//char数组转换成byte数组
private byte[] getBytes (char[] chars) {
Charset cs = Charset.forName ("UTF-8");
CharBuffer cb = CharBuffer.allocate (chars.length);
cb.put (chars);
cb.flip ();
ByteBuffer bb = cs.encode (cb);
return bb.array();
}
//byte数组转换成char数组
private char[] getChars (byte[] bytes) {
Charset cs = Charset.forName ("UTF-8");
ByteBuffer bb = ByteBuffer.allocate (bytes.length);
bb.put (bytes);
bb.flip ();
CharBuffer cb = cs.decode (bb);
return cb.array();
}
//常用函数 package com.boomdts.weather_monitor.util; import java.nio.charset.Charset;
import java.io.*;
import java.text.SimpleDateFormat;
import java.text.DecimalFormat;
import java.util.GregorianCalendar;
import java.util.Calendar;
import java.util.Date;
import java.math.BigDecimal; public class CommonFunctions
{ //世纪秒(是指1970年1月1日0时0分到指定时间过去的秒数)转换为年月日，时分秒 public static String centurySecondToDateTime(long time)
{
Calendar ca = Calendar.getInstance();
//Date d = ca.getTime();
//long l = ca.getTimeInMillis();
//ca.set(1970, 0, 1);
//long L1970 = ca.getTimeInMillis();
//ca.setTime(d);
//ca.setTimeInMillis(l); String out = "";
GregorianCalendar gc = new GregorianCalendar();
//System.out.print( "上传上来的毫秒数 :" + time*1000 );
gc.setTimeInMillis(time * 1000);
SimpleDateFormat sdformat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
out = sdformat.format(gc.getTime()); return out;
} //将十六进制字符串转换为double, 41AEF5C2
public static float hexStrToFloat(String str)
{
float result = 0;
try
{
int temp = Integer.parseInt(str.trim(), 16);
result = Float.intBitsToFloat(temp);
}
catch (NumberFormatException e)
{
long ltemp = Long.parseLong(str.trim(), 16);
//long ltemp = Integer.parseInt(str.trim(), 16);
result = Float.intBitsToFloat((int)ltemp);
}
//只保留小数点后两位
//result = (float)(Math.round(result*100))/100;
return result;
} //输入16进制字符串(如 5a5b5c)，输出相反顺序的16进制字符串(5c5b5a)。
public static String reverseOrder(String s)
{ char[] chA = s.toCharArray();
int l = s.length();
for(int i =0; i< l/2; i=i+2)
{
char cTmp1= 0;
char cTmp2= 0;
cTmp1 = chA[i];
cTmp2 = chA[i+1];
chA[i] = chA[l-i-2];
chA[i+1] = chA[l-i-1];
chA[l-i-2] = cTmp1;
chA[l-i-1] = cTmp2;
}
String sRet = new String(chA);
return sRet;
}
/**
* 字符串转换成十六进制字符串
* @param String str 待转换的ASCII字符串
* @return String 如: [616C6B]
*/
public static String strToHexStr(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]);
//sb.append(' ');
}
return sb.toString().trim();
} /**
* 十六进制转换字符串
* @param String str Byte字符串(Byte之间无分隔符 如:[616C6B])
* @return String 对应的字符串
*/
public static String hexStrToStr(String hexStr)
{
String str = "0123456789ABCDEF";
char[] hexs = hexStr.toCharArray();
byte[] bytes = new byte[hexStr.length() / 2];
int n; for (int i = 0; i < bytes.length; i++)
{
n = str.indexOf(hexs[2 * i]) * 16;
n += str.indexOf(hexs[2 * i + 1]);
bytes[i] = (byte) (n & 0xff);
}
return new String(bytes);
} /**
* bytes转换成十六进制字符串
* @param byte[] b byte数组
* @return String 每个Byte值之间空格分隔
*/
public static String byteToHexStr(byte[] b)
{
String stmp="";
StringBuilder sb = new StringBuilder("");
for (int n=0;n<b.length;n++)
{
stmp = Integer.toHexString(b[n] & 0xFF);
sb.append((stmp.length()==1)? "0"+stmp : stmp);
//sb.append(" ");
}
return sb.toString().toUpperCase().trim();
} /**
* bytes字符串转换为Byte值
* @param String src Byte字符串，每个Byte之间没有分隔符
* @return byte[]
*/
public static byte[] hexStrToBytes(String src)
{
int m=0,n=0;
int cc = src.length();
if(cc%2 != 0){
System.out.println("函数 hexStrToBytes 输入的字符为奇数，这有可能会有问题,输入的字符个数是: " + cc);
}
int l=src.length()/2;
byte[] ret = new byte[l];
String sSub ;
for (int i = 0; i < l; i++)
{
sSub = src.substring(i*2,i*2+2);
ret[i] = (byte)( Integer.parseInt(sSub, 16) ); /*
m=i*2+1;
n=m+1;
ret[i] = Byte.decode("0x" + src.substring(i*2, m) + src.substring(m,n));
*/
}
return ret;
} /**
* String的字符串转换成unicode的String
* @param String strText 全角字符串
* @return String 每个unicode之间无分隔符
* @throws Exception
*/
public static String strToUnicode(String strText)
throws Exception
{
char c;
StringBuilder str = new StringBuilder();
int intAsc;
String strHex;
for (int i = 0; i < strText.length(); i++)
{
c = strText.charAt(i);
intAsc = (int) c;
strHex = Integer.toHexString(intAsc);
if (intAsc > 128)
str.append("\\u" + strHex);
else // 低位在前面补00
str.append("\\u00" + strHex);
}
return str.toString();
} /**
* unicode的String转换成String的字符串
* @param String hex 16进制值字符串 （一个unicode为2byte）
* @return String 全角字符串
*/
public static String unicodeToString(String hex)
{
int t = hex.length() / 6;
StringBuilder str = new StringBuilder();
for (int i = 0; i < t; i++)
{
String s = hex.substring(i * 6, (i + 1) * 6);
// 高位需要补上00再转
String s1 = s.substring(2, 4) + "00";
// 低位直接转
String s2 = s.substring(4);
// 将16进制的string转为int
int n = Integer.valueOf(s1, 16) + Integer.valueOf(s2, 16);
// 将int转换为字符
char[] chars = Character.toChars(n);
str.append(new String(chars));
}
return str.toString();
}
/**
* 截取byte数据
* @param b 是byte数组
* @param j 是大小
* @return
*/
public static byte[] cutOutByte(byte[] b,int j){
if(b.length==0 || j==0){
return null;
}
byte[] bjq = new byte[j];
for(int i = 0; i<j;i++){
bjq[i]=b[i];
}
return bjq;
}
/**
* 合并两个byte数组
* @param pByteA
* @param pByteB
* @return
*/
public static byte[] getMergeBytes(byte[] pByteA, byte[] pByteB){
int aCount = pByteA.length;
int bCount = pByteB.length;
byte[] b = new byte[aCount + bCount];
for(int i=0;i<aCount;i++){
b[i] = pByteA[i];
}
for(int i=0;i<bCount;i++){
b[aCount + i] = pByteB[i];
}
return b;
} /**
* 字符转换为日期类型
* @param dateString
* @return
*/
public static Date parseDateTime(String dateString) {
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date result = null;
try {
result = df.parse(dateString);
} catch (Exception e) {
}
return result;
} /**
* 两个日期相减计算多少天
* @param firstDate
* @param lastDate
* @return A double days
*/
public static int compareDateToDays(Date firstDate, Date lastDate) {
if (firstDate == null || lastDate == null) {
System.out.print("NULL");
}
long time1 = firstDate.getTime();
long time2 = lastDate.getTime();
long tmpCal = time2 - time1;
long mm = 24 * 60 * 60 * 1000;
int days = (int) (tmpCal / mm);
return Math.abs(days);
} }