALUE), Float.floatToIntBits(value)); + } + + @Test + public void givenShiftOperator_whenConvertingFloatToByteArray_thenSuccess() { + byte[] bytes = convertFloatToByteArrayUsingShiftOperator(FLOAT_VALUE); + + assertArrayEquals(FLOAT_BYTE_ARRAY, bytes); + } + + @Test + public void givenShiftOperator_whenConvertingByteArrayToDouble_thenSuccess() { + double value = convertingByteArrayToDoubleUsingShiftOperator(DOUBLE_BYTE_ARRAY); + + assertEquals(Double.doubleToLongBits(DOUBLE_VALUE), Double.doubleToLongBits(value)); + } + + @Test + public void givenShiftOperator_whenConvertingDoubleToByteArray_thenSuccess() { + byte[] bytes = convertDoubleToByteArrayUsingShiftOperator(DOUBLE_VALUE); + + assertArrayEquals(DOUBLE_BYTE_ARRAY, bytes); + } + + @Test + public void givenByteBuffer_whenConvertingByteArrayToInt_thenSuccess() { + int value = convertByteArrayToIntUsingByteBuffer(INT_BYTE_ARRAY); + + assertEquals(INT_VALUE, value); + } + + @Test + public void givenByteBuffer_whenConvertingIntToByteArray_thenSuccess() { + byte[] bytes = convertIntToByteArrayUsingByteBuffer(INT_VALUE); + + assertArrayEquals(INT_BYTE_ARRAY, bytes); + } + + @Test + public void givenByteBuffer_whenConvertingByteArrayToLong_thenSuccess() { + long value = convertByteArrayToLongUsingByteBuffer(LONG_BYTE_ARRAY); + + assertEquals(LONG_VALUE, value); + } + + @Test + public void givenByteBuffer_whenConvertingLongToByteArray_thenSuccess() { + byte[] bytes = convertLongToByteArrayUsingByteBuffer(LONG_VALUE); + + assertArrayEquals(LONG_BYTE_ARRAY, bytes); + } + + @Test + public void givenByteBuffer_whenConvertingByteArrayToFloat_thenSuccess() { + float value = convertByteArrayToFloatUsingByteBuffer(FLOAT_BYTE_ARRAY); + + assertEquals(Float.floatToIntBits(FLOAT_VALUE), Float.floatToIntBits(value)); + } + + @Test + public void givenByteBuffer_whenConvertingFloatToByteArray_thenSuccess() { + byte[] bytes = convertFloatToByteArrayUsingByteBuffer(FLOAT_VALUE); + + assertArrayEquals(FLOAT_BYTE_ARRAY, bytes); + } + + @Test + public void givenByteBuffer_whenConvertingByteArrayToDouble_thenSuccess() { + double value = convertByteArrayToDoubleUsingByteBuffer(DOUBLE_BYTE_ARRAY); + + assertEquals(Double.doubleToLongBits(DOUBLE_VALUE), Double.doubleToLongBits(value)); + } + + @Test + public void givenByteBuffer_whenConvertingDoubleToByteArray_thenSuccess() { + byte[] bytes = convertDoubleToByteArrayUsingByteBuffer(DOUBLE_VALUE); + + assertArrayEquals(DOUBLE_BYTE_ARRAY, bytes); + } + + @Test + public void givenBigInteger_whenConvertingByteArrayToInt_thenSuccess() { + int value = convertByteArrayToIntUsingBigInteger(INT_BYTE_ARRAY); + + assertEquals(INT_VALUE, value); + } + + @Test + public void givenBigInteger_whenConvertingIntToByteArray_thenSuccess() { + byte[] bytes = convertIntToByteArrayUsingBigInteger(INT_VALUE); + + assertArrayEquals(INT_BYTE_ARRAY, bytes); + } + + @Test + public void givenBigInteger_whenConvertingByteArrayToLong_thenSuccess() { + long value = convertByteArrayToLongUsingBigInteger(LONG_BYTE_ARRAY); + + assertEquals(LONG_VALUE, value); + } + + @Test + public void givenBigInteger_whenConvertingLongToByteArray_thenSuccess() { + byte[] bytes = convertLongToByteArrayUsingBigInteger(LONG_VALUE); + + assertArrayEquals(LONG_BYTE_ARRAY, bytes); + } + + @Test + public void givenBigInteger_whenConvertingByteArrayToFloat_thenSuccess() { + float value = convertByteArrayToFloatUsingBigInteger(FLOAT_BYTE_ARRAY); + + assertEquals(Float.floatToIntBits(FLOAT_VALUE), Float.floatToIntBits(value)); + } + + @Test + public void givenBigInteger_whenConvertingFloatToByteArray_thenSuccess() { + byte[] bytes = convertFloatToByteArrayUsingBigInteger(FLOAT_VALUE); + + assertArrayEquals(FLOAT_BYTE_ARRAY, bytes); + } + + @Test + public void givenBigInteger_whenConvertingByteArrayToDouble_thenSuccess() { + double value = convertByteArrayToDoubleUsingBigInteger(DOUBLE_BYTE_ARRAY); + + assertEquals(Double.doubleToLongBits(DOUBLE_VALUE), Double.doubleToLongBits(value)); + } + + @Test + public void givenBigInteger_whenConvertingDoubleToByteArray_thenSuccess() { + byte[] bytes = convertDoubleToByteArrayUsingBigInteger(DOUBLE_VALUE); + + assertArrayEquals(DOUBLE_BYTE_ARRAY, bytes); + } + + @Test + public void givenGuava_whenConvertingByteArrayToInt_thenSuccess() { + int value = convertingByteArrayToIntUsingGuava(INT_BYTE_ARRAY); + + assertEquals(INT_VALUE, value); + } + + @Test + public void givenGuava_whenConvertingIntToByteArray_thenSuccess() { + byte[] bytes = convertIntToByteArrayUsingGuava(INT_VALUE); + + assertArrayEquals(INT_BYTE_ARRAY, bytes); + } + + @Test + public void givenGuava_whenConvertingByteArrayToLong_thenSuccess() { + long value = convertByteArrayToLongUsingGuava(LONG_BYTE_ARRAY); + + assertEquals(LONG_VALUE, value); + } + + @Test + public void givenGuava_whenConvertingLongToByteArray_thenSuccess() { + byte[] bytes = convertLongToByteArrayUsingGuava(LONG_VALUE); + + assertArrayEquals(LONG_BYTE_ARRAY, bytes); + } + + @Test + public void givenGuava_whenConvertingByteArrayToFloat_thenSuccess() { + float value = convertByteArrayToFloatUsingGuava(FLOAT_BYTE_ARRAY); + + assertEquals(Float.floatToIntBits(FLOAT_VALUE), Float.floatToIntBits(value)); + } + + @Test + public void givenGuava_whenConvertingFloatToByteArray_thenSuccess() { + byte[] bytes = convertFloatToByteArrayUsingGuava(FLOAT_VALUE); + + assertArrayEquals(FLOAT_BYTE_ARRAY, bytes); + } + + @Test + public void givenGuava_whenConvertingByteArrayToDouble_thenSuccess() { + double value = convertByteArrayToDoubleUsingGuava(DOUBLE_BYTE_ARRAY); + + assertEquals(Double.doubleToLongBits(DOUBLE_VALUE), Double.doubleToLongBits(value)); + } + + @Test + public void givenGuava_whenConvertingDoubleToByteArray_thenSuccess() { + byte[] bytes = convertDoubleToByteArrayUsingGuava(DOUBLE_VALUE); + + assertArrayEquals(DOUBLE_BYTE_ARRAY, bytes); + } + + @Test + public void givenCommonsLang_whenConvertingByteArrayToInt_thenSuccess() { + int value = convertByteArrayToIntUsingCommonsLang(INT_BYTE_ARRAY); + + assertEquals(INT_VALUE, value); + } + + @Test + public void givenCommonsLang_whenConvertingIntToByteArray_thenSuccess() { + byte[] bytes = convertIntToByteArrayUsingCommonsLang(INT_VALUE); + + assertArrayEquals(INT_BYTE_ARRAY, bytes); + } + + @Test + public void givenCommonsLang_whenConvertingByteArrayToLong_thenSuccess() { + long value = convertByteArrayToLongUsingCommonsLang(LONG_BYTE_ARRAY); + + assertEquals(LONG_VALUE, value); + } + + @Test + public void givenCommonsLang_whenConvertingLongToByteArray_thenSuccess() { + byte[] bytes = convertLongToByteArrayUsingCommonsLang(LONG_VALUE); + + assertArrayEquals(LONG_BYTE_ARRAY, bytes); + } + + @Test + public void givenCommonsLang_whenConvertingByteArrayToFloat_thenSuccess() { + float value = convertByteArrayToFloatUsingCommonsLang(FLOAT_BYTE_ARRAY); + + assertEquals(Float.floatToIntBits(FLOAT_VALUE), Float.floatToIntBits(value)); + } + + @Test + public void givenCommonsLang_whenConvertingFloatToByteArray_thenSuccess() { + byte[] bytes = convertFloatToByteArrayUsingCommonsLang(FLOAT_VALUE); + + assertArrayEquals(FLOAT_BYTE_ARRAY, bytes); + } + + @Test + public void givenCommonsLang_whenConvertingByteArrayToDouble_thenSuccess() { + double value = convertByteArrayToDoubleUsingCommonsLang(DOUBLE_BYTE_ARRAY); + + assertEquals(Double.doubleToLongBits(DOUBLE_VALUE), Double.doubleToLongBits(value)); + } + + @Test + public void givenCommonsLang_whenConvertingDoubleToByteArray_thenSuccess() { + byte[] bytes = convertDoubleToByteArrayUsingCommonsLang(DOUBLE_VALUE); + + assertArrayEquals(DOUBLE_BYTE_ARRAY, bytes); + } + +} \ No newline at end of file