JavaWeb开发工具

一、c3p0连接池

1.XML文件

c3p0-config.xml <?xml version="1.0" encoding="UTF-8"?> <c3p0-config> <default-config> <property name="user">root</property> <property name="password">abc</property> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="jdbcUrl">jdbc:mysql:///bookStore</property> </default-config>  </c3p0-config>

2.代码

import java.beans.PropertyVetoException; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.sql.DataSource; import com.mchange.v2.c3p0.ComboPooledDataSource; public class C3P0Util { // 得到一个数据源 private static DataSource dataSource = new ComboPooledDataSource(); // 从数据源中得到一个连接对象 public static Connection getConnection() { try { return dataSource.getConnection(); } catch (SQLException e) { throw new RuntimeException("服务器错误"); } } public static void release(Connection conn, Statement stmt, ResultSet rs) { // 关闭资源 if (rs != null) { try { rs.close(); } catch (Exception e) { e.printStackTrace(); } rs = null; } if (stmt != null) { try { stmt.close(); } catch (Exception e) { e.printStackTrace(); } stmt = null; } if (conn != null) { try { conn.close();// 关闭 } catch (Exception e) { e.printStackTrace(); } conn = null; } } }

 

 

二、get与post乱码过滤器

import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.Map; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; /** *  * 通用解决 get 和 post乱码过滤器  *   *   *    */ public class EncodingFilter implements Filter { @Override public void destroy() { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // 处理请求乱码 HttpServletRequest httpServletRequest = (HttpServletRequest) request; HttpServletRequest myRequest = new MyRequest(httpServletRequest); // 处理响应乱码 response.setContentType("text/html;charset=utf-8"); chain.doFilter(myRequest, response); } @Override public void init(FilterConfig filterConfig) throws ServletException { } } // 自定义request对象 class MyRequest extends HttpServletRequestWrapper { private HttpServletRequest request; private boolean hasEncode; public MyRequest(HttpServletRequest request) { super(request);// super必须写 this.request = request; } // 对需要增强方法 进行覆盖 @Override public Map getParameterMap() { // 先获得请求方式 String method = request.getMethod(); if (method.equalsIgnoreCase("post")) { // post请求 try { // 处理post乱码 request.setCharacterEncoding("utf-8"); return request.getParameterMap(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } else if (method.equalsIgnoreCase("get")) { // get请求 Map<String, String[]> parameterMap = request.getParameterMap(); if (!hasEncode) { // 确保get手动编码逻辑只运行一次 for (String parameterName : parameterMap.keySet()) { String[] values = parameterMap.get(parameterName); if (values != null) { for (int i = 0; i < values.length; i++) { try { // 处理get乱码 values[i] = new String( values[i].getBytes("ISO-8859-1"), "utf-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } } } hasEncode = true; } return parameterMap; } return super.getParameterMap(); } @Override public String getParameter(String name) { Map<String, String[]> parameterMap = getParameterMap(); String[] values = parameterMap.get(name); if (values == null) { return null; } return values[0]; // 取回参数的第一个值 } @Override public String[] getParameterValues(String name) { Map<String, String[]> parameterMap = getParameterMap(); String[] values = parameterMap.get(name); return values; } }

三、MD5加密

import java.math.BigInteger; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class MD5Utils { /** * 使用md5的算法进行加密 */ public static String md5(String plainText) { byte[] secretBytes = null; try { secretBytes = MessageDigest.getInstance("md5").digest( plainText.getBytes()); } catch (NoSuchAlgorithmException e) { throw new RuntimeException("没有md5这个算法！"); } String md5code = new BigInteger(1, secretBytes).toString(16);// 16进制数字 // 如果生成数字未满32位，需要前面补0 for (int i = 0; i < 32 - md5code.length(); i++) { md5code = "0" + md5code; } return md5code; } public static void main(String[] args) { System.out.println(md5("123")); } }

 

四、一次性验证码

import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * 验证码生成程序 * */ public class CheckImgServlet extends HttpServlet { // 集合中保存所有成语 private List<String> words = new ArrayList<String>(); @Override public void init() throws ServletException { // 初始化阶段，读取new_words.txt // web工程中读取 文件，必须使用绝对磁盘路径 String path = getServletContext().getRealPath("/WEB-INF/new_words.txt"); try { BufferedReader reader = new BufferedReader(new InputStreamReader( new FileInputStream(path), "UTF-8")); String line; while ((line = reader.readLine()) != null) { words.add(line); } reader.close(); } catch (IOException e) { e.printStackTrace(); } } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 禁止缓存 // response.setHeader("Cache-Control", "no-cache"); // response.setHeader("Pragma", "no-cache"); // response.setDateHeader("Expires", -1); int width = 120; int height = 30; // 步骤一 绘制一张内存中图片 BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 步骤二 图片绘制背景颜色 ---通过绘图对象 Graphics graphics = bufferedImage.getGraphics();// 得到画图对象 --- 画笔 // 绘制任何图形之前 都必须指定一个颜色 graphics.setColor(getRandColor(200, 250)); graphics.fillRect(0, 0, width, height); // 步骤三 绘制边框 graphics.setColor(Color.WHITE); graphics.drawRect(0, 0, width - 1, height - 1); // 步骤四 四个随机数字 Graphics2D graphics2d = (Graphics2D) graphics; // 设置输出字体 graphics2d.setFont(new Font("宋体", Font.BOLD, 18)); Random random = new Random();// 生成随机数 int index = random.nextInt(words.size()); String word = words.get(index);// 获得成语 // 定义x坐标 int x = 10; for (int i = 0; i < word.length(); i++) { // 随机颜色 graphics2d.setColor(new Color(20 + random.nextInt(110), 20 + random .nextInt(110), 20 + random.nextInt(110))); // 旋转 -30 --- 30度 int jiaodu = random.nextInt(60) - 30; // 换算弧度 double theta = jiaodu * Math.PI / 180; // 获得字母数字 char c = word.charAt(i); // 将c 输出到图片 graphics2d.rotate(theta, x, 20); graphics2d.drawString(String.valueOf(c), x, 20); graphics2d.rotate(-theta, x, 20); x += 30; } // 将验证码内容保存session request.getSession().setAttribute("checkcode_session", word); // 步骤五 绘制干扰线 graphics.setColor(getRandColor(160, 200)); int x1; int x2; int y1; int y2; for (int i = 0; i < 30; i++) { x1 = random.nextInt(width); x2 = random.nextInt(12); y1 = random.nextInt(height); y2 = random.nextInt(12); graphics.drawLine(x1, y1, x1 + x2, x2 + y2); } // 将上面图片输出到浏览器 ImageIO graphics.dispose();// 释放资源 ImageIO.write(bufferedImage, "jpg", response.getOutputStream()); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } /** * 取其某一范围的color * * @param fc * int 范围参数1 * @param bc * int 范围参数2 * @return Color */ private Color getRandColor(int fc, int bc) { // 取其随机颜色 Random random = new Random(); if (fc > 255) { fc = 255; } if (bc > 255) { bc = 255; } int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); } }

五、邮件发送工具

import java.util.Properties; import javax.mail.Address; import javax.mail.MessagingException; import javax.mail.Session; import javax.mail.Transport; import javax.mail.internet.InternetAddress; import javax.mail.internet.MimeMessage; public class SendJMail { public static void main(String[] args) { sendMail("823723873@qq.com","Hello Word"); } public static boolean sendMail(String email, String emailMsg) { String from = "********@163.com"; // 邮件发送人的邮件地址 String to = email; // 邮件接收人的邮件地址 final String username = "*********@163.com"; // 发件人的邮件帐户 final String password = "******"; // 发件人的邮件密码 // 定义Properties对象,设置环境信息 Properties props = System.getProperties(); // 设置邮件服务器的地址 props.setProperty("mail.smtp.host", "smtp.163.com"); // 指定的smtp服务器 props.setProperty("mail.smtp.auth", "true"); props.setProperty("mail.transport.protocol", "smtp");// 设置发送邮件使用的协议 // 创建Session对象,session对象表示整个邮件的环境信息 Session session = Session.getInstance(props); // 设置输出调试信息 session.setDebug(true); try { // Message的实例对象表示一封电子邮件 MimeMessage message = new MimeMessage(session); // 设置发件人的地址 message.setFrom(new InternetAddress(from)); // 设置主题 message.setSubject("用户激活"); // 设置邮件的文本内容 // message.setText("Welcome to JavaMail World!"); message.setContent((emailMsg), "text/html;charset=utf-8"); // 从session的环境中获取发送邮件的对象 Transport transport = session.getTransport(); // 连接邮件服务器 transport.connect("smtp.163.com", 25, username, password); // 设置收件人地址,并发送消息 transport.sendMessage(message, new Address[] { new InternetAddress( to) }); transport.close(); return true; } catch (MessagingException e) { e.printStackTrace(); return false; } } }