/**
* 将某个日期以固定格式转化成字符串
*
* @param date
* @return String
*/
public static String dateToStr(java.util.Date date)
{
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String str = sdf.format(date);
return str;
}
------------------------------------------------------------------------------------------
/**
* 判断任意一个整数是否素数
*
* @param n
* @return boolean
*/
public static boolean isPrimes(int n)
{
for (int i = 2; i <= Math.sqrt(n); i++)
{
if (n % i == 0)
{
return false;
}
}
return true;
}
------------------------------------------------------------------------------------------
/**
* 获得任意一个整数的阶乘,递归
*
* @param n
* @return n!
*/
public static int factorial(int n)
{
if (n == 1)
{
return 1;
}
return n * factorial(n - 1);
}
--------------------------------------------------------------------------------------------
/**
* 将指定byte数组以16进制的形式打印到控制台
*
* @param hint
* String
* @param b
* byte[]
* @return void
*/
public static void printHexString(String hint, byte[] b)
{
System.out.print(hint);
for (int i = 0; i < b.length; i++)
{
String hex = Integer.toHexString(b[i] & 0xFF);
if (hex.length() == 1)
{
hex = '0' + hex;
}
System.out.print(hex.toUpperCase() + " ");
}
System.out.println("");
}
-----------------------------------------------------------------------------------------
package net.java2000.tools;
/**
* Title: Java Bean 工具
* Description:
* Copyright: Copyright (c) 2001
* Company: JAVA世纪网 http://www.java2000.net
* @author 赵学庆
* @version 1.0
*/
import java.util.*;
import java.util.regex.Pattern;
public class StrTools {
/**
* 分割字符串
*
* @param str
* String 原始字符串
* @param splitsign
* String 分隔符
* @return String[] 分割后的字符串数组
*/
@SuppressWarnings("unchecked")
public static String[] split(String str, String splitsign) {
int index;
if (str == null || splitsign == null)
return null;
ArrayList al = new ArrayList();
while ((index = str.indexOf(splitsign)) != -1) {
al.add(str.substring(0, index));
str = str.substring(index + splitsign.length());
//System.out.println("str is : " +str);
}
al.add(str);
return (String[]) al.toArray(new String[0]);
}
/**
* 替换字符串
*
* @param from
* String 原始字符串
* @param to
* String 目标字符串
* @param source
* String 母字符串
* @return String 替换后的字符串
*/
public static String replace(String from, String to, String source) {
if (source == null || from == null || to == null)
return null;
StringBuffer bf = new StringBuffer("");
int index = -1;
while ((index = source.indexOf(from)) != -1) {
bf.append(source.substring(0, index) + to);
source = source.substring(index + from.length());
index = source.indexOf(from);
}
bf.append(source);
return bf.toString();
}
/**
* 替换字符串,能能够在HTML页面上直接显示(替换双引号和小于号)
*
* @param str
* String 原始字符串
* @return String 替换后的字符串
*/
public static String htmlencode(String str) {
if (str == null) {
return null;
}
return replace("\"", """, replace("<", "<", str));
}
/**
* 替换字符串,将被编码的转换成原始码(替换成双引号和小于号)
*
* @param str
* String
* @return String
*/
public static String htmldecode(String str) {
if (str == null) {
return null;
}
return replace(""", "\"", replace("<", "<", str));
}
private static final String _BR = "<br/>";
/**
* 在页面上直接显示文本内容,替换小于号,空格,回车,TAB
*
* @param str
* String 原始字符串
* @return String 替换后的字符串
*/
public static String htmlshow(String str) {
if (str == null) {
return null;
}
str = replace("<", "<", str);
str = replace(" ", " ", str);
str = replace("\r\n", _BR, str);
str = replace("\n", _BR, str);
str = replace("\t", " ", str);
return str;
}
/**
* 返回指定字节长度的字符串
*
* @param str
* String 字符串
* @param length
* int 指定长度
* @return String 返回的字符串
*/
public static String toLength(String str, int length) {
if (str == null) {
return null;
}
if (length <= 0) {
return "";
}
try {
if (str.getBytes("GBK").length <= length) {
return str;
}
} catch (Exception ex) {
}
StringBuffer buff = new StringBuffer();
int index = 0;
char c;
length -= 3;
while (length > 0) {
c = str.charAt(index);
if (c < 128) {
length--;
} else {
length--;
length--;
}
buff.append(c);
index++;
}
buff.append("...");
return buff.toString();
}
/**
* 判断是否为整数
*
* @param str
* 传入的字符串
* @return 是整数返回true,否则返回false
*/
public static boolean isInteger(String str) {
Pattern pattern = Pattern.compile("^[-\\+]?[\\d]*$");
return pattern.matcher(str).matches();
}
/**
* 判断是否为浮点数,包括double和float
*
* @param str
* 传入的字符串
* @return 是浮点数返回true,否则返回false
*/
public static boolean isDouble(String str) {
Pattern pattern = Pattern.compile("^[-\\+]?[.\\d]*$");
return pattern.matcher(str).matches();
}
/**
* 判断输入的字符串是否符合Email样式.
*
* @param str
* 传入的字符串
* @return 是Email样式返回true,否则返回false
*/
public static boolean isEmail(String str) {
Pattern pattern = Pattern
.compile("^\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*$");
return pattern.matcher(str).matches();
}
/**
* 判断输入的字符串是否为纯汉字
*
* @param str
* 传入的字符窜
* @return 如果是纯汉字返回true,否则返回false
*/
public static boolean isChinese(String str) {
Pattern pattern = Pattern.compile("[\u0391-\uFFE5]+$");
return pattern.matcher(str).matches();
}
/**
* 是否为空白,包括null和""
*
* @param str
* @return
*/
public static boolean isBlank(String str) {
return str == null || str.trim().length() == 0;
}
/**
* 判断是否为质数
*
* @param x
* @return
*/
public static boolean isPrime(int x) {
if (x <= 7) {
if (x == 2 || x == 3 || x == 5 || x == 7)
return true;
}
int c = 7;
if (x % 2 == 0)
return false;
if (x % 3 == 0)
return false;
if (x % 5 == 0)
return false;
int end = (int) Math.sqrt(x);
while (c <= end) {
if (x % c == 0) {
return false;
}
c += 4;
if (x % c == 0) {
return false;
}
c += 2;
if (x % c == 0) {
return false;
}
c += 4;
if (x % c == 0) {
return false;
}
c += 2;
if (x % c == 0) {
return false;
}
c += 4;
if (x % c == 0) {
return false;
}
c += 6;
if (x % c == 0) {
return false;
}
c += 2;
if (x % c == 0) {
return false;
}
c += 6;
}
return true;
}
public static void main(String[] args) {
String[] numbers = { "12345", "-12345", "123.45", "-123.45", ".12345",
"-.12345", "a12345", "12345a", "123.a45" };
for (String str : numbers) {
System.out
.println(str + "=" + isInteger(str) + " " + isDouble(str));
}
String[] emails = { "1@2.com", "1.2@3.com", "1@3.4.5.com" };
for (String str : emails) {
System.out.println(str + "=" + isEmail(str));
}
String[] chineses = { "中国", "1中国", "中国1", "1中国2", "中1国" };
for (String str : chineses) {
System.out.println(str + "=" + isChinese(str));
}
String str = "lin@san@fu@2009";
String[] strArray =split(str,"@");
for(String s: strArray)
System.out.println(s);
}
}
-------------------------------------------------------------------------------------------------
/* * Db.java
Created on 2007年8月20日, 上午 8:37
*/
import java.io.*;
import java.sql.*;
import java.util.Properties;
public class Db {
private String driver;
private String url;
private String user;
private String password;
private Connection conn;
private Statement stm;
private ResultSet rs;
public Db(){
this("DBConf.properties");
}
public Db(String conf) {
loadProperties(conf);
setConn();
}
public Connection getConn(){
return this.conn;
}
//handle the properties file to get the informations for connection
private void loadProperties(String conf){
Properties props = new Properties();
try {
props.load(new FileInputStream(conf));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
this.driver = props.getProperty("driver");
this.url = props.getProperty("url");
this.user = props.getProperty("user");
this.password = props.getProperty("password");
}
//implement the Connection
private void setConn(){
try {
Class.forName(driver);
this.conn = DriverManager.getConnection(url,user,password);
} catch(ClassNotFoundException classnotfoundexception) {
classnotfoundexception.printStackTrace();
System.err.println("db: " + classnotfoundexception.getMessage());
} catch(SQLException sqlexception) {
System.err.println("db.getconn(): " + sqlexception.getMessage());
}
}
public void doInsert(String sql) {
try {
Statement statement = conn.createStatement();
int i = stm.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeInset:" + sqlexception.getMessage());
}
}
public void doDelete(String sql) {
try {
stm = conn.createStatement();
int i = stm.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeDelete:" + sqlexception.getMessage());
}
}
public void doUpdate(String sql) {
try {
stm = conn.createStatement();
int i = stm.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeUpdate:" + sqlexception.getMessage());
}
}
public ResultSet doSelect(String sql) {
try {
stm = conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);
rs = stm.executeQuery(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeQuery: " + sqlexception.getMessage());
}
return rs;
}
public static void main(String[] args){
try{
Db db = new Db();
Connection conn = db.getConn();
if(conn != null && !conn.isClosed()) {
System.out.println("連結成功");
ResultSet rs = db.doSelect("select * from content");
while(rs.next()){
System.out.println(rs.getString(1)+":"+rs.getString(2)+":"+rs.getString(3));
}
rs.close();
conn.close();
}
}catch(SQLException e) {
e.printStackTrace();
}
}
}
posted on 2010-05-09 21:43
fly 阅读(180)
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