Character的常用工具类_character空指针

package com.cmcc.flow.common.util;
 
import java.io.UnsupportedEncodingException;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
import javax.servlet.http.HttpServletRequest;
 
public class CharacterUtil {
	/**
	 * 手机电话号码正则表达式
	 */
	private final static String MOBILE_PHONE_NUM_REGEXP="^1[3-8][0-9]{9}$";
	
	private final static String EMAIL_ADDR_REGEXP="^\\w+((-\\w+)|(\\.\\w+))*@[A-Za-z0-9]+((\\.|-)[A-Za-z0-9]+)*\\.[A-Za-z0-9]+$" ;
	
	public static String  stringTranscoding(String str){
		if(str!=null && str.trim().length()>0 && str.trim()!=""){ //TODO:chendw 重复判断
			try {
				return new String(str.toString().getBytes("iso-8859-1"),"UTF-8");
			} catch (UnsupportedEncodingException e) {
				// TODO Auto-generated catch block
//				e.printStackTrace();
				return null;
			}
		}
		return str;
	}
	
	/**
	 * @throws UnsupportedEncodingException 
	 * 
	 * @Title: getStringFromRequest 
	 * @Description: 得到请求参数
	 * @param @param request
	 * @param @param parameterName
	 * @param @return
	 * @return String
	 * @throws
	 */
	public static String getStringFromRequest(HttpServletRequest request, 
			String parameterName){
		try {
			request.setCharacterEncoding("utf-8");
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		if(request==null || parameterName==null)
			return null;
		
		String szName = request.getParameter(parameterName);
//		if(szName!=null &&
//				request.getMethod().equalsIgnoreCase("get")){
//			try {
				String szRequestCharset = request.getCharacterEncoding();
//				szName = new String(szName.getBytes("ISO-8859-1"), "UTF-8");
//			} catch (UnsupportedEncodingException e) {
//				// TODO Auto-generated catch block
//				//e.printStackTrace();
//				return null;
//			}
//		}
		
		szName = trimStringSafe(szName);		
		return szName;
	}
	
	/**
	 * 
	 * @Title: getStringFromRequest 
	 * @Description: 从页面请求获取相应的参数，如果参数为空或者NULL，统一返回空字符
	 * @param @param request
	 * @param @param parameterName
	 * @param @return
	 * @return String
	 * @throws
	 *//*
	public static String getStringFromRequest(HttpServletRequest request, 
				String parameterName)
	{
		try {
			return getStringFromRequest(request, parameterName, null);
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
			return "";
		}
	}*/
	
	public static String trimStringSafe(String oriString)
	{
		if(oriString!=null)
			return oriString.trim();
		return null;
	}
	
	public static String addQueryString(Map<String, String> queryParams, String oriString)
	{
		if(oriString==null || oriString.equals("")){
			return "";
		}
		
		oriString+="?";
		for(String szKey : queryParams.keySet()){
			String szTmpString = szKey + "=" + queryParams.get(szKey);
			oriString+=szTmpString;
			oriString+="&";
		}
		
		int nLength = oriString.length();
		return oriString.substring(0, nLength-1);
	}
	
	/**
	 * 
	 * @Title: isNullOrEmpty 
	 * @Description: 判断字符串是否为空值或空指针，如果是，抛出异常，并设置相应的异常信息
	 * @param @param str
	 * @param @param errorMsg
	 * @param @throws Exception
	 * @return void
	 * @throws
	 */
	public static void isNullOrEmpty(String str, String errorMsg)
		throws Exception
	{
		if(str==null || str.isEmpty()){
			Exception exception = new Exception(errorMsg);
			throw exception;
		}
	}
 
	/**
	 * 
	* @Title:isValidMobilePhone 
	* @Description: 判断一个字符串是否为有效的手机号码
	* @param szMobilePhone
	* @return
	* @throws
	 */
	public static boolean isValidMobilePhone(String szMobilePhone){
		return isValid(MOBILE_PHONE_NUM_REGEXP, szMobilePhone);
	}
	
	/**
	 * 
	* @Title:isValidEmailAddr 
	* @Description: 判断一个字符串是否为有效的邮箱地址
	* @param szEmailAddr
	* @return
	* @throws
	 */
	public static boolean isValidEmailAddr(String szEmailAddr){
		return isValid(EMAIL_ADDR_REGEXP, szEmailAddr);
	}
	
	/**
	 * 
	* @Title:isValid 
	* @Description: 通用的验证方法
	* @param regExp
	* @param szValue
	* @return
	* @throws
	 */
	public static boolean isValid(String regExp, String szValue){
		Pattern p = Pattern.compile(regExp);  
		Matcher m = p.matcher(szValue);  
		return m.find();
	}
}