前段时间大量密码泄漏的问题闹得挺严重的, 自己也发现我几乎所有网站的注册密码都是相同的. 非常不安全.
如果考虑每个网站使用不同的密码, 对自己来说也是一种负担. 于是就考虑是用md5对自己的密码进行加密.
自己提供一个私钥, 然后输入注册的网站. 之后程序在其中混入数字和符号. 计算md5, 取其中的某几位来生成密码.
这样我只要记住自己的私钥, 那么当我登录weibo的时候, 我的我就在WebSite中写weibo. 这样又好记, 又安全.
我只在自己的黑莓9780上6.0os上测试了, 按道理 96,97应该都能使用.

点击下载: MyMd5Tools - 已下载 25 次

功能描述
一个链表中保存多个不同长度的数组, 根据一个索引值, 能取到对应的元素所在的数组下标

public static int[] calcIndexArr(final List<String[]> list, int index) {
    int listSize;
    if (list == null || (listSize = list.size()) == 0) {
        return new int[0];
    }

    int max = 1;
    for (int i = 0; i < list.size(); i++) {
        max *= list.get(i).length;
    }
    while (index >= max) {
        index -= max;
    }

    int[] indexArr = new int[list.size()];

    for (int i = 0; i < listSize; i++) {
        int b = 1;
        for (int j = i + 1; j < listSize; j++) {
            b *= list.get(j).length;
        }
        int a = index / b;
        indexArr[i] = a;
        index = index - a * b;
    }
    return indexArr;
}

测试方法:

public void testCalcIndexArr() {
    List<String[]> list = new ArrayList<String[]>();
    list.add(new String[2]);
    list.add(new String[4]);
    list.add(new String[1]);
    for (int i = 0; i < 30; i++) {
        int arr[] = RandName.calcIndexArr(list, i);
        assertEquals(3, arr.length);
        System.out.println(arr[0] + "," + arr[1] + "," + arr[2]);
    }
}

测试结果

0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
1,2,0
1,3,0
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
1,2,0
1,3,0
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0
1,2,0
1,3,0
0,0,0
0,1,0
0,2,0
0,3,0
1,0,0
1,1,0

问题描述：
JSP网页里是charset=UTF-8： 

<%@ page contentType= “text/html; charset=UTF-8 ” language= “java ” import= “java.sql.* ” errorPage= “error.jsp ” %> 

Mysql5里存取的数据库的charset也设成了UTF-8，可是通过JSP网页存取中文还是显示乱码 

解决方案：加个过滤类 

package com.bx.util; 

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; 

public class SetEncodingFilter implements Filter { 

    // ----------------------------------------------------- Instance  Variables 

    /**
     * The default character encoding to set for requests that pass through this
     * filter.
     */
    protected String encoding = null; 

    /**
     * The filter configuration object we are associated with. If this value is
     * null, this filter instance is not currently configured.
     */
    protected FilterConfig filterConfig = null; 

    /**
     * Should a character encoding specified by the client be ignored?
     */
    protected boolean ignore = true; 

    // --------------------------------------------------------- Public Methods 

    /**
     * Take this filter out of service.
     */
    public void destroy() {
        this.encoding = null;
        this.filterConfig = null;
    } 

    /**
     * Select and set (if specified) the character encoding to be used to
     * interpret request parameters for this request.
     *
     * @param request
     * The servlet request we are processing
     * @param result
     * The servlet response we are creating
     * @param chain
     * The filter chain we are processing
     *
     * @exception IOException
     * if an input/output error occurs
     * @exception ServletException
     * if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        // Conditionally select and set the character encoding to be used
        if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null) {
                request.setCharacterEncoding(encoding);
            }
        } 

        // Pass control on to the next filter
        chain.doFilter(request, response);
    } 

    /**
     * Place this filter into service.
     *
     * @param filterConfig
     * The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException { 

        this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null) {
            this.ignore = true;
        } else if (value.equalsIgnoreCase("true")) {
            this.ignore = true;
        } else if (value.equalsIgnoreCase("yes")) {
           this.ignore = true;
        } else {
           this.ignore = false;
        }
    } 

    // ------------------------------------------------------ Protected Methods 

    /**
     * Select an appropriate character encoding to be used, based on the
     * characteristics of the current request and/or filter initialization
     * parameters. If no character encoding should be set, return
     * <code>null</code>.
     * <p>
     * The default implementation unconditionally returns the value configured
     * by the <strong>encoding</strong> initialization parameter for this
     * filter.
     *
     * @param request
     * The servlet request we are processing
     */
    protected String selectEncoding(ServletRequest request) {
        return (this.encoding);
    }
}

然后在web.xml文件中配置一下就可以了 

<filter>
    <filter-name>Set Character Encoding</filter-name>
    <filter-class>com.bx.util.SetEncodingFilter类的路径</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>Set Character Encoding</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>