Kaptcha验证码配置项

导包

web.xml:
<servlet>
        <servlet-name>Kaptcha</servlet-name>
        <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
        <init-param>
            <description> Border around kaptcha. Legal values are yes or no. </description>
            <param-name>kaptcha.border</param-name>
            <param-value>no</param-value>
        </init-param>
        <init-param>
            <description>Color of the border. Legal values are r,g,b (and optional alpha) or white,black,blue. </description>
            <param-name>kaptcha.border.color</param-name>
            <param-value>red</param-value>
        </init-param>
        <init-param>
            <description>Thickness of the border around kaptcha. Legal values are > 0. </description>
            <param-name>kaptcha.border.thickness</param-name>
            <param-value>5</param-value>
        </init-param>
        <init-param>
            <description>Width in pixels of the kaptcha image. </description>
            <param-name>kaptcha.image.width</param-name>
            <param-value>80</param-value>
        </init-param>
        <init-param>
            <description>Height in pixels of the kaptcha image. </description>
            <param-name>kaptcha.image.height</param-name>
            <param-value>40</param-value>
        </init-param>
        <init-param>
            <description>The image producer. </description>
            <param-name>kaptcha.producer.impl</param-name>
            <param-value>com.google.code.kaptcha.impl.DefaultKaptcha </param-value>
        </init-param>
        <init-param>
            <description>The text producer. </description>
            <param-name>kaptcha.textproducer.impl</param-name>
            <param-value>com.google.code.kaptcha.text.impl.DefaultTextCreator</param-value>
        </init-param>
        <init-param>
            <description>The characters that will create the kaptcha. </description>
            <param-name>kaptcha.textproducer.char.string</param-name>
            <param-value>abcde2345678gfynmnpwx </param-value>
        </init-param>
        <init-param>
            <description>The number of characters to display. </description>
            <param-name>kaptcha.textproducer.char.length</param-name>
            <param-value>5</param-value>
        </init-param>
        <init-param>
            <description>A list of comma separated font names.</description>
            <param-name>kaptcha.textproducer.font.names</param-name>
            <param-value>Arial, Courier</param-value>
        </init-param>
        <init-param>
            <description>The size of the font to use. </description>
            <param-name>kaptcha.textproducer.font.size</param-name>
            <param-value>23</param-value>
        </init-param>
        <init-param>
            <description>The color to use for the font. Legal values are r,g,b. </description>
            <param-name>kaptcha.textproducer.font.color</param-name>
            <param-value>black</param-value>
        </init-param>
        <init-param>
            <description>The noise producer. </description>
            <param-name>kaptcha.noise.impl</param-name>
            <param-value>com.google.code.kaptcha.impl.NoNoise </param-value>
        </init-param>
        <init-param>
            <description>The noise color. Legal values are r,g,b. </description>
            <param-name>kaptcha.noise.color</param-name>
            <param-value>black</param-value>
        </init-param>
        <init-param>
            <description>The obscurificator implementation. </description>
            <param-name>kaptcha.obscurificator.impl</param-name>
            <param-value>com.google.code.kaptcha.impl.ShadowGimpy</param-value>
        </init-param>
        <init-param>
            <description>The background implementation. </description>
            <param-name>kaptcha.background.impl</param-name>
            <param-value>com.google.code.kaptcha.impl.DefaultBackground</param-value>
        </init-param>
        <init-param>
            <description>Ending background color. Legal values are r,g,b. </description>
            <param-name>kaptcha.background.clear.to</param-name>
            <param-value>white</param-value>
        </init-param>
        <init-param>
            <description>The word renderer implementation. </description>
            <param-name>kaptcha.word.impl</param-name>
            <param-value>com.google.code.kaptcha.text.impl.DefaultWordRenderer</param-value>
        </init-param>
        <init-param>
            <description>The value for the kaptcha is generated and is put into the HttpSession. This is the key value for that item in the session. </description>
            <param-name>kaptcha.session.key</param-name>
            <param-value>KAPTCHA_SESSION_KEY</param-value>
        </init-param>
        <init-param>
            <description>The date the kaptcha is generated is put into the HttpSession. This is the key value for that item in the session. </description>
            <param-name>kaptcha.session.date</param-name>
            <param-value>KAPTCHA_SESSION_DATE</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>Kaptcha</servlet-name>
        <url-pattern>/Kaptcha.jpg</url-pattern>
    </servlet-mapping>



jsp:
<img id="kaptchaImg" src="<%=path%>/kaptcha.jpg" title="看不清，点击换一张"
onclick="updateImg(this)" style="cursor: pointer;float:left;" />

function updateImg(obj) {
obj.src = "<%=path%>/kaptcha.jpg?" + Math.floor(Math.random() * 100);
}

java:
String kaptchaExpected = (String)request.getSession()
.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);


if (yzm == null || !yzm.equalsIgnoreCase(kaptchaExpected))
{
request.setAttribute("err", "验证码错误!");
request.setAttribute("yh", yh);
return new JspView("/admin/login.jsp");
}