jsp+servlet+Oracle网上订书系统

package com.store.commons; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * 对字符串操作的工具类 * * @author Administrator * */ public class StringUtils { /** * 检查指定字符串是否为null或 "" * @param str * @return null或""返回 true, 否则返回false */ public static boolean isEmpty(String str){ if(str == null || str.length()==0){ return true; } return false; } /** * 检查指定字符串是否不为null或 "" * @param str * @return */ public static boolean isNotEmpty(String str){ if(str != null && str.length()!=0){ return true; } return false; } /** 检查字符中串是否是一个数字 * @param source * @return */ public static boolean isNumber(String source){ String regex = "\\d+\\.?\\d*?"; //创建一个模式对象 Pattern p = Pattern.compile(regex); //匹配器 Matcher m = p.matcher(source); boolean b = m.matches(); return b; } /** * 将字符串转换成Integer值 * @param str * @return */ public static Integer parseToInt(String str){ if (str == null || str.length()==0 || !isNumber(str)) { return null; }else{ return Integer.parseInt(str); } } /** * 将字符串转换成Double值 * @param str * @return */ public static Double parseToDouble(String str){ if (str == null || str.length()==0 || !isNumber(str)) { return null; }else{ return Double.parseDouble(str); } } static String[] patterns = {"yyyy-MM-dd","yyyy/MM/dd","dd-M月-yy","yyyy-MM-dd hh:mm:ss"}; /** * 把字符串转换成java.util.Date对象 * @param source * @return 成功返回：Date， 否则返回null */ public static Date parseToDate(String source){ SimpleDateFormat sdf = null; Date d = null; for (int i = 0; i < patterns.length; i++) { sdf = new SimpleDateFormat(patterns[i]); try { d = sdf.parse(source); } catch (ParseException e) { continue; } } return d; } public static String formatToString(Date source,String pattern){ SimpleDateFormat sdf = new SimpleDateFormat(pattern); String d = null; d = sdf.format(source); return d; } public static String subString(String source, int length){ if (isNotEmpty(source)) { return source.length()>=length ? source.substring(0, length) : source; } return ""; } public static void main(String[] args) { //System.out.println( parseToDate("2012/09/22") ); Date d = parseToDate("2012/11/22"); System.out.println(formatToString(d,"dd-M月-yy")); System.out.println(isNumber("3.")); // System.out.println(parseToDouble("300")); } }