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╰+哭是因爲堅強的太久メ 2022-05-29 03:17 181阅读 0赞

**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);
    	}
    
    }

![Image 1][]

**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;
    		}
    	}
    
    }

[Image 1]: