前言：用于处理Java基本数据的转换及进制转换操作工具
一、实现功能
1、int与byte互转
2、int与byte[]互转
3、short与byte互转
4、short与byte[]互转
5、16位short与byte[]互转
6、long与byte[]互转
7、byte[]与inputstream互转
8、byte与String互转
9、16进制字符转int
10、十进制转2进制
11、byte[]转16进制字符
12、byte[]数组指定位置抽取byte[]
二、代码实现
package cc.eguid.util; import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
/**
* 基本数据互转工具
* @author eguid
* eguid的官网：www.eguid.cc
* eguid的csdn博客：http://blog.csdn.net/eguid_1,博客园：http://www.cnblogs.com/eguid
*/
public class ByteUtil {
private static ByteBuffer buffer = ByteBuffer.allocate(8);
/**
* int转byte
* @param x
* @return
*/
public static byte intToByte(int x) {
return (byte) x;
}
/**
* byte转int
* @param b
* @return
*/
public static int byteToInt(byte b) {
//Java的byte是有符号，通过 &0xFF转为无符号
return b & 0xFF;
} /**
* byte[]转int
* @param b
* @return
*/
public static int byteArrayToInt(byte[] b) {
return b[3] & 0xFF |
(b[2] & 0xFF) << 8 |
(b[1] & 0xFF) << 16 |
(b[0] & 0xFF) << 24;
}
public static int byteArrayToInt(byte[] b, int index){
return b[index+3] & 0xFF |
(b[index+2] & 0xFF) << 8 |
(b[index+1] & 0xFF) << 16 |
(b[index+0] & 0xFF) << 24;
}
/**
* int转byte[]
* @param a
* @return
*/
public static byte[] intToByteArray(int a) {
return new byte[] {
(byte) ((a >> 24) & 0xFF),
(byte) ((a >> 16) & 0xFF),
(byte) ((a >> 8) & 0xFF),
(byte) (a & 0xFF)
};
}
/**
* short转byte[]
*
* @param b
* @param s
* @param index
*/
public static void byteArrToShort(byte b[], short s, int index) {
b[index + 1] = (byte) (s >> 8);
b[index + 0] = (byte) (s >> 0);
}
/**
* byte[]转short
*
* @param b
* @param index
* @return
*/
public static short byteArrToShort(byte[] b, int index) {
return (short) (((b[index + 0] << 8) | b[index + 1] & 0xff));
}
/**
* 16位short转byte[]
*
* @param s
* short
* @return byte[]
* */
public static byte[] shortToByteArr(short s) {
byte[] targets = new byte[2];
for (int i = 0; i < 2; i++) {
int offset = (targets.length - 1 - i) * 8;
targets[i] = (byte) ((s >>> offset) & 0xff);
}
return targets;
}
/**
* byte[]转16位short
* @param b
* @return
*/
public static short byteArrToShort(byte[] b){
return byteArrToShort(b,0);
} /**
* long转byte[]
* @param x
* @return
*/
public static byte[] longToBytes(long x) {
buffer.putLong(0, x);
return buffer.array();
}
/**
* byte[]转Long
* @param bytes
* @return
*/
public static long bytesToLong(byte[] bytes) {
buffer.put(bytes, 0, bytes.length);
buffer.flip();//need flip
return buffer.getLong();
}
/**
* 从byte[]中抽取新的byte[]
* @param data - 元数据
* @param start - 开始位置
* @param end - 结束位置
* @return 新byte[]
*/
public static byte[] getByteArr(byte[]data,int start ,int end){
byte[] ret=new byte[end-start];
for(int i=0;(start+i)<end;i++){
ret[i]=data[start+i];
}
return ret;
} /**
* 流转换为byte[]
* @param inStream
* @return
*/
public static byte[] readInputStream(InputStream inStream) {
ByteArrayOutputStream outStream = null;
try {
outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
byte[] data = null;
int len = 0;
while ((len = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
}
data = outStream.toByteArray();
return data;
}catch (IOException e) {
return null;
} finally {
try {
if (outStream != null) {
outStream.close();
}
if (inStream != null) {
inStream.close();
}
} catch (IOException e) {
return null;
}
}
}
/**
* byte[]转inputstream
* @param b
* @return
*/
public static InputStream readByteArr(byte[] b){
return new ByteArrayInputStream(b);
}
/**
* byte数组内数字是否相同
* @param s1
* @param s2
* @return
*/
public static boolean isEq(byte[] s1,byte[] s2){
int slen=s1.length;
if(slen==s2.length){
for(int index=0;index<slen;index++){
if(s1[index]!=s2[index]){
return false;
}
}
return true;
}
return false;
}
/**
* byte数组转换为Stirng
* @param s1 -数组
* @param encode -字符集
* @param err -转换错误时返回该文字
* @return
*/
public static String getString(byte[] s1,String encode,String err){
try {
return new String(s1,encode);
} catch (UnsupportedEncodingException e) {
return err==null?null:err;
}
}
/**
* byte数组转换为Stirng
* @param s1-数组
* @param encode-字符集
* @return
*/
public static String getString(byte[] s1,String encode){
return getString(s1,encode,null);
}
//测试
public static void main(String []args){
System.err.println(isEq(new byte[]{1,2},new byte[]{1,2}));
}
/**
* 字节数组转16进制字符串
* @param b
* @return
*/
public static String byteArrToHexString(byte[] b){
String result="";
for (int i=0; i < b.length; i++) {
result += Integer.toString( ( b[i] & 0xff ) + 0x100, 16).substring(1);
}
return result;
} /**
* 16进制字符创转int
* @param hexString
* @return
*/
public static int hexStringToInt(String hexString){
return Integer.parseInt(hexString,16);
}
/**
* 十进制转二进制
* @param i
* @return
*/
public static String intToBinary(int i){
return Integer.toBinaryString(i);
}
}