String类的一些常用操作方法

 package com.liveyc.framework.util;

 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.text.DecimalFormat;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.StringTokenizer;

 import org.apache.commons.collections.CollectionUtils;

 /**
 * @author aitf
 * @version 创建时间：2016年12月15日 下午2:38:30
 * 类说明
 */
 public class StringUtil {

     /**
      * <li>判断字符串是否为空值</li>
      * <li>NULL、空格均认为空值</li>.
      *
      * @param value
      *            the value
      *
      * @return true, if checks if is empty
      */
     public static boolean isEmpty(String value) {
         return null == value || "".equals(value.trim());
     }

     /**
      * 去除,分隔符，用于金额数值去格式化.
      *
      * @param value
      *            the value
      *
      * @return the string
      */
     public static String decimal(String value) {
         if (null == value || "".equals(value.trim())) {
             return "0";
         } else {
             return value.replaceAll(",", "");
         }
     }

     /**
      * 在数组中查找字符串.
      *
      * @param params
      *            the params
      * @param name
      *            the name
      * @param ignoreCase
      *            the ignore case
      *
      * @return the int
      */
     public static int indexOf(String[] params, String name, boolean ignoreCase) {
         if (params == null)
             return -1;
         for (int i = 0, j = params.length; i < j; i++) {
             if (ignoreCase && params[i].equalsIgnoreCase(name)) {
                 return i;
             } else if (params[i].equals(name)) {
                 return i;
             }
         }
         return -1;
     }

     /**
      * 查询Str2在Str1中出现几次
      *
      * @param str1
      * @param str2
      * @return
      */
     public static int indexAllOf(String str1, String str2) {
         int he = 0;
         for (int i = 0; i < str1.length(); i++) {
             int t = str1.indexOf(str2, i);
             if (i == t) {
                 he++;
             }
         }
         return he;
     }

     /**
      * 将字符转数组.
      *
      * @param str
      *            the str
      *
      * @return the string[]
      */
     public static String[] toArr(String str) {
         String inStr = str;
         String a[] = null;
         try {
             if (null != inStr) {
                 StringTokenizer st = new StringTokenizer(inStr, ",");
                 if (st.countTokens() > 0) {
                     a = new String[st.countTokens()];
                     int i = 0;
                     while (st.hasMoreTokens()) {
                         a[i++] = st.nextToken();
                     }
                 }
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
         return a;
     }

     /**
      * 将字符转数组.
      *
      * @param str
      *            the str
      * @param splitChar
      *            the split char
      *
      * @return the string[]
      */
     public static String[] toArr(String str, String splitChar) {
         String inStr = str;
         String a[] = null;
         try {
             if (null != inStr) {
                 StringTokenizer st = new StringTokenizer(inStr, splitChar);
                 if (st.countTokens() > 0) {
                     a = new String[st.countTokens()];
                     int i = 0;
                     while (st.hasMoreTokens()) {
                         a[i++] = st.nextToken();
                     }
                 }
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
         return a;
     }

     /**
      * 字符串数组包装成字符串.
      *
      * @param ary
      *            the ary
      * @param s
      *            包装符号如 ' 或 "
      *
      * @return the string
      */
     public static String toStr(String[] ary, String s) {
         if (ary == null || ary.length < 1)
             return "";
         StringBuffer bf = new StringBuffer();
         bf.append(s);
         bf.append(ary[0]);
         for (int i = 1; i < ary.length; i++) {
             bf.append(s).append(",").append(s);
             bf.append(ary[i]);
         }
         bf.append(s);
         return bf.toString();
     }

     /**
      * 得到字符的编码格式
      *
      * @param str
      * @return
      */
     public static String getEncoding(String str) {
         String encode = "GB2312";
         try {
             if (str.equals(new String(str.getBytes(encode), encode))) {
                 String s = encode;
                 return s;
             }
         } catch (Exception exception) {
         }
         encode = "ISO-8859-1";
         try {
             if (str.equals(new String(str.getBytes(encode), encode))) {
                 String s1 = encode;
                 return s1;
             }
         } catch (Exception exception1) {
         }
         encode = "UTF-8";
         try {
             if (str.equals(new String(str.getBytes(encode), encode))) {
                 String s2 = encode;
                 return s2;
             }
         } catch (Exception exception2) {
         }
         encode = "GBK";
         try {
             if (str.equals(new String(str.getBytes(encode), encode))) {
                 String s3 = encode;
                 return s3;
             }
         } catch (Exception exception3) {
         }
         return "";
     }

     /**
      * utf8转码 Description :.
      *
      * @param str
      *            the str
      *
      * @return the string
      */
     public static String utf8Decoder(String str) {
         try {
             if (str != null) {
                 return URLDecoder.decode(str, "UTF-8");
             }
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
         }
         return str;
     }

     public static String changeCharset(String str, String oldCharset, String newCharset)
             throws UnsupportedEncodingException {
         if (str != null) {
             // 用旧的字符编码解码字符串。解码可能会出现异常。
             byte[] bs = str.getBytes(oldCharset);
             // 用新的字符编码生成字符串
             return new String(bs, newCharset);
         }
         return null;
     }  

     /**
      * 过滤掉高亮的html
      * @param str
      * @return
      */
     public static String htmlFilter(String str) {
         if (isEmpty(str)) {
             return str;
         }
         str = str.replace("<font color='red'>", "");
         str = str.replace("<font color='blue'>", "");
         str = str.replace("</font>", "");

         return str;
     }

     public static String trimString(String str){
         if(isEmpty(str)){
             return str;
         }
         return str.trim();
     }

     public static String encodeToUtf(String str) throws Exception {
         if(isEmpty(str)){
             return str;
         }
         return new String(str.getBytes("iso-8859-1"), "UTF-8");
     }

     /**
      * 根据身份证号转性别
      * @param sfzh
      * @return
      */
     public static String converToSex(String sfzh){
         int sex = 0;
         if(StringUtil.isEmpty(sfzh)){
             return "";
         }else{
             if(sfzh.length()==15){
                 sex = Integer.parseInt(sfzh.substring(13,14));
             }else if(sfzh.length()==18){
                 sex = Integer.parseInt(sfzh.substring(16,17));
             }
             if(sex%2 == 0){
                 return "女";
             }else{
                 return "男";
             }
         }
     }

     /**
      * 设置地址的Map,并去重
      * @param addrMap
      * @param fromType
      * @param addrs
      */
     public static void setAddr2Map(Map addrMap,String addrs,String fromType){
         String[] addrls = null ;
         if(addrMap==null){
             addrMap = new HashMap();
         }
         if(addrMap.containsKey(fromType)){
             String strAddr = (String)addrMap.get(fromType);
             if(strAddr!=null && strAddr.trim().length()>0){
                 addrls = strAddr.split(",");
             }

             if(!isExsit(addrls,addrs)){
                 strAddr +=","+addrs;
                 addrMap.put(fromType, strAddr);
             }
         }else{
             addrMap.put(fromType, addrs);
         }
     }

     /**
      * 字符口串是否在数据组存在
      * @param addrls
      * @param addrs
      * @return
      */
     private static boolean isExsit(String[] addrls,String addrs){
         if(addrls!=null && addrls.length>0){
             for(int i=0;i<addrls.length;i++){
                 if(addrls[i].equals(addrs)){
                     return true;
                 }
             }
         }
         return false;
     }
     /**
      * 把Map转换成String
      * @param addrMap
      * @return
      */
     public static String convMap2String(Map addrMap){
         StringBuilder tempBuf =new StringBuilder();
         Iterator<Map.Entry> it = addrMap.entrySet().iterator();
         while (it.hasNext()) {
             Map.Entry<String, String> entry = it.next();
             String fldName = entry.getKey();
             String fldValue = entry.getValue();
             tempBuf.append(fldValue).append("(").append(fldName).append(");");
         }
         return tempBuf.toString();
     }

     //字节转换
     public static String formetFileSize(long fileS) {

         DecimalFormat df = new DecimalFormat("#.00");
         String fileSizeString = "";
         if (fileS < 1024) {
             fileSizeString = df.format((long) fileS) + "B";
         } else if (fileS < 1048576) {
             fileSizeString = df.format((long) fileS / 1024) + "KB";
         } else if (fileS < 1073741824) {
             fileSizeString = df.format((long) fileS / 1048576) + "MB";
         } else if(fileS < 1099511627776l) {
             fileSizeString = df.format((long) fileS / 1073741824) + "GB";
         } else{
             fileSizeString = df.format((long) fileS / 1099511627776l) + "TB";
         }
             return fileSizeString;
         }

     public static void main(String[] args) {

         long a = 1948065583104l;
         System.out.println(formetFileSize(a));
     }

 }