给大家提供一个常用的StringUtils工具类

package net.englishvod.common.utils;


import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.util.Calendar;
import java.util.Locale;
import java.util.UUID;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


import javax.servlet.http.HttpServletRequest;


import net.englishvod.common.security.Cryptos;
import net.englishvod.common.security.Digests;


import org.apache.commons.lang3.StringEscapeUtils;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.servlet.LocaleResolver;


/**
 * 字符串工具类
 * 
 * @author leon
 * @version Apr 10, 2014
 */
public class StringUtils extends org.apache.commons.lang3.StringUtils {


public static String lowerFirst(String str) {
if (isBlank(str)) {
return "";
} else {
return str.substring(0, 1).toLowerCase() + str.substring(1);
}
}


public static String upperFirst(String str) {
if (StringUtils.isBlank(str)) {
return "";
} else {
return str.substring(0, 1).toUpperCase() + str.substring(1);
}
}


/**
* 替换掉HTML标签方法
*/
public static String replaceHtml(String html) {
if (isBlank(html)) {
return "";
}
String regEx = "<.+?>";
Pattern p = Pattern.compile(regEx);
Matcher m = p.matcher(html);
String s = m.replaceAll("");
return s;
}


/**
* 缩略字符串（不区分中英文字符）
* 
* @param str
*            目标字符串
* @param length
*            截取长度
* @return
*/
public static String abbr(String str, int length) {
if (str == null) {
return "";
}
try {
StringBuilder sb = new StringBuilder();
int currentLength = 0;
for (char c : replaceHtml(StringEscapeUtils.unescapeHtml4(str)).toCharArray()) {
currentLength += String.valueOf(c).getBytes("GBK").length;
if (currentLength <= length - 3) {
sb.append(c);
} else {
sb.append("...");
break;
}
}
return sb.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return "";
}


/**
* 缩略字符串（替换html）
* 
* @param str
*            目标字符串
* @param length
*            截取长度
* @return
*/
public static String rabbr(String str, int length) {
return abbr(replaceHtml(str), length);
}


/**
* 转换为Double类型
*/
public static Double toDouble(Object val) {
if (val == null) {
return 0D;
}
try {
return Double.valueOf(trim(val.toString()));
} catch (Exception e) {
return 0D;
}
}


/**
* 转换为Float类型
*/
public static Float toFloat(Object val) {
return toDouble(val).floatValue();
}


/**
* 转换为Long类型
*/
public static Long toLong(Object val) {
return toDouble(val).longValue();
}


/**
* 转换为Integer类型
*/
public static Integer toInteger(Object val) {
return toLong(val).intValue();
}


/**
* 获得i18n字符串
*/
public static String getMessage(String code, Object[] args) {
LocaleResolver localLocaleResolver = SpringContextHolder.getBean(LocaleResolver.class);
HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
Locale localLocale = localLocaleResolver.resolveLocale(request);
return SpringContextHolder.getApplicationContext().getMessage(code, args, localLocale);
}


/**
* 获得用户远程地址
*/
public static String getRemoteAddr(HttpServletRequest request) {
String remoteAddr = request.getHeader("X-Real-IP");
if (isNotBlank(remoteAddr)) {
remoteAddr = request.getHeader("X-Forwarded-For");
} else if (isNotBlank(remoteAddr)) {
remoteAddr = request.getHeader("Proxy-Client-IP");
} else if (isNotBlank(remoteAddr)) {
remoteAddr = request.getHeader("WL-Proxy-Client-IP");
}
return remoteAddr != null ? remoteAddr : request.getRemoteAddr();
}


/**
* 获取uuid
* 
* @return
*/
public static String getUuid() {
return UUID.randomUUID().toString().replace("-", "");
}


/**
* 生成安全的密码，生成随机的16位salt并经过1024次 sha-1 hash
*/
public static String entryptPassword(String plainPassword) {
byte[] salt = Digests.generateSalt(Cryptos.SALT_SIZE);
byte[] hashPassword = Digests.sha1(plainPassword.getBytes(), salt, Cryptos.HASH_INTERATIONS);
return Encodes.encodeHex(salt) + Encodes.encodeHex(hashPassword);
}


/**
* 根据当前时间返回唯一id值
* 
* @return
*/
public synchronized static String getNowString() {
Calendar now = Calendar.getInstance();
return new String("" + now.get(Calendar.YEAR) + getDigit(2, (now.get(Calendar.MONTH) + 1)) + getDigit(2, now.get(Calendar.DAY_OF_MONTH))
+ getDigit(2, now.get(Calendar.HOUR_OF_DAY)) + getDigit(2, now.get(Calendar.MINUTE)) + getDigit(2, now.get(Calendar.SECOND))
+ getDigit(3, now.get(Calendar.MILLISECOND)));
}


/**
* 返回指定位数的字符串
* 
* @param digit
*            位数
* @param num
* @return
*/
public static String getDigit(int digit, int num) {
String str = "";
for (int i = 0; i < digit; i++) {
str = str + "0";
}
str = str + num;
str = str.substring((str.length() - digit), str.length());
return str;
}


/**
* 密码加密方法
* 
* @param password
* @param algorithm
* @return
*/
public static String encodePassword(String password, String algorithm) {
byte[] unencodedPassword = password.getBytes();


MessageDigest md = null;


try {
md = MessageDigest.getInstance(algorithm);
} catch (Exception e) {
return password;
}
md.reset();
md.update(unencodedPassword);
byte[] encodedPassword = md.digest();
StringBuffer buf = new StringBuffer();


for (int i = 0; i < encodedPassword.length; i++) {
if ((encodedPassword[i] & 0xff) < 0x10) {
buf.append("0");
}
buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
}
return buf.toString();
}
}