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目录我们在java开发中有很多常见的功能,像常见的字符串、日期、cookie的操作、日志、文件等的操作,加解密操作,这些每次都是用到了然后再去百度,很浪费时间,这里给大家梳理了常见的这些工具类,可以帮助你在开发中节省很多搜索的时间。同时,对这些常见的操作,多加练习,也可以稳固提升自己的编程能力。
part1:
part2:
[工具类] CookieCounter .java.txt
[工具类] Java中计算任意两个日期之间的工作天
[工具类] java抓取网页 .java.txt
[工具类] MD5 .java.txt
[工具类] MD5强化版 .java.txt
[工具类] MD5超强化版 .java.txt
[工具类] XML 实用工具类 .java.txt
[工具类] XML工具类2 .java.txt
[工具类] 一个压缩工具类.java.txt
[工具类] 中文验证.jsp.txt
[工具类] 使用Java程序来实现HTTP文件的队列下
[工具类] 分页split_page.jsp .jsp.txt
[工具类] 序列化保存为XML文件的工具类 .java.
[工具类] 文件FileUtil.java
[工具类] 文件操作工具类 .java.txt
[工具类] 日期DateUtil.java
[工具类] 时间Time.java
[工具类] 时间工具TimeUtil.java
[工具类] 框架StringUtil.java
[工具类] 测试Mysql的最大连接数 .java.txt
[工具类] 用java编写简单UDP网络通信程序 .jav
[工具类] 获取绝对路径 .java.txt
[工具类] 获得汉字拼音首字母的java工具类.jav
[工具类] 记录log日志文件的工具类 .java.txt
[工具类] 读取、打印输出、保存xml .java.txt
[工具类] 连接数据库的工具类 .java.txt
[工具类] 连数据库ConnectDB.java
[工具类] 通信客户端simpleClient.java
[工具类] 通信服务端simpleServer.java
[工具类] 验证码img .jsp.txt
1、文件(IO、文件、日志读写)操作类
2、通信类
3、jsp相关操作类
4、日期处理类
5、加解密操作类
6、字符串操作类
7、数据库操作类
8、其他
[工具类] CookieCounter .java
import java.io.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; /** * <p>Title: servlet读取cookie</p> * <p>Description: 这个servlet演示怎样创建和获取cookie并设置cookie的期限</p> * <p>Copyright: Copyright (c) 2003</p> * <p>Filename: CookieCounter.java</p> * @author 杜江 * @version 1.0 */ //必须继承HttpServlet类 public class CookieCounter extends HttpServlet { private int pageCount = 0; /** *<br>方法说明:初始化 *<br>输入参数:ServletConfig config 服务器配置对象 *<br>返回类型: */ public void init(ServletConfig config) throws ServletException { super.init(config); } /** *<br>方法说明:实现service方法 *<br>输入参数:HttpServletRequest req 客户请求对象 *<br>输入参数:HttpServletResponse res 服务器应答对象 *<br>返回类型: */ public void service(HttpServletRequest req, HttpServletResponse res) throws IOException { boolean cookieFound = false; Cookie thisCookie = null; // 设置内容类型 res.setContentType("text/html; charset=GB2312"); // 调用getWriter() PrintWriter out = res.getWriter(); // 从请求获取coolies Cookie[] cookies = req.getCookies(); if(cookies!=null){ for(int i=0; i < cookies.length; i++) { thisCookie = cookies[i]; //检查是否存在CookieCount数据 if (thisCookie.getName().equals("CookieCount")) { cookieFound = true; break; } } } if (cookieFound == false) { // 创建新的Cookie并设置它的存活期 thisCookie = new Cookie("CookieCount", "1"); thisCookie.setMaxAge(60*1); // 在response对象中加入cookie res.addCookie(thisCookie); } //输出页面 out.println("<html><head>\n" + "<title>Cookie计数器</title></head><body>\n" + "<center><h1>Cookie 计数器</h1></center></font>"); pageCount++; out.println("<p>"); out.println("<font color=blue size=+1>"); out.println("<p><br><br><br>这个页面您已经拜访了 " + pageCount + " 次.\n"); // 显示客户端详细信息,是否存在计数器cookie if (cookieFound) { int cookieCount = Integer.parseInt(thisCookie.getValue()); cookieCount++; // 设置cookie的新值, 加到相应对象中 thisCookie.setValue(String.valueOf(cookieCount)); thisCookie.setMaxAge(10); res.addCookie(thisCookie); out.println("<p>这是你近10秒内第 " + thisCookie.getValue() + " 次拜访这一页\n"); } else { out.println("<p>你在近10秒内没有拜访过此页或者你的浏览器不支持cookie "+ "如果你的浏览器支持cookie,请确认是否打开了!\n"); } out.println("</body></html>"); } }
[工具类] 连数据库ConnectDB.java:
package com.common.database; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; /** * 功能描述:连接数据库-mysql/oracle * * @author :FangHewei * @Date :Jul 18, 2008 * @Time :3:28:59 PM * @version :1.0 */ public class ConnectDB { private static final String MYSQL = "jdbc:mysql://"; private static final String ORACLE = "jdbc:oracle:thin:@"; private static final String SQLSERVER = "jdbc:microsoft:sqlserver://"; private ConnectDB() { } public static Connection getConnection(String DBType, String url, String user, String password) throws SQLException { if ("mysql".equalsIgnoreCase(DBType)) return getMySqlConn(url, user, password); if ("oracle".equalsIgnoreCase(DBType)) return getOracleConn(url, user, password); if ("sqlserver".equals(DBType)){ return getSqlServerConn(url, user, password); } return null; } public static void closeConn(Connection conn) { if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } private static Connection getMySqlConn(String url, String user, String password) throws SQLException { Connection conn = null; try { Class.forName("com.mysql.jdbc.Driver");// 加载驱动 } catch (ClassNotFoundException e) { e.printStackTrace(); } conn = DriverManager.getConnection(MYSQL + url, "root", "root"); return conn; } private static Connection getOracleConn(String url, String user, String password) throws SQLException { Connection conn = null; try { Class.forName("oracle.jdbc.driver.OracleDriver");// 加载驱动 } catch (ClassNotFoundException e) { e.printStackTrace(); } conn = DriverManager.getConnection(ORACLE + url, "scott", "tiger"); return conn; } private static Connection getSqlServerConn(String url, String user, String password) throws SQLException { Connection conn = null; try { Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");// 加载驱动 } catch (ClassNotFoundException e) { e.printStackTrace(); } conn = DriverManager.getConnection(SQLSERVER + url, "root", "root"); return conn; } public static void main(String[] args) { try { Connection conn = getConnection("MySQL", "127.0.0.1", "root", "root"); if (conn == null) { System.out.println("Connection the database is failled !"); } else { System.out.println(conn.toString()); } } catch (SQLException e) { e.printStackTrace(); } } }
[工具类] MD5 .java:
/************************************************ MD5 算法的Java Bean Last Modified:10,Mar,2001 *************************************************/ import java.lang.reflect.*; /************************************************* md5 类实现了RSA Data Security, Inc.在提交给IETF 的RFC1321中的MD5 message-digest 算法。 *************************************************/ public class MD5 { /* 下面这些S11-S44实际上是一个4*4的矩阵,在原始的C实现中是用#define 实现的, 这里把它们实现成为static final是表示了只读,切能在同一个进程空间内的多个 Instance间共享*/ static final int S11 = 7; static final int S12 = 12; static final int S13 = 17; static final int S14 = 22; static final int S21 = 5; static final int S22 = 9; static final int S23 = 14; static final int S24 = 20; static final int S31 = 4; static final int S32 = 11; static final int S33 = 16; static final int S34 = 23; static final int S41 = 6; static final int S42 = 10; static final int S43 = 15; static final int S44 = 21; static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; /* 下面的三个成员是MD5计算过程中用到的3个核心数据,在原始的C实现中 被定义到MD5_CTX结构中 */ private long[] state = new long[4]; // state (ABCD) private long[] count = new long[2]; // number of bits, modulo 2^64 (lsb first) private byte[] buffer = new byte[64]; // input buffer /* digestHexStr是MD5的唯一一个公共成员,是最新一次计算结果的 16进制ASCII表示. */ public String digestHexStr; /* digest,是最新一次计算结果的2进制内部表示,表示128bit的MD5值. */ private byte[] digest = new byte[16]; /* getMD5ofStr是类MD5最主要的公共方法,入口参数是你想要进行MD5变换的字符串 返回的是变换完的结果,这个结果是从公共成员digestHexStr取得的. */ public String getMD5ofStr(String inbuf) { md5Init(); md5Update(inbuf.getBytes(), inbuf.length()); md5Final(); digestHexStr = ""; for (int i = 0; i < 16; i++) { digestHexStr += byteHEX(digest[i]); } return digestHexStr; } // 这是MD5这个类的标准构造函数,JavaBean要求有一个public的并且没有参数的构造函数 public MD5() { md5Init(); return; } /* md5Init是一个初始化函数,初始化核心变量,装入标准的幻数 */ private void md5Init() { count[0] = 0L; count[1] = 0L; ///* Load magic initialization constants. state[0] = 0x67452301L; state[1] = 0xefcdab89L; state[2] = 0x98badcfeL; state[3] = 0x10325476L; return; } /* F, G, H ,I 是4个基本的MD5函数,在原始的MD5的C实现中,由于它们是 简单的位运算,可能出于效率的考虑把它们实现成了宏,在java中,我们把它们 实现成了private方法,名字保持了原来C中的。 */ private long F(long x, long y, long z) { return (x & y) | ((~x) & z); } private long G(long x, long y, long z) { return (x & z) | (y & (~z)); } private long H(long x, long y, long z) { return x ^ y ^ z; } private long I(long x, long y, long z) { return y ^ (x | (~z)); } /* Rotation is separate from addition to prevent recomputation. */ private long FF(long a, long b, long c, long d, long x, long s, long ac) { a += F (b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private long GG(long a, long b, long c, long d, long x, long s, long ac) { a += G (b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private long HH(long a, long b, long c, long d, long x, long s, long ac) { a += H (b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } private long II(long a, long b, long c, long d, long x, long s, long ac) { a += I (b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; } /* md5Update是MD5的主计算过程,inbuf是要变换的字节串,inputlen是长度,这个 函数由getMD5ofStr调用,调用之前需要调用md5init,因此把它设计成private的 */ private void md5Update(byte[] inbuf, int inputLen) { int i, index, partLen; byte[] block = new byte[64]; index = (int)(count[0] >>> 3) & 0x3F; // /* Update number of bits */ if ((count[0] += (inputLen << 3)) < (inputLen << 3)) count[1]++; count[1] += (inputLen >>> 29); partLen = 64 - index; // Transform as many times as possible. if (inputLen >= partLen) { md5Memcpy(buffer, inbuf, index, 0, partLen); md5Transform(buffer); for (i = partLen; i + 63 < inputLen; i += 64) { md5Memcpy(block, inbuf, 0, i, 64); md5Transform (block); } index = 0; } else i = 0; ///* Buffer remaining input */ md5Memcpy(buffer, inbuf, index, i, inputLen - i); } /* md5Final整理和填写输出结果 */ private void md5Final () { byte[] bits = new byte[8]; int index, padLen; ///* Save number of bits */ Encode (bits, count, 8); ///* Pad out to 56 mod 64. index = (int)(count[0] >>> 3) & 0x3f; padLen = (index < 56) ? (56 - index) : (120 - index); md5Update (PADDING, padLen); ///* Append length (before padding) */ md5Update(bits, 8); ///* Store state in digest */ Encode (digest, state, 16); } /* md5Memcpy是一个内部使用的byte数组的块拷贝函数,从input的inpos开始把len长度的 字节拷贝到output的outpos位置开始 */ private void md5Memcpy (byte[] output, byte[] input, int outpos, int inpos, int len) { int i; for (i = 0; i < len; i++) output[outpos + i] = input[inpos + i]; } /* md5Transform是MD5核心变换程序,有md5Update调用,block是分块的原始字节 */ private void md5Transform (byte block[]) { long a = state[0], b = state[1], c = state[2], d = state[3]; long[] x = new long[16]; Decode (x, block, 64); /* Round 1 */ a = FF (a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */ d = FF (d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */ c = FF (c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */ b = FF (b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */ a = FF (a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */ d = FF (d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */ c = FF (c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */ b = FF (b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */ a = FF (a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */ d = FF (d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */ c = FF (c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */ b = FF (b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */ a = FF (a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */ d = FF (d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */ c = FF (c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */ b = FF (b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */ /* Round 2 */ a = GG (a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */ d = GG (d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */ c = GG (c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */ b = GG (b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */ a = GG (a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */ d = GG (d, a, b, c, x[10], S22, 0x2441453L); /* 22 */ c = GG (c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */ b = GG (b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */ a = GG (a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */ d = GG (d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */ c = GG (c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */ b = GG (b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */ a = GG (a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */ d = GG (d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */ c = GG (c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */ b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */ /* Round 3 */ a = HH (a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */ d = HH (d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */ c = HH (c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */ b = HH (b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */ a = HH (a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */ d = HH (d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */ c = HH (c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */ b = HH (b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */ a = HH (a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */ d = HH (d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */ c = HH (c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */ b = HH (b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */ a = HH (a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */ d = HH (d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */ c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */ b = HH (b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */ /* Round 4 */ a = II (a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */ d = II (d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */ c = II (c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */ b = II (b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */ a = II (a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */ d = II (d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */ c = II (c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */ b = II (b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */ a = II (a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */ d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */ c = II (c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */ b = II (b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */ a = II (a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */ d = II (d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */ c = II (c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */ b = II (b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */ state[0] += a; state[1] += b; state[2] += c; state[3] += d; } /*Encode把long数组按顺序拆成byte数组,因为java的long类型是64bit的, 只拆低32bit,以适应原始C实现的用途 */ private void Encode (byte[] output, long[] input, int len) { int i, j; for (i = 0, j = 0; j < len; i++, j += 4) { output[j] = (byte)(input[i] & 0xffL); output[j + 1] = (byte)((input[i] >>> 8) & 0xffL); output[j + 2] = (byte)((input[i] >>> 16) & 0xffL); output[j + 3] = (byte)((input[i] >>> 24) & 0xffL); } } /*Decode把byte数组按顺序合成成long数组,因为java的long类型是64bit的, 只合成低32bit,高32bit清零,以适应原始C实现的用途 */ private void Decode (long[] output, byte[] input, int len) { int i, j; for (i = 0, j = 0; j < len; i++, j += 4) output[i] = b2iu(input[j]) | (b2iu(input[j + 1]) << 8) | (b2iu(input[j + 2]) << 16) | (b2iu(input[j + 3]) << 24); return; } /* b2iu是我写的一个把byte按照不考虑正负号的原则的"升位"程序,因为java没有unsigned运算 */ public static long b2iu(byte b) { return b < 0 ? b & 0x7F + 128 : b; } /*byteHEX(),用来把一个byte类型的数转换成十六进制的ASCII表示, 因为java中的byte的toString无法实现这一点,我们又没有C语言中的 sprintf(outbuf,"%02X",ib) */ public static String byteHEX(byte ib) { char[] Digit = { '0','1','2','3','4','5','6','7','8','9', 'A','B','C','D','E','F' }; char [] ob = new char[2]; ob[0] = Digit[(ib >>> 4) & 0X0F]; ob[1] = Digit[ib & 0X0F]; String s = new String(ob); return s; } }
[工具类] 分页split_page.jsp:
<%@ page contentType="text/html;charset=gbk"%> <% // 页面连接路径 String jspUrl = null ; // 定义如下分页变量 // 1、定义没页要显示的记录数,默认是10条每页 int lineSize = 10 ; // 2、定义一个当前是第几页 int currentPage = 1 ; // 计算出总页数 int pageSize = 0 ; // 总记录数 / 每页显示的记录数 int allRecorders = 0 ; // 加入查询关键字变量 String keyWord = null ; // 加入一个检索标记 String searchFlag = "F" ; %> <% // 需要从外面接收以下参数 // 当前页、每页显示的记录数、总记录数、查询关键字、连接地址 jspUrl = request.getParameter("jspUrl") ; keyWord = request.getParameter("keyWord") ; searchFlag = request.getParameter("searchFlag") ; try { lineSize = Integer.parseInt(request.getParameter("lineSize")) ; currentPage = Integer.parseInt(request.getParameter("currentPage")) ; allRecorders = Integer.parseInt(request.getParameter("allRecorders")) ; } catch(Exception e) { // s } %> <% // 计算总页数 pageSize = (allRecorders+lineSize-1)/lineSize ; %> <script language="javaScript"> function openPage(curpage) { document.spage.cp.value = curpage ; // alert(cupage) ; document.spage.submit() ; } function selOpenPage() { document.spage.cp.value = document.spage.selpage.value ; document.spage.submit() ; } function change() { if(document.spage.kw.value!="") { document.spage.status.value = "selectlike" ; } } </script> <form name="spage" action="<%=jspUrl%>" onSubmit="change()"> <input type="hidden" name="status" value="${status}"> <input type="hidden" name="${param.flagname}" value=${param.flagvalue}> <% if ("T".equals(searchFlag)) { %> 输入查询关键字:<input type="text" name="kw" value="<%=keyWord.equals("null") ? "" : keyWord%>"> <input type="submit" value="查询"> <br> <br> <% } %> <% if (allRecorders > 0) { %> <input type="button" value="首页" onClick="openPage(1)" <%=currentPage == 1 ? "disabled" : ""%>> <input type="button" value="上一页" onClick="openPage(<%=currentPage - 1%>)" <%=currentPage == 1 ? "disabled" : ""%>> <input type="button" value="下一页" onClick="openPage(<%=currentPage + 1%>)" <%=currentPage == pageSize ? "disabled" : ""%>> <input type="button" value="尾页" onClick="openPage(<%=pageSize%>)" <%=currentPage == pageSize ? "disabled" : ""%>> <input type="hidden" name="cp" value=""> <font color="red" size="5"><%=currentPage%></font> / <font color="red" size="5"><%=pageSize%></font> 跳转到 <select name="selpage" onChange="selOpenPage()"> <% for (int x = 1; x <= pageSize; x++) { %> <option value="<%=x%>" <%=currentPage == x ? "selected" : ""%>><%=x%></option> <% } %> </select> 页 <% } %> </form>
(代码由于太多贴不全,如果有问题或者需要所有源码,可以加博主V交流: Code2Life2)