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  • 验证码

    验证码图片生成以及与Struts2结合使用

    代码:

    1.ValidateCode类代码

    package cn.xjz.tools;

    import java.util.Arrays;

    /**
    * 工具类,生成随机验证码字符串
    * @author admin
    *
    */
    public class ValidateCode {
    /**
    * 验证码难度级别,Simple只包含数字,Medium包含数字和小写英文,Hard包含数字和大小写英文
    */
    public enum ValidateCodeLevel {Simple,Medium,Hard};

    /**
    * 产生默认验证码,4位中等难度
    * @return String 验证码
    */
    public static String getValidateCode(){
    return getValidateCode(4,ValidateCodeLevel.Medium,false);
    }

    /**
    * 产生长度和难度任意的验证码
    * @param length 长度
    * @param level 难度
    * @param isCanRepeat 是否能够出现重复的字符,如果为true,则可能出现 5578这样包含两个5,如果为false,则不可能出现这种情况
    * @return String 验证码
    */
    private static String getValidateCode(int length, ValidateCodeLevel level,
    boolean isCanRepeat) {
    //随机抽取len个字符
    int len = length;

    //字符集合(除去易混淆的数字0、数字1、字母l、字母o、字母O)
    char[] codes = {
    '1','2','3','4','5','6','7','8','9',
    'a','b','c','d','e','f','g','h','i',
    'j','k','m','n','p','q','r','s','t',
    'u','v','w','x','y','z','A','B','C',
    'D','E','F','G','H','I','J','K','L',
    'M','N','P','Q','R','S','T','U','V',
    'W','X','Y','Z'
    };

    //根据不同的难度截取字符数组
    if (level == ValidateCodeLevel.Simple) {
    codes = Arrays.copyOfRange(codes, 0, 9);
    }else if(level == ValidateCodeLevel.Medium){
    codes = Arrays.copyOfRange(codes, 0, 33);
    }
    //字符集合长度
    int n = codes.length;

    //如果要获取的验证码的长度大于所对应难度的数组长度并且不可以重复时,抛异常
    if (len > n && isCanRepeat == false) {
    throw new RuntimeException(
    String.format("调用SecurityCode.getSecurityCode(%1$s,%2$s,%3$s)出现异常," +
    "当isCanRepeat为%3$s时,传入参数%1$s不能大于%4$s",
    len,level,isCanRepeat,n));
    }

    //存放抽取出来的字符
    char[] result = new char[len];

    //判断是否可以出现重复的字符
    if (isCanRepeat) {
    for (int i = 0; i < result.length; i++) {
    int r = (int) (Math.random() * n);
    //将result中的第I个元素设置为codes[r]存放的数值
    result[i] = codes[r];
    }
    }else{

    for (int i = 0; i < result.length; i++) {
    int r = (int) (Math.random() * n);
    //将result中的第I个元素设置为codes[r]存放的数值
    result[i] = codes[r];
    //必须确保不会再次抽取到那个字符,因为所有抽取的字符必须不相同。
    //因此,这里用数组中的最后一个字符改写codes[r],并将n减1
    codes[r] = codes[n-1];
    n--;
    }

    }
    return String.valueOf(result);
    }

    }

    2.ValidateImage类代码:

    package cn.xjz.tools;

    import java.awt.Color;
    import java.awt.Font;
    import java.awt.Graphics;
    import java.awt.image.BufferedImage;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.util.Random;

    import com.sun.image.codec.jpeg.ImageFormatException;
    import com.sun.image.codec.jpeg.JPEGCodec;
    import com.sun.image.codec.jpeg.JPEGImageEncoder;

    /**
    * 工具类,生成验证码图片
    * @author admin
    *
    */
    public class ValidateImage {
    public static BufferedImage createImage(String validateCode){
    //验证码长度
    int codeLength = validateCode.length();
    //字体大小
    int fSize = 15;
    int fWidth = fSize + 1;
    //图片宽度
    int width = codeLength * fWidth + 6;
    //图片高度
    int height = fSize * 2 + 1;

    //图片
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    //画笔
    Graphics g = image.createGraphics();

    //设置背景色
    g.setColor(Color.WHITE);
    //填充背景
    g.fillRect(0, 0, width, height);

    //设置边框颜色
    g.setColor(Color.GRAY);
    //字体样式
    g.setFont(new Font("Arial",Font.BOLD,height - 2));
    //绘置边框
    g.drawRect(0, 0, width - 1, height - 1);

    //绘制噪点
    Random rand = new Random();
    //设置噪点颜色
    g.setColor(Color.LIGHT_GRAY);
    for (int i = 0; i < codeLength * 6; i++) {
    int x = rand.nextInt(width);
    int y = rand.nextInt(height);
    g.drawRect(x, y, 1, 1);
    }

    //绘制验证码
    int codeY = height - 10;
    //设置字体颜色和样式
    g.setColor(new Color(19,148,246));
    g.setFont(new Font("Georgia", Font.BOLD, fSize));
    for (int i = 0; i < codeLength; i++) {
    g.drawString(String.valueOf(validateCode.charAt(i)), i*16 + 5, codeY);
    }
    g.dispose();
    return image;
    }

    /**
    * 返回验证码图片的流格式
    * @param validateCode 验证码
    * @return ByteArrayInputStream 图片流
    */
    public static ByteArrayInputStream getImageAsInputStream(String validateCode){
    BufferedImage image = createImage(validateCode);
    return convertImageToStream(image);
    }

    /**
    * 将BufferedImage转换成ByteArrayInputStream流
    * @param image 要转换的图片
    * @return ByteArrayInputStream 字节数组流
    */
    private static ByteArrayInputStream convertImageToStream(BufferedImage image) {
    ByteArrayInputStream inputStream = null;
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    JPEGImageEncoder jepg = JPEGCodec.createJPEGEncoder(bos);
    try {
    jepg.encode(image);
    byte[] imageByte = bos.toByteArray();
    inputStream = new ByteArrayInputStream(imageByte);
    } catch (ImageFormatException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    }
    return inputStream;
    }
    }

    3.配置文件代码:

    <struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />

    <package name="default" namespace="/" extends="struts-default">

    <action name="validateImage" class="cn.xjz.actions.ValidateImageAction">
    <result name="success" type="stream">
    <param name="contentType">iamge/jpeg</param>
    <param name="inputName">imageStream</param>
    <param name="bufferSize">2048</param>
    </result>
    </action>

    <action name="login" class="cn.xjz.actions.LoginAction">
    <result name="success">success.jsp</result>
    </action>

    </package>

    </struts>

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  • 原文地址:https://www.cnblogs.com/dangzhenjiuhao/p/5398467.html
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