网上书城项目-暂时用到的五个工具类-JavaWeb

1. 生成注册激活码的工具类

import java.util.UUID;
/**
 * 生成注册激活码的工具类
 */
public class ActiveCodeUtils {
    public static String createActiveCode() {
        return UUID.randomUUID().toString();
    }
}

2. 生成id的工具类

import java.util.UUID;
/**
 * 生成id的工具类
 */
public class IdUtils {
    public static String getUUID() {
        return UUID.randomUUID().toString();
    }
}

3. 生成验证码的工具类

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.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;
/**
 * 生成验证码的工具类
 */
public class CheckImageServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    // 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 = 180;
        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 - 1);// 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 += 40;
        }
        // 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);
    }
}

4. 数据源工具

import java.sql.Connection;
import java.sql.SQLException;
import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;
/**
 * 数据源工具
 */
public class DataSourceUtils {
    //得到数据源对象
    private static DataSource dataSource = new ComboPooledDataSource();
    //处理事物：保证事物里面的是同一个连接对象，t1对象低层使用的map集合存的值<线程编号，Connection>
    private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();
    
    //提供静态方法得到数据源对象
    public static DataSource getDataSource() {
        return dataSource;
    }
    //提供得到唯一链接对象的方式
    /**
     * 当DBUtils需要手动控制事务时，调用该方法获得一个连接
     *
     * @return
     * @throws SQLException
     */
    public static Connection getConnection() throws SQLException {
        Connection con = tl.get();
        if (con == null) {//本地对象t1里面没有链接对象
            con = dataSource.getConnection();
            tl.set(con);
        }
        return con;
    }
    //开启事务
    /**
     * 开启事务
     *
     * @throws SQLException
     */
    public static void startTransaction() throws SQLException {
        Connection con = getConnection();
        if (con != null)
            con.setAutoCommit(false);
    }
    //释放链接，结束事物
    /**
     * 从ThreadLocal中释放并且关闭Connection,并结束事务
     *
     * @throws SQLException
     */
    public static void releaseAndCloseConnection() throws SQLException {
        Connection con = getConnection();
        if (con != null) {
            con.commit();
            tl.remove();
            con.close();
        }
    }
    //错误的情况下，回滚事物
    /**
     * 事务回滚
     *
     * @throws SQLException
     */
    public static void rollback() throws SQLException {
        Connection con = getConnection();
        if (con != null) {
            con.rollback();
        }
    }
}

5. 文件上传工具类

import java.util.UUID;
public class FileUploadUtils {
    /**
     * 截取真实文件名
     *
     * @param fileName
     * @return
     */
    public static String subFileName(String fileName) {
        // 查找最后一个 \出现位置
        int index = fileName.lastIndexOf("\\");
        if (index == -1) {
            return fileName;
        }
        return fileName.substring(index + 1);
    }
    
    // 获得随机UUID文件名
    public static String generateRandonFileName(String fileName) {
        // 获得扩展名
        int index = fileName.lastIndexOf(".");
        if (index != -1) {
            String ext = fileName.substring(index);
            return UUID.randomUUID().toString() + ext;
        }
        return UUID.randomUUID().toString();
    }
    
    // 获得hashcode生成二级目录
    public static String generateRandomDir(String uuidFileName) {
        int hashCode = uuidFileName.hashCode();
        // 一级目录
        int d1 = hashCode & 0xf;
        // 二级目录
        int d2 = (hashCode >> 4) & 0xf;
        return "/" + d1 + "/" + d2;
    }
}