java 项目中经常用到的工具类

package com.tools;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.text.DateFormat;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.Map;
import java.util.Random;

import javax.servlet.http.HttpServletRequest;

import com.opensymphony.xwork2.inject.ContainerBuilder.Command;

public class BaseUtil {

	public static final String PROJECT_DEFAULT_ENCODING = "UTF-8";

		
	
/**

	 * 判断字符串是否为空

	 */

	public static boolean isEmpty(Object arg) {

		if (StringSafe(arg).equals("")) {

			return true;

		}

		return false;

	}



	/**

	 * 转换null字符串为""

	 */

	public static String StringSafe(Object strParam) {

		String value = "";

		if (strParam == null) {

			value = "";

		} else {

			try {

				value = String.valueOf(strParam);

			} catch (Exception e) {

				value = "";

			}

		}

		if (value.equals("null") || value.equals("[]")) {

			value = "";

		}

		return value.trim();

	}



	/**

	 * 将ISO流内容转换为项目默认编码格式内容

	 */

	public static String ISO2DefaultCode(String arg) {

		String strWrk = "";

		arg = StringSafe(arg);

		try {

			strWrk = new String(arg.getBytes("ISO-8859-1"), "UTF-8");

		} catch (Exception e) {

			strWrk = "*** ERROR convStr()";

		}

		return strWrk;

	}

	

	/**

	 * 将字符串内容转换为项目UTF-8编码格式内容

	 */

	public static String ISO2UTF_8Code(String arg) {

		

//		String utf8 = new String(t.getBytes( "UTF-8"));  

//		System.out.println(utf8);  

//		String unicode = new String(utf8.getBytes(),"UTF-8");  

//		System.out.println(unicode);  

//		String gbk = new String(unicode.getBytes("GBK"));    

//		System.out.println(gbk);  



			

			

		String strWrk = "";

		arg = StringSafe(arg);

		try {

			strWrk = new String(arg.getBytes("UTF-8"), "UTF-8");

		} catch (Exception e) {

			strWrk = "*** ERROR convStr()";

		}

		return strWrk;

	}

	

	/*

	 * 将GBK编码格式转换为UTF-8

	 */

	public static String getUTF8StringFromGBKString(String gbkStr){   

	   try {   

	       return new String(getUTF8BytesFromGBKString(gbkStr), "UTF-8");   

	       } catch (UnsupportedEncodingException e) {   

	        throw new InternalError();   

	   }   

   }

	

	/**

	 * 

	 * @param gbkStr

	 * @return

	 * @description 将UTF-8编码格式转换成GBK格式

	 * @version 1.0

	 * @author liutao

	 * @update Apr 15, 2013 10:20:05 AM

	 */

	public static byte[] getUTF8BytesFromGBKString(String gbkStr) {   

		   int n = gbkStr.length();   

		   byte[] utfBytes = new byte[3 * n];   

		    int k = 0;   

		    for (int i = 0; i < n; i++) {   

		        int m = gbkStr.charAt(i);   

		        if (m < 128 && m >= 0) {   

		            utfBytes[k++] = (byte) m;   

		            continue;   

		        }   

		        utfBytes[k++] = (byte) (0xe0 | (m >> 12));   

		        utfBytes[k++] = (byte) (0x80 | ((m >> 6) & 0x3f));   

		        utfBytes[k++] = (byte) (0x80 | (m & 0x3f));   

		    }   

		    if (k < utfBytes.length) {   

		        byte[] tmp = new byte[k];   

		        System.arraycopy(utfBytes, 0, tmp, 0, k);   

		       return tmp;   

		    }   

		    return utfBytes;   

	}  







	/**

	 * 将项目默认编码格式内容转换为ISO流内容

	 */

//	public static String DefaultCode2ISO(String arg) {

//		String strWrk = "";

//		arg = StringSafe(arg);

//		try {

//			strWrk = new String(arg.getBytes(Command.ENCODING), "ISO-8859-1");

//		} catch (Exception e) {

//			strWrk = "*** ERROR convStr()";

//		}

//		return strWrk;

//	}



	/***************************************************************************

	 * 字符串左补位<br>

	 * orginString 需要补位的字符串<br>

	 * addStr 需要填补的内容 len 需要填补的长度

	 */

	public static String padLeft(String orginString, String addStr, int len) {

		StringBuffer strBuffer = new StringBuffer("");

		if (orginString == null) {

			orginString = "";

		}

		if (orginString.length() >= len) {

			return orginString;

		}

		if (addStr != null) {

			//System.out.println(strBuffer.length()+"*");

			while (strBuffer.length() + orginString.length() < len) {

				System.out.println(strBuffer.length()+orginString.length());

				strBuffer.append(addStr);

			}

		}

		strBuffer.append(orginString);

		return strBuffer.toString();

	}



	/***************************************************************************

	 * 字符串右补位<br>

	 * orginString 需要补位的字符串<br>

	 * addStr 需要填补的内容 len 需要填补的长度

	 */

	public static String padRight(String orginString, String addStr, int len) {

		StringBuffer strBuffer = new StringBuffer("");

		if (orginString == null) {

			orginString = "";

		}

		if (orginString.length() >= len) {

			return orginString;

		}

		if (addStr != null) {

			strBuffer.append(orginString);

			while (strBuffer.length() < len) {

				strBuffer.append(addStr);

			}

		}

		return strBuffer.toString();

	}



	/***************************************************************************

	 * 将null字符串转换为0

	 */

	public static String NumSafe(Object strParam) {

		String value = "0";

		if (strParam == null) {

			value = "0";

		}

		try {

			value = String.valueOf(strParam);

		} catch (Exception e) {

			value = "0";

		}

		if (value == "null" || value.length() == 0) {

			value = "0";

		}

		return value.trim();

	}



	/***************************************************************************

	 * 将字符串转换为Int

	 */

	public static int String2Int(Object argValue) {

		if (isEmpty(argValue)) {

			return 0;

		} else {

			return Integer.parseInt(String.valueOf(argValue));

		}

	}

	

	/***************************************************************************

	 * 将字符串转换为Long

	 */

	public static long String2Long(Object argValue) {

		if (isEmpty(argValue)) {

			return 0;

		} else {

			return Long.parseLong(String.valueOf(argValue));

		}

	}



	/***************************************************************************

	 * 格式化SQL语句

	 */

	public static String FormatSQLStr(String argValue) {

		String returnValue = StringSafe(argValue);

		if (returnValue.length() == 0) {

			return "";

		} else {

			returnValue = returnValue.replaceAll("\"\"", "\"\"\"\"")

					.replaceAll("'", "''");

		}

		return returnValue;

	}

	

//	public static void main(String[] args) {

//		String sql="select * from sec where name='dsdf' +'and name=sfsd' "; 

//		System.out.println(FormatSQLStr(sql));

//		

//	}



	/***************************************************************************

	 * 格式化钱四舍五入小数点后两位

	 */

	public static String fmtMoney(Object strParam) {

		String value = "0";

		if (strParam == null) {

			value = "0";

		}

		try {

			Double dblValue = Double.valueOf(strParam.toString());

			if (dblValue.doubleValue() == 0) {

				value = "0.00";

			} else {

				DecimalFormat df1 = new DecimalFormat("######.00");

				value = df1.format(dblValue.doubleValue());

			}

			if (Double.parseDouble(value) < 1 && Double.parseDouble(value) > 0) {

				value = "0" + value;

			}

		} catch (Exception e) {

			value = "0";

		}

		if (value == "null" || value.length() == 0) {

			value = "0";

		}

		return value.trim();

	}



	/***************************************************************************

	 * 将超出长度的字符串转换为...

	 */

	public static String trancate(String input, int len) {

		StringBuffer sb = new StringBuffer(len);

		int count = 0;

		for (int i = 0; i < input.length(); i++) {

			char c = input.charAt(i);

			if (c <= '\u00ff') {

				count++;

			} else {

				count += 2;

				if (count > len) {

					return sb.append(

							" <font color='blue'><strong>...<strong/></font>")

							.toString().trim();

				}

			}

			sb.append(c);

			if (count >= len) {

				return sb.append(

						" <font color='blue'><strong>...<strong/></font>")

						.toString().trim();

			}

		}

		return input;

	}



	/**

	 * 将一字符串数组以某特定的字符串作为分隔来变成字符串

	 * 

	 * @since 1.0

	 * @param strs

	 *            字符串数组

	 * @param token

	 *            分隔字符串

	 * @return 以token为分隔的字符串

	 */

	public static String join(String[] strs, String token) {

		if (strs == null) {

			return null;

		}

		StringBuffer sb = new StringBuffer();

		for (int i = 0; i < strs.length; i++) {

			if (i != 0) {

				sb.append(token);

			}

			sb.append(strs[i]);

		}

		return sb.toString();

	}



	/**

	 * 验证字符串合法性

	 * 

	 * @since 1.0

	 * @param str

	 *            需要验证的字符串

	 * @param test

	 *            非法字符串（如："~!#$%^&*()',;:?"）

	 * @return true:非法;false:合法

	 */

	public static boolean StringCheck(String str, String test) {

		if (str == null || str.equals("")) {

			return false;

		}

		boolean flag = false;

		for (int i = 0; i < test.length(); i++) {

			if (str.indexOf(test.charAt(i)) != -1) {

				flag = true;

				break;

			}

		}

		return flag;

	}



	/**

	 * 替换字符串

	 * 

	 * @since 1.1

	 * @param strSc

	 *            需要进行替换的字符串

	 * @param oldStr

	 *            源字符串

	 * @param newStr

	 *            替换后的字符串

	 * @return 替换后对应的字符串

	 */

	public static String replace(String strSc, String oldStr, String newStr) {

		String ret = strSc;

		if (ret != null && oldStr != null && newStr != null) {

			ret = strSc.replaceAll(oldStr, newStr);

		}

		return ret;

	}



	/**

	 * 替换字符串，修复java.lang.String类的replaceAll方法时第一参数是字符串常量正则时(如："address".

	 * replaceAll("dd","$");)的抛出异常：java.lang.StringIndexOutOfBoundsException:

	 * String index out of range: 1的问题。

	 * 

	 * @param strSc

	 *            需要进行替换的字符串

	 * @param oldStr

	 *            源字符串

	 * @param newStr

	 *            替换后的字符串

	 * @return 替换后对应的字符串

	 */

	public static String replaceAll(String strSc, String oldStr, String newStr) {

		int i = -1;

		while ((i = strSc.indexOf(oldStr)) != -1) {

			strSc = new StringBuffer(strSc.substring(0, i)).append(newStr)

					.append(strSc.substring(i + oldStr.length())).toString();

		}

		return strSc;

	}



	/**

	 * 将字符串转换成HTML格式的字符串

	 * 

	 * @since 1.1

	 * @param str

	 *            需要进行转换的字符串

	 * @return 转换后的字符串

	 */

	public static String toHtml(String str) {

		String html = StringSafe(str);

		if (str == null || str.length() == 0) {

			return "";

		} else {

			html = replace(html, "&", "&amp;");

			html = replace(html, "<", "&lt;");

			html = replace(html, ">", "&gt;");

			html = replace(html, "\"", "&quot;");

			html = replace(html, " ", "&nbsp");

			html = replace(html, "\r\n", "<br>");

			return html;

		}

	}



	/**

	 * 将HTML格式的字符串转换成常规显示的字符串

	 * 

	 * @since 1.1

	 * @param str

	 *            需要进行转换的字符串

	 * @return 转换后的字符串

	 */

	public static String toText(String str) {

		String text = StringSafe(str);

		if (str == null || str.length() == 0) {

			return "";

		} else {

			text = replace(text, "&amp;", "&");

			text = replace(text, "&lt;", "<");

			text = replace(text, "&gt;", ">");

			text = replace(text, "<br>\n", "\n");

			text = replace(text, "<br>", "\n");

			text = replace(text, "&quot;", "\"");

			text = replace(text, "&nbsp;", " ");

			return text;

		}

	}



	public static int alphabet2No(String str) {

		String[] alphabet = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",

				"K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",

				"W", "X", "Y", "Z" };

		int no = 0;

		for (int i = 0; i < alphabet.length; i++) {

			no++;

			if (str.toUpperCase().equals(alphabet[i])) {

				break;

			}

		}

		return no;

	}



	public static String No2alphabet(int no) {

		String[] alphabet = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",

				"K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",

				"W", "X", "Y", "Z" };

		for (int i = 0; i < alphabet.length; i++) {

			if (no == i + 1) {

				return alphabet[i];

			}

		}

		return "";

	}



	/** 获取客户端IP */

	public static String getIpAddr(HttpServletRequest request) {

		String ip = request.getHeader(" x-forwarded-for ");

		if (ip == null || ip.length() == 0 || " unknown ".equalsIgnoreCase(ip)) {

			ip = request.getHeader(" Proxy-Client-IP ");

		}

		if (ip == null || ip.length() == 0 || " unknown ".equalsIgnoreCase(ip)) {

			ip = request.getHeader(" WL-Proxy-Client-IP ");

		}

		if (ip == null || ip.length() == 0 || " unknown ".equalsIgnoreCase(ip)) {

			ip = request.getRemoteAddr();

		}

		return ip;

	}



	/** 字符串转换 */

	public static String convStr(String arg, boolean flg) {

		String strWrk = "";

		if (arg == null) {

			arg = "";

		}

		if (flg) {

			try {

				strWrk = new String(arg.getBytes("ISO-8859-1"),

						PROJECT_DEFAULT_ENCODING);

			} catch (IOException e) {

				strWrk = "*** ERROR convStr()";

			}

		} else {

			strWrk = arg;

		}



		return strWrk;

	}



	/**

	 * 产生一定长度的随机数

	 */

	public static final String randomString(int length) {

		Random randGen = null;

		char[] numbersAndLetters = null;

		Object initLock = new Object();

		if (randGen == null) {

			synchronized (initLock) {

				if (randGen == null) {

					randGen = new Random();

					numbersAndLetters = ("0123456789abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ")

							.toCharArray();

				}

			}

		}

		char[] randBuffer = new char[length];

		for (int i = 0; i < randBuffer.length; i++) {

			randBuffer[i] = numbersAndLetters[randGen.nextInt(71)];

		}

		return new String(randBuffer);

	}



	public static double add(double d1, double d2) { // 进行加法计算

		BigDecimal b1 = new BigDecimal(d1);

		BigDecimal b2 = new BigDecimal(d2);

		return b1.add(b2).doubleValue();

	}



	public static double sub(double d1, double d2) { // 进行减法计算

		BigDecimal b1 = new BigDecimal(d1);

		BigDecimal b2 = new BigDecimal(d2);

		return b1.subtract(b2).doubleValue();

	}



	public static double mul(double d1, double d2) { // 进行乘法计算

		BigDecimal b1 = new BigDecimal(d1);

		BigDecimal b2 = new BigDecimal(d2);

		return b1.multiply(b2).doubleValue();

	}



	public static double div(double d1, double d2, int len) { // 进行除法计算

		BigDecimal b1 = new BigDecimal(d1);

		BigDecimal b2 = new BigDecimal(d2);

		return b1.divide(b2, len, BigDecimal.ROUND_HALF_UP).doubleValue();

	}



	public static double round(double d, int len) { // 进行四舍五入

		BigDecimal b1 = new BigDecimal(d);

		BigDecimal b2 = new BigDecimal(1);

		return b1.divide(b2, len, BigDecimal.ROUND_HALF_UP).doubleValue();

	}

	

	

	/**

	  * 根据输入的日期字符串 和 提前天数 ，

	  * 获得 指定日期提前几天的日期对象

	  * @param dateString 日期对象 ，格式如 1-31-1900

	  * @param lazyDays 倒推的天数

	  * @return 指定日期倒推指定天数后的日期对象

	  * @throws ParseException 

	  */

	 public static Date getDate(String dateString , int beforeDays) throws ParseException{

	  

	  DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");

	  Date inputDate = dateFormat.parse(dateString);

	  

	  Calendar cal = Calendar.getInstance();

	  cal.setTime(inputDate);

	  

	  int inputDayOfYear = cal.get(Calendar.DAY_OF_YEAR);

	  cal.set(Calendar.DAY_OF_YEAR , inputDayOfYear-beforeDays );

	  

	  return cal.getTime();

	}



	 

	/*

	 * 换算两个数的百分数

	 * 

	 */

	public  static String getPercentCount(int num,int allCount) {

		String result="";

		if(allCount==0){

			return "0"+"%";

		}else{

			double a= (double)num;

			double b= (double)allCount;

			double c = divide(a, b, 2);

			result =  String.valueOf(c)+"%";

		}

		return result;

		

	}

	public static double divide(double v1, double v2, int scale) {

	 	

	  double c = divPercent(v1, v2, scale + 2);

	  // System.out.println(c+"%");

	  return div(c * 100.0, 1, scale);

	}

	public static double divPercent(double v1, double v2, int scale) {

	  if (scale < 0) {

	   throw new IllegalArgumentException(

	     "The scale must be a positive integer or zero");

	  }

	  BigDecimal b1 = new BigDecimal(Double.toString(v1));

	  BigDecimal b2 = new BigDecimal(Double.toString(v2));

	  return b1.divide(b2, scale, BigDecimal.ROUND_HALF_UP).doubleValue();

	 }

	

	/*

	 * map 按照key 值排序输出其Value值

	 */

	public static String sortMapKeyValue(Map<String,String> map){

		if (map==null) {

			return "";

		}

		String str="";

		Object[] key =  map.keySet().toArray();    

		Arrays.sort(key);    

		for(int i = 0; i<key.length; i++){    

//		    System.out.println(map.get(key[i]));    

		    str+= BaseUtil.StringSafe(map.get(key[i]));

		} 

		return str;

	}

}