2021年1月29日
Java 字符串格式转换
/** * 通信格式转换 * * Java和一些windows编程语言如c、c++、delphi所写的网络程序进行通讯时,需要进行相应的转换 * 高、低字节之间的转换 * windows的字节序为低字节开头 * linux,unix的字节序为高字节开头 * java则无论平台变化,都是高字节开头 */ public class FormatTransfer { /** * 将int转为低字节在前,高字节在后的byte数组 * @param n int * @return byte[] */ public static byte[] toLH(int n) { byte[] b = new byte[4]; b[0] = (byte) (n & 0xff); b[1] = (byte) (n >> 8 & 0xff); b[2] = (byte) (n >> 16 & 0xff); b[3] = (byte) (n >> 24 & 0xff); return b; } /** * 将int转为高字节在前,低字节在后的byte数组 * @param n int * @return byte[] */ public static byte[] toHH(int n) { byte[] b = new byte[4]; b[3] = (byte) (n & 0xff); b[2] = (byte) (n >> 8 & 0xff); b[1] = (byte) (n >> 16 & 0xff); b[0] = (byte) (n >> 24 & 0xff); return b; } /** * 将short转为低字节在前,高字节在后的byte数组 * @param n short * @return byte[] */ public static byte[] toLH(short n) { byte[] b = new byte[2]; b[0] = (byte) (n & 0xff); b[1] = (byte) (n >> 8 & 0xff); return b; } /** * 将short转为高字节在前,低字节在后的byte数组 * @param n short * @return byte[] */ public static byte[] toHH(short n) { byte[] b = new byte[2]; b[1] = (byte) (n & 0xff); b[0] = (byte) (n >> 8 & 0xff); return b; } /** * 将将int转为高字节在前,低字节在后的byte数组 public static byte[] toHH(int number) { int temp = number; byte[] b = new byte[4]; for (int i = b.length - 1; i > -1; i--) { b = new Integer(temp & 0xff).byteValue(); temp = temp >> 8; } return b; } public static byte[] IntToByteArray(int i) { byte[] abyte0 = new byte[4]; abyte0[3] = (byte) (0xff & i); abyte0[2] = (byte) ((0xff00 & i) >> 8); abyte0[1] = (byte) ((0xff0000 & i) >> 16); abyte0[0] = (byte) ((0xff000000 & i) >> 24); return abyte0; } */ /** * 将float转为低字节在前,高字节在后的byte数组 */ public static byte[] toLH(float f) { return toLH(Float.floatToRawIntBits(f)); } /** * 将float转为高字节在前,低字节在后的byte数组 */ public static byte[] toHH(float f) { return toHH(Float.floatToRawIntBits(f)); } /** * 将String转为byte数组 */ public static byte[] stringToBytes(String s, int length) { while (s.getBytes().length < length) { s += " "; } return s.getBytes(); } /** * 将字节数组转换为String * @param b byte[] * @return String */ public static String bytesToString(byte[] b) { StringBuffer result = new StringBuffer(""); int length = b.length; for (int i=0; i<length; i++) { result.append((char)(b & 0xff)); } return result.toString(); } /** * 将字符串转换为byte数组 * @param s String * @return byte[] */ public static byte[] stringToBytes(String s) { return s.getBytes(); } /** * 将高字节数组转换为int * @param b byte[] * @return int */ public static int hBytesToInt(byte[] b) { int s = 0; for (int i = 0; i < 3; i++) { if (b >= 0) { s = s + b; } else { s = s + 256 + b; } s = s * 256; } if (b[3] >= 0) { s = s + b[3]; } else { s = s + 256 + b[3]; } return s; } /** * 将低字节数组转换为int * @param b byte[] * @return int */ public static int lBytesToInt(byte[] b) { int s = 0; for (int i = 0; i < 3; i++) { if (b[3-i] >= 0) { s = s + b[3-i]; } else { s = s + 256 + b[3-i]; } s = s * 256; } if (b[0] >= 0) { s = s + b[0]; } else { s = s + 256 + b[0]; } return s; } /** * 高字节数组到short的转换 * @param b byte[] * @return short */ public static short hBytesToShort(byte[] b) { int s = 0; if (b[0] >= 0) { s = s + b[0]; } else { s = s + 256 + b[0]; } s = s * 256; if (b[1] >= 0) { s = s + b[1]; } else { s = s + 256 + b[1]; } short result = (short)s; return result; } /** * 低字节数组到short的转换 * @param b byte[] * @return short */ public static short lBytesToShort(byte[] b) { int s = 0; if (b[1] >= 0) { s = s + b[1]; } else { s = s + 256 + b[1]; } s = s * 256; if (b[0] >= 0) { s = s + b[0]; } else { s = s + 256 + b[0]; } short result = (short)s; return result; } /** * 高字节数组转换为float * @param b byte[] * @return float */ public static float hBytesToFloat(byte[] b) { int i = 0; Float F = new Float(0.0); i = ((((b[0]&0xff)<<8 | (b[1]&0xff))<<8) | (b[2]&0xff))<<8 | (b[3]&0xff); return F.intBitsToFloat(i); } /** * 低字节数组转换为float * @param b byte[] * @return float */ public static float lBytesToFloat(byte[] b) { int i = 0; Float F = new Float(0.0); i = ((((b[3]&0xff)<<8 | (b[2]&0xff))<<8) | (b[1]&0xff))<<8 | (b[0]&0xff); return F.intBitsToFloat(i); } /** * 将byte数组中的元素倒序排列 */ public static byte[] bytesReverseOrder(byte[] b) { int length = b.length; byte[] result = new byte[length]; for(int i=0; i<length; i++) { result[length-i-1] = b; } return result; } /** * 打印byte数组 */ public static void printBytes(byte[] bb) { int length = bb.length; for (int i=0; i<length; i++) { System.out.print(bb + " "); } System.out.println(""); } public static void logBytes(byte[] bb) { int length = bb.length; String out = ""; for (int i=0; i<length; i++) { out = out + bb + " "; } } /** * 将int类型的值转换为字节序颠倒过来对应的int值 * @param i int * @return int */ public static int reverseInt(int i) { int result = FormatTransfer.hBytesToInt(FormatTransfer.toLH(i)); return result; } /** * 将short类型的值转换为字节序颠倒过来对应的short值 * @param s short * @return short */ public static short reverseShort(short s) { short result = FormatTransfer.hBytesToShort(FormatTransfer.toLH(s)); return result; } /** * 将float类型的值转换为字节序颠倒过来对应的float值 * @param f float * @return float */ public static float reverseFloat(float f) { float result = FormatTransfer.hBytesToFloat(FormatTransfer.toLH(f)); return result; } }