例:将字符串内容转为浮点数,再还原出原字符串内容
import java.io.UnsupportedEncodingException; import java.nio.ByteBuffer; import java.nio.DoubleBuffer; import java.nio.FloatBuffer; public class test3 { public static void main(String[] args) { new test3(); } /** * 第一种方法 */ /** * 1,整数到字节数组的转换 * * @param number * @return */ public static byte[] intToByte(int number) { int temp = number; byte[] b = new byte[4]; for (int i = b.length - 1; i > -1; i--) { b[i] = new Integer(temp & 0xff).byteValue(); // 将最高位保存在最低位 temp = temp >> 8; // 向右移8位 } return b; } /** * 2,字节数组到整数的转换 * * @param b * @return */ public static int byteToInt(byte[] b) { int s = 0; for (int i = 0; i < 3; i++) { if (b[i] >= 0) s = s + b[i]; else s = s + 256 + b[i]; s = s * 256; } if (b[3] >= 0) // 最后一个之所以不乘,是因为可能会溢出 s = s + b[3]; else s = s + 256 + b[3]; return s; } /** * 3,字符到字节转换 * * @param ch * @return */ public static byte[] charToByte(char ch) { int temp = (int) ch; byte[] b = new byte[2]; for (int i = b.length - 1; i > -1; i--) { b[i] = new Integer(temp & 0xff).byteValue(); // 将最高位保存在最低位 temp = temp >> 8; // 向右移8位 } return b; } /** * 4,字节到字符转换 * * @param b * @return */ public static char byteToChar(byte[] b) { int s = 0; if (b[0] > 0) s += b[0]; else s += 256 + b[0]; s *= 256; if (b[1] > 0) s += b[1]; else s += 256 + b[1]; char ch = (char) s; return ch; } /** * 5,双精度浮点到字节转换 * * @param d * @return */ public static byte[] doubleToByte(double d) { byte[] b = new byte[8]; long l = Double.doubleToLongBits(d); for (int i = 0; i < b.length; i++) { b[i] = new Long(l).byteValue(); l = l >> 8; } return b; } /** * 6,字节到双精度浮点转换 * * @param b * @return */ public static double byteToDouble(byte[] b) { long l; l = b[0]; l &= 0xff; l |= ((long) b[1] << 8); l &= 0xffff; l |= ((long) b[2] << 16); l &= 0xffffff; l |= ((long) b[3] << 24); l &= 0xffffffffl; l |= ((long) b[4] << 32); l &= 0xffffffffffl; l |= ((long) b[5] << 40); l &= 0xffffffffffffl; l |= ((long) b[6] << 48); l |= ((long) b[7] << 56); return Double.longBitsToDouble(l); } /** * 7,单精度浮点转换为字节 * * @param f * @return */ public static byte[] float2byte(float f) { // 把float转换为byte[] int fbit = Float.floatToIntBits(f); byte[] b = new byte[4]; for (int i = 0; i < 4; i++) { b[i] = (byte) (fbit >> (24 - i * 8)); } // 翻转数组 int len = b.length; // 建立一个与源数组元素类型相同的数组 byte[] dest = new byte[len]; // 为了防止修改源数组,将源数组拷贝一份副本 System.arraycopy(b, 0, dest, 0, len); byte temp; // 将顺位第i个与倒数第i个交换 for (int i = 0; i < len / 2; ++i) { temp = dest[i]; dest[i] = dest[len - i - 1]; dest[len - i - 1] = temp; } return dest; } /** * ,8,字节转换为单精度浮点 * * @param b * 字节(至少4个字节) * @param index * 开始位置 * @return */ public static float byte2float(byte[] b, int index) { int l; l = b[index + 0]; l &= 0xff; l |= ((long) b[index + 1] << 8); l &= 0xffff; l |= ((long) b[index + 2] << 16); l &= 0xffffff; l |= ((long) b[index + 3] << 24); return Float.intBitsToFloat(l); } /** * 将Byte转换为String 或者将String转换为Byte * * @author Administrator * */ /** * 默认的字符集编码 UTF-8 一个汉字占三个字节 */ private static String CHAR_ENCODE = "UTF-8"; /** * 设置全局的字符编码 * * @param charEncode */ public static void configCharEncode(String charEncode) { CHAR_ENCODE = charEncode; } /** * @param str * 源字符串转换成字节数组的字符串 * @return */ public static byte[] StringToByte(String str) { return StringToByte(str, CHAR_ENCODE); } /** * * @param srcObj * 源字节数组转换成String的字节数组 * @return */ public static String ByteToString(byte[] srcObj) { return ByteToString(srcObj, CHAR_ENCODE); } /** * UTF-8 一个汉字占三个字节 * * @param str * 源字符串 转换成字节数组的字符串 * @return */ public static byte[] StringToByte(String str, String charEncode) { byte[] destObj = null; try { if (null == str || str.trim().equals("")) { destObj = new byte[0]; return destObj; } else { destObj = str.getBytes(charEncode); } } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return destObj; } /** * @param srcObj * 源字节数组转换成String的字节数组 * @return */ public static String ByteToString(byte[] srcObj, String charEncode) { String destObj = null; try { destObj = new String(srcObj, charEncode); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return destObj.replaceAll("\0", " "); } /** * Convert byte[] to hex string * * @param src * @return */ public static String bytesToHexString(byte[] src) { StringBuilder stringBuilder = new StringBuilder(""); if (src == null || src.length <= 0) { return null; } for (int i = 0; i < src.length; i++) { int v = src[i] & 0xFF; String hv = Integer.toHexString(v); if (hv.length() < 2) { stringBuilder.append(0); } stringBuilder.append(hv); } return stringBuilder.toString(); } /** * Convert hex string to byte[] * * @param hexString * @return */ public static byte[] hexStringToBytes(String hexString) { if (hexString == null || hexString.equals("")) { return null; } hexString = hexString.toUpperCase(); int length = hexString.length() / 2; char[] hexChars = hexString.toCharArray(); byte[] d = new byte[length]; for (int i = 0; i < length; i++) { int pos = i * 2; d[i] = (byte) (charToBytes(hexChars[pos]) << 4 | charToBytes(hexChars[pos + 1])); } return d; } /** * Convert char to byte * * @param c * @return */ private static byte charToBytes(char c) { return (byte) "0123456789ABCDEF".indexOf(c); } /** * 第二种方法 */ /** * 1,BYTE转INT * * @param b * @return */ protected int byteArrayToInt(byte[] b) { return (b[0] << 24) + ((b[1] & 0xFF) << 16) + ((b[2] & 0xFF) << 8) + (b[3] & 0xFF); } /** * ,2,BYTE转SHORT * * @param b * @return */ protected int byteArrayToShort(byte[] b) { return (b[0] << 8) + (b[1] & 0xFF); } /** * ,3,SHORT转BYTE数据 * * @param s * @return */ protected byte[] shortToByteArray(short s) { byte[] shortBuf = new byte[2]; for (int i = 0; i < 2; i++) { int offset = (shortBuf.length - 1 - i) * 8; shortBuf[i] = (byte) ((s >>> offset) & 0xff); } return shortBuf; } /** * ,4,INT数据转BYTE数据 * * @param i * @return */ protected byte[] intToByteArray(int i) { byte[] result = new byte[4]; result[0] = (byte) ((i >> 24) & 0xFF); result[1] = (byte) ((i >> 16) & 0xFF); result[2] = (byte) ((i >> 8) & 0xFF); result[3] = (byte) (i & 0xFF); return result; } /** * ,5,转换long型为byte数组 * * @param bb * @param x * @param index */ public byte[] longToByteArray(long x, int index) { byte[] bb = new byte[8]; bb[index + 7] = (byte) (x >> 56); bb[index + 6] = (byte) (x >> 48); bb[index + 5] = (byte) (x >> 40); bb[index + 4] = (byte) (x >> 32); bb[index + 3] = (byte) (x >> 24); bb[index + 2] = (byte) (x >> 16); bb[index + 1] = (byte) (x >> 8); bb[index + 0] = (byte) (x >> 0); return bb; } /** * ,6,通过byte数组取到long * * @param bb * @param index * @return */ public long byteArrayToLong(byte[] bb, int index) { return ((((long) bb[index + 7] & 0xff) << 56) | (((long) bb[index + 6] & 0xff) << 48) | (((long) bb[index + 5] & 0xff) << 40) | (((long) bb[index + 4] & 0xff) << 32) | (((long) bb[index + 3] & 0xff) << 24) | (((long) bb[index + 2] & 0xff) << 16) | (((long) bb[index + 1] & 0xff) << 8) | (((long) bb[index + 0] & 0xff) << 0)); } /** * ,7,float转换byte * * @param bb * @param x * @param index */ public static byte[] floatTobyteArray(float v) { ByteBuffer bb = ByteBuffer.allocate(4); byte[] ret = new byte[4]; FloatBuffer fb = bb.asFloatBuffer(); fb.put(v); bb.get(ret); return ret; } /** * ,8,通过byte数组取得float * * @param bb * @param index * @return */ public static float byteArrayToFloat(byte[] v) { ByteBuffer bb = ByteBuffer.wrap(v); FloatBuffer fb = bb.asFloatBuffer(); return fb.get(); } /** * ,9,double转换byte * * @param bb * @param x * @param index */ public byte[] doubleToByteArray(double x) { ByteBuffer bb = ByteBuffer.allocate(8); byte[] ret = new byte[8]; DoubleBuffer fb = bb.asDoubleBuffer(); fb.put(x); bb.get(ret); return ret; } /** * ,10,通过byte数组取得float * * @param bb * @param index * @return */ public double byteArrayToDouble(byte[] b) { ByteBuffer bb = ByteBuffer.wrap(b); DoubleBuffer fb = bb.asDoubleBuffer(); return fb.get(); } public test3() { //例:将字符串内容转为浮点数,再还原出原字符串内容 String Content = "Contiune"; System.out.println("例:将字符串内容转为浮点数,再还原出原字符串内容"); // 1,字符串转为浮点 // (1)先将字符串转为数组 System.out.println("1,字符串转为浮点:(1)先将字符串转为数组Content=" + StringToByte(Content)); // (2)再将数组转化为浮点 System.out.println("1,字符串转为浮点:(1)再将数组转化为浮点Content=" + byteToDouble(StringToByte(Content))); // 2,浮点转成字符串 // (1)先将浮点转为字节数组 System.out.println("2,浮点转成字符串:(1)先将浮点转为字节数组Content=" + doubleToByte(byteToDouble(StringToByte(Content)))); // (2)再将字节数组转为字符串 System.out .println("2,浮点转成字符串:(2)再将字节数组转为字符串Content=" + ByteToString(doubleToByte(byteToDouble(StringToByte(Content))))); } }
例:将字符串内容转为浮点数,再还原出原字符串内容
1,字符串转为浮点:(1)先将字符串转为数组Content=[[email protected]
1,字符串转为浮点:(1)再将数组转化为浮点Content=3.949643824749462E180
2,浮点转成字符串:(1)先将浮点转为字节数组Content=[[email protected]
2,浮点转成字符串:(2)再将字节数组转为字符串Content=Contiune,即还原出原字符串内容。
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时间: 2024-10-05 14:57:36