BlogJava-冉翔的技术专栏-文章分类-09.Utils Code

利用正则表达式来对数字进行判断的一个类

冉翔 — Fri, 09 Dec 2005 07:36:00 GMT

/*
* Created on 2005-5-13
* 利用正则表达式对数字进行判断
* 代码来源自PIGO，有改动
*/
package org.waityou.utils;

import java.util.regex.*;

/**
* @author Ace
*     thanks, pigo
*
*/
public class ValidationNumber {

    private static Pattern intnumPattern;

    private static Pattern numberPattern;

    private static Pattern doublenumPattern;

    public static boolean isintNumber(String aString) {
        //      检查一个字符串是否是整数允许一个正负符号位

        if (aString == null || aString.length() < 1) {
            return false;
        }

        if (intnumPattern == null) {
            intnumPattern = Pattern.compile("^[+-]?[\\d]+$");
        }

        return intnumPattern.matcher(aString).find();
    }

    public static boolean isNumber(String aString) {
        //      检查一个字符串是否全部是数字

        if (aString == null || aString.length() < 1) {
            return false;
        }

        if (numberPattern == null) {
            numberPattern = Pattern.compile("^[\\d]+$");     //  "^[+-]?([\\d]+)|([\\d]+\\.[\\d]+)$"
        }

        return numberPattern.matcher(aString).find();
    }

    public static boolean isdoubleNumber(String aString) {
        //检查一个字符串是否是浮点小数,浮点小数至少一个数字开头,允许一个正负符号位
        //中间只出现一个小数点,小数点之后至少一个数字

        if (aString == null || aString.length() < 1) {
            return false;
        }

        if (doublenumPattern == null) {
            doublenumPattern = Pattern.compile("^[+-]?[\\d]+\\.[\\d]+$");
        }
        return doublenumPattern.matcher(aString).find();
    }

    public static void main(String[] args) {

        // 测试
        String intnum1 = "-23423";
        String intnum2 = "234";
        String numstring = "234sdf";
        String num1 = "234234";
        String doublenum1 = "0.123456";
        String doublenum2 = "-0.23";
        String doublenum3 = ".123123";

        System.out.println("" + isintNumber(intnum1));
        System.out.println("" + isintNumber(intnum2));
        System.out.println("" + isintNumber(numstring));

        System.out.println("" + isNumber(num1));
        System.out.println("" + isNumber(numstring));

        System.out.println("" + isdoubleNumber(doublenum1));
        System.out.println("" + isdoubleNumber(doublenum2));
        System.out.println("" + isdoubleNumber(doublenum3));
        System.out.println("" + isdoubleNumber(numstring));
    }
}

冉翔 2005-12-09 15:36 发表评论

两个Filter类：登录过滤和编码过滤

冉翔 — Fri, 09 Dec 2005 07:35:00 GMT

LoginFilter.java:

import javax.servlet.FilterChain;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import javax.servlet.FilterConfig;

/*
*
* @author Ace
* web.xml配置如下：
*
* login
*
* org.waityou.news.util.filters.LoginFilter
*
*
*
* login
* /manager/*
*
*/
public class LoginFilter implements Filter {

    protected FilterConfig filterConfig;

    public void doFilter(final ServletRequest req, final ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest hreq = (HttpServletRequest) req;
        HttpServletResponse hres = (HttpServletResponse) res;
        String isLog = (String) hreq.getSession().getAttribute("isLog");
        if ((isLog != null) && ((isLog.equals("true")) || (isLog == "true")))//检查是否登录
        {
            chain.doFilter(req, res);
            return;
        } else
            hres.sendRedirect("/error.html");//如果没有登录，把视图派发到登录页面
    }

    public void destroy() {
        this.filterConfig = null;
    }

    public void init(FilterConfig config) {
        this.filterConfig = config;
    }

    public void setFilterConfig(final FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }
}

SetCharacterEncodingFilter.java:

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
* @author Ace 编码过滤，一律设置成UTF-8
*
* web.xml中配置如下：
*
* Set Character Encoding
*
* org.waityou.news.util.filters.SetCharacterEncodingFilter
*
*
*
* Set Character Encoding
* /*
*
*/
public class SetCharacterEncodingFilter implements Filter {

    public void destroy() {}
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("UTF-8");
        // 传递控制到下一个过滤器
        chain.doFilter(request, response);
    }

    public void init(FilterConfig filterConfig) throws ServletException {}

}

冉翔 2005-12-09 15:35 发表评论

【转载】MD5 算法的Java Bean

冉翔 — Fri, 09 Dec 2005 07:25:00 GMT

摘要: /** *//************************************************ MD5 算法的Java Bean @author:Topcat Tuppin Last Modified:10,Mar,2001 ****************************... 阅读全文

冉翔 2005-12-09 15:25 发表评论