Java算法大全,java进制装换,java日期转换
2024-04-24 11:05:39
// 十进制转化为十六进制，结果为C8。 Integer.toHexString(200); // 十六进制转化为十进制，结果140。 Integer.parseInt("8C",16); Java的16进制与字符串的相互转换函数/** * 将指定byte数组以16进制的形式打印到控制台 * @param hint String * @param b byte[] * @return void */ public static void printHexString(String hint, byte[] b) { System.out.print(hint); for (int i = 0; i < b.length; i++) { String hex = Integer.toHexString(b[i] & 0xFF); if (hex.length() == 1) { hex = '0' + hex; } System.out.print(hex.toUpperCase() + " "); } System.out.println(""); }/** * * @param b byte[] * @return String 字节转字符串*/ public static String Bytes2HexString(byte[] b) { String ret = ""; for (int i = 0; i < b.length; i++) { String hex = Integer.toHexString(b[i] & 0xFF); if (hex.length() == 1) { hex = '0' + hex; } ret += hex.toUpperCase(); } return ret; }/** * 将两个ASCII字符合成一个字节； * 如："EF"--> 0xEF * @param src0 byte * @param src1 byte * @return byte */ public static byte uniteBytes(byte src0, byte src1) { byte _b0 = Byte.decode("0x" + new String(new byte[]{src0})).byteValue(); _b0 = (byte)(_b0 << 4); byte _b1 = Byte.decode("0x" + new String(new byte[]{src1})).byteValue(); byte ret = (byte)(_b0 ^ _b1); return ret; }/** * 将指定字符串src，以每两个字符分割转换为16进制形式 * 如："2B44EFD9" --> byte[]{0x2B, 0x44, 0xEF, 0xD9} * @param src String * @return byte[] */ public static byte[] HexString2Bytes(String src){ byte[] ret = new byte[8]; byte[] tmp = src.getBytes(); for(int i=0; i<8; i++){ ret[i] = uniteBytes(tmp[i*2], tmp[i*2+1]); } return ret; 14. }CRC16Utilpackage com.sunwei.sim4xian;import sun.misc.CRC16;public class Crc16Util {private static final byte[] hex = "0123456789ABCDEF".getBytes(); public static int getCRC16(byte[] data) {int CRCTABLE[] = { 0xF078, 0xE1F1, 0xD36A, 0xC2E3, 0xB65C, 0xA7D5,0x954E, 0x84C7, 0x7C30, 0x6DB9, 0x5F22, 0x4EAB, 0x3A14, 0x2B9D,0x1906, 0x088F, 0xE0F9, 0xF170, 0xC3EB, 0xD262, 0xA6DD, 0xB754,0x85CF, 0x9446, 0x6CB1, 0x7D38, 0x4FA3, 0x5E2A, 0x2A95, 0x3B1C,0x0987, 0x180E, 0xD17A, 0xC0F3, 0xF268, 0xE3E1, 0x975E, 0x86D7,0xB44C, 0xA5C5, 0x5D32, 0x4CBB, 0x7E20, 0x6FA9, 0x1B16, 0x0A9F,0x3804, 0x298D, 0xC1FB, 0xD072, 0xE2E9, 0xF360, 0x87DF, 0x9656,0xA4CD, 0xB544, 0x4DB3, 0x5C3A, 0x6EA1, 0x7F28, 0x0B97, 0x1A1E,0x2885, 0x390C, 0xB27C, 0xA3F5, 0x916E, 0x80E7, 0xF458, 0xE5D1,0xD74A, 0xC6C3, 0x3E34, 0x2FBD, 0x1D26, 0x0CAF, 0x7810, 0x6999,0x5B02, 0x4A8B, 0xA2FD, 0xB374, 0x81EF, 0x9066, 0xE4D9, 0xF550,0xC7CB, 0xD642, 0x2EB5, 0x3F3C, 0x0DA7, 0x1C2E, 0x6891, 0x7918,0x4B83, 0x5A0A, 0x937E, 0x82F7, 0xB06C, 0xA1E5, 0xD55A, 0xC4D3,0xF648, 0xE7C1, 0x1F36, 0x0EBF, 0x3C24, 0x2DAD, 0x5912, 0x489B,0x7A00, 0x6B89, 0x83FF, 0x9276, 0xA0ED, 0xB164, 0xC5DB, 0xD452,0xE6C9, 0xF740, 0x0FB7, 0x1E3E, 0x2CA5, 0x3D2C, 0x4993, 0x581A,0x6A81, 0x7B08, 0x7470, 0x65F9, 0x5762, 0x46EB, 0x3254, 0x23DD,0x1146, 0x00CF, 0xF838, 0xE9B1, 0xDB2A, 0xCAA3, 0xBE1C, 0xAF95,0x9D0E, 0x8C87, 0x64F1, 0x7578, 0x47E3, 0x566A, 0x22D5, 0x335C,0x01C7, 0x104E, 0xE8B9, 0xF930, 0xCBAB, 0xDA22, 0xAE9D, 0xBF14,0x8D8F, 0x9C06, 0x5572, 0x44FB, 0x7660, 0x67E9, 0x1356, 0x02DF,0x3044, 0x21CD, 0xD93A, 0xC8B3, 0xFA28, 0xEBA1, 0x9F1E, 0x8E97,0xBC0C, 0xAD85, 0x45F3, 0x547A, 0x66E1, 0x7768, 0x03D7, 0x125E,0x20C5, 0x314C, 0xC9BB, 0xD832, 0xEAA9, 0xFB20, 0x8F9F, 0x9E16,0xAC8D, 0xBD04, 0x3674, 0x27FD, 0x1566, 0x04EF, 0x7050, 0x61D9,0x5342, 0x42CB, 0xBA3C, 0xABB5, 0x992E, 0x88A7, 0xFC18, 0xED91,0xDF0A, 0xCE83, 0x26F5, 0x377C, 0x05E7, 0x146E, 0x60D1, 0x7158,0x43C3, 0x524A, 0xAABD, 0xBB34, 0x89AF, 0x9826, 0xEC99, 0xFD10,0xCF8B, 0xDE02, 0x1776, 0x06FF, 0x3464, 0x25ED, 0x5152, 0x40DB,0x7240, 0x63C9, 0x9B3E, 0x8AB7, 0xB82C, 0xA9A5, 0xDD1A, 0xCC93,0xFE08, 0xEF81, 0x07F7, 0x167E, 0x24E5, 0x356C, 0x41D3, 0x505A,0x62C1, 0x7348, 0x8BBF, 0x9A36, 0xA8AD, 0xB924, 0xCD9B, 0xDC12,0xEE89, 0xFF00 };int CRCVal = 0;int i = 0;for (i = 0; i < data.length; i++) {CRCVal = CRCTABLE[(CRCVal ^= ((data[i]) & 0xFF)) & 0xFF]^ (CRCVal >> 8);}// return Integer.toHexString(CRCVal);
// return String.valueOf(CRCVal);return CRCVal;}public static String crcTable(byte[] bytes) {int[] table = { 0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280,0xC241, 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481,0x0440, 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81,0x0E40, 0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880,0xC841, 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81,0x1A40, 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80,0xDC41, 0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680,0xD641, 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081,0x1040, 0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281,0x3240, 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480,0xF441, 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80,0xFE41, 0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881,0x3840, 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80,0xEA41, 0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81,0x2C40, 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681,0x2640, 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080,0xE041, 0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281,0x6240, 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480,0xA441, 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80,0xAE41, 0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881,0x6840, 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80,0xBA41, 0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81,0x7C40, 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681,0x7640, 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080,0xB041, 0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280,0x9241, 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481,0x5440, 0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81,0x5E40, 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880,0x9841, 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81,0x4A40, 0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80,0x8C41, 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680,0x8641, 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081,0x4040, };int crc = 0x0000;for (byte b : bytes) {crc = (crc >>> 8) ^ table[(crc ^ b) & 0xff];}return Integer.toHexString(crc);}public static String mkCrc16(byte[] b) {CRC16 crc16 = new CRC16();for (int i = 0; i < b.length; i++) {crc16.update(b[i]);}return Integer.toHexString(crc16.value);}public static final String evalCRC16(byte[] data) {int crc = 0xFFFF;for (int i = 0; i < data.length; i++) {crc = (data[i] << 8) ^ crc;for (int j = 0; j < 8; ++j) {if ((crc & 0x8000) != 0)crc = (crc << 1) ^ 0x1021;elsecrc <<= 1;}}return Integer.toHexString((crc ^ 0xFFFF) & 0xFFFF);}private static int parse(char c) {if (c >= 'a') {return (c - 'a' + 10) & 0x0f;}if (c >= 'A') {return (c - 'A' + 10) & 0x0f;}return (c - '0') & 0x0f;}public static byte[] HexString2Bytes(String hexstr) {byte[] b = new byte[hexstr.length() / 2];int j = 0;for (int i = 0; i < b.length; i++) {char c0 = hexstr.charAt(j++);char c1 = hexstr.charAt(j++);b[i] = (byte) ((parse(c0) << 4) | parse(c1));}return b;}public static void main(String[] args) {//byte[] test = Crc16Util.HexString2Bytes("0200fb000130");byte[] test = {(byte)0x21, (byte)0x02, (byte)0x64,(byte)0x80, (byte)0x00, (byte)0x00,(byte)0x80, (byte)0x00, (byte)0x9c, (byte)0x47,(byte)0x00, (byte)0x37,(byte)0x00, (byte)0x00,(byte)0x0C,(byte)0x31,(byte)0x30, (byte)0x30, (byte)0x34, (byte)0x30, (byte)0x30,(byte)0x39, (byte)0x39, (byte)0x71,(byte)0x30, (byte)0x30, (byte)0x34, (byte)0x33, (byte)0x30, (byte)0x30, (byte)0x30, (byte)0x31,(byte)0x33, (byte)0x30, (byte)0x39, (byte)0x34, (byte)0x39, (byte)0x32, (byte)0x39,(byte)0x33, (byte)0x34, (byte)0x31, (byte)0x35, (byte)0x35, (byte)0x39,(byte)0x4E,(byte)0x31, (byte)0x30, (byte)0x39, (byte)0x30, (byte)0x30, (byte)0x30, (byte)0x30,(byte)0x45,(byte)0x00};System.out.println(Crc16Util.mkCrc16(test));System.out.println(Crc16Util.evalCRC16(test));System.out.println(Crc16Util.crcTable(test));System.out.println(Crc16Util.getCRC16(test));}
}JAVA时间格式化处理import java.util.Date;
import java.text.SimpleDateFormat;
class dayTime
{
public static void main(String args[])
{
Date nowTime=new Date();
System.out.println(nowTime);
SimpleDateFormat time=new SimpleDateFormat("yyyy MM dd HH mm ss");
System.out.println(time.format(nowTime));
}
}将毫秒转化为日期import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.TextArea;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.text.SimpleDateFormat;
import java.util.Date;
public class ConvertLong2Date extends Frame{TextField tf = new TextField();TextArea ta = new TextArea();public static void main(String[] args) {new ConvertLong2Date().launchFrame();}public String convertL2D(long l) {long _l = 0L;Date _d = null;SimpleDateFormat _sdf = null;String _s = null;_l = l;_d = new Date(_l);_sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");_s = _sdf.format(_d);return _s;}public void launchFrame() {setLocation(300, 300);setSize(480, 320);setResizable(false);add(tf,BorderLayout.SOUTH);add(ta,BorderLayout.NORTH);pack();tf.addActionListener(new tfActionListener());this.setVisible(true);this.addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {System.exit(0);}});}public class tfActionListener implements ActionListener {public void actionPerformed(ActionEvent e) {long l = Long.parseLong(tf.getText());ta.setText(new ConvertLong2Date().convertL2D(l));tf.setText("");}}
}文本的倒序输出文件before:
Hello
World
要求输出文件after:
World
Hello
代码如下：import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.ListIterator;public class ReverseOrder extends ArrayList {public static String read(String fileName) throws IOException {StringBuffer sb = new StringBuffer();LinkedList lines = new LinkedList();BufferedReader in = new BufferedReader(new FileReader(fileName));String s;while ((s = in.readLine()) != null)lines.add(s);in.close();ListIterator it = lines.listIterator(lines.size());while (it.hasPrevious()) {sb.append(it.previous());sb.append("\n");}return sb.toString();}public static void write(String fileName, String text) throws IOException {PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(fileName)));out.print(text);out.close();}public ReverseOrder(String fileName) throws IOException {super(Arrays.asList(read(fileName).split("\n")));}public void write(String fileName) throws IOException {PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(fileName)));for (int i = 0; i < size(); i++)out.println(get(i));out.close();}public static void main(String[] args) throws Exception {String fileName = "e:\\1124\\before.txt";ReverseOrder text = new ReverseOrder(fileName);text.write("e:\\1124\\after.txt");}/** 最后会多一个空行，手工删除一下*/
}判断一个数字是奇数还是偶数判断一个数是否是奇数：
public static boolean isOdd(int i) {return (i&1) != 0;
}判断一个数是否是偶数
public static boolean isEven(int i) {return (i&1) = 0;
}//位运算符说明在java文件夹里面用Hibernate实现分页 public List queryByStatus(int status, int currentPage, int lineSize)throws Exception {List all = null;String hql = "FROM Question AS q WHERE q.status=? ORDER BY q.questiontime desc";Query q = super.getSession().createQuery(hql);q.setInteger(0, status);q.setFirstResult((currentPage - 1) * lineSize);q.setMaxResults(lineSize);all = q.list();return all;}35选7彩票程序public class caipiao
{ static void generate() { int a[]=new int[7]; int i,m,j; fan:for(j=0;j <7;j++){//外循环实现随机生成每组7个数 a[j]=(int)(Math.random()*35+1); m=a[j]; if(j>=1){ for(i=0;i <j;i++)//内循环实现无重复 if(a[i]==m){ j--; continue fan; } } if(a[j] <10) System.out.print("0"+a[j]+" "); else System.out.print(a[j]+" "); } }
public static void main (String args[]){
int n=Integer.parseInt(args[0]);
System.out.println("中国福利彩票35选7");
for(int i=0;i <n;i++){//循环调用方法实现输出n组数
generate();
System.out.println(); }
}
}获取GMT8时间/*** Description: 获取GMT8时间* @return 将当前时间转换为GMT8时区后的Date*/public static Date getGMT8Time(){Date gmt8 = null;try {Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT+8"),Locale.CHINESE); Calendar day = Calendar.getInstance();day.set(Calendar.YEAR, cal.get(Calendar.YEAR));day.set(Calendar.MONTH, cal.get(Calendar.MONTH));day.set(Calendar.DATE, cal.get(Calendar.DATE));day.set(Calendar.HOUR_OF_DAY, cal.get(Calendar.HOUR_OF_DAY));day.set(Calendar.MINUTE, cal.get(Calendar.MINUTE));day.set(Calendar.SECOND, cal.get(Calendar.SECOND));gmt8 = day.getTime();} catch (Exception e) {System.out.println("获取GMT8时间 getGMT8Time() error !");e.printStackTrace();gmt8 = null;}return gmt8;}中文乱码转换public String china(String args)
{ String s=null; String s=new String(args.getBytes("ISO-8859-1"),"gb2312"); return s;
}小标签 import java.io.IOException;
import java.util.List; import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport; import com.formcontent.show.ShowFormTypeOperateDb;
import com.forum.hibernatePrj.Space;
public class OutPrintForumType extends TagSupport{ public int doStartTag() throws JspException { String printStr=""; ShowFormTypeOperateDb showtype=new ShowFormTypeOperateDb(); List list=showtype.getForumType();
if(list!=null&&list.size()>0)
{ for(int i=0;i <list.size();i++) { Space space=(Space)list.get(i); if(space!=null) {
printStr+=" <tr> <td>"+" <div align='left' class='TypeCss'>"+ space.getSpaceName()+" "+space.getSpaceDescription()+" <br/>目前登陆总人数:"+i+" 人访问数:"+i+"人 </div> </td> </tr>" +" <tr> <td> </td> </tr>"; } }
} try {
pageContext.getOut().write(printStr);
} catch (IOException e) {
e.printStackTrace();
} return super.doStartTag(); } }Big5字与Unicode的互换/**
* Big5字与Unicode的互换
* 转换后的正常字型
*/import java.io.*;public class MyUtil{public static String big5ToUnicode(String s){try{return new String(s.getBytes("ISO8859_1"), "Big5");}catch (UnsupportedEncodingException uee){return s;}}public static String UnicodeTobig5(String s){try{return new String(s.getBytes("Big5"), "ISO8859_1");}catch (UnsupportedEncodingException uee){return s;}}public static String toHexString(String s){String str="";for (int i=0; i<s.length(); i++){int ch=(int)s.charAt(i);String s4="0000"+Integer.toHexString(ch);str=str+s4.substring(s4.length()-4)+" ";}return str;}
}取得服务器当前的各种具体时间/**
* 取得服务器当前的各种具体时间
* 回车：日期时间
*/import java.util.*;public class GetNowDate{Calendar calendar = null;public GetNowDate(){calendar = Calendar.getInstance();calendar.setTime(new Date());}public int getYear(){return calendar.get(Calendar.YEAR);}public int getMonth(){return 1 + calendar.get(Calendar.MONTH);}public int getDay(){return calendar.get(Calendar.DAY_OF_MONTH); } public int getHour(){return calendar.get(Calendar.HOUR_OF_DAY); } public int getMinute(){return calendar.get(Calendar.MINUTE);}public int getSecond(){return calendar.get(Calendar.SECOND);}public String getDate(){return getMonth()+"/"+getDay()+"/"+getYear();}public String getTime(){return getHour()+":"+getMinute()+":"+getSecond();}public String getDate2(){String yyyy="0000", mm="00", dd="00";yyyy = yyyy + getYear();mm = mm + getMonth();dd = dd + getDay();yyyy = yyyy.substring(yyyy.length()-4);mm = mm.substring(mm.length()-2);dd = dd.substring(dd.length()-2);return yyyy + "/" + mm + "/" + dd;}public String getTime2(){String hh="00", mm="00", ss="00";hh = hh + getHour();mm = mm + getMinute();ss = ss + getSecond();hh = hh.substring(hh.length()-2, hh.length());mm = mm.substring(mm.length()-2, mm.length());ss = ss.substring(ss.length()-2, ss.length());return hh + ":" + mm + ":" + ss;}
}用半角的特殊符号代替全角的特殊符号/**
* 用半角的特殊符号代替全角的特殊符号
* 防止特殊字符在传输参数时出现错误
*
*/public class ReplaceStrE{public static String rightToError(String ss){String strs;String strs1;String strs2;String strs3;String strs4;try{strs = ss.replace('＃','#');}catch(Exception ex){return ss;}try{strs1 = strs.replace('＂','"');}catch(Exception ex){return strs;}try{strs2 = strs1.replace(' ','&');}catch(Exception ex){return strs1;}try{strs3 = strs2.replace('＋','+');}catch(Exception ex){return strs2;}try{strs4 = strs3.replace('＇','\'');}catch(Exception ex){return ss;}return strs4;}
}数组和数组之间的转换代码import java.lang.reflect.Array;
import java.util.Date;public class TestCast {/*** @param args*///public static void main(String[] args) {/** *//*** * 一般情况下数组和数组是不能直接进行转换的,例如:* Object[] t1={"1","2"};* String[] t2=(String[])t1;//这里会出现转换错误* * 下面提供了一种方式进行转换*///1.0测试一般基础类/* Object[] t1={"1","2","3","4","5"};String[] m1=(String[])TestCast.cast(t1,String.class);for(int i=0;i<m1.length;i++)System.out.println(m1[i]);//2.0测试复杂对象Object[] t2={new Date(1000),new Date(2000)};Date[] m2=(Date[])TestCast.cast(t2,Date.class);for(int i=0;i<m2.length;i++)System.out.println(m2[i].toString());*/// } /** *//*** 将数组array转换成clss代表的类型后返回* @param array 需要转换的数组* @param clss 要转换成的类型* @return 转换后的数组*/public static Object cast(Object array,Class clss){if(null==clss)throw new IllegalArgumentException("argument clss cannot be null");if(null==array)throw new IllegalArgumentException("argument array cannot be null");if(false==array.getClass().isArray())throw new IllegalArgumentException("argument array must be array");Object[] src=(Object[])array;Object[] dest=(Object[])Array.newInstance(clss, src.length);System.arraycopy(src, 0, dest, 0, src.length);return dest;}}从资源文件里读取值的类从资源文件里读取值的类，文件后缀不一定要.Properties，只要里面内容如：url=www.cnsec.net
可通过key（url）取得值-www.cnsec.net，简单、强大
Java code import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;
/*** ReadProperties.java* Description: 读取操作属性配置文件* @author li.b* @version 2.0* Jun 26, 2008*/
public class ReadProperties {/*** Description: 获取属性配置文件* @param path 资源文件路径* @return Properties Object* @throws FileNotFoundException* @throws IOException*/public static Properties getProperties(String path) throws FileNotFoundException, IOException{Properties props = null;File file = new File(path);if(file.exists() && file.isFile()){props = new Properties();props.load(new FileInputStream(file));}else{System.out.println(file.toString() + "不存在！");}return props;}/*** Description: 从属性文件获取值* @param props Properties Object* @param key* @return 通过key匹配到的value*/public static String getValue(Properties props,String key,String encod){String result = "";String en = "";String localEN = System.getProperty("file.encoding");if(encod !=null && !encod.equals("") ){en = encod;}else{en = localEN;}try {key = new String(key.getBytes(en),"ISO-8859-1");result = props.getProperty(key);if(!result.equals("")){result = new String(result.getBytes("ISO-8859-1"),en); }} catch (Exception e) {}finally{if(result == null)result = "";return result;}}public static String getValue(Properties props,String key){return getValue(props, key, "");}}一个随机类/*
* @author talent_marquis<��˺��>
* Email: talent_marquis@163.com
* Copyright (C) 2007 talent_marquis<��˺��>
* All rights reserved.
*/
package com.dextrys.trilogy.util;import java.util.Arrays;import org.eclipse.swt.graphics.RGB;public class RandomUtil
{/*** @param args*/public static void main( String[] args ){//System.out.println( getRandomNormalString( 8 ) );int[] test = getRandomIntWithoutReduplicate( 0, 40, 39 );Arrays.sort( test );for( int i : test ){System.out.println( i );}}/*** get a integer array filled with random integer without reduplicate [min, max)* @param min the minimum value* @param max the maximum value* @param size the capacity of the array* @return a integer array filled with random integer without redupulicate*/public static int[] getRandomIntWithoutReduplicate( int min, int max, int size ){int[] result = new int[size];int arraySize = max - min;int[] intArray = new int[arraySize];// init intArrayfor( int i = 0 ; i < intArray.length ; i++ ){intArray[i] = i + min;}// get randome interger without reduplicatefor( int i = 0 ; i < size ; i++ ){int c = getRandomInt( min, max - i );int index = c - min;swap( intArray, index, arraySize - 1 - i );result[i] = intArray[ arraySize - 1 - i ];}return result;}private static void swap( int[] array, int x, int y ){int temp = array[x];array[x] = array[y];array[y] = temp;}/*** get a random Integer with the range [min, max)* @param min the minimum value* @param max the maximum value* @return the random Integer value*/public static int getRandomInt( int min, int max ){// include min, exclude maxint result = min + new Double( Math.random() * ( max - min ) ).intValue();return result;}/*** get a random double with the range [min, max)* @param min the minimum value* @param max the maximum value* @return the random double value*/public static double getRandomDouble( double min, double max ){// include min, exclude maxdouble result = min + ( Math.random() * ( max - min ) );return result;}/*** * @return a random char with the range ASCII 33(!) to ASCII 126(~)*/public static char getRandomChar(){// from ASCII code 33 to ASCII code 126int firstChar = 33; // "!"int lastChar = 126; // "~"char result = ( char ) ( getRandomInt( firstChar, lastChar + 1 ) );return result;}/*** * @return a random rgb color*/public static RGB getRandomRGB(){int red = getRandomInt(0,256);int green = getRandomInt(0,256);int blue = getRandomInt(0,256);return new RGB( red, green, blue );}/*** * @return a random char with the range [0-9],[a-z],[A-Z]*/public static char getRandomNormalChar(){// include 0-9,a-z,A-Zint number = getRandomInt( 0, 62 );int zeroChar = 48;int nineChar = 57;int aChar = 97;int zChar = 122;int AChar = 65;int ZChar = 90;char result;if( number < 10 ){result = ( char ) ( getRandomInt( zeroChar, nineChar + 1 ) );return result;}else if( number >= 10 && number < 36 ){result = ( char ) ( getRandomInt( AChar, ZChar + 1 ) );return result;}else if( number >= 36 && number < 62 ){result = ( char ) ( getRandomInt( aChar, zChar + 1 ) );return result;}else{return 0;}}/*** * @param length the length of the String* @return a String filled with random char*/public static String getRandomString( int length ){// include ASCII code from 33 to 126StringBuffer result = new StringBuffer();for( int i = 0; i < length; i++ ){result.append( getRandomChar() );}return result.toString();}/*** * @param length the length of the String* @return a String filled with normal random char*/public static String getRandomNormalString( int length ){// include 0-9,a-z,A-ZStringBuffer result = new StringBuffer();for( int i = 0; i < length; i++){result.append( getRandomNormalChar() );}return result.toString();}
}计算传入值是否星期六/**
* 计算传入值是否星期六
* 回车：true or false
*/import java.util.*;public class Week6 {public boolean checkWeek6(String str){boolean flag=false;int week6=0;str.replace('/','-');Calendar cal=Calendar.getInstance();cal.setTime(java.sql.Date.valueOf(str.substring(0,10)));week6=cal.get(Calendar.DAY_OF_WEEK);if(week6==7){flag=true;}return flag;}
}为RootPaneContainer组件添加键盘事件/*** 为RootPaneContainer组件添加键盘事件* @param rpc RootPaneContainer组件* @param action 需要执行的动作* @param keyName 键的名称* @param keyCode 键的数字代码* @param modifiers 任意修饰符的按位或组合*/public static void registerKeyEvent(RootPaneContainer rpc, Action action, String keyName, int keyCode, int modifiers){JRootPane rp = rpc.getRootPane();InputMap inputMap = rp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);inputMap.put(KeyStroke.getKeyStroke(keyCode, modifiers), keyName);rp.getActionMap().put(keyName, action);}将数组转成字符串 在调试或记录日志时用到/*** 将数组转成字符串 在调试或记录日志时用到* * @param array* @return*/public static String byte2string(byte[] array) {StringBuilder sb = new StringBuilder();sb.append("Length " + array.length + " Content ");for (int i = 0; i < leng; i++) {sb = sb.append(String.format("%02X", array[i])).append(":");}int ind = sb.lastIndexOf(":");sb.delete(ind, ind + 1);return sb.toString();}转换文件大小 import java.text.DecimalFormat;
import java.util.Hashtable;/**
* 文件大小单位转换
* @author Administrator
*
*/
public class UnitsConversion extends DecimalFormat {private static final long serialVersionUID = 3168068393840262910L;/*** 存放有效单位的数组*/private static Hashtable<String, String> validUnits = new Hashtable<String, String>();/*** 限制文件大小上限为1G*/private static int GB_MAX_SIZE = 1;/*** 最大的MB值*/private static int MB_MAX_SIZE = GB_MAX_SIZE * 1024;/*** 最大的KB值*/private static int KB_MAX_SIZE = MB_MAX_SIZE * 1024;/*** 最大的Bytes值*/private static int BYTES_MAX_SIZE = KB_MAX_SIZE * 1024;/*** 数字部分的值*/private Double numPart;/*** 原始的单位字符串*/private String originalUnit;/*** 标准的单位字符串*/private String unit;/*** 转换后的结果*/private String result;// 添加所有有效单位static {validUnits.put("字节", "Bytes");validUnits.put("bytes", "Bytes");validUnits.put("byte", "Bytes");validUnits.put("kb", "KB");validUnits.put("k", "KB");validUnits.put("兆", "MB");validUnits.put("mb", "MB");validUnits.put("m", "MB");validUnits.put("gb", "GB");validUnits.put("g", "GB");}/*** 构造方法：指定了数字格式，初始所有属性为NULL*/public UnitsConversion() {super("########.##");numPart = null;result = null;unit = null;originalUnit = null;}/*** 根据单位、数字大小按照常用的转换原则进行转换* * @param input* @return 成功转换后的结果是非空字符串；若失败了，结果为空字符串*/public String defaultConversion(String input) {analyzeString(input);if (result != null) {return result;}// 单位 Bytesif (unit.equals("Bytes")) {int numPart2Int = numPart.intValue();// 输入大小与1G相差0.5M之内，返回1GBif ((BYTES_MAX_SIZE - numPart2Int) < (1024 * 1024) / 2) {return "1 GB";}// (0,1KB)if (numPart2Int < 1024) {return numPart2Int + " Bytes";}// [1KB,1023KB]if (numPart2Int >= 1024 && numPart2Int <= (1024 - 1) * 1024) {return format(numPart / 1024) + " KB";}// (1023KB,1GB)if (numPart2Int > (1024 - 1) * 1024 && numPart2Int < BYTES_MAX_SIZE) {return format(numPart / (1024 * 1024)) + " MB";} elseresult = "";return result;}if (unit.equals("KB")) {return "还没实现....";}if (unit.equals("MB")) {return "还没实现....";}if (unit.equals("GB")) {return "还没实现....";}result = "";return result;}/** * 把字符串的数字部分与单位分离，并对数字、单位的有效性进行检验， 若有非法状况，把结果赋值为 "" ，将其返回给用户 * * @param input*/public void analyzeString(String input) {// 初步检验输入的字符串if (input == null || input.trim().length() < 2) {System.out.println("输入的字符串有误");result = "";return;}input = input.replaceAll(" ", "");int firstIndexOfUnit;// 单位的起始位置String strOfNum;// 数字部分的字符串// 从尾部开始遍历字符串for (int i = input.length() - 1; i >= 0; i--) {if (Character.isDigit(input.charAt(i))) {firstIndexOfUnit = i + 1;originalUnit = input.substring(firstIndexOfUnit,input.length()).toLowerCase();if (!isValidUnit(originalUnit)) {System.out.println("无效单位。");result = "";return;}unit = validUnits.get(originalUnit);strOfNum = input.substring(0, firstIndexOfUnit);numPart = Double.parseDouble(strOfNum);if (!isValidNum(numPart, unit)) {System.out.println("文件大小非法");result = "";return;}if (numPart == 0) {result = "0 Bytes";return;}break;}}if (unit == null || numPart == null) {System.out.println("输入的字符串有误");result = "";return;}}/*** 文件大小越界检查* * @param num* @param unit* @return 在1G范围内（包括1G），返回true；否则返回false*/public boolean isValidNum(Double num, String unit) {if (num == null || num < 0 || num > BYTES_MAX_SIZE) {return false;}if (unit.equals("KB") && num > KB_MAX_SIZE) {return false;}if (unit.equals("MB") && num > MB_MAX_SIZE) {return false;}if (unit.equals("GB") && num > GB_MAX_SIZE) {return false;}return true;}/*** 检查原始单位originalUnit是否有效* * @param originalUnit* @return 若originalUnit为空，那么会给他赋默认值 bytes ，并返回true；<br>* 若originalUnit是有效单位集合中之一，返回true。*/public boolean isValidUnit(String originalUnit) {if (originalUnit == null || originalUnit.trim().length() < 1) {originalUnit = "bytes";return true;}for (String validUnit : validUnits.keySet()) {if (validUnit.equalsIgnoreCase(originalUnit)) {return true;}}return false;}//测试public static void main(String[] args) {System.out.println("-------------");for (int i = 1020 * 1024; i <= 1024 * 1111; i += 9) {String input = i + " ";System.out.println(input + " ---> "+ new UnitsConversion().defaultConversion(input));}}}多线程的世界时钟，显示巴黎，罗马，上海时间, AWT界面/*心得：TimeZone tz1=TimeZone.getTimeZone("Europe/Paris");
* Calendar cld=Calendar.getInstance(tz);
* clk.setText(cld.get(Calendar.HOUR_OF_DAY)+":"+cld.get(Calendar.MINUTE)+":"+cld.get(Calendar.SECOND));
*/import java.awt.*;
import java.awt.event.*;
import java.util.*;public class WorldClock{Frame f=new Frame("WorldClock");Label l1=new Label();Label l2=new Label();Label l3=new Label();Label cl1=new Label();Label cl2=new Label();Label cl3=new Label();public WorldClock(){l1.setFont(new Font("Arial",Font.BOLD,30));l2.setFont(new Font("Arial",Font.BOLD,30));l3.setFont(new Font("Arial",Font.BOLD,30));cl1.setFont(new Font("Arial",Font.BOLD,30));cl2.setFont(new Font("Arial",Font.BOLD,30));cl3.setFont(new Font("Arial",Font.BOLD,30));cl1.setForeground(Color.red);cl2.setForeground(Color.red); cl3.setForeground(Color.red);f.setLayout(new GridLayout(2,3));f.add(l1);f.add(l2);f.add(l3);f.add(cl1);f.add(cl2);f.add(cl3);TimeZone tz1=TimeZone.getTimeZone("Europe/Paris");clock c1=new clock(l1,cl1,tz1);new Thread(c1).start();TimeZone tz2=TimeZone.getTimeZone("Asia/Shanghai");clock c2=new clock(l2,cl2,tz2);new Thread(c2).start();TimeZone tz3=TimeZone.getTimeZone("Europe/Rome");clock c3=new clock(l3,cl3,tz3);new Thread(c3).start();f.setLocation(200,200);f.setVisible(true);f.pack();}public static void main(String[] args){new WorldClock();String[] s=TimeZone.getAvailableIDs();int i=0;while(++i<s.length){System.out.println (s[i]);}}
}class clock implements Runnable{private Label l;private Label clk;TimeZone tz;public clock(Label l,Label clk,TimeZone tz){this.l=l;this.clk=clk;this.tz=tz;}public void run(){l.setText(tz.getID());while(true){Calendar cld=Calendar.getInstance(tz);clk.setText(cld.get(Calendar.HOUR_OF_DAY)+":"+cld.get(Calendar.MINUTE)+":"+cld.get(Calendar.SECOND));try{Thread.sleep(1000);}catch(Exception e){e.printStackTrace();}}}
}Java日期格式化及其使用例子 1 SimpleDateFormat担当重任,怎样格式化都行 import java.util.Date;
import java.text.SimpleDateFormat;
public class Demo
{
public static void main(String[] args)
{ Date now=new Date(); SimpleDateFormat f=newSimpleDateFormat("今天是"+"yyyy年MM月dd日 E kk点mm分"); System.out.println(f.format(now)); f=new SimpleDateFormat("a hh点mm分ss秒"); System.out.println(f.format(now)); }
} 2 从字符串到日期类型的转换： import java.util.Date;
import java.text.SimpleDateFormat;
import java.util.GregorianCalendar;
import java.text.*;
publicclass Demo
{
public static void main(String[] args)
{ String strDate="2005年04月22日"; //注意：SimpleDateFormat构造函数的样式与strDate的样式必须相符 SimpleDateFormat simpleDateFormat=new SimpleDateFormat("yyyy年MM月dd日"); //必须捕获异常 try { Date date=simpleDateFormat.parse(strDate); System.out.println(date); } catch(ParseException px) { px.printStackTrace(); }
}
} 3 将毫秒数换转成日期类型 import java.util.Date;
import java.text.SimpleDateFormat;
import java.util.GregorianCalendar;
import java.text.*;
public class Demo
{
public static void main(String[] args)
{ long now=System.currentTimeMillis(); System.out.println("毫秒数："+now); Date dNow=new Date(now); System.out.println("日期类型："+dNow);
}
} 这3例源自http://blog.csdn.net/zhoujian2003/archive/2005/04/22/358363.aspx 4 获取系统时期和时间，转换成SQL格式后更新到数据库
(http://blog.csdn.net/netrope/archive/2005/11/19/532729.aspx) java.util.Date d=new java.util.Date(); //获取当前系统的时间 //格式化日期 new java.text.SimpleDateFormat s= new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateStr = s.format(d); //转为字符串 使用RS更新数据库，仍然要用rs.updateString，而不是rs.updateDade。
rs.updateString("regtime",dateStr); //regtime字段为datetime类型的
下面两例源自 http://blog.csdn.net/kingter520/archive/2004/10/27/155435.aspx 5 按本地时区输出当前日期 Date myDate = new Date();
System.out.println(myDate.toLocaleString());
输出结果为：
2003-5-30 6 如何格式化小数 DecimalFormat df = new DecimalFormat(",###.00");
double aNumber = 33665448856.6568975;
String result = df.format(aNumber);
Sytem. out.println(result); 输出结果为：
33,665,448,856.66 其他：获取毫秒时间 System.currentTimeMillis(); 7 在数据库里的日期只以年-月-日的方式输出
(http://blog.csdn.net/zzsxvzzsxv/archive/2007/08/27/1761004.aspx)
定义日期格式：SimpleDateFormat sdf = new SimpleDateFormat(yy-MM-dd);
sql语句为：String sqlStr = "select bookDate from roomBook where bookDate between '2007-4-10' and '2007-4-25'";
输出：
System.out.println(df.format(rs.getDate("bookDate")));几个常用方法字符串
1、获取字符串的长度
length()
2 、判断字符串的前缀或后缀与已知字符串是否相同
前缀 startsWith(String s)
后缀 endsWith(String s)
3、比较两个字符串
equals(String s)
4、把字符串转化为相应的数值
int型 Integer.parseInt(字符串)
long型 Long.parseLong(字符串)
float型 Folat.valueOf(字符串).floatValue()
double型 Double.valueOf(字符串).doubleValue()
4、将数值转化为字符串
valueOf(数值)
5、字符串检索
indexOf(Srting s) 从头开始检索
indexOf(String s ,int startpoint) 从startpoint处开始检索
如果没有检索到，将返回-1
6、得到字符串的子字符串
substring(int startpoint) 从startpoint处开始获取
substring(int start,int end) 从start到end中间的字符
7、替换字符串中的字符,去掉字符串前后空格
replace(char old,char new) 用new替换old
trim()
8、分析字符串
StringTokenizer(String s) 构造一个分析器，使用默认分隔字符（空格，换行，回车，Tab，进纸符）
StringTokenizer(String s,String delim) delim是自己定义的分隔符
nextToken() 逐个获取字符串中的语言符号
boolean hasMoreTokens() 只要字符串还有语言符号将返回true，否则返回false
countTokens() 得到一共有多少个语言符号 Java中的鼠标和键盘事件
1、使用MouseListener借口处理鼠标事件
鼠标事件有5种：按下鼠标键，释放鼠标键，点击鼠标键，鼠标进入和鼠标退出
鼠标事件类型是MouseEvent，主要方法有：
getX(),getY() 获取鼠标位置
getModifiers() 获取鼠标左键或者右键
getClickCount() 获取鼠标被点击的次数
getSource() 获取鼠标发生的事件源
事件源获得监视器的方法是addMouseListener()，移去监视器的方法是removeMouseListener()
处理事件源发生的时间的事件的接口是MouseListener 接口中有如下的方法
mousePressed(MouseEvent) 负责处理鼠标按下事件
mouseReleased(MouseEvent) 负责处理鼠标释放事件
mouseEntered(MouseEvent) 负责处理鼠标进入容器事件
mouseExited(MouseEvent) 负责处理鼠标离开事件
mouseClicked(MouseEvent) 负责处理点击事件
2、使用MouseMotionListener接口处理鼠标事件
事件源发生的鼠标事件有2种：拖动鼠标和鼠标移动
鼠标事件的类型是MouseEvent
事件源获得监视器的方法是addMouseMotionListener()
处理事件源发生的事件的接口是MouseMotionListener 接口中有如下的方法
mouseDragged() 负责处理鼠标拖动事件
mouseMoved() 负责处理鼠标移动事件
3、控制鼠标的指针形状
setCursor(Cursor.getPreddfinedCursor(Cursor.鼠标形状定义)) 鼠标形状定义见（书 P 210）
4、键盘事件
键盘事件源使用addKeyListener 方法获得监视器
键盘事件的接口是KeyListener 接口中有3个方法
public void keyPressed(KeyEvent e) 按下键盘按键
public void keyReleased(KeyEvent e) 释放键盘按键
public void keyTypde(KeyEvent e) 按下又释放键盘按键 判断字符是否属于中文 public class IsChineseOrEnglish {
// GENERAL_PUNCTUATION 判断中文的“号
// CJK_SYMBOLS_AND_PUNCTUATION 判断中文的。号
// HALFWIDTH_AND_FULLWIDTH_FORMS 判断中文的，号public static boolean isChinese(char c) {Character.UnicodeBlock ub = Character.UnicodeBlock.of(c); if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS|| ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS|| ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A|| ub == Character.UnicodeBlock.GENERAL_PUNCTUATION || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION|| ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS){return true;}return false;}public static void isChinese(String strName) {char[] ch = strName.toCharArray();for (int i = 0; i < ch.length; i++) {char c = ch[i];if(isChinese(c)==true){System.out.println(isChinese(c));return;}else{System.out.println(isChinese(c));return ;}}}public static void main(String[] args){isChinese("zhongguo");isChinese("中国");}}异常处理类/**
* (#)ThrowableManager.java 1.0 Apr 10, 2008
*
* Copyright 2007- wargrey , Inc. All rights are reserved.
*/
package net.wargrey.application;import java.awt.Component;
import javax.swing.JOptionPane;/**
* This class <code>ExceptionManager</code> and its subclasses are a form of
* <code>Exception</code>. It is used to wrap all the <code>Throwable</code> instances
* and handle them in a unified way. It will show the information which consists of
* StackTraces and Messages by using JOptionPanel.
*
* @author Estelle
* @version 1.0
* @see java.lang.Exception
* @since jdk 1.5
*/
public class ExceptionManager extends Exception {/*** This field <code>alerter</code> is used to show the information the Class offered.* * @see javax.swing.JOptionPane*/private JOptionPane alerter;/*** This static method create an instance of the ExceptionManager by invoking the * constructor <code>ExceptionManager(String msg)</code>.* * @param msg The message will pass the specified constructor* @return An instance of the ExceptionManager created by invoking the constructor* <code>ExceptionManager(String msg)</code>.*/public static ExceptionManager wrap(String msg){return new ExceptionManager(msg);}/*** This static method create an instance of the ExceptionManager by invoking the * constructor <code>ExceptionManager(Throwable throwable)</code>.* * @param throwable The cause will pass the specified constructor* @return An instance of the ExceptionManager created by invoking the constructor* <code>ExceptionManager(Throwable throwable)</code>.*/public static ExceptionManager wrap(Throwable throwable){return new ExceptionManager(throwable);}/*** This static method create an instance of the ExceptionManager by invoking the * constructor <code>ExceptionManager(String msg,Throwable throwable)</code>. * * @param msg The message will pass the specified constructor* @param throwable The cause will pass the specified constructor* @return An instance of the ExceptionManager created by invoking the constructor* <code>ExceptionManager(String msg, Throwable throwable)</code>*/public static ExceptionManager wrap(String msg,Throwable throwable){return new ExceptionManager(msg,throwable);}/*** Constructs a new instance with the specified detail message. The concrete handler * is its super class. This constructor always used to construct a custom exception* not wrapping the exist exception.* * @param msg the detail message which is the part of the information will be* shown.*/public ExceptionManager(String msg){super(msg);}/*** Constructs a new instance with the specified detail cause. The concrete handler * is its super class. This constructor always used to wrap an exist exception.* * @param throwable the cause which has been caught. It's detail message and * stacktrace are the parts the information will be shown.*/public ExceptionManager(Throwable throwable){super(throwable);}/*** Constructs a new instance with the specified detail message and cause. The * concrete handler is its super class. This constructor always used to construct* an exception wrapping the exist exception but requires a custom message. * * @param msg the detail message which is the part of the information will * be shown.* @param throwable the cause which has been caught. It's stacktrace is the parts* the information will be shown.*/public ExceptionManager(String msg,Throwable throwable){super(msg,throwable);}/*** Show the information with everything is default.*/public synchronized void alert(){alert((Component)null);}/*** Show the information in a dialog with the specified title * "ThrowableManager Alerter". The dialog belongs to the given component which * default is the screen. * * @param parent The component cause the exception.*/public synchronized void alert(Component parent){alert(parent,"ThrowableManager Alerter");}/*** Show the information in a dialog with the specified title.* * @param title The title of the dialog.*/public synchronized void alert(String title){alert((Component)null,title);}/*** Show the information in a dialog which has the specified title and belongs to the* specified component.* * @param parent The component cause the exception.* @param title The title of the dialog.*/public synchronized void alert(Component parent,String title){StringBuilder errorMessage=new StringBuilder();errorMessage.append(this.toString());for (StackTraceElement st:((this.getCause()==null)?this:this.getCause()).getStackTrace()){errorMessage.append("\n\t at ");errorMessage.append(st.toString());} alerter.showMessageDialog(parent, errorMessage, title ,JOptionPane.ERROR_MESSAGE);}
}去掉字符串中重复的子字符串/*** 去掉字符串中重复的子字符串* * @param str* @return String*/private static String removeSameString(String str){Set<String> mLinkedSet = new LinkedHashSet<String>();String[] strArray = str.split(" ");StringBuffer sb = new StringBuffer();for (int i = 0; i < strArray.length; i++){if (!mLinkedSet.contains(strArray[i])){mLinkedSet.add(strArray[i]);sb.append(strArray[i] + " ");}}System.out.println(mLinkedSet);return sb.toString().substring(0, sb.toString().length() - 1);}将指定byte数组以16进制的形式打印到控制台/*** 将指定byte数组以16进制的形式打印到控制台* * @param hint* String* @param b* byte[]* @return void*/public static void printHexString(String hint, byte[] b){System.out.print(hint);for (int i = 0; i < b.length; i++){String hex = Integer.toHexString(b[i] & 0xFF);if (hex.length() == 1){hex = '0' + hex;}System.out.print(hex.toUpperCase() + " ");}System.out.println("");}获得任意一个整数的阶乘，递归/*** 获得任意一个整数的阶乘，递归* * @param n* @return n!*/public static int factorial(int n){if (n == 1){return 1;}return n * factorial(n - 1);}拷贝一个目录或者文件到指定路径下/*** 拷贝一个目录或者文件到指定路径下* * @param source* @param target*/public static void copy(File source, File target){File tarpath = new File(target, source.getName());if (source.isDirectory()){tarpath.mkdir();File[] dir = source.listFiles();for (int i = 0; i < dir.length; i++) { copy(dir[i], tarpath); } } else{try{InputStream is = new FileInputStream(source);OutputStream os = new FileOutputStream(tarpath);byte[] buf = new byte[1024];int len = 0;while ((len = is.read(buf)) != -1){os.write(buf, 0, len);}is.close();os.close();}catch (FileNotFoundException e){e.printStackTrace();}catch (IOException e){e.printStackTrace();}}}简单的txt转换xml package com.liu;import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.StringTokenizer;public class TxtToXml {
private String strTxtFileName;private String strXmlFileName;public TxtToXml() {strTxtFileName = new String();strXmlFileName = new String();
}public void createXml(String strTxt, String strXml) {strTxtFileName = strTxt;strXmlFileName = strXml;String strTmp;try {BufferedReader inTxt = new BufferedReader(new FileReader( strTxtFileName)); BufferedWriter outXml = new BufferedWriter(new FileWriter(strXmlFileName));outXml.write("<?xml version= \"1.0\" encoding=\"gb2312\"?>");outXml.newLine();outXml.write("<people>");while ((strTmp = inTxt.readLine()) != null) {StringTokenizer strToken = new StringTokenizer(strTmp, "，");String arrTmp[];arrTmp = new String[3];for (int i = 0; i < 3; i++)arrTmp[i] = new String("");int index = 0;outXml.newLine();outXml.write(" <students>");while (strToken.hasMoreElements()) {strTmp = (String) strToken.nextElement();strTmp = strTmp.trim();arrTmp[index++] = strTmp;}outXml.newLine();outXml.write(" <name>" + arrTmp[0] + "</name>");outXml.newLine();outXml.write(" <sex>" + arrTmp[1] + "</sex>");outXml.newLine();outXml.write(" <age>" + arrTmp[2] + "</age>");outXml.newLine();outXml.write(" </students>");}outXml.newLine();outXml.write("</people>");outXml.flush();} catch (Exception e) {e.printStackTrace();}
}public static void main(String[] args) {String txtName = "testtxt.txt";String xmlName = "testxml.xml";TxtToXml thisClass = new TxtToXml();thisClass.createXml(txtName, xmlName);
}
}字母排序(A-Z)(先大写，后小写)import java.util.Arrays;
import java.util.Comparator;public class SortTest
{public static void main(String args[]){char[] chs = {'f', 'F', 'K', 'A', 'a', 'j', 'z'};chs = sortChars(chs, false);for(char c: chs){System.out.println(c);}}/*** 对给定的字符数组进行字典排序* @param chs 目标字符数组* @param upperFisrt 大写字母是否在前* @return 排序后的字符数组*/public static char[] sortChars(char[] chs, final boolean upperFisrt){Character[] srcArray = new Character[chs.length];char[] retArray = new char[chs.length];int index = 0;for(char ch: chs){srcArray[index++] = ch;}Arrays.sort(srcArray, new Comparator<Character>(){public int compare(Character c1, Character c2){char ch1 = Character.toUpperCase(c1);char ch2 = Character.toUpperCase(c2);if(ch1 == ch2){int tempRet = c1.charValue() - c2.charValue();return upperFisrt? tempRet: -tempRet;}else{return ch1 - ch2;}}});index = 0;for(char ch: srcArray){retArray[index++] = ch;}return retArray;}
}列出某文件夹及其子文件夹下面的文件，并可根据扩展名过滤/*** 列出某文件夹及其子文件夹下面的文件，并可根据扩展名过滤* * @param path*/public static void list(File path){if (!path.exists()){System.out.println("文件名称不存在!");}else{if (path.isFile()){if (path.getName().toLowerCase().endsWith(".pdf")|| path.getName().toLowerCase().endsWith(".doc")|| path.getName().toLowerCase().endsWith(".html")|| path.getName().toLowerCase().endsWith(".htm")){System.out.println(path);System.out.println(path.getName());}}else{File[] files = path.listFiles();for (int i = 0; i < files.length; i++){list(files[i]);}}}}字符串匹配的算法. public String getMaxMatch(String a,String b) { StringBuffer tmp = new StringBuffer(); String maxString = ""; int max = 0; int len = 0; char[] aArray = a.toCharArray(); char[] bArray = b.toCharArray(); int posA = 0; int posB = 0; while(posA<aArray.length-max) { posB = 0; while(posB<(bArray.length-max)) { if(aArray[posA]==bArray[posB]) { len = 1; tmp = new StringBuffer(); tmp.append(aArray[posA]); while((posA+len<aArray.length)&&(posB+len<bArray.length)&&(aArray[posA+len]==bArray[posB+len])) { tmp.append(aArray[posA+len]); len++; } if(len>max) { max = len; maxString = tmp.toString(); } } posB++; } posA++; } return maxString; }写入日志/*** 写入日志* filePath 日志文件的路径* code 要写入日志文件的内容*/
public static boolean print(String filePath,String code) {try {File tofile=new File(filePath);FileWriter fw=new FileWriter(tofile,true);BufferedWriter bw=new BufferedWriter(fw);PrintWriter pw=new PrintWriter(bw);System.out.println(getDate()+":"+code);pw.println(getDate()+":"+code);pw.close();bw.close();fw.close();return true;} catch (IOException e) {return false;}
}//将Unicode字符串转换成bool型数组
public boolean[] StrToBool(String input){
boolean[] output=Binstr16ToBool(BinstrToBinstr16(StrToBinstr(input)));
return output;
}
//将bool型数组转换成Unicode字符串
public String BoolToStr(boolean[] input){
String output=BinstrToStr(Binstr16ToBinstr(BoolToBinstr16(input)));
return output;
}
//将字符串转换成二进制字符串，以空格相隔
private String StrToBinstr(String str) {
char[] strChar=str.toCharArray();
String result="";
for(int i=0;i<strChar.length;i++){
result +=Integer.toBinaryString(strChar[i])+ " ";
}
return result;
}
//将二进制字符串转换成Unicode字符串
private String BinstrToStr(String binStr) {
String[] tempStr=StrToStrArray(binStr);
char[] tempChar=new char[tempStr.length];
for(int i=0;i<tempStr.length;i++) {
tempChar[i]=BinstrToChar(tempStr[i]);
}
return String.valueOf(tempChar);
}
//将二进制字符串格式化成全16位带空格的Binstr
private String BinstrToBinstr16(String input){
StringBuffer output=new StringBuffer();
String[] tempStr=StrToStrArray(input);
for(int i=0;i<tempStr.length;i++){
for(int j=16-tempStr[i].length();j>0;j--)
output.append('0');
output.append(tempStr[i]+" ");
}
return output.toString();
}
//将全16位带空格的Binstr转化成去0前缀的带空格Binstr
private String Binstr16ToBinstr(String input){
StringBuffer output=new StringBuffer();
String[] tempStr=StrToStrArray(input);
for(int i=0;i<tempStr.length;i++){
for(int j=0;j<16;j++){
if(tempStr[i].charAt(j)=='1'){
output.append(tempStr[i].substring(j)+" ");
break;
}
if(j==15&&tempStr[i].charAt(j)=='0')
output.append("0"+" ");
}
}
return output.toString();
}
//二进制字串转化为boolean型数组 输入16位有空格的Binstr
private boolean[] Binstr16ToBool(String input){
String[] tempStr=StrToStrArray(input);
boolean[] output=new boolean[tempStr.length*16];
for(int i=0,j=0;i<input.length();i++,j++)
if(input.charAt(i)=='1')
output[j]=true;
else if(input.charAt(i)=='0')
output[j]=false;
else
j--;
return output;
}
//boolean型数组转化为二进制字串 返回带0前缀16位有空格的Binstr
private String BoolToBinstr16(boolean[] input){
StringBuffer output=new StringBuffer();
for(int i=0;i<input.length;i++){
if(input[i])
output.append('1');
else
output.append('0');
if((i+1)%16==0)
output.append(' ');
}
output.append(' ');
return output.toString();
}
//将二进制字符串转换为char
private char BinstrToChar(String binStr){
int[] temp=BinstrToIntArray(binStr);
int sum=0;
for(int i=0; i<temp.length;i++){
sum +=temp[temp.length-1-i]<<i;
}
return (char)sum;
}
//将初始二进制字符串转换成字符串数组，以空格相隔
private String[] StrToStrArray(String str) {
return str.split(" ");
}
//将二进制字符串转换成int数组
private int[] BinstrToIntArray(String binStr) {
char[] temp=binStr.toCharArray();
int[] result=new int[temp.length];
for(int i=0;i<temp.length;i++) {
result[i]=temp[i]-48;
}
return result;
}
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