byte[]与各种数据类型互相转换示例
public class TestCase {/** * short到字节数组的转换. */public static byte[] shortToByte(short number) {int temp = number;byte[] b = new byte[2];for (int i = 0; i < b.length; i++) {b[i] = new Integer(temp & 0xff).byteValue();// 将最低位保存在最低位temp = temp >> 8;// 向右移8位}return b;}/** * 字节数组到short的转换. */public static short byteToShort(byte[] b) {short s = 0;short s0 = (short) (b[0] & 0xff);// 最低位short s1 = (short) (b[1] & 0xff);s1 <<= 8;s = (short) (s0 | s1);return s;}/** * int到字节数组的转换. */public static byte[] intToByte(int number) {int temp = number;byte[] b = new byte[4];for (int i = 0; i < b.length; i++) {b[i] = new Integer(temp & 0xff).byteValue();// 将最低位保存在最低位temp = temp >> 8;// 向右移8位}return b;}/** * 字节数组到int的转换. */public static int byteToInt(byte[] b) {int s = 0;int s0 = b[0] & 0xff;// 最低位int s1 = b[1] & 0xff;int s2 = b[2] & 0xff;int s3 = b[3] & 0xff;s3 <<= 24;s2 <<= 16;s1 <<= 8;s = s0 | s1 | s2 | s3;return s;}/** * long类型转成byte数组 */public static byte[] longToByte(long number) {long temp = number;byte[] b = new byte[8];for (int i = 0; i < b.length; i++) {b[i] = new Long(temp & 0xff).byteValue();// 将最低位保存在最低位 temp = temp// >> 8;// 向右移8位}return b;}/** * 字节数组到long的转换. */public static long byteToLong(byte[] b) {long s = 0;long s0 = b[0] & 0xff;// 最低位long s1 = b[1] & 0xff;long s2 = b[2] & 0xff;long s3 = b[3] & 0xff;long s4 = b[4] & 0xff;// 最低位long s5 = b[5] & 0xff;long s6 = b[6] & 0xff;long s7 = b[7] & 0xff;// s0不变s1 <<= 8;s2 <<= 16;s3 <<= 24;s4 <<= 8 * 4;s5 <<= 8 * 5;s6 <<= 8 * 6;s7 <<= 8 * 7;s = s0 | s1 | s2 | s3 | s4 | s5 | s6 | s7;return s;}/** * double到字节数组的转换. */public static byte[] doubleToByte(double num) { byte[] b = new byte[8]; long l = Double.doubleToLongBits(num); for (int i = 0; i < 8; i++) { b[i] = new Long(l).byteValue(); l = l >> 8; }return b;}/** * 字节数组到double的转换. */public static double getDouble(byte[] b) { long m; m = b[0]; m &= 0xff; m |= ((long) b[1] << 8); m &= 0xffff; m |= ((long) b[2] << 16); m &= 0xffffff; m |= ((long) b[3] << 24); m &= 0xffffffffl; m |= ((long) b[4] << 32); m &= 0xffffffffffl; m |= ((long) b[5] << 40); m &= 0xffffffffffffl; m |= ((long) b[6] << 48); m &= 0xffffffffffffffl; m |= ((long) b[7] << 56); return Double.longBitsToDouble(m); }/** * float到字节数组的转换. */public static void floatToByte(float x) {//先用 Float.floatToIntBits(f)转换成int}/** * 字节数组到float的转换. */public static float getFloat(byte[] b) { // 4 bytes int accum = 0; for ( int shiftBy = 0; shiftBy < 4; shiftBy++ ) { accum |= (b[shiftBy] & 0xff) << shiftBy * 8; } return Float.intBitsToFloat(accum); } /** * char到字节数组的转换. */ public static byte[] charToByte(char c){byte[] b = new byte[2];b[0] = (byte) ((c & 0xFF00) >> 8);b[1] = (byte) (c & 0xFF);return b; } /** * 字节数组到char的转换. */ public static char byteToChar(byte[] b){char c = (char) (((b[0] & 0xFF) << 8) | (b[1] & 0xFF));return c; }/** * string到字节数组的转换. */public static byte[] stringToByte(String str) throws UnsupportedEncodingException{return str.getBytes("GBK");}/** * 字节数组到String的转换. */ public static String bytesToString(byte[] str) { String keyword = null; try { keyword = new String(str,"GBK"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return keyword; } /** * object到字节数组的转换 */@Testpublic void testObject2ByteArray() throws IOException,ClassNotFoundException {// Object obj = "";Integer[] obj = { 1, 3, 4 };// // object to bytearrayByteArrayOutputStream bo = new ByteArrayOutputStream();ObjectOutputStream oo = new ObjectOutputStream(bo);oo.writeObject(obj);byte[] bytes = bo.toByteArray();bo.close();oo.close();System.out.println(Arrays.toString(bytes));Integer[] intArr = (Integer[]) testByteArray2Object(bytes);System.out.println(Arrays.asList(intArr));byte[] b2 = intToByte(123);System.out.println(Arrays.toString(b2));int a = byteToInt(b2);System.out.println(a);}/** * 字节数组到object的转换. */private Object testByteArray2Object(byte[] bytes) throws IOException,ClassNotFoundException {// byte[] bytes = null;Object obj;// bytearray to objectByteArrayInputStream bi = new ByteArrayInputStream(bytes);ObjectInputStream oi = new ObjectInputStream(bi);obj = oi.readObject();bi.close();oi.close();System.out.println(obj);return obj;}}
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