java中long,int,short与byte数组之间的转换
转的两篇文章的实现都很全面里面有些细节不同,现在项目进度紧张.先保留以后整理.
文章一:http://hi.baidu.com/menglinxi_a/item/35a43d5d50e79212abf6d753
//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;
}
//byte数组转成long
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;
}
/**
* 注释：int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 = 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;
}
/**
* 注释：字节数组到int的转换！
*
* @param b
* @return
*/
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;
}
/**
* 注释：short到字节数组的转换！
*
* @param s
* @return
*/
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;
}
/**
* 注释：字节数组到short的转换！
*
* @param b
* @return
*/
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;
}
文章二:
Java的byte，short, int, long等转换方法
public static byte[] shortToBytes(short n) {
byte[] b = new byte[2];
b[1] = (byte) (n & 0xff);
b[0] = (byte) ((n >> 8) & 0xff);
return b;
}
public static short bytesToShort(byte[] b) {
return (short) (b[1] & 0xff
| (b[0] & 0xff) << 8);
}
/**
* int类型转换成byte[]
*
* @param num
* int数
* @return byte[]
*/
public static byte[] intToBytes(int num) {
byte[] b = new byte[4];
for (int i = 0; i < 4; i++) {
b[i] = (byte) (num >>> (24 - i * 8));
}
return b;
}
public static int bytes2int(byte[] b) {
//byte[] b=new byte[]{1,2,3,4};
int mask = 0xff;
int temp = 0;
int res = 0;
for (int i = 0; i < 4; i++) {
res <<= 8;
temp = b[i] & mask;
res |= temp;
}
return res;
}
public static byte[] longToBytes(long num) {
byte[] b = new byte[8];
for (int i = 0; i < 8; i++) {
b[i] = (byte) (num >>> (56 - i * 8));
}
return b;
}
public static String str2HexStr(String str) {
char[] chars = "0123456789ABCDEF".toCharArray();
StringBuilder sb = new StringBuilder("");
byte[] bs = str.getBytes();
int bit;
for (int i = 0; i < bs.length; i++) {
bit = (bs[i] & 0x0f0) >> 4;
sb.append(chars[bit]);
bit = bs[i] & 0x0f;
sb.append(chars[bit]);
}
return sb.toString();
}
public static String bytesToHexString(byte[] bArray) {
StringBuffer sb = new StringBuffer(bArray.length);
String sTemp;
for (int i = 0; i < bArray.length; i++) {
sTemp = Integer.toHexString(0xFF & bArray[i]);
if (sTemp.length() < 2) {
sb.append(0);
}
sb.append(sTemp.toUpperCase());
}
return sb.toString();
}
public static byte[] hexStringToBytes(String hexString) {
String chars = "0123456789ABCDEF";
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) (chars.indexOf(hexChars[pos]) << 4 | chars.indexOf(hexChars[pos + 1]));
}
return d;
}
package com.dst.util;
import java.io.*;
/**
* 流操作工具类
*
* @author 崔素强
*/
public class StreamTool {
/**
* @方法功能 InputStream 转为 byte
* @param InputStream
* @return 字节数组
* @throws Exception
*/
public static byte[] inputStream2Byte(InputStream inStream)
throws Exception {
// ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
// byte[] buffer = new byte[1024];
// int len = -1;
// while ((len = inStream.read(buffer)) != -1) {
// outSteam.write(buffer, 0, len);
// }
// outSteam.close();
// inStream.close();
// return outSteam.toByteArray();
int count = 0;
while (count == 0) {
count = inStream.available();
}
byte[] b = new byte[count];
inStream.read(b);
return b;
}
/**
* @方法功能 byte 转为 InputStream
* @param 字节数组
* @return InputStream
* @throws Exception
*/
public static InputStream byte2InputStream(byte[] b) throws Exception {
InputStream is = new ByteArrayInputStream(b);
return is;
}
/**
* @功能 短整型与字节的转换
* @param 短整型
* @return 两位的字节数组
*/
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;
}
/**
* @功能 字节的转换与短整型
* @param 两位的字节数组
* @return 短整型
*/
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;
}
/**
* @方法功能 整型与字节数组的转换
* @param 整型
* @return 四位的字节数组
*/
public static byte[] intToByte(int i) {
byte[] bt = new byte[4];
bt[0] = (byte) (0xff & i);
bt[1] = (byte) ((0xff00 & i) >> 8);
bt[2] = (byte) ((0xff0000 & i) >> 16);
bt[3] = (byte) ((0xff000000 & i) >> 24);
return bt;
}
/**
* @方法功能 字节数组和整型的转换
* @param 字节数组
* @return 整型
*/
public static int bytesToInt(byte[] bytes) {
int num = bytes[0] & 0xFF;
num |= ((bytes[1] << 8) & 0xFF00);
num |= ((bytes[2] << 16) & 0xFF0000);
num |= ((bytes[3] << 24) & 0xFF000000);
return num;
}
/**
* @方法功能 字节数组和长整型的转换
* @param 字节数组
* @return 长整型
*/
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;
}
/**
* @方法功能 字节数组和长整型的转换
* @param 字节数组
* @return 长整型
*/
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;
}
}